URMIS Elisabeth Cunin
email: elisabeth.cunin@ird.fr

Blackness and mestizaje: Afro-Caribbean music in Chetumal, Mexico 1

Keywords: Afro-Caribbean music, mestizaje, black, ethnicity, race, Chetumal

This paper has been written within the framework of the research project of ANR Suds -AIRD Afrodesc (ANR-07-SUDS-008) "Afrodescendants and slaveries: domination, identification

Campeche and Quintana Roo, the presence of Africans and population of African descent during the colonial period has now been widely documented (Aguirre Beltrán 1989[1946]; [START_REF] Restall | Otredad y ambigüedad: las percepciones que los españoles y mayas tenían de los africanos en el Yucatán Colonial[END_REF]Restall , 2005;;[START_REF] Fernández Repetto | Una población perdida en la memoria. Los negros de Yucatán[END_REF][START_REF] Zabala | La población africana en la villa colonial de Campeche: un estudio interdisciplinario[END_REF][START_REF] Campos García | Castas, Feligresía y Ciudadanía en Yucatán[END_REF][START_REF] Collí Collí | Componentes culturales africanos en Quintana Roo, Memoria etnográfica para optar al título de licenciado en Ciencias Antropológicas[END_REF][START_REF] Ojeda | Microhistoria de una comunidad afroamericana en Yucatán[END_REF]. In the case of the state of Quintana Roo, there are numerous references to escapes of Belizean slaves to the south of the Yucatan peninsula [START_REF] Bolland | Colonialism and resistance in Belize[END_REF]) and a few mentions of the presence of black populations in Bacalar, the Spain's only colonial holding in the region [START_REF]La frontera sureste de la Nueva España[END_REF]. Nevertheless, I will focus on another aspect of the Black Atlantic, little known in Mexico: the migrations of Afro-Caribbean workers at the end of the 19 th century and the beginning of the 20 th , thus resituating Mexico in the history of post-slavery diasporas studied elsewhere [START_REF] Chomsky | West Indian Workers and the United Fruit Company in Costa Rica, 1870-1940[END_REF][START_REF] Mcleod | Undesirable Aliens: Race, Ethnicity, and Nationalism in the Comparison of Haitian and British West Indian Immigrant Workers in Cuba, 1912-1939[END_REF][START_REF] Douglass Opie | Black Labor Migration In Caribbean Guatemala, 1882-1923[END_REF][START_REF] Putnam | Eventually Alien: The Multigenerational Saga of British Western Indians in Central America, 1870-1940[END_REF]. A border region, at the periphery of the national territory, Quintana Roo has maintained, at least until the end of the 1930s, greater ties with Belize and the rest of the Caribbean and Central American than with Mexico. Black Belizean workers, vital to the timber industry (chicle, wood), were thus the principal actors in economic development and territorial colonization of the region at the beginning of the 20 th century. I will examine in particular the success of Afro-Caribbean music 2 in the city of Chetumal, capital of the state of Quintana Roo. In the southern part of the state there are some twenty groups of reggae and ska, and many more across the peninsula (including reggae groups that sing in Maya, in the Mayan area of the state, such as Santos Santiago and Chan Santa Roots). This phenomenon 2 The term "Afro-Caribbean" includes several musical genres in the discourse of the inhabitants of Chetumal: reggae, ska, calypso, punta, etc. It refers especially to the music that comes from neighboring Belize, although it could also refer to all types of music associated with black people and/or with the Caribbean (salsa, son).

Latin American and Caribbean Ethnic Studies, Volume 9, Issue 1, 2014, p. 1-22 6 is quite different from the one analyzed by Peter [START_REF] Wade | Música, Raza y Nación. Música tropical en Colombia[END_REF] on Colombia's Caribbean coast. Indeed, he shows how a black, peripheral form of music became a component of the national identity. By appropriating a musical style, tropicalism, associated with the Caribbean coast, the elites were introducing heterogeneity into the national unity, considered as mestiza. The music of Chetumal, for its part, remains perfectly local and is only marginally distributed on a national level; it causes even less of a rift in the national identity and the ideology of racial mixing. But it is nationalized, in the sense that its foreignness is erased little by little, its heterogeneity made commonplace, its blackness dissolved through mestizaje. Colombian tropical music of the beginning of the 20 th century has, without a doubt, developed to a far greater extent than the Afro-Caribbean music of Chetumal (number of musicians, commercial impact, etc.).

Furthermore, the Colombian Caribbean coast occupies a fundamental position in national history, which is not the case of Quintana Roo. Nevertheless, this discrepancy also corresponds to the specific hegemony of the ideology of Mexican racial mixing, in particular in the postrevolutionary years, and to the efficiency of the national assimilation action of the state. I will thus try to show that blackness was integrated into mestizaje, without disappearing and without transforming the national identity.

I will refer, in the first part, to the music's insertion in the history of the region in order to analyze the historical context of the appearance and disappearance, the transformation and negotiation, the appreciation and denial of the "African" and the "Caribbean". Whereas Caribbean music becomes Mexican and mestiza through its local appropriation, its alterity reemerges periodically, although a domesticated, familiar, normalized alterity. I will then analyze the manifestation of blackness in a mestizo state: beyond the interpretations in terms of racism or instrumentalization, the reference to black culture in Chetumal corresponds to much wider logics of action, which meet unintentionally and tend to integrate blackness into local cultural politics. Finally, I will turn to the actors involved in this "black music without blacks" or "Afro-Caribbean music without ethnicity", in the same way that Livio [START_REF] Sansone | Blackness Without Ethnicity. Constructing Race in Brazil[END_REF] refers to a "blackness without ethnicity". I will present an analysis of the logic of identity construction associated with the music, giving emphasis to the mechanisms of heritage and invention of a "Chetumal identity" which is mestiza and "not only" mestiza.

I. The genealogy of Afro-Caribbean music in southern Quintana Roo

To address the history of Afro-Caribbean music in the region, I will start by situating it in the history of the territory, and subsequently in the state of Quintana Roo. Far from following a linear development, the music appears and disappears, it undergoes transformations in terms of its expressions, its actors, its significance. From this inscription of the music in local history, we can observe simultaneous processes of "mestization" of the "afro" and of nationalization of what is Belizean, which characterizes the construction of the territory/state of Quintana Roo.

From the brukdown and Sambay of the forest camps to the dance of the chicleros From a historical standpoint, the southeastern part of the Yucatan Peninsula was to a large extent outside of the control of Spain, and later of Mexico. Between 1847 and 1901, the Caste War [START_REF] Reed | [END_REF][START_REF] Lapointe | Histoire du Yucatán. XIXe-XXIe siècles[END_REF]) led to the integration of the region into the Mexican Federation, with the delineation of the border between Mexico and Belize in 1893, and the creation of the territory of Quintana Roo in 1902. It preserved for decades a specificity that gave it a separate place within the Mexican nation: the strong presence of the Mayan people, whose hostility to the Mexican power was maintained; multiple exchanges with neighboring Belize-then a British colony-and, generally speaking, with the Caribbean [START_REF] Vallarta | Los payobispenses. Identidad, población y cultura en la frontera México-Belice[END_REF]. In fact, southern Quintana Roo was inhabited in part by descendants of refugees from the Caste War who, for nearly half a century, had settled in Belize. It was also characterized by the migration of Belizean forestry workers of African descent3 . After 1908, the first official figures on migration, derived from the immigration law adopted that year, show significant results (Cunin, forthcoming): between 1908 and 1911 4 , 81% of the immigrants who had entered the territory through Chetumal Bay were "English" and it can be assumed that most of these were from the British colony of Belize; of these British immigrants, 56% were classified as "black" (the migration forms established three racial categories: "white", "black" and "yellow"). In a region characterized by large migratory movements, both domestic and international, related to dynamics of population growth that remained precarious, Belizean workers were added to a workforce that came from the north of the peninsula (Yucatan) or the rest of the country (Veracruz, Guerrero) to exploit the main local asset: the forest (wood, then chicle).

The first reference to Afro-Caribbean music appears amidst this context of concentrations of workers in isolated camps, especially on the border between Mexico and Belize. The styles mentioned are the brukdown (often written with random spellings: Brok Dow, brochdown) and the sambay (sometimes spelt zambay), a name that has been subject to different interpretations: dance of the zambos (people of mixed black and Amerindian origin); "son de la bahía", or sound of the Bay; distortion of the English phrase "let's go to some buy" (see Ramírez Canul 2001, pp. 249-250) 5 . Beyond the uncertainties surrounding the origin of sambay and brukdown, it should be emphasized that these two genres, which refer to a style of music as well as to a dance, are related to a Caribbean origin and more specifically to Belize, and with rhythms of African origin (Ramirez Canul 2001, p. 250;Macias Zapata 1988, pp. 375, 378), which in turn would mix with Mexican rhythms transmitted by the workers of Veracruz (son jarocho) or of Yucatan (jarana yucateca).

From that moment, sambay and brukdown formed an integral part not only of the logging camps, but also of the social and cultural life of the newly founded capital of the territory, Payo Obispo -Chetumal6 . Thus, according to Marcos Ramirez Canul, author and composer of popular music and a researcher at the Quintana Roo Institute of Culture, sambay music and dance were developed "through popular expressions in the 1930s in Chetumal, and [sambay] is the name given to the people's festivals that were held in some neighborhoods, primarily in Barrio Bravo, Punta Estrella and el Hulubal" (Ramírez Canul 2001, p. 248). In addition, groups from Belize often arrived to participate in the festivities or the official celebrations of the city.

Latin American and Caribbean Ethnic Studies, Volume 9, Issue 1, 2014, p. 1-22 10 In spite of its natural resources, the territory of Quintana Roo had an uncertain future at the beginning of the century: it disappeared between 1913 and 1915, and again between 1931 and 1935; its population was stagnant, its administration deficient; the Maya had a certain degree of autonomy. However, the arrival of Lazaro Cárdenas to the presidency of the Republic (December 1934) and of Rafael Melgar as governor of the territory allowed it to solidify its economic and institutional foundations. A new dynamism was accompanied by an accelerated integration into the Federation, especially after the implementation of a policy of "Mexicanization"7 and the reaffirmation of the ideology of mestizaje as a symbol of national identity. Local authorities were gradually forging the historical account that would make Quintana Roo "the birthplace of mestizaje". Signs of regional specificity also emerged on the cultural level. The brukdown and sambay were gradually becoming visible as part of local folklore and as symbols of the emerging identity of the territory of Quintana Roo-an identity that was yet to be invented. And they were simultaneously transformed. Particularly instructive in this regard is the work of the Yucatecan intellectual Luis Rosado [START_REF] Vega | Un pueblo y un hombre[END_REF], written in tribute to Rafael Melgar, the governor of Quintana Roo from 1935 to 1940. This work describes the application of the policy of Cárdenas in the region, and gives an account of the form adopted by its nationalist ideology: distrust of the Belizean population present on Mexican soil and of the Belizean authorities in general (accused of having appropriated a part of Mexican territory); a selective immigration policy8 , tending to favor the population considered "assimilable"; the promotion of a local "mestizo" culture. Within this framework, the Afro-Caribbean origin of sambay and brukdown became problematic, and both rhythms were subject to a "Mexicanization" that transformed them and made them acceptable. "We got to know the dance Zambay Macho. It seems that its very name should be sufficient to indicate its black origin. But it was not entirely so. It is a superimposition. It is the classical jarana yucateca but with a black spice. Since in the colony [Belize] there is a lot of influence from the peninsula, it can be seen that the jarana was acclimatized there, and the Belizean black took it over… In Belize, this dance is called the Brok Down. It is danced by a man and a woman, and although it is an authentic jarana, it is danced in the style of the Cuban rumba.

It is a dance full of lewdness, in which fevered bodies intertwine until reaching orgasm. Poor jarana yucateca, how they have made you in British!..." (Rosado Vega 1940, p. 215). In the words of Rosado Vega, Sambay and brukdown are nothing more than an adaptation of the jarana yucateca, and their origin is in Mexico, while their African-American dimension is delegitimized.

In this manner, the sambay and brukdown were giving way to a name that encompassed and nationalized them: "the dance of the chicleros" (el baile de los chicleros). Musical exchanges between the Caribbean and Mexico somehow stopped and took root in the region of Chetumal, to become a marker of autochthony and heritage, accompanied in the same period by the creation of the "chetumaleña costume", the "typical" dress of the woman of Chetumal, or by the destruction of the wooden houses "of English colonial style" of Chetumal (Bautista Pérez 2004, p. 71). What was being played out in those years of Cardenismo was the "invention" of a mestiza popular culture that would be different both from the Mayan culture, a symbol of rebellion and archaism, and from the Belizean Afro-Caribbean culture, a double symbol of foreign invasion and of an affinity with black people.

From territory to state: a new renaissance and a new disappearance As mentioned, it was not until the mid-1930s that the territory of Quintana Roo was consolidated and integrated politically and economically into the rest of the country. Hurricane Janet, which destroyed part of Chetumal in 1955, symbolizes a turning point, a break with a past of marginalization from the nation and a reaffirmed determination to join it. However, the Mexicanization of the territory did not involve the suspension of interchanges-in particular cultural-with the Caribbean. Certainly the status of Chetumal as a customs-free perimeter (along with Cozumel, Isla Mujeres and Xcalak), established in 1933, and then the status of Free Zone attributed to the entire territory in 1972, played a central role: while Chetumal was being progressively inserted into the rest of the country, it continued to be, on the economic level, the entry point for products from Belize, the Caribbean and Latin America, including musical productions.

A revival of Afro-Caribbean music (calypso, soca, reggae, ska, brukdown, funk) can be observed in the 1960s, arriving in Chetumal via Belize. The Jamaican-born musician Byron Lee and his band The Dragonaires, Belizean groups the Lord Rhaburn Combo, Jesus Acosta and the Professionals, and the Harmonettes, exerted considerable influence over the cultural landscape and local composers 9 . Above all, Chetumal saw the birth of two groups now considered the precursors of reggae in Mexico: Benny and his group, and the Ely Combo. 10 They mixed brukdown, calypso and soca, and latter ska and reggae, and often adapted songs from Belize or Jamaica. In Chetumal, many recall the success of their music in the years 1960-1970, and associate it with the popular dances in the Explanada de la Bandera and during the Carnival.

Ely's real name is Eliseo Pech Yamá; he is from a Maya family from the state of Yucatan; indeed, the group members are Mayans and mestizos, and were often accompanied by a black Belizean singer, Anthony Jones. Ely Combo, which emerged in the years 1966-67, is now regarded as the first reggae group 11 in Mexico; it recorded two albums (long play) with Son-Art that mainly include covers of songs by the Jamaican Byron Lee, and it took part in numerous tours in Mexico. Ely was a professional musician and also a member of the state orchestra.

Benito Loeza Rivadeneyra, for his part, leader of Benny and his group, with a mother born in Orange Walk, Belize, and a father from the state of Veracruz, was a typical representative of 11 In reality, the group found inspiration in brukdown, soca, and calypso, but the term "reggae" is often used today as a synonym of "Afro-Caribbean music", thus including a range of styles independently of their musical and historical specificities. A more specialized study of musical rhythms, lyrics, and instruments, etc. has not yet been endeavored.

these Mexican-Belizean families that were, at that time, a large proportion of the population of Chetumal. Until his death in 2011, Benny was associated with a bar-nightclub in Chetumal popular among Belizeans.

In 1972, for four straight weeks, Ely Combo was the guest of the TV music and variety show Siempre en domingo, with renowned presenter Raúl Velasco, which gave him a wide audience and national recognition. The group took special care with its presentation, and welcomed the producers of the show in a rustic palm hut by the sea, built especially for the occasion. In fact, within the framework of Siempre en domingo, the Ely Combo appeared in the folklore section "Mexico, magic, and encounter," which endorsed the treasures and idiosyncrasies of Mexican culture. In each region, "typical" and "traditional" cultural traits were presented, and in the case of Chetumal and Quintana Roo, the Ely Combo and its Afro-Caribbean music was selected as representatives of the "culture of Quintana Roo".

By way of anecdote, Jimmy Pech, the son of Eliseo Pech, who was one of the musicians in the group Ely Combo, recalls the origin of his name, which emerged during an interview with the group in the city of Tuxtla Gutierrez: the reporter asked each one to say his name, "and since we had already spoken about Anthony Jones, we supposedly came from a border area with British Honduras. And what do they call you sir? I am Jimmy P. C. H. [with an English accent] so as not to say that I was Jaime Pech! 12 ". He thus reminds us of the importance of the English "touch" to this music, almost always sung in English and associated to its proximity to Belize. Jimmy Pech also recalls: when the producers of Siempre en domingo "saw Anthony Jones, the black man, singing and dancing, and especially dancing, they were fascinated and they filmed us for four weeks". Likewise, Benny and his group often performed along with a black dancer of Belizean origin, Anselm Anthony, nicknamed El Bule. The black component of the music is not the result of an identification with an Afro-Caribbean cultural world, or to Paul Gilroy's "Black Atlantic", nor does it produce some "African-American identity"; however, both groups made efforts to be accompanied by a musician that was black and from Belize, and especially to have him on stage, as if this were a double guarantee of legitimacy and authenticity 13 .

In his thesis "African Cultural components in Quintana Roo", Mario Baltazar Collí Collí, member of the Third Root program in Quintana Roo, dedicated a long interview to Benny, focusing in particular on the Afro-Caribbean dimension of his music. The association with "blackness" is, for Benny, a proof of musical quality, as part of a racialized valorization of cultural practices. "I am happy to come from the black group, like my grandmother and my grandfather . . . in music it helped me a lot, ah, a lot of rhythm, a lot of cunning in the music, Caribbean music, it helped me to have a certain rhythm, not everyone has it, the rhythm that the black race has, not a lot of people in the world have it . . . There [in Belize] is where we base ourselves for our music, we imitate something of them to fuse it with the Mexican and make a different type of music" (Collí Collí 2005, p. 52).

13 Today, another musician plays this role of legitimization on the local music scene: Wisdom, the leader of the group Roots and Wisdom, rasta musician of Nigerian origin located in Felipe Carrillo Puerto. Thanks to his contacts in the United States and Europe, to his great dynamism and his cultural projects (see the web page of its African and Maya cultural center http://www.rootsandwisdommusic.com/spanish.htm), he contributes to consolidating and enhancing the reputation of Afro-Caribbean music.

However, the success of Afro-Caribbean music in southern Quintana Roo would not endure beyond the 1980s. Indeed, in 1974, the region underwent a radical transformation: the territory of Quintana Roo became the state of Quintana Roo, the youngest state of the Mexican Federation, along with Baja California Sur. Quintana Roo did not meet one of the legal requirements14 to obtain the status of a state: to possess more than 80,000 inhabitants. Hence the implementation of a particularly strong national migration policy, characterized by incentives designed to attract population from the interior of the country, which would result in the creation of new settlements, called Nuevos Centros de Población Ejidal (Fort, 1977), especially on the Rio Hondo border with Belize. This policy caused a massive influx of population from the rest of the country, to the extent that it radically changed the demographic composition of the future state. The decade of the 1970s also witnessed the sustained development of national infrastructure in Quintana Roo Skuadron 16, Hierba Santa, Korto Circuito, I Wanna: these are the main reggae/ska groups currently active in the city of Chetumal. At the state and peninsular level, it would be necessary to supplement this list with dozens of additional groups. I will return here to the existence of this music scene that emerged in the early 2000s, highlighting the actors who animate it and the social norms that govern it. Although it is based on a relatively autonomous organization, Afro-Caribbean music is part of a context that has favored its development: the intervention of intermediaries through radio programs; university activities and cultural policies; the impact of the International Festival of Caribbean Culture; the influence of the development of tourism in the northern part of the state (Cancun, Playa del Carmen, Tulum). I will analyse the actors, the policies, the spaces that make possible the existence of an Afro-Caribbean music scene in Chetumal and in Quintana Roo. We will then see that blackness is not a rupture or a counterculture, but that it is perfectly integrated into local administrative practices, cultural policies, and tourist representations.

Intermediaries and agents of legitimation: radio, university and policy

In the same way that Howard Becker speaks of "moral entrepreneurs", we will evoke here the "cultural entrepreneurs" who help to normalize the Afro-Caribbean music scene, to institutionalize it and give it visibility, to furnish it with relevance and legitimacy. These The evocation of the Caribbean is loaded-implicitly or explicitly-with meanings not only associated with cultural diversity, but also with the presence of people of African descent. In a working paper by the organizing committee of the Third Festival, it is said that the Caribbean is "one of the largest zones of cultural power in the world, both in its diversity as in its multilingual identity… It is important to emphasize that where there is the presence of blacks, the Caribbean is present. The African contribution, which fortunately came to our America, unifies the great culture of the Caribbean. It is because of this cultural melting pot that we feel the need to hold the III International Festival of Caribbean Culture" (Comité organizador, 1991). On November 6 th , 7 th and 8 th of that year a discussion forum was held in Chetumal, coordinated by Guillermo Bonfil Batalla, initiator of the national program "The Third Root", around the theme of "the influence of African culture in the cultural formation of the Caribbean" 16 .

Within this framework, the Festival offered many Caribbean groups the opportunity to perform in The Riviera Maya, favorite international tourist site

In the early twentieth century Afro-Caribbean music developed in Chetumal because of the isolation of that city from the rest of the country and because of exchanges, economic as much as cultural and demographical, that Chetumal and its region maintained with Belize. A century later this music reemerges in an entity perfectly integrated in the Mexican Federation and that hosts one of the most important poles of international tourism in the world. Hence the resurgence of this original music may no longer be explained by the area's isolation from the rest of the nation, but rather as a reaction against national homogenization and a search for local idiosyncrasies.

Furthermore, traditional exchanges with the Caribbean through Belize have given way to more diffuse, mediated and standardized connections, at the level of the Caribbean and the entire world, through the development of tourism.

In fact, the emergence of the state of Quintana Roo in 1974 coincided with the implementation of an extremely ambitious international project: the creation of the tourist resort of Cancun (Richard Macias, Perez Aguilar 2009), which now extends to much of the coastal area of the state (from Cancun to Tulum, passing by Isla Mujeres and Cozumel) under the name of the Riviera Maya.

The northern part of the state, until then sparsely populated, was confronted with a massive influx of labor from the rest of the peninsula, the interior of the country and Central America. The city of Cancun experienced explosive growth, reaching in some thirty years the number of 500,000 inhabitants (census 2005), soon followed by Playa del Carmen and, more recently, by Tulum.

The Riviera Maya thus became one of the main centers of global tourist attraction, welcoming 3.1 million visitors during the first half of 2010.

In this context, groups have emerged that are apparently the direct result of this globalization and that make interchanges and samplings on global level the very essence of their musical expression. Such is the case, for example, of Bandikoro, a Tulum group that describes itself on its website (in English) as follows: "Contemporary band with their feet submerged in ancient musical roots from the most remote corners of the world. Bandikoro bases their musical proposal on polyrhythmic African percussion extracted from the profound veins of these aged traditions, but transformed by the fusion with bold modern sounds. The balafon, an African instrument and grandfather of the marimba, is one of their most valued gems. Bandits of the third millennium, the integrants of this group are pursued for the shameless display of vigorous rhythms originating in the black continent, such as the rumba and its afro Cuban derivates, along with the Colombian cumbia, the American rap, and the Jamaican reggae. The filibusters of this singular musical vessel could not have more dissimilar origins: Mexico, France, Sweden and the United States"

(http://www.myspace.com/bandikoro, retrieved on November 12, 2010). Thus, all the rhythms described as "afro" in the Americas (rumba, cumbia, rap, reggae) are used to make this fusion that finds a certain resonance with visitors from multiple horizons (United States, Europe, Latin America), who love this "world music", simultaneously artificial and in search of roots, a product of marketing and of a bohemian life. Cancun, Playa del Carmen and Tulum thus attract a steady stream of musicians who find in these places all the necessary conditions for their performance (technical, communications, audience, spaces, etc.). Likewise in Cozumel, Freedom in Paradise and Rasta's bar and restaurant, created in homage to Bob Marley, located in the southern point of the island, seduce North American visitors from cruise ships and also young musicians from the state (organization of concerts, place of reference).

In a more diffuse manner, the very tourist profile of the state of Quintana Roo has a dynamic effect on the musicians of Chetumal, although the city does not belong to the Riviera Maya and is located outside the area of tourism development. This is because some of them had the opportunity to live and work for a time in the Riviera; or because the upstate groups represent for them a source of inspiration, given their more international character, their access to a wider audience, their higher profile; or simply because the local music scene is thus inscribed within a more global space, with multiple connections and ramifications. Tourism, by placing Quintana Roo in a globalized space that displays easily consumable cultural and ethnic differences, itself facilitates the acceptance of the blackness associated with Afro-Caribbean music.

III. "In Chetumal, we are not rasta but we like reggae" (Alvrix). Rooting and uprooting, amnesia and memory

Unlike the analysis by Carla Guerrón-Montero ( 2006) of calypso in Panama, the presence of Afro-Caribbean music in Chetumal does not signify a "cultural revival", permitting the affirmation of an "Afro-Mexican identity". The musicians, like their audience, have no phenotypical characteristics, exhibit no cultural signs or dress codes, and do not sing committed texts that would distinguish them from the other young people of their generation and manifest their willingness to belong to an Afro-Caribbean universe. As suggested by the title of a song of Alvrix (Arturo Alvarez), in his CD "Chetumal Rasta" 17 , "in Chetumal, we are not rasta but we like reggae". The success of Afro-Caribbean music in Chetumal fits into the social logics already analyzed elsewhere: consumption of African-American symbols by a white, middle class youth that has access to globalized resources [START_REF] Collins | New Commodities, New Consumers. Selling Blackness in a Global Marketplace[END_REF]; new manifestations of blackface and the fascination for black bodies, present in the Caribbean since the nineteenth century [START_REF] Lhamon | Raising Cain. Blackface performance from Jim Crow to Hip-Hop[END_REF]. It also takes a more local form that I will study through two groups of actors, who generally ignore each other and develop their practices in different social settings, although both groups are organized around Afro-Caribbean music. On the one hand, the music groups that appeared in the 2000s do not explicitly place themselves in a musical tradition that goes back to sambay or brukdown or to the hits of Benny and Ely. However, their trajectories show that they are part of a music scene structured by its relations with Belize and the presence of Afro-Caribbean music. On the other hand, a group of people recently emerged who make the memory of the golden age of Afro-Caribbean music in Chetumal the starting point for defending and giving value to a "Chetumal identity". The absence of memory, in the first case, is accompanied by a music rooted in localized musical practices; the mobilization of memory, in the second case, seeks to assert an "invented" identity, in the Hobsbawm sense.

Black music without black people

During the Carnival of 2010, the two venues located on the Explanada de la Bandera, the historic center of Chetumal, attracted a family audience with its rhythms of tropical music, simultaneously "folkloric" and commercialized. A few hundred yards away, far from the taco stands and street vendors of cotton candy, another stage, much smaller, made room for local stars of reggae and ska: Corpus Klan (from Cancun) and Hierba Santa. There were many young people in small groups, dancing, singing, calling to each other in a relaxed atmosphere. But several police intervened to detain three marijuana smokers who had hidden behind a trailer, from which they came out triumphantly, handcuffed and with a smile on their lips. Although it was far from resembling heated or subversive concerts where illicit substances are consumed (even alcohol is hardly present here), in the context of Chetumal this type of concert conveys an image of transgression that is nevertheless very relative. Most of the public, among which the average age ranges between 15 and 25, is a student population. It is not unusual to find the same individuals in other reggae/ska concerts, since they form a small community that is identified through this musical genre and distinguishes itself from the fans of rock, reggeaton or techno. Nevertheless, displaying signs of identity is rare, though some young people wear rasta colors or shirts with the image of Bob Marley, and a few musicians port dread locks (in particular, those of Corpus Klan); generally speaking, there is no observed intention to identify with an "afro" universe. Above all, this is about the cultural expression of a generation (15-25 years) for which Afro-Caribbean music is one element of recognition among others, without necessarily being synonymous with membership in a wider symbolic universe.

The reggae and ska concerts, which have a very variable frequency, without any programming in the medium to long term, take many forms: participation in the Carnival, official events organized by the Secretaría de Cultura and the University of Quintana Roo, informal presentations ("toquines") for entertainment during a party, concerts at a bar, nightclub or Sindicato de volqueteros. In more important events three or four groups appear, each with a relatively limited repertoire (seven or eight songs). Also, concerts are sometimes organized where an entrance fee is charged, in order to acquire musical instruments, pay for the use of a studio, or produce a CD.

The oldest groups emerged at the beginning of the 2000s; the concerts are offered on a regular basis; the musicians know each other; their fans are faithful: there is no doubt that an Afro-Caribbean music scene exists in Chetumal. However, it is difficult to speak of organization or planning, of places associated with this music, or a night dedicated to reggae or ska (as is the case, for example, with the Son Jarocho or the danzón in the city of Veracruz). It is rather an informal setting, without organizers, with little support from local authorities or cultural policies (although these do not manifest any rejection), without a market (the CDs recorded remain rare and are quickly pirated, the musicians do not live off their music). But it depends on the musicians' mobilization of a real symbolic capital, leading one to believe that this scene is as likely to consolidate in the near future as it is to disappear overnight. The internet plays a key role in this respect, promoting the existence of a music scene that is uncertain, decentralized, multiple;

simultaneously it allows musicians to dispense with more formal and institutionalized production and communication tools. All groups have their sites on Facebook or My Space, where they present information about themselves, musical excerpts, links to videos of their concerts on YouTube. It is through these channels-not to mention the SMS messages by mobile phonethat information about the scheduled concerts flows. Hence, public announcements concerning Afro-Caribbean music are never seen in the street or in the press. Similarly, it is less necessary to resort to recording in a studio or to produce a CD, because of the numerous uploads by internet users of concert videos on YouTube. Chat conversations allow for the virtual expansion of the "community" that has formed as a result of the concerts, among an audience that shares a similar demographic status (youth, students, middle class).

Nothing, apparently, links the young musicians of today with their parents' generation, when

Benny and his band, Ely Combo or a visiting Belizean group animated the Chetumal evenings.

The music of the forest camps-brukdown, sambay or dance of the chicleros-seems even further away and in fact is never mentioned. Several contemporary musicians began their careers playing other genres (mostly rock), so that they do not know Benny, nor Ely, nor the musical diversity of neighboring Belize. In addition, for some, reggae is also related to the movement of "latin reggae", sung in Spanish by Argentine, Cuban or Mexican groups; in this sense, they do not necessarily connect, at least initially, reggae with Afro-Caribbean music. It is only after they have been initiated in reggae or ska that some begin to show interest in the music their parents listened to or to locate these rhythms in a Caribbean musical trend. In their blogs, Hierba Santa, Korto Circuito y Skuadron 16 do not refer to an Afro-Caribbean culture, nor do they provide any details about their interest in reggae or ska. The statements of the group leaders usually do not show any desire or need to situate themselves within a determined continuity or heritage, and the music appears first and foremost as a symbolic capital which can be used immediately, in daily relations or at parties, to enjoy a valued status among their peers.

However, when the conversation focuses on more practical details-for example, the composition of the group, their musical education, early influences-this indifference gives way to a diffuse inscription within a local tradition, where the references to Afro-Caribbean music are ubiquitous. And so, we learn that Jorge, the leader of Hierba Santa, is the son of Roque Cervera, one of the best known musicians of Chetumal, who won national recognition. Roque Cervera played numerous musical genres-jazz and bossa nova, among others-and he maintained close ties with Benny and Ely. He is the author of the song "La Turraya", a Belizean deformation of "tu tarraya" [your fishnet], which recalls, with an English accent and Afro-Caribbean rhythm, the activities of a "little black" (negrito) Belizean fisherman in the Bay of Chetumal. Furthermore, in Jorge's first group (rock), Benny's nephew played as a saxophonist. Finally, Jorge's cousin is Arturo Alvarez, composer of "Chetumal Rasta", mentioned before, and producer of Policarpo Aguilar's "Chiclero", where he explicitly recalled that Afro-Caribbean music took root in the region since the early twentieth century through the forest camps 18 .

These relationships, exchanges and continuities are rarely presented explicitly, because they appear both as very obvious and lacking in relevance, although in fact they are structured and play a key role. In a small provincial society, where the music scene is not very developed, the range of opportunities is ultimately limited both in terms of personal relationships and musical options. The decision to form a reggae or ska group does not necessarily respond to an identity posture 19 ; in a more pragmatic manner, it results from the very structure of the local music scene 18 Bahía del Sol Records, 2004. The libretto states: "a man of his time and of his world, Don Policarpo Aguilar was a chiclero in the 1930s, a mahogany cutter and fisherman, whose sensitivity allowed him to translate to a musical language the history of the micro cosmos which he lived. He shared work with men from places like Belize, who he used to hear sing while they were extracting chicle".

19 Although this might be the case for a new generation of musicians or for groups from places with a different or broader musical repertoire. It is interesting to observe that the I and I and Polok Tolok blogs, in Mérida, or Corpus Klan, in Cancún, have recourse in a much more explicit manner to practices or ideas associated with Afro-Caribbean culture; thus, I and I places itself under the protection of Jah Rastafari, and sends a message of peace and tolerance;

and its relationship with Belize-which, as we have seen, is far from being linear. Reggae and ska are the expression of a legacy that is not truly conceived in cultural terms (except for certain intermediaries/ entrepreneurs), but rather responds to an internal organizational logic of the world of amateur and professional musicians.

Afro-Caribbean music and "Chetumal identity"

If young Chetumal musicians illustrate a case of the inheritance of social practices without the explicit mobilization of a memory linked to these practices, the second example given could be analyzed in terms of the "invention of tradition", i.e. the construction of identity traits in continuity with the past.

On November 26, 2010 the "Sambay of memory" event took place in the Bellavista lounge of Chetumal, the term "Sambay" referring here to both the chicle tradition and a generic term meaning "to go dancing". The date was not chosen at random: it makes reference to November 24 th , 1902, the date of the creation of the territory of Quintana Roo (the event was held two days later to coincide with a Friday). Behind the stage, a canvas represents the clock tower, a symbol of Chetumal and also recalling the dances in the Explanada de la Bandera 20 , and a fisherman Polok Tolok refers to Jamaican music as against Babylon; the logo of Corpus Klan is the face of a man with dread locks and rasta colours. 20 The Explanada de la Bandera, an emblematic site of Chetumal, was constructed by Governor Rafael Melgar during the administration of President Cardenas, within the dynamics of integration into the nation, and was also the favorite site for the dances linked to the proximity with Belize; it is now a symbol of the defense of a "Chetumal identity". Juarez Civic Group, Committee for the Defense of the Borders of Quintana Roo, etc.), which organized the event "Sambay of memory". The motto of the Committee is to defend "our town", "our history", "our identity": these "ours" refer to the "authentic" chetumaleños and this "authenticity" to the cultural and family relationships with Belize. Thus, Afro-Caribbean music is the most visible marker, the one easiest to mobilize around a local identity that is constructed as against hegemonic, national or regional (Yucatán), tendencies. The reference to the Caribbean allows some mystification of the past and its contrast with the present: the prestige of culture, the harmonious relationship with Belize, Caribbean brotherhood, a classless society that lived together in the symbolic place of the Explanada.

In fact, it is important to stress that what is valued is belonging to the Caribbean, a Caribbean cultural specificity, but not the "Afro-Caribbean". "Caribbean" supposes the presence of the "Afro" without mentioning it and works as a metaphor that assumes the "Afro" or implies, euphemizes and neutralizes it. When one questions the young musicians from Chetumal or the nostalgic audience at the "Sambay of memory", their responses are very similar: "this is black people's music". There is thus an essentialized relationship of the music with "blackness", so obvious, so natural, that it is taken for granted and unnecessary to mention. Only when Chetumal music is presented abroad, faced with the "other", as for example in the program Siempre en Domingo, or when it needs a touch of legitimacy through the presence of a black singer or dancer, does "blackness" reemerge. Similarly, the leader of Hierba Santa evokes the concert of this group in San Pedro (Belize) before an audience of "rastas, authentic blacks," as a "baptism of fire"; or again, the leader of the Mérida group Polok Tolok wonders whether the two reggae musicians from Belize invited to an event organized by the University of Quintana Roo (October 15, 2010) consider his music as "authentic reggae".

Conclusions

In the case of the Colombian coast studied by Peter Wade, a black, peripheral music became a component of the national identity. In Panama, Carla Guerrón-Montero identified a black cultural revival as a way to assert distinctive identities in the national culture. Chetumal, in the Mexican state of Quintana Roo, shows us a different dynamics: the presence of Afro-Caribbean music is not a revision of mestizaje that includes a « third root », since blackness is not exterior or peripheral (Hoffmann, Rinaudo 2011). It is not either a way to denounce and reject the national mestizo project, considered unable to transcend the European /Indigenous duality and to integrate other components of the population into discourses and practices. Beyond the denunciation of mestizaje as a form of racism and as a homogenizing national project, beyond, as well, an enchanted vision of cultural mixing and post-modern hybridity, it can be observed that Afro-Caribbean music is distributed, promoted, legitimized by Mexican institutions, but also assimilated, normalized, standardized. Blackness has become mestiza because of its integration into local history and identity and because of its appropriation by government institutions, while continuing to exist as a regional cultural specificity. The narrative of Gonzalo Guerrero and of the "birthplace of mestizaje" still have a robust future in Chetumal; they do not prevent the Afro-Caribbean groups from playing regularly in the auditoriums, discotheques, and public spaces of the city. The Mexican society is thus able to transform a double exogenous otherness, in racial and national terms, into a non-salient and non-problematic, endogenous one.

These three examples (Colombia, Panama, Mexico) bring us to insist on the diversity of Afro-Caribbean music and the multiple configurations of ethnicity in Latin America. Not only the expression of a transnational collective identity, music must also be situated in national dynamics. Afro-Caribbean music in Chetumal shows the force of nationalist frames, in terms of ideology, but also on the level of state intervention. The recent resurgence (in the 2000s) of this music also reflects a complex social logic, diffuse and local, involving the history of the region throughout the twentieth century as much as the structuring of the musical framework, the role of certain intermediaries or the search for a local identity. Afro-Caribbean music is part of the mestizaje, which thus acquires an additional facet, at the same time that it is enriched with the expression of a new local culture. In this sense, blackness is not an alternative to mestizaje or a questioning of it, but rather a shading, a degree within a mixture that is, in turn, heterogeneous and simultaneously includes the categories of mestizo, Maya and Afro-Caribbean.

This malleable mixture, of a variable geometry and inherently ambiguous, generates and accepts new differences, while excluding or transforming individuals, traits, ideas considered "inappropriate" for the national identity, which itself is in perpetual construction. Hence, Afro-Caribbean music was accepted in the periphery until the 1930s, before being nationalized and made mestiza under Cárdenas and his local representative, Melgar, to resurface in the death throes of a cross-border cultural movement (1960s-1970s), disappear during the institutionalization of a new state and be reborn in the framework of an integrated and globalized region, in search of a Caribbean specificity.

In general terms, contemporary Afro-American studies in Latin America tend to emphasize an opposition between mestizaje and blackness, to see black identities as a "challenge" to mestizaje [START_REF] Anderson | ¿Auténtica cultura africana en Honduras? Los afrocentroamericanos desafían el mestizaje indohispano en Honduras[END_REF] or mestizaje as a negation of black culture and africaness as a recent emergence "of centuries of obscurity" (Vaughn 2005, p. 55). The Chetumal situation reveals that mestizaje and blackness are not antagonistic: Afro-Caribbean music is not a forgotten "third root" resurfacing on the periphery of the nation and does not call into question the concept of mestizaje. In fact the "mestizo identity" is not threatened by an "African identity", through a festive and globalized contestation. Blackness is integrated into mestizaje, while embodying « a kind of difference that doesn't make a difference of any kind » to borrow the words of Stuart Hall (1996, p. 467). Black music is part of the local culture but doesn't produce any Afro-American identities, as difference is dissolved into sameness, through the ideology and politics of mestizaje.

9

  See the compilation Belize City Boil-Up, Stonetree Records, which brings together the principal interpreters of these Belizean rhythms of the years 1950-1970, in a surprising mix of disco music, jazz and funk. There are very few written records of the influence of Belizean and Caribbean music in Chetumal in the years 1960-1970 (however, see Ortega 2008; Manríquez 2007). 10 Eddie Ortega (2008) also mentions other less well-known groups: Los Cuervos, Los Flyers, Los Brotherhoods, Los Reclutas.

(

  completion of the roads to the interior of the country, the arrival of television) and an incorporation into the nation, lived out in daily practice and not only in the mobilization of symbols (flag, anthem). Simultaneously, in Belize, the musical apogee of the years was weakening: some groups had disintegrated, others had settled in the U.S. (this was particularly the case with Byron Lee) and it no longer fed the Mexican music market. A few years later, the creation of the Free Trade Agreement (NAFTA) between Mexico, Canada and the United States on the first of January 1994, meant the loss of the privileged economic relations between Belize and Quintana Roo. The importation of European products (Belize being a British colony) and international goods (through the proximity to the Panama Canal) to the Yucatan Peninsula and Mexico, which had characterized the border region during the twentieth century, could not resist the creation of a free market turned towards the north of the country. In this way, the arrival of Belizean and Caribbean music to Chetumal was interrupted, along with other elements of economic flows, while the new inhabitants of the state and media communications brought other musical genres from the interior of the country (norteña music, rock).The two key moments of the territory's integration into the country (Cárdenas in the second half of the 1930s, the creation of the state of Quintana Roo in 1974) correspond with the dilution of Afro-Caribbean music in the national project. In this way, the music has not resisted logics of belonging and nationalism. But it reemerged for the first time in the 1960-70s, then, as we will see, in the 2000s at the initiative of a young generation of musicians who generally had not known the epoch of Benny and Ely and who today embody a musical scene both popular and fragile, local and globalized. These recurrences are not ruptures in relation to the dominant cultural model or contestations of the national ideology of mestizaje : blackness is not foreign to mestizaje but was, on the contrary, interiorized, standardized, integrated into the national identity that imposes itself at the periphery of the territory.II. Blackness in a mestizostate: the development of an Afro-Caribbean music scene in the 21 st Century

"

  entrepreneurs" serve as intermediaries between various social fields (communication, knowledge, policy), thereby promote the circulation of the music beyond its practitioners and fans, at the same time conferring recognition in multiple areas. They are not by any means solely associated with Afro-Caribbean music, which is for them an element of their activities among others, but they nevertheless contribute to the creation of a local Afro-Caribbean cultural manifestation.As a radio director and producer, Eddie Ortega hosted, among other things, for about ten years, the program "Rastaman Vibration", the first program to spread not only the hits of Jamaican reggae, but also Afro-American music from Latin America, Europe or Japan, as well as local classics by Benny and Ely. He now presents the program "Reggae y otras yerbas" on Friday evenings, and is also departmental director of the radio Chetumal AM, controlled by the state of Quintana Roo (Sistema Quintanarroense de Comunicación Social). Raised in a family of musicians and a tireless collector of music, Eddie Ortega accompanies his radio broadcasts with numerous comments, analysis and news about the musicians he presents and about Afro-Caribbean music in general. Regularly invited by various institutions in the city, Eddie is also one of the few who has written articles on reggae in Chetumal (in the press), and plans to publish a book. In fact, he has participated in all three editions of an Afro-Caribbean music seminar, organized at the University of Quintana Roo by Raciel Manríquez, another actor who embraces the local music scene. As a reporter of "La Gaceta de la Universidad de Quintana Roo", Raciel Manríquez is also involved in two worlds-academic and media-thereby giving recognition and institutional legitimacy to Chetumal musicians, many of whom have passed through the classrooms of the University of Quintana Roo. As a final example of this confluence of different fields, Arturo Enriquez is a producer and presenter of the radio program "Puerto Pirata", specializing in reggae music. He has moreover been involved in organizing several concerts of Afro-Caribbean music: Massive International Reggae Concert, under the International Art Festival Chetumal Bay; Festival of Reggae and Ska Bacaroots, etc. Finally, in 2010 he obtained a grant of Incentive for Creativity and Artistic Development, awarded by the Secretaría de Cultura of the state of Quintana Roo, thanks to his project "Caribbean Brotherhood, the Reggae Scene in Latin American and Caribbean Ethnic Studies, Volume 9, Issue 1, 2014, p. 1-22 20 the Mexican Caribbean" which aims to establish an inventory of the groups, sites and products related to reggae in the state.In fact, Arturo Enriquez's grant shows that the institutions of the city and state are not oblivious to the development of the Afro-Caribbean music scene, which is neither denied nor segregated, neither instrumentalized nor commodified, but is sometimes included in the activities that are planned by city institutions. On June 4 th and 5 th , 2010, the Department of Popular Culture in Chetumal-a department of the Secretaría de Cultura of the state-organized a concert entitled "Afro-Caribbean Music in Quintana Roo" in the towns of Chetumal and Bacalar, with the bands Bandikoro (Tulum), Nankama (Bacalar) and Hierba Santa (Chetumal). The concert was presented as follows: "three groups of recognized artistic quality and trajectory which have as their essential ingredient the powerful rhythm of African music. Born or living in our state, the members of these three groups are an example of the current generation of creative artists of Quintana Roo who, facing the waters of the Caribbean, proclaim the musical heritage of this ancient continent, from the pure rhythm emanating from the drums, to the fusion with rhythms of other American latitudes such as reggae, rumba and rap". This episode is part of a larger program, complemented by two other events: one that focuses on indigenous dances and music and another that pays tribute to the orchestra of the state. In the words of Karin, head of musical entertainment at the Office of Popular Culture in Chetumal, the goal is to "disseminate this diversity that exists in the state. It is not to seek an identity in what makes us the same, but in what makes us different. There have always been Belizean influences, so the African element is not out of place. Today's groups would not be as well received without the connection to Belize.We consider them within the musical gamut of the state" (interview, June 10, 2010).The International Festival of Culture of the Caribbean: international stars in Quintana Roo Another element that most likely facilitated the emergence or resurgence of Afro-Caribbean music in the 2000s was the International Festival of Caribbean Culture. Created in 1988, the Festival had a successful debut, during which several high quality concerts alternated with a series of lectures and cultural events around the Caribbean. During the first edition of the Festival, the inaugural speech pronounced by Miguel Borge, then governor of Quintana Roo, in the presence of the President of the Republic, reflects its impact and the desire to establish roots in the Mexican Caribbean through the state of Quintana Roo: "Today the Caribbean heart of this land of Quintana Roo beats strongly. Tonight, all together, we accompany President Miguel de la Madrid in laying the foundation stone of a magnificent work that we should always look at through sensitive eyes. Today, at a singular event in our history, Quintana Roo becomes the apex of unity and encounters with fourteen brother countries in the Caribbean basin, who for five days will unfurl the offering of the most representative of their cultural and artistic manifestations, to share them with our own"(Cultura del Caribe 1988, p. 19). Such statements are indicative of the objectives implicit in the realization of this festival: to reaffirm the membership of the young state of Quintana Roo in the Mexican nation, and at the same time to give value to a "Caribbean identity" specific to the region 15 .

  Veracruz is also Caribbean", and then with the Afro-Caribbean Festival of 1994. It should likewise be emphasized that there was greater development and continuity in the local cultural policies in Veracruz. Also, in the case of Veracruz, the Caribbean is more explicitly related to the Afro-Caribbean, thanks to the program The Third Root: in this period, Luz María Martínez Montiel was the director of the cultural heritage program of IVEC and coordinator of Third Root (Rinaudo 2012). Despite the presence of Guillermo Bonfil Batalla in the International Cultural Festival of the Caribbean in 1991, the connection between "Caribbean-ness" and The Third Root did not parts of the state (Cancun, Chetumal, Cozumel, Isla Mujeres). It presented renowned international guests, often associated with Afro-Caribbean music: Jimmy Cliff, Lucky Dube, November 20 th 2011). The Festival had in this logic reserved the evening of November 16 th for local representative of this style of music: Chan Santa Roots from Felipe Carrillo Puerto, Corpus Klan from Cancún, Korto Circuito, Skuadrón 16 and Hierba Santa from Chetumal. In this way, the Festival permitted, in the 1980-90s, the local distribution of a style of Afro music that was widely recognized and established on the international scene, while promoting an Afro-Caribbean specificity that was unique to Quintana Roo in its relation to the rest of the nation. With its renaissance, the 2011 Festival made the new generation of musicians in the 2000s the heirs of stars heard over 20 years before, and the representatives of a local culture that enjoys institutional recognition.

	Celia Cruz, Willie Colon, Compay Segundo, Andy Palacio. All Chetumal musicians, young and
	old, regard it as a reference point, a key step both for their musical careers and for the acceptance
	of Afro-Caribbean music at the institutional and grassroots level. The festival has given way to
	more limited events (in particular, to its direct heir: the Chetumal Bay International Art Festival,
	which has also disappeared), some of which are dedicated specifically to Afro-Caribbean music:
	Reggae Fest International (Cancún, 2007), Massive International Reggae Concert (Chetumal,
	2006 and 2007), Reggae and Ska Bacaroots Festival (Bacalar, 2006).

16

Margarito Molina, coordinator of the Office of Popular Cultures in Chetumal, recalls that the affirmation of a Mexican Caribbean character appeared in the state of Quintana Roo in 1988, that is to say before the state of Veracruz, now considered the "Caribbean state" of

Mexico (interview, November 24, 2010)

. In Veracruz, this Caribbean dimension is affirmed in 1989 with the organization by the Veracruz Institute of Culture (IVEC) of the first forum "function in Quintana Roo. It seems that the only impact of the program in the state was the work of Mario Baltazar Collí Collí from the state Office of Popular Cultures in Felipe Carrillo Puerto (1992). different After several years of absence, the Festival reappears in 2011. Roberto Borge Angulo, governor of the state of Quintana Roo, nephew of Miguel Borge, emphasizes in his closing remarks on the Explanada de la Bandera in Chetumal, the role of Afro-Caribbean music in the region. "The Festival of Caribbean Culture presented residents and visitors a vast cultural and artistic offering.

Reggae, ska, soca, punta, cumbia, salsa and other typical Caribbean rhythms were the delight of the public" (the newspaper Respuesta,

Latin American and Caribbean Ethnic Studies, Volume 9, Issue 1, 2014, p. 1-22 33 with

  his fishnet, a symbol of an old Chetumal that is disappearing. A Chetumal group, Son 3, with its black singer from Jamaica, started the concert, mostly with old hits well known to the public, from Benny, Ely or Belizean groups. Then, Lucio and his New Generation, a group from Orange Walk, Belize, played until five in the morning. José, Benny's brother, the saxophonist of Benny and his group, accompanied Lucio on stage for some songs, and tribute was paid to some of the celebrities of the state present in the room: Jesús Martínez Ross, first governor of the state of Quintana Roo, Abraham Martínez Ross, his brother, state representative, Marcos Ramírez Canul, a musicologist and composer of the hymn of Quintana Roo.The event represents the juxtaposition of two dynamics (interview with Francisco Ortega, organizer, 2 February 2011). Firstly, it is the result of a certain nostalgia for a generation of people who lived during the time of the public dances in the Explanada de la Bandera, often as children, who heard at home, through their parents, the old LPs of Benny, Ely or Belizean groups. This musical influence is lost: Belizean groups and Afro-Caribbean CDs disappeared from the venues of nocturnal entertainment and even private parties (coming-out parties, weddings, etc.). Secondly, these personal and cultural preoccupations intersect with a more public commitment, related to the defense of the urban heritage of Chetumal. In 2009 and 2010, various downtown development projects (especially in the famous Explanada de la Bandera) sparked concerns in a sector of the population worried about the risk of the disappearance of local urban "tradition". Such mobilization is rooted in an older concern, expressed for example in certain statements by the official historian of the city (El cronista), Ignacio Herrera Muñoz, over the architectural heritage of Chetumal, especially its wooden houses, a symbol of the "English Caribbean" style in Mexico. Thus was the Committee for the Defense of the Heritage of Chetumal formed, from a group of existing associations (Builders of Quintana Roo, Benito

Until the abolition of slavery in 1833, Belize was a slave society that was dedicated to forestry exploitation[START_REF] Bolland | Colonialism and resistance in Belize[END_REF].

Apart from missing a few months, the data is interrupted from September 1911, probably because of the disturbances associated with the Revolution, until 1926 (Archivo General de la Nación, Secretaría de Gobernación, Sec. 4a 908).

For an analysis of sambay and brukdown from a Belizean perspective, see[START_REF] Hyde | Stoan Baas" People: an Ethnohistorical Study of the Gales Point Manatee Comunitye of Belize, Master of Arts Heritage Studies[END_REF].

Payo Obispo became the capital in 1915, replacing Chan Santa Cruz, the future Felipe Carrillo Puerto.

Among other things, in that period certain place names were "Mexicanized": Payo Obispo became Chetumal, Chan Santa Cruz became Felipe Carrillo Puerto, Campamento Mengel became Alvaro Obregón, etc. Likewise, the cooperative was adopted as a form of socioeconomic organization; forestry ejidos were formed; the first projects to link Chetumal by road to the rest of the country were implemented; programs of civic education were introduced; policies of internal settlement were established, etc.

A secret circular in May 1924 prohibited the immigration of black people into Mexico; the years 1930-1940 were characterized by the implementation of restrictive immigration measures, which were guided in particular by racial criteria (see Yankelevich 2009; Saade 2009).

Interview in the movie "Reggae from Chetumal for the world," directed by Eduardo Medina Zetina, Chetumal, Santa CeciliaProducciones, 2008.

It was also necessary to satisfy certain criteria with regard to agricultural, industrial and commercial infrastructure and to local government revenues.

The association with the Caribbean is an element of the affirmation of a local identity, very strong in the administration of Miguel Borge (it also marks the foundation of the University of Quintana Roo in 1991), but that would not have great influence thereafter, at least in public policies, although it is present in an indirect way.

Roo (UQROO) in Chetumal. She coordinates the international project ANR-AIRD


Christophe Lavelle
email: lavelle@mnhn.fr

A U R Élien Bancaud

Pierre Recouvreux

Maria Barbi

J E A N -M A R Cvictor

Jean-Louis Viovy

Progress of Theoretical Physics Supplement 1 Chromatin topological transitions

DNA transaction events occurring during a cell cycle (transcription, repair, replication) are always associated with severe topological constraints on the double helix. However, since nuclear DNA is bound to various proteins (including histones) that control its accessibility and 3D organization, these topological constraints propagate or accumulate on a chromatin substrate. This paper focuses on chromatin fiber response to physiological mechanical constraints expected to occur during transcription elongation. We will show in particular how recent single molecule techniques help us to understand how chromatin conformational dynamics could manage harsh DNA supercoiling changes.

§1. Introduction

Genomic DNA in eukaryotic cells is organized in discrete chromosome territories, each consisting of a single huge supercoiled nucleosomal fiber. Through structural changes resulting from the transient modifications of its constituents (recruitment of histone variants and non-histone proteins, histone chemical modifications, nucleosome remodeling), chromatin plays a critical role in the regulation of all DNA transaction processes, such as repair, replication, recombination and transcription. Namely, since DNA is almost never naked in eukaryotic nuclei, chromatin processing necessarily precedes DNA processing. Hence, chromatin not only provides a convenient way to pack two meters of DNA into the nucleus volume, it is also a polymorphic and highly dynamic structure which regulatory role is now largely acknowledged.

Chromatin fibers are made of a repetitive unit, the nucleosome, which consists of 147 bp of DNA wrapped ∼1,7 times in a left-handed superhelix around an octamer of histones containing two copies each of the four core histones H2A, H2B, H3 and H4. 1) This leads to both compaction and topological deformation of the DNA by one negative turn per nucleosome. 2) Acting both as a compaction and regulatory tool, nucleosomes must be reasonably stable while keeping some dynamic properties to allow transient DNA access for, e.g. transcription factor or RNA polymerase binding to specific sequences upon transcription initiation, or, even more dramatically, chromatin clearance during transcription elongation. These seemingly contradictory properties raise many questions, such the way RNA polymerase progresses along chromatin template, the subsequent fate of nucleosomes, and the mechanistic role of various elongation factors and topoisomerases. 3)-6) What happens to nucleosomes during transcription (or, equivalently, what happens to polymerase as it encounters nucleosomes) is indeed a question that has not lost much of its mystery, 3), 7) partly due to the difficulty to obtain a clear and unifying picture from the apparently inconsistent results arising from many different experimental studies (see references in Ref. 3)) In particular, it is often hard to make the difference between direct (mechanical, through contact) or distal (topological, through DNA elastic constraints propagation) effects of polymerase tracking.

In this review, we wish to focus on the distal aspects. Single-molecule manipulations have indeed recently complemented conventional biochemical and biophysical techniques to decipher the complex mechanisms ruling chromatin dynamics. Micromanipulations with magnetic tweezers opened opportunities to handle single chromatin fibers and to measure their mechanical response to forces and torques mimicking the constraints produced by various molecular motors acting on DNA. 8) We will show how these experiments unveiled (i) the unsuspected high torsional resilience of chromatin fiber 9) and (ii) the nucleosome capacity to change its chirality. 10) §2. Dealing with supercoiling waves produced by a transcribing polymerase

Several nuclease digestion assays gave early evidences that although chromatin structure is usually altered during gene activity, 11) nucleosomes are not completely lost. 12), 13) To what extent nucleosomes dissociate or simply unfold when polymerase gets through remains an open question, as are the partners and mechanisms involved. 14) The different histone-DNA destabilization models rely on direct interaction with the polymerase and elongation factors potentially assisted by the propagation of topological stress ahead of the polymerase. 3) Namely, as RNA polymerase tracks along the DNA template, it follows an helical path: transcription elongation thus requires a rotation of the transcription complex relative to the DNA template. 15) Now, the question remains whether polymerase rotates around DNA or DNA rotates through polymerase. 16), 17) In the later case, tracking would generate positive supercoils ahead of the polymerase and negative supercoils behind it, as it was proposed by Wang and coworkers in the "twin supercoiled domain" model to describe bacterial transcription 18) (Fig. 1a) and since then sustained by many experimental evidences (see Ref. 3) for a review).

Foreseeing the consequence of such a model in a chromatin context, Lee and Garrard proposed that positive supercoiling in front of the RNA polymerase could provide a mechanism to unfold the nucleosomes and decondense the chromatin fiber in preparation for polymerase passage 19), 20) (Fig. 1b). In a further refinement of this model, Bancaud et al proposed that part of the supercoiling constraints could be absorbed by changes in the crossing status of nucleosomes within chromatin fiber, hence enabling a smooth elongation 9) (Fig. 1c). Indeed, from a kinetic point of view, the amount of supercoiling generated by a polymerase translocating at ∼10-100 bp/s, as suggested from polymerase transcriptional velocity measurement in vitro 21) an in vivo, 22) should be roughly 1-10 supercoils/s, potentially exceeding the relaxation capability of DNA topoisomerases. By comparing yeast minichromosomes relaxation by topoisomerase I (topoI) and II (topoII) in vivo, Roca and co-workers showed that, in contrast to what is observed with naked DNA, topoII is much more efficient than topoI. 25) Considering that chromatin could impose barriers for DNA twist diffusion (which impair the DNA strandrotation mechanism of topoI), whereas it favors the juxtaposition of DNA segments (which facilitates the DNA cross-inversion mechanism of topoII), transcription elongation could doubly benefit from the high torsional resilience of chromatin evidenced in Ref. 9). First, it could cushion the supercoiling waves generated by polymerases and dampen the driving torque produced by polymerase translocation. Second, it could simultaneously favor the DNA transport activity of topoII by increasing the juxtaposition probability of DNA segments and facilitate nucleosome entry/exit DNAs to shift from a crossed negative state to a crossed positive one. 3), 25) Moreover, one can speculate that topoI mainly relaxes negative supercoiling produced in the wake of the polymerase and present as negative torsional constraint in linker DNA, 26) while topoII relaxes positive supercoiling produced in front of the polymerase and present as positive writhe, since no sink for torsional stress such as melting exists in this case. 27) On the other hand, in regions where the transcription rate is high, nucleosomes may be depleted due to frequent polymerases passage, and DNA-pulling forces (see below) exerted by polymerases may hinder the formation of writhe: he-lical tension would then deform DNA mostly by twist, allowing topoI to be more efficient than topoII. This hypothesis still needs to be tested in vitro and in vivo. §3. Mimicking transcription elongation constraints in vitro, at the single molecule level

Several studies showed that genomic regions dynamically expand from the surface of chromosome territories upon transcription 28), 29) (Fig. 2a). In this scheme, transcription complexes have been suggested to be part of fixed structures called "transcription factories" that participate into the functional partitioning of the genome. 30)- 33) Polymerases are indeed among the most powerful molecular motors, potentially exerting tenth of piconewtons (pN) on DNA templates. 34)-36) Although these measurements were made with prokaryotic enzymes, one can reasonably postulate that eukaryotic polymerases (potentially assisted by secondary molecular motors such as myosin; see Ref. 37) for discussion) have enough power to pull the chromatin template through the viscous nucleus medium. At the same time, this could unfold the so-called 30 nm fiber into a linear 10 nm nucleosomal array 38) (Fig. 2b), and even disrupt nucleosomes, as shown by many single molecule studies (see Ref. 8) and references therein). Indeed, single-molecule manipulation techniques appear as convenient tools to investigate DNA or chromatin response to mechanical constraints. In our magnetic tweezers set up, a pair of external magnets is used to physically twist and pull microscopic paramagnetic beads to which a piece of chromatin is attached (Fig. 2d). Then, by approaching and/or rotating the magnets, we can change the tension and torsion applied to the fiber, hence mimicking the action of a translocation polymerase (Fig. 2c).

In a typical experiment, one follows the extension of the molecule as a function of torsion (Fig. 3a). The response of naked DNA (dotted red curve) displays the signature of a supercoilable (non-nicked) single duplex DNA. The central (plateau-like) part of the curve corresponds to the elastic regime, and the quasi-linear compactions on either side to the formation of positive or negative plectonemes upon introduction of positive or negative rotations. 39) The lower compaction on the negative side is due to a force-dependent DNA melting at high negative torsions, which prevents further increase of the torque on the molecule and prevents further plectoneme formation. 39) Compared to DNA, chromatin is shorter and its centre of rotation is shifted to negative values (blue curve). The shift is the expected consequence of the absorption of approximately one negative superhelical turn per nucleosome (∆Lkp ∼ -1), the observed shortening (∼-50 nm, i.e. 150 bp per nucleosome) resulting from DNA wrapping around the histone core. Compared to DNA of the same length, the fiber appears to be torsionally extremely flexible, i.e. it can absorb large amounts of torsion without much shortening. 9) This large torsional resilience was interpreted as a reflection of the nucleosome dynamic equilibrium between the three conformational states previously identified in minicircles studies. 40)-42) A tt h es a m et i m e ,t h i se xperiment provides a prediction of the torque exerted by chromatin fiber as a function of its torsion: this torque can go up to 3 pN.nm.rad-1 (compared to 6 pN.nm.rad-1 for naked DNA), that is, in any way, smaller than that exerted by advancing poly- merase (> 5p Nn m . r a d -1 ) , 15) further suggesting that chromatin torsional resilience may facilitate transcription elongation. 9) Now, since a sufficient amount of tension was shown to disrupt nucleosomes, 9) we set out to test the Lee and Garrard scenario, 19) and measure the amount of torsion necessary to destabilize nucleosomes. To our surprise, virtually any positive or negative supercoiling could be applied to chromatin fibers without loss of nucleosomes. 10) Even more surprisingly, these chromatin fibers, after extensive positive supercoiling, display a hysteretic behavior (Fig. 3a; blue and green curves). This hysteresis was interpreted as a consequence of the trapping of positive turns in individual nucleosomes through their transition to an altered "chirally reversed" form, called reversome (for reverse nucleosome), to which the next section is dedicated. §4. Chiral issues Nucleosomes depicted with right-handed chirality are usually the result of inadvertent infographics errors, either because artists who draw these pictures are not aware of chirality matters, or if canonical nucleosome pictures are accidentally fiber length (µm) rotation (turns) Hysteresis is observed between the onward (blue) and backward (green) curves when a high positive torsion is applied. The zero-turn rotation reference corresponds to the relaxed state of naked DNA (red dotted curve). The shortening, shifting and flattening of the blue and green curves are interpreted as the consequence of nucleosome reconstitution (each nucleosome wraps 50 nm of DNA in one negative superhelical turn) and conformational flexibility (three-state model), 9) while the hysteresis between both curves is interpreted as the consequence of a transient chiral transition of nucleosomes upon high positive torsional stress to an altered right-handed form called "reversome". 10) (b) The nucleosome-reversome transition has been modeled: 47) starting from a canonical nucleosome [1], constraints accumulate in DNA (forming plectonemes) [2] and trigger the unfolding of the nucleosome [3] that refold in a righthanded reversome, relaxing at the same time the plectonemes [4]. The whole scenario can be conveniently experimented at desk by using an old XXth century phone (inset): starting from a relaxed cord [1'], one can pick up the phone and apply a few turns (opposite to the cord chirality) before putting the telephone down; the constraint first accumulate as plectonemes within the cord [2'], but is eventually relaxed by the spontaneous chiral inversion of some cord gyres [3',4'].

mirrored upon publication. 43) DNA is another victim of neglected chirality, which results in journal covers and commercial advertisements full of unintentional lefthanded DNA. Amazingly, nucleosome chirality must have evolved as a consequence of DNA chirality. Indeed, since a canonical nucleosome constrains one negative turn of DNA, 2) the removal of a nucleosome to gain access to a particular sequence, such as a promoter, simultaneously favours the melting of DNA, which is a necessary step for initiating transcription. In other words, a gene with right-handed nucleosomes would be condemned to silence: each time a nucleosome is removed, the DNA helix would tighten and thus restrict its unwinding. However, several papers have challenged the idea of unalterable cylindrical left-handed nucleosomes and have accumulated evidence for the existence of alternative histone/DNA assemblies, some of which being potentially topologically reversed (right-handed) (reviewed in Ref. 44)).

Based on topological assays of particles reconstituted on DNA minicircles, Prunell and colleagues provided the first in vitro evidence for the existence of right-handed (H3-H4)2 tetrasomes. 45), 46) We then showed that nucleosome arrays submitted to large positive torsional stress transiently trap approximately one positive turn of DNA topological deformation per particle 10) (Fig. 3). We suggested this to reflect the chiral transition of nucleosomes, resulting into metastable octameric particles built on the right-handed tetrasome, that we called reversomes. We were then able to model the transition steps and to propose an atomic structure for the reversome 47) (Fig. 3b). The role of such a transition during transcription elongation is easily visualized by looking at a phone cord (Fig. 3b, the most difficult part nowadays being to find such a phone apparatus...). By repetitive picking up/putting down cycles at each phone call, supercoiling constraints potentially accumulate within the cord, 48) which first triggers plectonemes formation within the cord, eventually subsequently relaxed by chiral inversion of some cord gyres. This potential cooperative ("dominolike") transition of successive gyres has been proposed to facilitate transcription elongation, thanks to the high relaxation efficiency of a so-called "reversome wave" in front of the polymerase. 49) Note however that, in order to truly facilitate transcription, these left-to-right chiral transitions of nucleosomes triggered by the propagation of the supercoiling wave are expected to occur far in front of the polymerase, acting as a topological buffer to absorb excess of positive supercoiling. On the opposite, the presence of stable right-handed reversomes in the path of the polymerase would rather create a block for transcription, since these positively constrained structures would either be further stabilized by the positive supercoiling wave pushed ahead of the polymerase (therefore causing quite intractable steric hindrance) or prevent local DNA strand separation in case of reversome destabilization (see former discussion on the co-evolution of DNA and nucleosome chirality). Now, one should keep in mind that this model mainly applies to intense transcription events, where local loss and exchange of all core histones during passage of the polymerase are observed, while moderately transcribed genes show no nucleosome displacement (see Refs. 3),50),51) and references therein). In that case, nucleosome as well as reversome, even if present in the vicinity of the polymerase, are not expected to represent a strong constraint for the elongating enzyme coming into contact of (and turning around) these particles. To sum up, we propose a model in which, in the vicinity of the polymerase, elongation factors (such as FACT; see Refs. 3), 7) for reviews) help to destabilize nucleosome (potentially benefiting from the nucleosome unfolding during the course of the chiral transition to catch histones "on the run"), while complete reversome transition could happen farther in the front ((in absence of elongation factors, outside the transcribed sequence, therefore on a place polymerase would never reach) to alleviate excess positive supercoiling. Indeed, the reversome transition may take place in uncondensed (non-transcribed) regions, as supported by our recent data showing that this transition happen even in the presence of linker histones. 52) Remarkably, a totally unrelated study provided two years later the first in vivo evidence for constitutively right-handed supercoiled chromatin particles. 53) Henikoff and co-workers previously identified half-nucleosomes in interphasic Drosophila centromeres. 54) These tetrameric particles, further called hemisomes, 44) were then proposed to wrap DNA with an opposite helicity in comparison to "canonical" nucleosomes, as observed from in vivo investigation of yeast centromeres topology. 53) This raised intriguing new questions, such as how centromeric histone variants may be assembled in a right-handed particle, and how/why chromatin would retain negative supercoiling in chromosome arms but positive supercoiling in centromeres. Obviously, from the discussion above, stable particles with positive supercoiling would provide a natural block to transcription, suggesting an evolutionary reason for the presence of constitutive positive supercoiling constraints in centromeres. Now, because histone composition was not clearly determined in Henikoff's studies, the question remains as to whether these centromeric particles are truly made of right-handed hemisomes, or rather right-handed tetrasomes, hexasomes (a tetramer plus one H2A-H2B dimer), nucleosome or even other kind of histone/DNA assemblies. 47), 55), 56) Indeed, we showed that chromatin fibers reconstituted with CENP-A-containing (octameric) nucleosomes undergo the reversome transition under positive torsional constraints (unpublished data). These results indicate that the right-handed centromeric particles could, in principle, be made of reversomes. Furthermore, right-handedness is not expected to be an intrinsic property of CENH3-containing particles alone. Many in vitro studies showed that centromeric nucleosomes are canonical nucleosomes. 57)-61) although their conformational dynamics is somewhat different from that of H3-containing nucleosomes. 58) Now, to reconcile these data, it could be possible that other factors (such as centromeric histone chaperones) modulate nucleosome topology in vivo, potentially in a cell-cycle dependent manner. 56), 62) Further investigations are required to unravel this exciting chiral issue. §5.

Conclusion and perspectives

Chromatin is constantly changing its structure to dynamically and functionally accommodate DNA transcription. How transcription elongation takes place on a nucleosomal substrate remains a puzzling question, as is the precise role and/or fate of topological constraints generated by the tracking polymerase. While tension and positive supercoiling in front of the polymerase may help destabilize nucleosomes, negative supercoiling in its rear may help reassemble nucleosomes, and potentially induce some regulatory DNA secondary structures. 26), 27) Using magnetic tweezers to manipulate single nucleosomes arrays, we showed that chromatin is not inert for these torsional constraints, as the existence of a dynamic equilibrium between different crossing statuses of the entry/exit DNAs of each nucleosomes enabled chromatin fibers to reversibly accommodate large amount of supercoiling. 9) Moreover, we showed that the application of large positive torsional stress -mimicking the supercoiling wave produced in front of a polymerase-can potentially trigger nucleosomes chiral transition to a metastable right-handed form. 10) Remarkably, nucleosomes are far from being "tuna cans", 63) but are instead highly polymorphic and dynamic entities. This polymorphic nature has been exten-sively documented by molecular biology techniques, showing that post-translational modifications or histone variant substitutions play key roles in the regulation of genome transactions. However, the conformational dynamics of nucleosomes have remained disregarded because it could easily be sensed. Yet, our view that nucleosomes continuously fluctuate between crossed and uncrossed states and can transiently form subparticles or other altered forms to appropriately respond to surrounding constraints 37), 44), [START_REF] Sivolob | Mathematics of DNA Structure, Function, and Interactions[END_REF] adds a new line to the already rich palette of chromatin properties, and will deserve future work to understand how chromatin interacting proteins modulate these properties.

Fig. 1 .

 1 Fig. 1. The twin-supercoiled model and its transcriptional consequences. (a) Twin-supercoiled domain model : when a transcription ensemble R (include polymerase, nascent RNA, and eventually proteins bound to RNA) tracks along DNA without rotating, the DNA in front of the polymerase becomes positively supercoiled and the DNA behind becomes negatively supercoiled. 18) (b) In a nucleosomal context, positive supercoils in front of the transcription complex could unfold nucleosomes, while negative supercoils in the back would re-fold them and tightly pack the structure. 19) (c) In the three-state model of chromatin fiber, chromatin fiber in front of the polymerase shifts to a positive state (nucleosomes cross positively) whereas chromatin in the back shifts to a negative state (nucleosomes cross negatively). 9)

Fig. 2 .

 2 Fig. 2. The transcription factory model and its mechanical consequences assessed in vitro (a) Upon transcription, a chromatin loop expands out of a chromosome territory and polymerase pulls chromatin through the factory (potentially shared by other transcribed genes from adjacent chromosome territories). (b) Inside the factory, chromatin is pumped and screwed through the polymerase, undergoing both tension and torsion. (c,d) Both of these constraints can be reproduced in vitro by attaching a chromatin fiber between a glass slide and a paramagnetic bead which rotation and displacement is controlled by a pair of magnets. Reconstituted chromatin fibers from purified components (DNA and histones) are used for these studies, and usually checked by transmission electron microscopy (see picture in (d)) before use.

Fig. 3 .

 3 Fig.3. The reversome hypothesis. (a) Length vs. rotation response of a saturated reconstituted nucleosomal array. Hysteresis is observed between the onward (blue) and backward (green) curves when a high positive torsion is applied. The zero-turn rotation reference corresponds to the relaxed state of naked DNA (red dotted curve). The shortening, shifting and flattening of the blue and green curves are interpreted as the consequence of nucleosome reconstitution (each nucleosome wraps 50 nm of DNA in one negative superhelical turn) and conformational flexibility (three-state model),9) while the hysteresis between both curves is interpreted as the consequence of a transient chiral transition of nucleosomes upon high positive torsional stress to an altered right-handed form called "reversome". 10) (b) The nucleosome-reversome transition has been modeled:47) starting from a canonical nucleosome[1], constraints accumulate in DNA (forming plectonemes)[2] and trigger the unfolding of the nucleosome[3] that refold in a righthanded reversome, relaxing at the same time the plectonemes[4]. The whole scenario can be conveniently experimented at desk by using an old XXth century phone (inset): starting from a relaxed cord [1'], one can pick up the phone and apply a few turns (opposite to the cord chirality) before putting the telephone down; the constraint first accumulate as plectonemes within the cord [2'], but is eventually relaxed by the spontaneous chiral inversion of some cord gyres[3',4'].

Acknowledgments

We thank all of our colleagues that participate to this work, and more particularly Natalia Conde e Silva, Julien Mozziconacci, Hua Wong and Ariel Prunell. Part of this work was supported by ANR programs "Nanosciences" and "PCV".