W181
Transposable Element Distribution, Abundance and Impact in Genome Evolution in the Genus Coffea

Date: Sunday, January 11, 2015
Time: 5:40 PM
Room: Esquire - Meeting House
Romain Guyot , IRD UMR DIADE, Montpellier cedex 5, France
Thibaud Darre , Institut de Recherche pour le Développement, Montpellier cedex 5, France
Dominique Crouzillat , Centre R&D Nestlé Tours, Tours, France
Michel Rigoreau , Centre R&D Nestlé Tours, Tours, France
Serge Hamon , Institut de Recherche pour le Développement, Montpellier Cedex 5, France
Alexandre de Kochko , Institut de Recherche pour le Développement, Montpellier cedex 5, France
Emmanuel Couturon , IRD UMR DIADE, Montpellier cedex 5, France
Perla Hamon , IRD UMR DIADE, Montpellier cedex 5, France
The genus Coffea is composed of 124 distinct species: 123 diploid and 1 polyploid species (Coffea arabica). They are classified into three botanical sections according to their geographic distribution: Eucoffea (West and Middle Central Africa), Mozambicoffea (East Africa) and Mascarocoffea (Indian Ocean Islands), and genome size variations are about 2-fold (C. humblotiana: 469 Mb and C. heterocalyx: 863 Mb for diploid species and 1,240 Mb for C. arabica). Despite the fact that the Coffea genus includes the world’s most traded agricultural product: coffee beans, the phylogeny, origin and evolution of species as well as their genome size variations remain particularly poorly understood. 

To study the evolution of Coffea species and analyze their transposable elements composition, we used the Roche 454 technology to perform a low-coverage sequencing (ranged between 5-10X) of 11 species representative of the geographic distribution of the genus. The composition and distribution of transposable elements were studied. Despite the previous assumption that transposable elements don’t seem to play an important role in genome size variation in Coffea, we found a clear variation of one LTR Retrotransposon family called SIRE: SIREs are abundant in Eucoffea but almost absent from Mozambicoffea while Mascarocoffea species are completely devoid of these elements. These results suggest that SIRE are involved in Coffea genome differentiation and the restructuring of the Eucoffea genomes.