The repetitive component of the A genome of peanut (Arachis hypogaea) and its role in remodelling intergenic sequence space since its evolutionary divergence from the B genome

• Autores: Bertioli, David J.; Vidigal, Bruna; Nielen, Stephan; Ratnaparkhe, Milind B.; Lee, Tae-Ho; Leal-Bertioli, Soraya C. M.; Kim, Changsoo; Guimaraes, Patrica M.; Seijo, Jose Guillermo; Schwarzacher, Trude; Paterson, Andrew H.; Heslop-Harrison, Pat; Araujo, Ana C. G.
• Año de publicación: 2013
• Idioma: español castellano
• Tipo de recurso: artículo
• Materia: Arachis Hypogaea; A. Duranensis; Peanut; Groundnut; Bac-Fish; Bac; Sequencing; Retrotransposons; Genome Evolution; Phylogeny; Homeology
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Background and Aims Peanut (Arachis hypogaea) is an allotetraploid (AABB-type genome) of recent origin, with a genome of about 2•8 Gb and a high repetitive content. This study reports an analysis of the repetitive component of the peanut A genome using bacterial artificial chromosome (BAC) clones from A. duranensis, the most probable A genome donor, and the probable consequences of the activity of these elements since the divergence of the peanut A and B genomes. Methods The repetitive content of the A genome was analysed by using A. duranensis BAC clones as probes for fluorescence in situ hybridization (BAC-FISH), and by sequencing and characterization of 12 genomic regions. For the analysis of the evolutionary dynamics, two A genome regions are compared with their B genome homeologues. Key Results BAC-FISH using 27 A. duranensis BAC clones as probes gave dispersed and repetitive DNA characteristic signals, predominantly in interstitial regions of the peanut A chromosomes. The sequences of 14 BAC clones showed complete and truncated copies of ten abundant long terminal repeat (LTR) retrotransposons, characterized here. Almost all dateable transposition events occurred <3•5 million years ago, the estimated date of the divergence of A and B genomes. The most abundant retrotransposon is Feral, apparently parasitic on the retrotransposon FIDEL, followed by Pipa, also non-autonomous and probably parasitic on a retrotransposon we named Pipoka. The comparison of the A and B genome homeologous regions showed conserved segments of high sequence identity, punctuated by predominantly indel regions without significant similarity. Conclusions A substantial proportion of the highly repetitive component of the peanut A genome appears to be accounted for by relatively few LTR retrotransposons and their truncated copies or solo LTRs. The most abundant of the retrotransposons are non-autonomous. The activity of these retrotransposons has been a very significant driver of genome evolution since the evolutionary divergence of the A and B genomes.
Fil: Bertioli, David J.. Universidade Do Brasilia; Brasil; Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil;
Fil: Vidigal, Bruna. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil;
Fil: Nielen, Stephan. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil;
Fil: Ratnaparkhe, Milind B.. University of Georgia; Estados Unidos de América;
Fil: Lee, Tae-Ho. University of Georgia; Estados Unidos de América;
Fil: Leal-Bertioli, Soraya C. M.. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil;
Fil: Kim, Changsoo. University of Georgia; Estados Unidos de América;
Fil: Guimaraes, Patrica M.. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil;
Fil: Seijo, Jose Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina; Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; Argentina;
Fil: Schwarzacher, Trude. University of Leicester; Reino Unido;
Fil: Paterson, Andrew H.. University of Georgia; Estados Unidos de América;
Fil: Heslop-Harrison, Pat. University of Leicester; Reino Unido;
Fil: Araujo, Ana C. G.. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil;