Tracking the evolution of sex chromosome systems in Melanoplinae grasshoppers through chromosomal mapping of repetitive DNA sequences

Autor(es)

Palacios-Gimenez, Octavio M. ^[1] ; Castillo, Elio R. ^[2] ; Marti, Dardo A. ^[2] ; Cabral-de-Mello, Diogo C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, UNESP, Inst Biociencias IB, Dept Biol, Rio Claro, SP - Brazil

^[2] Univ Nacl Misiones, Fac Ciencias Exactas Quim & Nat, IBS, Lab Genet Evolutiva, RA-3300 Posadas - Argentina

• Tipo de documento: Artigo Científico
• Fonte: BMC Evolutionary Biology; v. 13, AUG 9 2013.
• Citações Web of Science: 34

Resumo

Background: The accumulation of repetitive DNA during sex chromosome differentiation is a common feature of many eukaryotes and becomes more evident after recombination has been restricted or abolished. The accumulated repetitive sequences include multigene families, microsatellites, satellite DNAs and mobile elements, all of which are important for the structural remodeling of heterochromatin. In grasshoppers, derived sex chromosome systems, such as neo-XY male/XX female and neo-X1X2Y male/X1X1X2X2 female, are frequently observed in the Melanoplinae subfamily. However, no studies concerning the evolution of sex chromosomes in Melanoplinae have addressed the role of the repetitive DNA sequences. To further investigate the evolution of sex chromosomes in grasshoppers, we used classical cytogenetic and FISH analyses to examine the repetitive DNA sequences in six phylogenetically related Melanoplinae species with X0 male/XX female, neo-XY male/XX female and neo-X1X2Y male/X1X1X2X2 female sex chromosome systems. Results: Our data indicate a non-spreading of heterochromatic blocks and pool of repetitive DNAs (C(0)t-1 DNA) in the sex chromosomes; however, the spreading of multigene families among the neo-sex chromosomes of Eurotettix and Dichromatos was remarkable, particularly for 5S rDNA. In autosomes, FISH mapping of multigene families revealed distinct patterns of chromosomal organization at the intra- and intergenomic levels. Conclusions: These results suggest a common origin and subsequent differential accumulation of repetitive DNAs in the sex chromosomes of Dichromatos and an independent origin of the sex chromosomes of the neo-XY and neo-X1X2Y systems. Our data indicate a possible role for repetitive DNAs in the diversification of sex chromosome systems in grasshoppers. (AU)

• Processo FAPESP: 12/01421-7 - Contribuições a elucidação da estrutura, origem e evolução de neo-cromossomos em gafanhotos utilizando como modelo espécies dos gêneros Chlorus, Dichromatos e Eurotettix (Melanoplinae; Acrididae)
• Beneficiário: Octavio Manuel Palacios Gimenez
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 11/19481-3 - Contribuições a elucidação do significado biológico de cromossomos B utilizando como modelos Rhammatocerus brasiliensis (Orthoptera) e Haplochromis obliquidens (Teleostei): estrutura, evolução e padrões de modificações em proteínas histônicas
• Beneficiário: Diogo Cavalcanti Cabral de Mello
• Modalidade de apoio: Auxílio à Pesquisa - Regular