ew insights into the six decades of Mesa's hypothesis of chromosomal evolution in Ommexechinae grasshoppers (Orthoptera: Acridoidea

Autor(es)

Santander, Mylena D. ^{[1, 2]} ; Cabral-de-Mello, Diogo C. ^[3] ; Taffarel, Alberto ^[2] ; Marti, Emiliano ^[3] ; Marti, Dardo A. ^[2] ; Palacios-Gimenez, Octavio M. ^[4] ; Castillo, Elio Rodrigo D. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Genet & Biol Evolut, Inst Biociencias, Sao Paulo, SP - Brazil

^[2] FCEQyN, CONICET UNaM, Inst Biol Subtrop IBS, Lab Genet Evolut Dr Claudio J Bidau, Posadas, Misiones - Argentina

^[3] Univ Estadual Paulista UNESP, Inst Biociencias IB, Dept Biol Geral & Aplicada, Rio Claro, SP - Brazil

^[4] Uppsala Univ, Evolutionary Biol Ctr, Dept Organismal Biol, Systemat Biol Program, Uppsala - Sweden

• Tipo de documento: Artigo Científico
• Fonte: ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY; v. 193, n. 4, p. 1141-1155, DEC 2021.
• Citações Web of Science: 0

Resumo

In Acridoidea grasshoppers, chromosomal rearrangements are frequently found as deviations from the standard acrocentric karyotype (2n = 23 male/24 female, FN = 23 male/24 female) in either phylogenetically unrelated species or shared by closely related ones, i.e. genus. In the South American subfamily Ommexechinae, most of the species show a unique karyotype (2n = 23 male/24 female, FN = 25 male/26 female) owing to the occurrence of a large autosomal pair (L-1) with submetacentric morphology. In the early 1960s, Alejo Mesa proposed the hypothesis of an ancestral pericentric inversion to explain this karyotype variation. Furthermore, in Ommexechinae, extra chromosomal rearrangements (e.g. centric fusions) are recorded between the ancestral X chromosome and autosomes that originated the so-called neo-sex chromosomes. However, the evolutionary significance of the pericentric inversions and centric fusions in Ommexechinae remains poorly explored. Aiming for a better understanding of chromosomal evolution in Ommexechinae, we performed a detailed cytogenetic analysis in five species. Our findings support the hypothesis about the occurrence of an early pericentric inversion in the ancestor of Ommexechinae. Moreover, our results show a complex karyotype diversification pattern due to several chromosome rearrangements, variations in heterochromatin and repetitive DNA dynamics. Finally, the chromosomal mapping of U2 snDNA in L-1 provided new insights about the morphological evolution of this autosomal pair and revealed unnoticed chromosome reorganizations. (AU)

• Processo FAPESP: 14/11763-8 - Contribuições ao entendimento da estrutura e evolução de sistemas de cromossomos sexuais utilizando como modelos espécies de gafanhotos e grilos
• Beneficiário: Diogo Cavalcanti Cabral de Mello
• Modalidade de apoio: Auxílio à Pesquisa - Regular