Neo-sex chromosomes of Ronderosia bergi: insight into the evolution of sex chromosomes in grasshoppers

Author(s)

Palacios-Gimenez, O. M. ^[1] ; Marti, D. A. ^[2] ; Cabral-de-Mello, D. C. ^[1]

Affiliation

^[1] Univ Estadual Paulista, UNESP, Dept Biol, Inst Biociencias, BR-13506900 Rio Claro, SP - Brazil

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

• Document type: Journal article
• Source: CHROMOSOMA; v. 124, n. 3, p. 353-365, SEP 2015.
• Web of Science Citations: 13

Abstract

Sex chromosomes have evolved many times from morphologically identical autosome pairs, most often presenting several recombination suppression events, followed by accumulation of repetitive DNA sequences. In Orthoptera, most species have an X0a (TM), sex chromosome system. However, in the subfamily Melanoplinae, derived variants of neo-sex chromosomes (neo-XYa (TM), or neo-X1X2Ya (TM),) emerged several times. Here, we examined the differentiation of neo-sex chromosomes in a Melanoplinae species with a neo-XYa (TM),/XXa (TM) Euro system, Ronderosia bergi, using several approaches: (i) classical cytogenetic analysis, (ii) mapping via fluorescent in situ hybridization of some selected repetitive DNA sequences and microdissected sex chromosomes, and (iii) immunolocalization of distinct histone modifications. The microdissected sex chromosomes were also used as sources for Polymerase chain reaction (PCR) amplification of RNA-coding multigene families, to study variants related to the sex chromosomes. Our data suggest that the R. bergi neo-Y has become differentiated after its formation by a Robertsonian translocation and inversions, and has accumulated repetitive DNA sequences. Interestingly, the ex autosomes incorporated into the neo-sex chromosomes retain some autosomal post-translational histone modifications, at least in metaphase I, suggesting that the establishment of functional modifications in neo-sex chromosomes is slower than their sequence differentiation. (AU)

• FAPESP's process: 12/01421-7 - Contributions to the knowledge of structure, origin and evolution od neo sex chromosomes in grasshoppers using as model species of the genera Chlorus, Dichromatos and Eurotettix (Melanoplinae: Acrididae)
• Grantee: Octavio Manuel Palacios Gimenez
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/11763-8 - Contributions to understanding of structure and evolution of sex chromosome systems using as models grashopper and cricket species
• Grantee: Diogo Cavalcanti Cabral de Mello
• Support Opportunities: Regular Research Grants