High dynamism for neo-sex chromosomes: satellite DNAs reveal complex evolution in a grasshopper

Author(s)

Ferretti, Ana B. S. M. ^[1] ; Milani, Diogo ^[1] ; Palacios-Gimenez, Octavio M. ^{[2, 3]} ; Ruiz-Ruano, Francisco J. ^{[2, 3]} ; Cabral-de-Mello, Diogo C. ^[1]

Affiliation

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

^[2] Uppsala Univ, Evolutionary Biol Ctr, Dept Ecol & Genet, Uppsala - Sweden

^[3] Uppsala Univ, Evolutionary Biol Ctr, Dept Organismal Biol, Uppsala - Sweden

• Document type: Journal article
• Source: HEREDITY; v. 125, n. 3, p. 124-137, SEP 2020.
• Web of Science Citations: 6

Abstract

A common characteristic of sex chromosomes is the accumulation of repetitive DNA, which accounts for their diversification and degeneration. In grasshoppers, the X0 sex-determining system in males is considered ancestral. However, in some species, derived variants like neo-XY in males evolved several times independently by Robertsonian translocation. This is the case ofRonderosia bergii, in which further large pericentromeric inversion in the neo-Y also took place, making this species particularly interesting for investigating sex chromosome evolution. Here, we characterized the satellite DNAs (satDNAs) and transposable elements (TEs) of the species to investigate the quantitative differences in repeat composition between male and female genomes putatively associated with sex chromosomes. We found a total of 53 satDNA families and 56 families of TEs. The satDNAs were 13.5% more abundant in males than in females, while TEs were just 1.02% more abundant in females. These results imply differential amplification of satDNAs on neo-Y chromosome and a minor role of TEs in sex chromosome differentiation. We showed highly differentiated neo-XY sex chromosomes owing to major amplification of satDNAs in neo-Y. Furthermore, chromosomal mapping of satDNAs suggests high turnover of neo-sex chromosomes inR. bergiiat the intrapopulation level, caused by multiple paracentric inversions, amplifications, and transpositions. Finally, the species is an example of the action of repetitive DNAs in the generation of variability for sex chromosomes after the suppression of recombination, and helps understand sex chromosome evolution at the intrapopulation level. (AU)

• FAPESP's process: 15/16661-1 - Sex and B chromosome enigmas: model systems for the study of chromosome and genome evolution
• Grantee: César Martins
• Support Opportunities: Research Projects - Thematic Grants
• 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