The impact of the presence of a multiple sex chromosomes system in the genetic diversity and speciation: Erythrinidade family (Teleostei, Characiforms) as model

Abstract

The Neotropical region has the largest diversity of freshwater fish species on the planet. However, the processes responsible for this enormous biodiversity remain largely unexplored and the causes of the high rates of speciation found in this region have not yet been fully elucidated. Thus, a better evaluation of the genetic mechanisms that may be acting in the formation of this biodiversity, may contribute to a better understanding of the biodiversity of Neotropical fishes. Several mechanisms promote speciation. The influence of allopatry, the occurrence of chromosomal rearrangements and the emergence of sex chromosomes in the process of genetic differentiation and speciation is the subject of long debate. However, there is still no consensus on this real influence, and more natural populations need to be studied to investigate these processes. To address these issues, it is particularly useful to identify pairs of species or natural populations in which variations related to effects of allopatry, chromosomal rearrangements and the occurrence of sex chromosome systems are found. Thus, Erythrinidae fishes are excellent models for these analyzes, as they gather all these scenarios within some of their species. Thus, this project aims to analyze the impact of the emergence of multiple sex chromosome systems on population dynamics and genetic diversity in different populations of the species Hoplias malabaricus and Erythrinus erythrinus, highlighted by the presence of enormous karyotypic variation and sex chromosome systems. The presence of multiple sex chromosomes has implications for genetic diversity of a species or between populations of the same species, representing a more effective evolutionary force than just the action of allopatry to generate genetic diversity and reducing gene flow? The use of molecular markers widely distributed throughout the genome obtained by next-generation sequencing, combined with the abundant cytogenetic information available for these groups, will allow a broad investigation into the influence of the development of multiple sex chromosome systems in genetic diversity, gene flow reduction, and consequently, in the speciation process. (AU)