The process of sexual determination and chromosomal evolution in Psalidodon fasciatus (Teleostei, Characiformes).

• Grant number: 25/11628-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2025
• End date: September 30, 2028
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Fausto Foresti
• Grantee: Caio Augusto Gomes Goes
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 24/03891-8 - Sex chromosomes evolution in Characoidei fishes, AP.TEM

Abstract

Fish have a wide variety of sex determination systems, unlike what occurs in more stable vertebrate groups such as birds and mammals. In this context, the Teleost group constitutes an excellent model for the study of the evolution of sex chromosomes and master sex determination genes. Even though genetic sex determination is the basis, several species in different representative Neotropical fish families do not present heteromorphic sex chromosome systems, as observed in fish of the Acestrorhamphidae family. Thus, genomic techniques have been applied to identify loci related to sex determination and are presented as fundamental tools, mainly in groups in which there is no information related to the identification of factors related to sex determination. The species Psalidodon fasciatus is one of the representatives of the Acestrorhamphidae family widely used in cytogenetic studies, whose karyotype does not present sex chromosome heteromorphism. The present proposal aims to analyze the genome of P. fasciatus by constructing pools of males and females in order to identify heterologous regions between the sexes. In addition, we intend to carry out an in-depth study of the sexual determination pathway in this species by analyzing the transcriptomes of the embryos. It is believed that the results generated in this proposal may contribute significantly to a better understanding of the sex determination process in the species Psalidodon fasciatus, as well as the evolution of the mechanisms involved in sexual determination in representatives of the complex group of characid fishes, contributing to evolutionary studies in this group.