Study of the supranumerary chromosomes frequency in Astyanax bockmanni (Teleostei, Characiformes)

• Grant number: 12/04591-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2012
• End date: December 31, 2013
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Fábio Porto-Foresti
• Grantee: Maíce Giovanini Ramos
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

B chromosomes have been described in various species of animals, plants, and fungus. They are often heterochromatic, and generally do not present any homology with the complement chromosome A, varying in the number and morphology. In freshwater fish, the occurrence of B chromosomes has been reported in 61 species, distributed in 16 families. In the genus Astyanax, B chromosomes have been described in several species. Recent research shows that A. bockmanni has an extra chromosome in its complement, resulting in an individual with a diploid number equal to 51 chromosomes, and this additional chromosome is characterized as a microchromosome B type acrocentric (Ba). This species in question hasn't data related to the origin, frequency, maintenance, function, or distribution of B chromosomes. This study aims to analyze the frequency and reported the possible different morphotypes of B chromosomes of a population natural A. bockmanni from Alambari river, Paranapanema Basin. Additionally, it will be checked the possible occurrence of morphotypes existing in the population. These results may contribute to studies aimed at discovering the origin and evolution of these chromosomes in Astyanax and others fish groups.(AU)