Functional and Evolutionary Analysis of B Chromosome in Astyanax paranae (Characiformes, Characidae)

Author(s)

Duílio Mazzoni Zerbinato de Andrade Silva

• Document type: Doctoral Thesis
• Press: Botucatu. 2018-03-16.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
• Defense date: 2018-02-26
• Advisor: Fausto Foresti

Abstract

About 15% of eukaryotic organisms have additional and dispensable genomic elements called B chromosomes. In most cases the composition and effects of the presence of these chromosomes is unknown. These elements are present in several species of fish of the genus Astyanax. Thus, the objectives of the present work were to characterize the composition of the B chromosome of A. paranae, as well as the effects of the presence of this chromosome in this species and its relation with B chromosomes of nearby species. Seven protein-coding genes were identified on the B chromosome of A. paranae, of which four showed differential expression in the ovaries of females 0B and 1B. In addition, five of these genes are present on the B chromosomes of A. fasciatus and A. bockmanni. Thus, we conclude that the B chromosome of A. paranae interferes with the expression of the genes it carries for its own benefit and has a common origin with B chromosomes found in other species of Astyanax. In addition to this main objective of the work, an analysis of the mitochondrial DNA of A. paranae and, by extension, of the vertebrates in general was also performed. This analysis initially revealed that the base content of vertebrate mitochondrial DNA tends to a common pattern, and it was possible to distinguish groups among vertebrate classes with similar contents in mitochondrial DNA bases, indicating that the DNA evolution of these organelles could be related to the biological characteristics of each group, such as the type of respiration, occupation of the terrestrial or aquatic environment, freshwater or salt water livelihood and metabolic rates of organisms. (AU)

• FAPESP's process: 13/24367-0 - FUNCTIONAL AND EVOLUTIVE ANALYSIS OF B-CHROMOSOME OF Astyanax paranae (CHARACIFORMES, CHARACIDAE)
• Grantee: Duílio Mazzoni Zerbinato de Andrade Silva
• Support Opportunities: Scholarships in Brazil - Doctorate