Cytogenomic analyzes in Ancistrus (Siluriformes: Loricariidae): search for repetitive sequences and chromosome mapping

• Grant number: 20/14370-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2021
• End date: January 31, 2023
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Patricia Pasquali Parise Maltempi
• Grantee: Gabriel Esbrisse dos Santos
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

The genomes of eukaryotes are characterized by containing a large number of highly dynamic repetitive sequences, either at the chromosomal or nucleotide level, with several factors contributing to their duplication and expansion, modulating or evolving to karyotype evolution in different organisms. Among these sequences, satellite DNAs (satDNAs) are among the most dynamic repetitive elements, and are usually located mainly in pericentromeric chromosomal regions, sex chromosomes and B chromosomes. The genus Ancistrus Kner, 1854, belongs to the Loricariidae family and from a cytogenetic point of view is a very interesting group, as its representatives have a large karyotype variation, with individuals with 2n = 34 to 2n = 54 chromosomes, in addition to heteromorphic sexual chromosomal systems of the type ZZ / ZW, XX / XY and multiple systems, which contributed to the karyotype diversification in the genre. The characterization and mapping of satDNAs by means of genomic sequencing data, has contributed to clarify evolutionary mechanisms in different species of fish. In Ancistrus, this knowledge is still limited, and there are no updated and complete data about satDNAs, despite all the chromosomal diversification and differentiation recorded in the genus. A complete characterization of these sequences can provide interesting data, which can be crucial for understanding the evolution of these sequences in the genre. In this work, the characterization of sequences of satDNAs in Ancistrus initiated in the animal cytogenetics laboratory at UNESP in Rio Claro will be continued, using bioinformatics analysis with genomic data for a complete characterization of the repetitive sequences present in the genome of one of the species of the genus.