Exploring the Diversity and Evolution of the As51 Satellite DNA in Characidae Fish: A Comparative Genomic Approach

• Grant number: 24/00232-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2024
• End date: February 28, 2025
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Ricardo Utsunomia
• Grantee: Leticia Masiero Desajacomo
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

The As51 satellite DNA (satDNA), characterized over two decades ago, stands out as the primary chromosomal marker in species of the genera Astyanax and Psalidodon, extensively mapped across various species/populations. As a typical satDNA, this sequence accumulates in heterochromatic regions and often displays interpopulation variations in the number of chromosomal sites. Additionally, co-localization and inactivation of 18S rDNA sites have been observed in a single species (Astyanax janeiroensis), indicating a potential relationship between these two sequence types. Despite its historical significance, no comparative study has addressed crucial questions such as: i) what is the extent of the occurrence of this satDNA among Characidae family species? ii) Is the co-localization between As51 and 18S rDNA exclusive to A. janeiroensis? iii) Is this co-localization an ancestral or derived condition? iv) Do Characidae species exhibit sequences similar to As51 in their 45S rDNA spacers? In this context, the present project employs bioinformatics-based comparative genomics methods to address these questions, providing an in-depth understanding of the origin and evolution of this significant satDNA.