INTEGRATING CHROMOSOME AND GENOMIC ANALYSES FOR FUNCTIONAL AND EVOLUTIONARY STUDIES OF SATELLITE DNAS IN Astyanax (TELEOSTEI, CHARACIFORMES)

Abstract

Eukaryotic genomas are mainly composed of repetitive DNA sequences. Among them, satellide DNAs (satDNAs) constitute unique tandemly repeated sequences. For a long time, satDNAs were considered as junk DNA; however, the transcription of this kind of sequence in distinct organisms points to different possible established functions. Historically, distinct methods were used to characterize satDNAs, but just the rise of next generation sequencing (NGS) technologies and, mainly, novel bioinformatics tools, allowed significant analyses to characterize whole catalogues of satellite DNAs (satellitome) from distinct organisms, at a relatively low cost. Recently, the first fish satellitome for Astyanax paranae was published and revealed a significant amount of satDNA families in this genome, including several ones allocated exclusively on the B chromosomes of this species. These data raised novel questions about those sequences, which are pretended to be investigated here. Thus, the objectives of this project involve get deepen on the knowledge of satellite DNAs in a. paranae using long reads; an initial functional characterization about these sequences; and a better knowledge about the satDNA libraries in distinct Characidae species and the differential expansion/retraction of satDNA families in distinct species. (AU)