AUTHOR=Valeri Mirela Pelizaro , Dias Guilherme Borges , do Espírito Santo Alice Alves , Moreira Camila Nascimento , Yonenaga-Yassuda Yatiyo , Sommer Iara Braga , Kuhn Gustavo C. S. , Svartman Marta 

TITLE=First Description of a Satellite DNA in Manatees’ Centromeric Regions

JOURNAL=Frontiers in Genetics

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2021.694866

DOI=10.3389/fgene.2021.694866

ISSN=1664-8021

ABSTRACT=<p><italic>Trichechus manatus</italic> and <italic>Trichechus inunguis</italic> are the two Sirenia species that occur in the Americas. Despite their increasing extinction risk, many aspects of their biology remain understudied, including the repetitive DNA fraction of their genomes. Here we used the sequenced genome of <italic>T. manatus</italic> and TAREAN to identify satellite DNAs (satDNAs) in this species. We report the first description of TMAsat, a satDNA comprising ~0.87% of the genome, with ~684bp monomers and centromeric localization. In <italic>T. inunguis</italic>, TMAsat showed similar monomer length, chromosome localization and conserved CENP-B box-like motifs as in <italic>T. manatus</italic>. We also detected this satDNA in the <italic>Dugong dugon</italic> and in the now extinct <italic>Hydrodamalis gigas</italic> genomes. The neighbor-joining tree shows that TMAsat sequences from <italic>T. manatus</italic>, <italic>T. inunguis</italic>, <italic>D. dugon</italic>, and <italic>H. gigas</italic> lack species-specific clusters, which disagrees with the predictions of concerted evolution. We detected a divergent TMAsat-like homologous sequence in elephants and hyraxes, but not in other mammals, suggesting this sequence was already present in the common ancestor of Paenungulata, and later became a satDNA in the Sirenians. This is the first description of a centromeric satDNA in manatees and will facilitate the inclusion of Sirenia in future studies of centromeres and satDNA biology.</p>