Dados do Trabalho

Título:

COMPARATIVE ANALYSES OF SATELLITE DNAS IN FIVE XENARTHRA SPECIES

Resumo:

Sequenced genomes of five species from the superorder Xenarthra became recently available in GenBank: Bradypus variegatus, Myrmecophaga tridactyla, and Tamandua tetradactyla, from the order Pilosa, and Chaetophractus vellerosus and Tolypeutes matacus, from the order Cingulata. We used the pipeline TAREAN to identify and characterize the most abundant satellite DNA sequences (satDNAs) in these genomes, in which 40 different satDNAs were found. We focused on the sequences that are putative subfamilies of SATCHO1, a centromeric satDNA from the genus Choloepus, recently described in C. didactylus and C. hoffmanni. After a similarity analysis among these 40 satDNAs and SATCHO1, we found ten candidates for the SATCHO1 subfamily. B. variegatus has two candidate sequences, M. tridactyla has only one, C. vellerosus and T. matacus have five and two candidate sequences, respectively. We did not identify any satDNA on the Tamandua tetradactyla genome that shares similarity with SATCHO1. We performed a phylogenetic analysis with copies of satDNAs with ~117 bp in length retrieved from the five species and from the two Choloepus species. This analysis showed that only in B. variegatus the 117 bp satDNA sequences have a complete species-specific pattern of homogenization. Some of the satDNAs from SATCHO1 have a higher-order (HOR) organization, and all of them also have a putative 17 bp binding-domain for the centromeric protein B (CENP-B), a conserved sequence in mammalian genomes. Our results show that SATCHO1 is an important satDNA subfamily, present in several Xenarthra species, which may play some centromeric function, and be related to genome evolution. Keywords: Repetitive DNA, RepeatExplorer, TAREAN, Xenarthra

Financiamento:

CAPES, FAPEMIG, CNPq

Área

Genética