Conservation, divergence and functions of centromeric satellite DNA families in the Bovidae.

Repetitive satellite DNA (satDNA) sequences are abundant in eukaryote genomes, with a structural and functional role in centromeric function. We analysed the nucleotide sequence and chromosomal location of the five known cattle (Bos taurus) satDNA families in seven species from the tribe Tragelaphini (Bovinae subfamily). One of the families (SAT1.723) was present at the chromosomes' centromeres of the Tragelaphini species, as well in two more distantly related bovid species, Ovis aries and Capra hircus. Analysis of the interaction of SAT1.723 with centromeric proteins revealed that this satDNA sequence is involved in the centromeric activity in all the species analysed and that it is preserved for at least 15-20 My across Bovidae species. The satDNA sequence similarity among the analysed species reflected different stages of homogeneity/heterogeneity, revealing the evolutionary history of each satDNA family. The SAT1.723 monomer-flanking regions showed the presence of transposable elements, explaining the extensive shuffling of this satDNA between different genomic regions

Bovine satellite DNAs–a history of the evolution of complexity and its impact in the Bovidae family

Despite the many questions regarding satellite DNA sequences and their cellular roles, the evolutionary history of eukaryotic genomes seems to have been largely influenced by this dynamic and multifaceted genomic component. The bovine genome is highly rich in diverse satDNA sequences that differ in monomer sequence and length, complexity, chromosomal location and abundance, as well as in their sequences’ evolutionary mechanisms. In the evolution of the Bovidae family, the genomes’ repetitive fraction played a central role in karyotype reorganisation, and in the last few decades several studies have demonstrated and reinforced an association between centromeric satDNAs and the process of chromosome evolution in remodelling genomes of Bovidae species. Here, we review different aspects of the molecular nature and genome behaviour of all the satDNA families identified in the bovine genome, including their organisation, abundance, chromosome localisation, variation in sequence, and evolutionary history in the Bovidae family and in particular in the Bovinae subfamily, taking an integrative perspective. “Evolution and satDNA” can be addressed through two complementary views: the satDNA sequence evolution per se, and genome evolution promoted by the satDNA dynamism. SatDNA both provides phylogenetic information and is a critical genomic component that enables sequence and chromosome evolution–features arising from its presence, absence or alteration