Characterization of the satellite DNA Msat-160 from species of Terricola (Microtus) and Arvicola (Rodentia, Arvicolinae)

• Published in: Genetica 2010-10, Vol.138 (9-10), p.1085-1098
• Main Authors: Acosta, Manuel J, Marchal, Juan A, Fernández-Espartero, Cecilia, Romero-Fernández, Ismael, Rovatsos, Michail T, Giagia-Athanasopoulou, Eva B, Gornung, Ekaterina, Castiglia, Riccardo, Sánchez, Antonio
• Format: Article
• Language: English
• Subjects: Animal Genetics and Genomics; Animals; Arvicola; Arvicolinae; Arvicolinae - genetics; Base Sequence; Biomedical and Life Sciences; Chromosomes; DNA, Satellite - genetics; Evolutionary Biology; Heterochromatin; Human Genetics; In Situ Hybridization, Fluorescence; Karyotypes; Karyotyping; Life Sciences; Microbial Genetics and Genomics; Molecular Sequence Data; Msat-160; Original Research; Pericentromeric heterochromatin; Phylogeny; Plant Genetics and Genomics; satellite DNA; Sequence Alignment; Species Specificity; Terricola
• ISSN: 0016-6707; 1573-6857
• DOI: 10.1007/s10709-010-9496-2

In the subfamily Arvicolinae (Cricetidae, Rodentia) the satellite DNA Msat-160 has been so far described in only some species from the genus Microtus and in one species from another genus, Chionomys nivalis. Here we cloned and characterized this satellite in two new arvicoline species, Microtus (Terricola) savii and Arvicola amphibius (terrestris). We have also demonstrated, by PCR and FISH, its existence in the genomes of several other species from both genera. These results suggest that Msat-160 already occurred in the common ancestor of the four genera/subgenera of Arvicolinae (Microtus, Chionomys, Arvicola, and Terricola). In Arvicola and Terricola, Msat-160 showed the basic monomer length of 160 bp, although a higher-order repeat (HORs) of 640 bp could have been probably replacing the original monomeric unit in A. a. terrestris. Msat-160 was localized by FISH mostly on the pericentromeric regions of the chromosomes, but the signal intensity and the number of carrier chromosomes varied extremely even between closely related species, resulting in a species-specific pattern of chromosomal distribution of this satellite. Such a variable pattern most likely is a consequence of a rapid amplification and contraction of particular repeats in the pericentromeric regions of chromosomes. In addition, we proposed that the rapid variation of pericentromeric repeats is strictly related to the prolific species radiation and diversification of karyotypes that characterize Arvicolinae lineage. Finally, we performed phylogenetic analysis in this group of related species based on Msat-160 that results to be in agreement with previously reported phylogenies, derived from other molecular markers.