Cytogenetic and molecular analysis of the satellite DNA of the genus Ctenomys (Rodentia Octodontidae) from Uruguay
Novello, A.; Cortinas, M.N.; Suárez, M.; Musto, H.
Chromosome Research An International Journal on the Molecular Supramolecular and Evolutionary Aspects of Chromosome Biology 4(5): 335-339
ISSN/ISBN: 0967-3849 PMID: 8871821 DOI: 10.1007/bf02257268
The genus of subterranean rodents Ctenomys presents the widest range of variability in diploid number among mammals (from 2n = 10 to 2n = 70). In Uruguay, this variability is observed in karyotypes with 2n = 44, 50 or 58 and two geographically isolated populations with 70 chromosomes but different karyotypic structure. The last three populations were analyzed in the present study. They present a satellite DNA, which was isolated from genomic DNA after AluI digestion. In situ hybridization showed that this satellite DNA is located in the centromeric region of a few chromosomes, coincident with Hoechst 33258 staining and C-banding patterns. A similar satellite DNA was detected in Argentinian species of this genus. We established that, in spite of differences in number of positive heterochromatic blocks per karyotype, the C value is the same in the three populations studied. The nature and possible evolutionary path of this repeated DNA is discussed.