title: Cytogenetic and molecular analysis of the satellite DNA of the genus Ctenomys (Rodentia Octodontidae) from Uruguay.
abstract: 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.
authors.affiliation: Sección Genética Evolutiva, Facultad de Ciencias, Montevideo, Uruguay.
authors.forename: A
authors.initials: A
authors.lastname: Novello
authors.forename: M N
authors.initials: MN
authors.lastname: Cortinas
authors.forename: M
authors.initials: M
authors.lastname: Suárez
authors.forename: H
authors.initials: H
authors.lastname: Musto
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002871:Chromosome Banding; D003582:Cytogenetics; D004276:DNA, Satellite / Q000235:genetics*; D004171:Diploidy; D005260:Female; D005828:Genetics, Population; D006570:Heterochromatin / Q000235:genetics; D007621:Karyotyping; D008297:Male; D012091:Repetitive Sequences, Nucleic Acid; D012377:Rodentia / Q000235:genetics*; D013045:Species Specificity; D014583:Uruguay
chemical_list: D004276:DNA, Satellite; D006570:Heterochromatin