Localization of Telomeric Sequences in the Chromosomes of Three Species of Calomys (Rodentia, Sigmodontinae)

Abstract

SummaryThe distribution of telomeric sequences in 3 species of the phyllotine genus Calomys, whose members are distributed through an extensive area of South America, were analyzed by FISH with a PNA probe. C. musculinus, with a highly reordered karyotype with respect to other species of the genus, and C. venustus only showed fluorescent signals in a telomeric position. C. laucha, on the other hand, presented in addition a remarkable set of internal telomeric signals (ITS). ITS were seen constantly in the centromeric regions of biarmed pairs 1 and 2 and the X chromosome of this species, being the latter signal formed by 2 separated marks. On the basis of previous karyotypic information, these constant signals are interpreted as resulting from rearrangements occurred during karyotypic evolution. Additional signals of generally lower intensity were observed with different frequencies in up to 6 subterminal chromosomes of this species.

Diversity and Karyotypic Evolution in the Genus <b><i>Neacomys </i></b>(Rodentia, Sigmodontinae)

“…A huge karyotype reorganization among Neacomys species clearly occurred, and probably the ITS were eliminated from the genome. Similar results were described in other rodents [Ortiz et al, 2007;Swier et al, 2012].…”