Chromosomal variability in tuco-tucos (Ctenomys, Rodentia) from the Argentinean northeastern wetlands

Abstract

Chromosomal diversity is a key feature for understanding the evolution of mammalian species. Rodents, the most diversified taxon among mammals, depict a wide chromosomal diversity; the study of their karyomorphs has contributed greatly to understand the evolution in this group. South American subterranean rodents of the genus Ctenomys (tuco-tucos) are one of the most specious mammalian genera. Chromosomal variability in several lineages of Ctenomys has been characterized; however, a description of the karyomorphs concerning the tuco-tucos that inhabit the broad area under the influence of the Iberá marsh in the northeast of Argentina (the Corrientes group) is incomplete. This work provides new chromosomal information of the Ctenomys Corrientes group that includes the description of 3 new and 5 previously undescribed karyomorphs. We found four fundamental numbers (FNs): 76, 78, 80 and 84 with chromosomal numbers (2n) that ranged between 41-44, 44-46, 48 and 50-70, respectively. In addition, we found a new sampling site of C. roigi, a critically endangered species.