Extensive chromosomal variation in a Ctenomys talarum talarum population of Buenos Aires Province (Rodentia: Octodontidae)
MASSARINI A; MIZRAHI D; TIRANTI S; TOLOZA A; LUNA F; SCHLEICH CE
UNIDAD DE ZOOLOGÃA Y ECOLOGÃA ANIMAL, INSTITUTO ARGENTINO DE INVESTIGACIÃN DE LAS ZONAS ARIDAS, CRICYT, CONICET
Año: 2002 vol. 9 p. 199 - 199
A sample of 72 specimens from a population of Ctenomys talarum talarum was collected along a transect of 103 km in the Atlantic coast of Buenos Aires Province, Argentina. The cytogenetic analysis indicated a wide chromosomal variability, with nine different karyotypes having diploid numbers ranging from 2N= 44 to 2N=48 and NF=78 and 80. Cand G- band patterns revealed that a Robertsonian change and a tandem fusion affecting two different chromosomes pairs could explain these chromosomal polymorphisms. In addition the relationship between chromosomal variation and environmental factors that limit Ctenomys distribution was analyzed along the transect. We discuss the significance of the observed pattern of chromosomal variability in the light of two alternative hypotheses: ecological adaptive vs. historical demographic factors.