Patterns of evolution in Graomys griseoflavus (Rodentia, Cricetidae). I. Protein polymorphism in populations with...

Protein polymorphism has been studied by means of starch gel electrophoresis of tissue extracts in three population samples of Graomys griseoflavus collected at different sites in central-west Argentina. Individuals from two of the samples had chromosomal number 2n = 42 and those from the other sample, 2n = 38, 37 or 36. A total of 28 loci were analyzed. High levels of variability were observed in three samples (P ranging between 0.46 and 0.66; H (epsilon) from 0.160 to 0.188). Genetic distance values between populations with different chromosome numbers were 0.088 and 0.093. Tests in the laboratory showed the existence of post-zygotic reproductive isolation between animals with 2n = 42 and those with 2n = 38, 37 or 36.