A Single Genetic Determinant that Prevents Sex Reversal in C57BL-YPOS Congenic Mice

Eleven heterologous primers were investigated in 119 individuals of 11 species of rodents of the Oryzomyine and Thomasomyine groups. The animals were collected at four sites of the “Cerrado,” a dryland biome located on the Brazilian Plateau, all of them being karyotyped and taxonomically allocated according to the karyotype. Four of these primers, R47, R65, R75 (from Rattus), and ATP (from Mus) cross-amplified in at least one of these taxa, giving products of seven, nine, one, and three bands, respectively. These values are of the same order as others obtained when heterologous primers were amplified in other orders of mammals. Of the 20 products amplified in these two rodent groups by these four primers, only 7 of the bands were seen in a heteromorphic state (one individual presenting two bands), in two species (Rhipidomys aff. leucodactylus and Oryzomys megacephalus). The others occurred as monomorphic bands.