Cytogenetics of two subspecies of White-Tailed deer (Odocoileus) from Venezuela

We studied the cytogenetics of two subspecies of deer in Venezuela: Odocoileus virginianus gymnotis, distributed almost nationwide and O. v. margaritae, endemic to Margarita Island. All individuals examined showed karyotypes of (2n=70), with the same fundamental number (FN=70). The first pair of chromosomes was metacentric (small-sized) and the other 33 pairs were acrocentric (medium- and small-sized). Chromosomes of sexual pair were metacentric (medium-sized (X) and small-sized (Y). C-Banding revealed pericentromeric heterochromatin in all the acrocentric chromosomes, while the metacentric autosomal pair did not show well defined bands. In both subspecies, the X chromosome presented pericentromeric constitutive heterochromatin. The Y chromosome did not show the presence of any C band in O. v. gymnotis. This could not be determined in O. v. margaritae because the only animal available was a female. NOR bands were located on the telomeric region of both chromosomes of pair 2 and in the centromeric region of pair 3. G-banding revealed similar patterns of bands in all chromosomes of both subspecies, except in the autosomal second pair. Odocoileus v. gymnotis showed a terminal band that seems to be absent in O. v. margaritae. These karyotypic analyses do not allow us to assure that the studied entities are two different species. We propose a series of chromosomal rearrangements the could have produced the current karyotypic diversity in the family Cervidae