Karyotypic analysis of five rodents and a marsupial from Belize, Central America.

Abstract

Karyotypes and chromosomal banding patterns of six species of small mammals from Belize are presented and discussed in light of relevant data in the literature. Individuals of Heteromys desma-restianus had FN values of 72, which differs from previous reports. G-bands were obtained and compared to fluorescent bands (DAPI) and with the location of NOR sites. The karyotypes of Pero-myscus mexicanus, Sigmodon hispidus, Oryzomys couesi, and Ototylomys phyllotis are identical to the karyotypes for these species described in the literature. Active NORs were located on four pairs of chromosomes in O. phyllotis and fluorescent bands obtained with the stain Hoechst 33258. The karyotype of Marmosa robinsoni appears similar to that described by Hsu and Benirschke (1971). Autosomal C-bands were located at the centromeres. The X had interstitial C-bands and the Y was entirely heterochromatic. Silver stained NORs were present on five chromosomes corresponding to chromosomal pairs 4, 5, and 6.