Chromosome comparison between two species of Phyllostomus (Chiroptera Phyllostomidae) from Eastern Amazonia, with some phylogenetic insights

The karyotypes of Phyllostomus discolor and P. hastatus from Eastern Amazon ia were studied by G-, C-, G/C sequential and Ag-NOR techniques. Both speci es presented 2n = 32, with the autosome complement composed of 30 bi-armed in P. discolor and 28 bi-armed plus I acrocentric in P. hastatus. In both s pecies, the X chromosome is medium submetacentric while the Y is minute acr ocentric. The present study found only one difference between the karyotype s of P. discolor and P. hastatus: the smallest autosome (pair 15) is bi-arm ed in discolor and acrocentric in hastatus, a result best explained by peri centric inversion. The C-banding revealed constitutive heterochromatin only at the centromeric regions of all chromosomes, with the NOR site located a t the distal region of short arm of pair 15, in both species. The taxon P. discolor is considered primitive for genus Phyllostomus and the bi-armed fo rm of pair 15 is the assumed primitive condition which, rearranged by a per icentric inversion originated the acrocentric form found in P. hastatus.