Chromosomal Homologies among Vampire Bats Revealed by Chromosome Painting (Phyllostomidae, Chiroptera)

Abstract

Substantial effort has been made to elucidate karyotypic evolution of phyllostomid bats, mostly through comparisons of G-banding patterns. However, due to the limited number of G-bands in respective karyotypes and to the similarity of non-homologous bands, an accurate evolutionary history of chromosome segments remains questionable. This is the case for vampire bats (Desmodontinae). Despite several proposed homologies, banding data have not yet provided a detailed understanding of the chromosomal changes within vampire genera. We examined karyotype differentiation of the 3 species within this subfamily using whole chromosomal probes from Phyllostomus hastatus (Phyllostominae) and Carollia brevicauda (Carolliinae). Painting probes of P. hastatus respectively detected 22, 21 and 23 conserved segments in Diphylla ecaudata, Diaemus youngi, and Desmodus rotundus karyotypes, whereas 27, 27 and 28 were respectively detectedwith C. brevicauda paints. Based on the evolutionary relationships proposed by morphological and molecular data, we present probable chromosomal synapomorphies for vampire bats and propose chromosomes that were present in the common ancestor of the 5 genera analyzed. Karyotype comparisons allowed us to relate a number of conserved chromosomal segments among the 5 species, providing a broader database for understanding karyotype evolution in the family.

Two new cytotypes reinforce that Micronycteris hirsuta Peters, 1869 does not represent a monotypic taxon

“…Recent data from chromosome painting, associated with G-banding, confirm that Robertsonian fusions with the complete conservation of chromosome or whole arms, and inversions are the main mechanisms of karyotypic differentiation in the Order Chiroptera [19,20,22,24,25,32]. Herein we found conservatism in many chromosomal segments shared between Micronycteris hirsuta , Phyllostomus hastatus and Carollia brevicauda , but homology of whole chromosomes was not detected in the autosomal set.…”

“…These chromosomes have been suggested to be present on the ancestral karyotype of the family Phyllostomidae, since it was present and conserved in the karyotype of such phylogenetically distant species of uncorrelated subfamilies mapping so far [17,18,32]. Although MHI represent a basal clade for Phyllostomidae, and has previously been suggested that basal taxa could contribute to confirm the chromosomal ancestrality [32], we argue that not necessarily basal taxa have primitive karyotypes.…”

“…A comparison of Micronycteris hirsuta painted chromosomal map with other phyllostomids previously investigated [17,18,32], revealed that many rearrangements have occurred in the differentiation of the M. hirsuta karyotype from the phyllostomid common ancestor. Even the highly conserved syntenic group (PHA-11; CBR-7), shared by Phyllostomus , Carollia, Artibeus, Uroderma magnirostrum [17,18] and Desmodontinae bats [32], was broken in the MHI genome (MHI-3 and MHI-4) (Figure 1).…”

“…Even the highly conserved syntenic group (PHA-11; CBR-7), shared by Phyllostomus , Carollia, Artibeus, Uroderma magnirostrum [17,18] and Desmodontinae bats [32], was broken in the MHI genome (MHI-3 and MHI-4) (Figure 1). In the other hand, although not broken, the chromosome PHA-14 is fusioned with PHA-11 in MHI, with PHA-9 in UBI and, in the Desmodontinae bats with two distinct chromosomal segments: 12 in DYO and 13 in DRO [32]. …”

“…Until now, just six species encompassing few Phyllostomidae subfamilies were studied by ZOO-FISH using probes from Phyllostomus hastatus (Phyllostominae) and Carollia brevicauda (Carolliinae) [17]: Desmodus rotundus , Diaemus youngi and Dyphylla ecaudata (Desmodontinae) [32], Artibeus obscurus , Uroderma bilobatum and U. magnirostrum (Stenodermatinae) [18]. Two chromosomes were found entirely preserved in karyotypes of these subfamilies: (CBR7 = PHA11 and CBR9 = PHA14), and probably were present of the ancestral karyotype of Phyllostomidae since they are preserved in different species distant phylogenetically.…”