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

Abstract

BackgroundThe genus Micronycteris is a diverse group of phyllostomid bats currently comprising 11 species, with diploid number (2n) ranging from 26 to 40 chromosomes. The karyotypic relationships within Micronycteris and between Micronycteris and other phyllostomids remain poorly understood. The karyotype of Micronycteris hirsuta is of particular interest: three different diploid numbers were reported for this species in South and Central Americas with 2n = 26, 28 and 30 chromosomes. Although current evidence suggests some geographic differentiation among populations of M. hirsuta based on chromosomal, morphological, and nuclear and mitochondrial DNA markers, the recognition of new species or subspecies has been avoided due to the need for additional data, mainly chromosomal data.ResultsWe describe two new cytotypes for Micronycteris hirsuta (MHI) (2n = 26 and 25, NF = 32), whose differences in diploid number are interpreted as the products of Robertsonian rearrangements. C-banding revealed a small amount of constitutive heterochromatin at the centromere and the NOR was located in the interstitial portion of the short arm of a second pair, confirmed by FISH. Telomeric probes hybridized to the centromeric regions and weakly to telomeric regions of most chromosomes. The G-banding analysis and chromosome painting with whole chromosome probes from Carollia brevicauda (CBR) and Phyllostomus hastatus (PHA) enabled the establishment of genome-wide homologies between MHI, CBR and PHA.ConclusionsThe karyotypes of Brazilian specimens of Micronycteris hirsuta described here are new to Micronycteris and reinforce that M. hirsuta does not represent a monotypic taxon. Our results corroborate the hypothesis of karyotypic megaevolution within Micronycteris, and strong evidence for this is that the entire chromosome complement of M. hirsuta was shown to be derivative with respect to species compared in this study.

Centromeric enrichment of LINE-1 retrotransposons and its significance for the chromosome evolution of Phyllostomid bats

“…Extant lineages (11 subfamilies) present considerable karyotypic diversity, with diploid numbers varying from 2n = 14 to 46, as well as varying rates and diverse patterns of chromosome evolution in lineages with similar diversification ages (Baker and Bickham 1980;Martinez et al 2017). Most of the extreme reshuffling of karyotypes occurred at the base of each subfamily radiation from an ancestral karyotype of 2n = 46, FN = 60, mainly through Robertsonian fusions, but also other more complex rearrangements (Baker and Bickham 1980;Pieczarka et al 2005Pieczarka et al , 2013Ribas et al 2013Ribas et al , 2015Sotero-Caio et al 2011. Furthermore, bat clades are distinguished by reduced genome size, mainly derived from elimination of repetitive sequences (Baker et al 1992;Smith et al 2013).…”

Phylogenetic Reconstruction by Cross-Species Chromosome Painting and G-Banding in Four Species of Phyllostomini Tribe (Chiroptera, Phyllostomidae) in the Brazilian Amazon: An Independent Evidence for Monophyly

“…Until now, seven species in three phyllostomid subfamilies were studied by cross-species chromosome painting using probes of Phyllostomus hastatus and Carollia brevicauda [ 39 ]: Dhyphylla eucaudata , Diaemus youngi , Desmodus rotundus (Desmodontinae) [ 40 ], Artibeus obscurus , Uroderma bilobatum , U . magnirostrum (Stenodermatinae) [ 41 ], Micronycteris hirsuta (Micronycterinae) [ 36 ]. Here, we analyzed three species of subfamily Phyllostominae, Tonatia saurophila , Lophostoma silvicola and Phyllostomus discolor from the Amazon rainforest (Brazil), by cross-species chromosome painting using chromosome-specific probes from Carollia brevicauda and Phyllostomus hastatus .…”

Inventário de morcegos em uma área de Caatinga no Nordeste brasileiro, com uma nova ocorrência para o estado da Paraíba

“…The validity of Micronycteris microtis can be questioned due to conflicting data (Porter et al, 2007). The incongruence between the field data and the literature, and the superposition of diagnostic traits might indicate the necessity of a revision of the genus (Ecsobedo-Cabrera et al, 2006;Ribas et al, 2013). We support the adoption of M. megalotis as it is also the taxon recognized for the longest time (Alonso-Mejía and Medellín, 1991).…”