RESUMO
The sensory drive theory of speciation predicts that populations of the same species inhabiting different environments can differ in sensory traits, and that this sensory difference can ultimately drive speciation. However, even in the best-known examples of sensory ecology driven speciation, it is uncertain whether the variation in sensory traits is the cause or the consequence of a reduction in levels of gene flow. Here we show strong genetic differentiation, no gene flow and large echolocation differences between the allopatric Myanmar and Thai populations of the world's smallest mammal, Craseonycteris thonglongyai, and suggest that geographic isolation most likely preceded sensory divergence. Within the geographically continuous Thai population, we show that geographic distance has a primary role in limiting gene flow rather than echolocation divergence. In line with sensory-driven speciation models, we suggest that in C. thonglongyai, limited gene flow creates the suitable conditions that favour the evolution of sensory divergence via local adaptation.
Assuntos
Quirópteros/genética , Ecolocação/fisiologia , Especiação Genética , Variação Genética , Genética Populacional , Adaptação Fisiológica , Sequência de Aminoácidos , Animais , Teorema de Bayes , Evolução Biológica , Quirópteros/classificação , Impressões Digitais de DNA , DNA Mitocondrial , Ecologia , Fluxo Gênico , Deriva Genética , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Mianmar , Fenótipo , Filogenia , TailândiaRESUMO
The phylogenetic relationships within the horseshoe bats (genus Rhinolophus) are poorly resolved, particularly at deeper levels within the tree. We present a better-resolved phylogenetic hypothesis for 30 rhinolophid species based on parsimony and Bayesian analyses of the mitochondrial cytochrome b gene and three nuclear introns (TG, THY and PRKC1). Strong support was found for the existence of two geographic clades within the monophyletic Rhinolophidae: an African group and an Oriental assemblage. The relaxed Bayesian clock method indicated that the two rhinolophid clades diverged approximately 35 million years ago and results from Dispersal Vicariance (DIVA) analysis suggest that the horseshoe bats arose in Asia and subsequently dispersed into Europe and Africa.
Assuntos
Quirópteros/genética , Evolução Molecular , Filogenia , Animais , Teorema de Bayes , Quirópteros/classificação , DNA Mitocondrial/genética , Especiação Genética , Geografia , Íntrons , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
Daubenton's bat (Myotis daubentonii) is a known reservoir for European bat lyssavirus type 2 (EBLV-2). An appreciation of the potential for epidemiological spread and disease risk requires an understanding of the dispersal of the primary host, and any large-scale geographical barriers that may impede gene flow. The spatial pattern of microsatellite and mitochondrial DNA variation was examined to infer patterns of dispersal of bats among 35 populations across Scotland. DNA sequence variation at the mitochondrial control region and ND1 genes revealed two distinct phylogeographical clades, with generally nonoverlapping geographical distributions except for a small number of populations where both matrilines were found in sympatry. Such discontinuity suggests that Scotland was recolonized twice following the retreat of the Pleistocene ice sheet with little subsequent matrilineal introgression. However, eight microsatellite loci showed low levels of genetic divergence among populations, even between populations from the two distinct mitochondrial DNA clades. An overall, macrogeographical genetic isolation-by-distance pattern was observed, with high levels of gene flow among local populations. Apparently contrasting patterns of mitochondrial and microsatellite divergence at different scales could be explained by sex-specific differences in gene flow at large scales.
Assuntos
Quirópteros/genética , DNA Mitocondrial/genética , Variação Genética , Repetições de Microssatélites/genética , Animais , Quirópteros/classificação , Quirópteros/fisiologia , DNA Mitocondrial/química , Fluxo Gênico/genética , Geografia , Haplótipos , Modelos Genéticos , Dados de Sequência Molecular , Filogenia , Polimorfismo Genético , Escócia , Análise de Sequência de DNARESUMO
We report the first seroprevalence study of the occurrence of specific antibodies to European bat lyssavirus type 2 (EBLV-2) in Daubenton's bats. Bats were captured from 19 sites across eastern and southern Scotland. Samples from 198 Daubenton's bats, 20 Natterer's bats, and 6 Pipistrelle's bats were tested for EBLV-2. Blood samples (N = 94) were subjected to a modified fluorescent antibody virus neutralization test to determine antibody titer. From 0.05% to 3.8% (95% confidence interval) of Daubenton's bats were seropositive. Antibodies to EBLV-2 were not detected in the 2 other species tested. Mouth swabs (N = 218) were obtained, and RNA was extracted for a reverse transcription-polymerase chain reaction (RT-PCR). The RT-PCR included pan lyssavirus-primers (N gene) and internal PCR control primers for ribosomal RNA. EBLV-2 RNA was not detected in any of the saliva samples tested, and live virus was not detected in virus isolation tests.