University Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive UMR5558, F-69622, Villeurbanne, France.
Université de Lyon, LabEx Ecofect, Nadine Cizaire, 92 rue Pasteur, CS 30122 69361, Lyon Cedex 07, France.
BMC Evol Biol. 2018 Nov 20;18(1):175. doi: 10.1186/s12862-018-1289-8.
The distinction between lineages of neotropical bats from the Pteronotus parnellii species complex has been previously made according to mitochondrial DNA, and especially morphology and acoustics, in order to separate them into two species. In these studies, either sample sizes were too low when genetic and acoustic or morphological data were gathered on the same individuals, or genetic and other data were collected on different individuals. In this study, we intensively sampled bats in 4 caves and combined all approaches in order to analyse genetic, morphologic, and acoustic divergence between these lineages that live in the same caves in French Guiana.
A multiplex of 20 polymorphic microsatellite markers was developed using the 454-pyrosequencing technique to investigate for the first time the extent of reproductive isolation between the two lineages and the population genetic structure within lineages. We genotyped 748 individuals sampled between 2010 and 2015 at the 20 nuclear microsatellite loci and sequenced a portion of the cytochrome c oxydase I gene in a subset of these. Two distinct, non-overlapping haplogroups corresponding to cryptic species P. alitonus and P. rubiginosus were revealed, in accordance with previous findings. No spatial genetic structure between caves was detected for both species. Hybridization appeared to be quite limited (0.1-4%) using microsatellite markers whereas introgression was more common (7.5%) and asymmetric for mitochondrial DNA (mtDNA).
The extremely low rate of hybridization could be explained by differences in life cycle phenology between species as well as morphological and acoustical distinction between sexes in one or the other species. Taken together, these results add to our growing understanding of the nature of species boundaries in Pteronotus parnelli, but deserve more in-depth studies to understand the evolutionary processes underlying asymmetric mtDNA introgression in this group of cryptic species.
此前，根据线粒体 DNA，尤其是形态和声学特征，已将新热带蝙蝠的 Pteronotus parnellii 种复合物的谱系区分开来，将它们分为两个物种。在这些研究中，要么在对同一个体进行遗传和声学或形态学数据收集时样本量太小，要么在对不同个体收集遗传和其他数据时样本量太小。在这项研究中，我们在 4 个洞穴中密集采样，并结合所有方法，以分析生活在法属圭亚那同一洞穴中的这些谱系之间的遗传、形态和声学差异。
使用 454 焦磷酸测序技术开发了一个 20 个多态微卫星标记的多重扩增，首次调查了这两个谱系之间的生殖隔离程度以及谱系内的种群遗传结构。我们在 20 个核微卫星基因座中对 2010 年至 2015 年间采集的 748 个个体进行了基因分型，并对其中一部分个体的细胞色素 c 氧化酶 I 基因进行了部分测序。与先前的发现一致，揭示了两个截然不同的、不重叠的单倍型群，对应于隐种 P. alitonus 和 P. rubiginosus。两种物种在洞穴之间均未检测到空间遗传结构。微卫星标记显示杂交似乎相当有限（0.1-4%），而线粒体 DNA（mtDNA）的基因渗入更为常见（7.5%）且不对称。
物种间生命周期物候的差异以及一个或另一个物种中雌雄间的形态和声学差异可能导致杂交率极低。综合来看，这些结果增加了我们对 Pteronotus parnelli 物种界限本质的认识，但需要更深入的研究来了解这种隐种群中不对称 mtDNA 基因渗入的进化过程。
