Proćków Małgorzata, Strzała Tomasz, Kuźnik-Kowalska Elżbieta, Proćków Jarosław, Mackiewicz Paweł
Museum of Natural History, University of Wrocław, Wrocław, Poland.
Department of Genetics, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
PLoS One. 2017 Jan 20;12(1):e0170460. doi: 10.1371/journal.pone.0170460. eCollection 2017.
Geographical isolation, selection and genetic drift can cause the geographical diversification of populations and lead to speciation. Land snail species in the genus Trochulus show overlaps in geographical ranges as well as in morphology, but genetic data do not always support the species-level taxonomy based on morphological characters. Such a group offers an excellent opportunity to explore the processes involved. We have addressed the problem by determining the status of the restricted endemic T. graminicola within the larger context of Trochulus taxonomy. We used an integrated approach based on morphological features, ecological preferences and two molecular markers: mitochondrial COI sequences and microsatellites. Comparison of these results demonstrated: (i) conchological distinction of T. striolatus and T. sericeus; (ii) anatomical, ecological and genetic differentiation of T. graminicola and (iii) concordance between morphological characters and mtDNA markers in T. striolatus. Moreover, our data showed an intricate evolutionary history within the genus Trochulus, which can be best explained by: (i) recent or ongoing gene flow between taxa or (ii) their large ancestral polymorphism. Both of these hypotheses suggest that diversification within this group of snails has occurred relatively recently. The mismatches between species defined on morphology and on molecular genetics indicate the complexity of the processes involved in the diversification of this genus.
地理隔离、选择和遗传漂变会导致种群的地理分化并引发物种形成。Trochulus属的陆地蜗牛物种在地理分布范围和形态上存在重叠，但遗传数据并不总是支持基于形态特征的物种分类。这样一组物种为探索其中涉及的过程提供了绝佳机会。我们通过在Trochulus分类学的更大背景下确定分布受限的特有物种T. graminicola的地位来解决这个问题。我们采用了一种基于形态特征、生态偏好以及两个分子标记（线粒体COI序列和微卫星）的综合方法。这些结果的比较表明：（i）T. striolatus和T. sericeus在贝壳学上的区别；（ii）T. graminicola在解剖学、生态和遗传上的分化；以及（iii）T. striolatus的形态特征与线粒体DNA标记之间的一致性。此外，我们的数据显示Trochulus属内有着复杂的进化历史，这可以用以下两种情况来最好地解释：（i）分类群之间近期或正在进行的基因流动；或者（ii）它们庞大的祖先多态性。这两种假设都表明这组蜗牛的分化相对较近才发生。基于形态学定义的物种与基于分子遗传学定义的物种之间的不匹配表明了该属分化过程的复杂性。
