Research Unit in Environmental and Evolutionary Biology, University of Namur, Belgium.
BMC Evol Biol. 2011 May 27;11:147. doi: 10.1186/1471-2148-11-147.
The genus Corbicula is one of the most invasive groups of molluscs. It includes both sexual and androgenetic lineages. The present study re-assessed the different morphotypes and haplotypes of West European Corbicula in order to clarify their taxonomic identification and phylogenetic relationships with American and Asian Corbicula clams. We studied several populations from West European river basins (Meuse, Seine, Rhine and Rhône) through an "integrative taxonomy" approach. We combined morphology, partial mitochondrial COI and cyt b sequences and eleven microsatellite loci. Furthermore, we looked for discrepancies between mtDNA and nrDNA/morphology, indicative of androgenesis between lineages.
There are three Corbicula morphotypes in Western Europe associated to three mitochondrial lineages and three genotypes. Form R shares the same COI haplotype as the American form A and the Japanese C. leana. Form S and the American form C have the same haplotype, although their morphologies seem divergent. The European form Rlc belongs to the same mitochondrial lineage as both the American form B and the Asian C. fluminea.Interestingly, within each haplotype/genotype or lineage, no genetic diversity was found although their invasive success is high. Moreover, we detected rare mismatches between mtDNA and nrDNA/morphology, indicative of androgenesis and mitochondrial capture between form R and form S and therefore challenging the phylogenetic relatedness and the species status within this genus. The global phylogenetic analysis revealed that the sexual Corbicula lineages seem restricted to the native areas while their androgenetic relatives are widespread and highly invasive.
We clarified the discrepancies and incongruent results found in the literature about the European morphotypes of Corbicula and associated mitochondrial lineages. The three West European morphotypes belong to three distinct nuclear and mitochondrial lineages. However mitochondrial capture occurs in sympatric populations of forms R and S. The species status of the morphotypes therefore remains doubtful. Moreover the androgenetic lineages seem widely distributed compared to their sexual relatives, suggesting that androgenesis and invasive success may be linked in the genus Corbicula.
Corbicula 属是最具入侵性的软体动物之一。它包括有性和雄性生殖系。本研究重新评估了西欧 Corbicula 的不同形态型和单倍型，以澄清它们的分类鉴定和与美洲和亚洲 Corbicula 蛤的系统发育关系。我们通过“综合分类学”方法研究了来自西欧河流流域（默兹河、塞纳河、莱茵河和罗纳河）的多个种群。我们结合了形态学、部分线粒体 COI 和 cyt b 序列和 11 个微卫星标记。此外，我们还观察了 mtDNA 和 nrDNA/形态之间的差异，这表明谱系之间存在雄性生殖。
西欧有三种 Corbicula 形态型，与三种线粒体谱系和三种基因型相关。R 型与美洲 A 型和日本 C. leana 具有相同的 COI 单倍型。S 型和美洲 C 型具有相同的单倍型，尽管它们的形态似乎不同。欧洲 Rlc 型与美洲 B 型和亚洲 C. fluminea 属于同一线粒体谱系。有趣的是，在每个单倍型/基因型或谱系内，尽管它们的入侵成功率很高，但没有发现遗传多样性。此外，我们在 mtDNA 和 nrDNA/形态之间检测到罕见的不匹配，这表明 R 型和 S 型之间存在雄性生殖和线粒体捕获，从而挑战了该属内的系统发育关系和物种地位。全球系统发育分析表明，有性 Corbicula 谱系似乎局限于原生地区，而它们的雄性生殖相关谱系则广泛分布且具有高度入侵性。
我们澄清了文献中关于欧洲 Corbicula 形态型和相关线粒体谱系的差异和不一致的结果。西欧的三种形态型属于三个不同的核和线粒体谱系。然而，在 R 型和 S 型的同域种群中发生了线粒体捕获。因此，形态型的物种地位仍然值得怀疑。此外，与有性亲缘相比，雄性生殖谱系的分布范围更广，这表明雄性生殖和入侵成功可能在 Corbicula 属中相关。
