Geller J B, Carlton J T, Powers D A
Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950.
Mol Mar Biol Biotechnol. 1993 Feb;2(1):44-50.
A 560-base pair portion of the mitochondrial 16S ribosomal DNA (16S rDNA) from three morphologically similar mussels, Mytilus edulis, M. galloprovincialis, and M. trossulus, was amplified with the polymerase chain reaction, and 349 base pairs were sequenced. These data showed that this gene in M. edulis and M. galloprovincialis has not diverged; however, the north Pacific mussel, M. trossulus, showed fixed differences from M. edulis and M. galloprovincialis at 5 nucleotide positions. Furthermore, the population of M. trossulus at Tillamook Bay, Oregon, was found to contain two very divergent 16S rDNA genotypes that differ at 37 nucleotide positions. Thus, intraspecific variation in this gene in M. trossulus is greater than that seen interspecifically in M. edulis and M. galloprovincialis. Despite this large difference, in the absence of evidence of genetic isolation between these groups of M. trossulus, no taxonomic changes are proposed. These data are consistent with a north Pacific origin of the genus with subsequent dispersal to the Atlantic Ocean across the Artic Sea, giving rise to M. edulis in northern Europe and subsequently M. galloprovincialis in southern Europe and the Mediterranean Sea.
利用聚合酶链反应扩增了三种形态相似的贻贝（紫贻贝、加利福尼亚贻贝和翡翠贻贝）线粒体16S核糖体DNA（16S rDNA）的一段560个碱基对的片段，并对349个碱基对进行了测序。这些数据表明，紫贻贝和加利福尼亚贻贝中的该基因没有分化；然而，北太平洋贻贝翡翠贻贝在5个核苷酸位置上与紫贻贝和加利福尼亚贻贝存在固定差异。此外，在俄勒冈州蒂拉穆克湾的翡翠贻贝种群中发现了两种差异很大的16S rDNA基因型，它们在37个核苷酸位置上存在差异。因此，翡翠贻贝中该基因的种内变异大于紫贻贝和加利福尼亚贻贝的种间变异。尽管存在如此大的差异，但在没有证据表明这些翡翠贻贝群体之间存在遗传隔离的情况下，不建议进行分类学上的改变。这些数据与该属起源于北太平洋，随后经北冰洋扩散到大西洋，在北欧产生紫贻贝，随后在南欧和地中海产生加利福尼亚贻贝的观点一致。
