Young C R, Fujio S, Vrijenhoek R C
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039-9644, USA.
Mol Ecol. 2008 Apr;17(7):1718-31. doi: 10.1111/j.1365-294X.2008.03609.x.
This study examined relationships between bathymetrically induced deep-ocean currents and the dispersal of the hydrothermal vent tubeworm Ridgeia piscesae along the northeast Pacific ridge system. A robust diagnostic model of deep-ocean circulation in this region predicted strong southeasterly currents following contours of the Blanco Transform Fault, a 450-km lateral offset that separates the Gorda and Juan de Fuca ridge systems. Such currents should facilitate the southward dispersal of R. piscesae larvae. Immigration rates for populations north and south of the Blanco Transform Fault were estimated from molecular population genetic data. Mitochondrial DNA evidence revealed population subdivision across the Blanco Transform Fault, and a strong directional bias in gene flow that was consistent with predictions of the circulation model. The distribution of mitochondrial diversity between the northern and southern populations of R. piscesae suggests that the Gorda Ridge tubeworms have maintained larger effective population sizes than the northern populations, a pattern that also exists in co-occurring limpets. Together, these data suggest that the northern vent fields may experience a higher frequency of habitat turnover and consequently more rapid losses of genetic diversity.
本研究调查了地形引发的深海海流与热液喷口管虫（Ridgeia piscesae）在东北太平洋海岭系统沿线扩散之间的关系。该区域深海环流的一个可靠诊断模型预测，沿着布兰科转换断层的等高线会有强劲的东南向海流，这条长450公里的横向偏移断层将戈尔达海岭和胡安德富卡海岭系统分隔开来。这样的海流应有助于R. piscesae幼虫向南扩散。根据分子群体遗传数据估算了布兰科转换断层以北和以南种群的迁入率。线粒体DNA证据揭示了布兰科转换断层两侧的种群细分情况，以及基因流中存在的强烈方向偏差，这与环流模型的预测一致。R. piscesae南北种群之间线粒体多样性的分布表明，戈尔达海岭的管虫比北方种群维持了更大的有效种群规模，这种模式在同时出现的帽贝中也存在。综合这些数据表明，北部喷口区可能经历更高频率的栖息地更替，因此遗传多样性丧失更快。
