Mock K E, Brim-Box J C, Miller M P, Downing M E, Hoeh W R
Department of Forest, Range, and Wildlife Sciences, Utah State University, 5230 Old Main Hill, Logan, UT 84322-5230, USA.
Mol Ecol. 2004 May;13(5):1085-98. doi: 10.1111/j.1365-294X.2004.02143.x.
Populations of the freshwater mussel genus Anodonta appear to be in a state of rapid decline in western North America, following a trend that unfortunately seems to be prevalent among these animals (Mollusca: Unionoida). Here we describe the patterns of molecular divergence and diversity among Anodonta populations in the Bonneville Basin, a large sub-basin of the Great Basin in western North America. Using amplified fragment length polymorphism (AFLP) analysis, we found a striking lack of nuclear diversity within some of these populations, along with a high degree of structuring among populations (FST = 0.61), suggesting post-Pleistocene isolation, due either to a long-term loss of hydrologic connectivity among populations or to more recent fish introductions. We also found evidence of recent hybridization in one of these populations, possibly mediated by fish-stocking practices. Using mitochondrial sequence data, we compared the Bonneville Basin populations to Anodonta in several other drainages in western North America. We found a general lack of resolution in these phylogenetic reconstructions, although there was a tendency for the Bonneville Basin Anodonta (tentatively A. californiensis) to cluster with A. oregonensis from the adjacent Lahontan Basin in Nevada. We recommend further investigation of anthropogenic factors that may be contributing to the decline of western Anodonta and a broad-scale analysis and synthesis of genetic and morphological variation among Anodonta in western North America.
在北美洲西部，淡水贻贝无齿蚌属的种群数量似乎正在迅速减少，这种趋势在这些动物（软体动物门：蚌目）中不幸地普遍存在。在此，我们描述了北美洲西部大盆地的一个大型子流域邦纳维尔盆地无齿蚌种群间的分子分化和多样性模式。通过扩增片段长度多态性（AFLP）分析，我们发现其中一些种群内明显缺乏核多样性，同时种群间存在高度的结构分化（FST = 0.61），这表明更新世后的隔离，原因可能是种群间长期失去水文连通性，或者是更近时期引入了鱼类。我们还在其中一个种群中发现了近期杂交的证据，可能是由鱼类放养活动介导的。利用线粒体序列数据，我们将邦纳维尔盆地的种群与北美洲西部其他几条排水流域的无齿蚌进行了比较。尽管邦纳维尔盆地的无齿蚌（暂定为加州无齿蚌）有与内华达州相邻的拉洪坦盆地的俄勒冈无齿蚌聚类的趋势，但我们发现这些系统发育重建中普遍缺乏分辨率。我们建议进一步调查可能导致北美洲西部无齿蚌数量下降的人为因素，并对北美洲西部无齿蚌的遗传和形态变异进行广泛的分析和综合。
