Phylogeography and regional endemism of a passively dispersing zooplankter:: mitochondrial DNA variation in rotifer resting egg banks
Phylogeography and regional endemism of a passively dispersing zooplankter:: mitochondrial DNA variation in rotifer resting egg banks
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DOI：
10.1098/rspb.2000.1268
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发表时间：
2000-11-07
影响因子：
4.7
通讯作者：
Lunt, DH
中科院分区：
文献类型：
--
作者：
Gómez, A;Carvalho, GR;Lunt, DH
我们调查了咸水轮虫褶皱臂尾轮虫，一个周期性的孤雌生殖与被动扩散机制，利用从盐湖沉积物中回收的休眠卵的生态地理。个体休眠蛋从一个大的选择，这是代表五个内流盆地和链的沿海池塘在伊比利亚半岛的湖泊。休眠蛋的新用途允许整合季节性和年度变化以及漂移和局部灭绝等随机效应的影响。从98个卵中测定了线粒体细胞色素氧化酶亚基I（COI）基因的653 bp片段。我们的研究结果揭示了一个深的地理结构，在这个物种中，分为两个主要的血统，具有不同的地理分布，这可能是在更新世初期分歧。大多数线粒体DNA单倍型仅限于单个湖泊。巢式分支分析支持早更新世破碎的人口，低基因流和一些长距离殖民。这些结论强烈对比与以前的想法轮虫化石，这种模式是一致的伊比利亚半岛从两个冰川避难所。这些结果提供了新的见解的过程负责的被动扩散，典型的动物寄生性bioprostic的生活史特征的遗传多样性。
We investigated the phylogeography of the salt water rotifer Brachionus plicatilis, a cyclical parthenogen with passive dispersal mechanisms, using resting eggs recovered from saline lake sediments. Individual resting eggs were obtained from a large selection of lakes which were representative of five endorheic basins and the chain of coastal ponds in the Iberian Peninsula. The novel use of resting eggs allows the integration of seasonal and annual variations as well as the impact of stochastic effects such a drift and local extinction. A 653 bp fragment of the mitochonrial cytochrome oxidase subunit I (COI) gene was sequenced from 98 eggs. Our results revealed a deep phylogeographical structure in this species, with a division into two main lineages with distinct geographical distributions, which probably diverged at the beginning of the Pleistocene period. Most of the mitochondrial DNA haplotypes were restricted to single lakes. Nested clade analysis supported Early Pleistocene fragmentation of populations, low gene flow and some long-distance colonization. These conclusions contrast strongly with previous ideas on rotifer biogeography and this pattern is consistent with a recolonization of the Iberian Peninsula from two glacial refugia. The results provide new insights into the processes responsible for the genetic diversification of passive dispersers, a life-history trait typical of zooplanktonic biotas.