Molecular population genetics and phenotypic sensitivity to ethanol for a globally diverse sample of the nematode Caenorhabditis briggsae
Molecular population genetics and phenotypic sensitivity to ethanol for a globally diverse sample of the nematode Caenorhabditis briggsae
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DOI：
10.1111/j.1365-294x.2009.04491.x
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发表时间：
2010-02-01
影响因子：
4.9
通讯作者：
Felix, Marie-Anne
中科院分区：
文献类型：
--
作者：
Cutter, Asher D.;Yan, Weiang;Felix, Marie-Anne
过去几年新的基因组资源和遗传工具使线虫属成为比较生物学的模式。然而，在分子和表型水平上对自然遗传变异的理解对于该属的大多数物种来说仍然是初级的，特别是对于C.briggsae。在这里，我们表征了全球不同菌株对潜在重要和可变的环境毒素乙醇的敏感性的表型变异。我们还量化了来自四大洲(包括小岛)的32个菌株的新样本的核苷酸变异，以及该物种的已知近亲(C.sp.9)。我们证明，对于乙醇对生存和繁殖的反应规范的影响，桥毛藻表现出很小的遗传变异。此外，在我们对这种物质的反应方面，布里格萨线虫和线虫并没有明显的不同，这两个物种都可能经常在腐烂的水果和植被的栖息地遇到这种物质。然而，我们发现了比以前已知的该物种更多的分子遗传变异，尽管大多数菌株，包括所有岛屿菌株，都符合前面描述的广泛的生物地理模式。利用种群间和物种间的序列差异模式，我们估计桥胸锦鸡儿两性生殖的自交方式可能是在0.9至1000万代之前的某个时候进化出来的。这些对布里奇萨斯自然历史和自然遗传变异的洞察极大地扩展了这种生物作为分子和数量遗传学、发育进化和生态遗传学研究的新兴模式的潜力。
New genomic resources and genetic tools of the past few years have advanced the nematode genus Caenorhabditis as a model for comparative biology. However, understanding of natural genetic variation at molecular and phenotypic levels remains rudimentary for most species in this genus, and for C. briggsae in particular. Here we characterize phenotypic variation in C. briggsae's sensitivity to the potentially important and variable environmental toxin, ethanol, for globally diverse strains. We also quantify nucleotide variation in a new sample of 32 strains from four continents, including small islands, and for the closest-known relative of this species (C. sp. 9). We demonstrate that C. briggsae exhibits little heritable variation for the effects of ethanol on the norm of reaction for survival and reproduction. Moreover, C. briggsae does not differ significantly from C. elegans in our assays of its response to this substance that both species likely encounter regularly in habitats of rotting fruit and vegetation. However, we uncover drastically more molecular genetic variation than was known previously for this species, despite most strains, including all island strains, conforming to the broad biogeographic patterns described previously. Using patterns of sequence divergence between populations and between species, we estimate that the self-fertilizing mode of reproduction by hermaphrodites in C. briggsae likely evolved sometime between 0.9 and 10 million generations ago. These insights into C. briggsae's natural history and natural genetic variation greatly expand the potential of this organism as an emerging model for studies in molecular and quantitative genetics, the evolution of development, and ecological genetics.