Molecular evolution and quantitative variation for chemosensory behaviour in the nematode genus Caenorhabditis
Molecular evolution and quantitative variation for chemosensory behaviour in the nematode genus Caenorhabditis
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DOI：
10.1046/j.1365-294x.2003.01805.x
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发表时间：
2003-05-01
影响因子：
4.9
通讯作者：
Phillips, PC
中科院分区：
文献类型：
--
作者：
Jovelin, R;Ajie, BC;Phillips, PC
秀丽隐杆线虫是生物学中的模式生物，然而，尽管遗传、基因组和功能分析产生了大量信息，但秀丽隐杆线虫很少被用来解决生态遗传学问题。在这里，我们分析了三个秀丽隐杆线虫属物种的化学感应行为的遗传变异，这是一种生态上重要的性状，在表型和分子水平上也得到了很好的遗传表征。我们证明 G 蛋白 ODR-3 在化学感应回避行为中发挥重要作用，并在 C. briggsae 和 C. remanei 中鉴定出 odr-3 的直系同源物。化学感应行为的定量遗传分析和 odr-3 的分子群体遗传分析均表明，主要自交线虫的世界范围内的分离株之间几乎没有遗传变异，而异交的雷马尼线虫的单个种群内则存在显着更多的变异。尽管这三个物种中 odr-3 内的沉默位点存在大量取代，但蛋白质水平的分子进化极其保守，表明 odr-3 在 C. remanei 和 C. briggsae 的化学感受和/或神经元纤毛发育过程中的细胞信号传导中发挥着重要作用，就像在秀丽隐杆线虫中一样。我们的结果表明，雷马尼秀丽隐杆线虫可能比秀丽隐杆线虫更适合生态和进化遗传学研究。
Caenorhabditis elegans is a model organism in biology, yet despite the tremendous information generated from genetic, genomic and functional analyses, C. elegans has rarely been used to address questions in ecological genetics. Here, we analyse genetic variation for chemosensory behaviour, an ecologically important trait that is also genetically well characterized, at both the phenotypic and molecular levels within three species of the genus Caenorhabditis. We show that the G-protein ODR-3 plays an important role in chemosensory avoidance behaviour and identify orthologues of odr-3 in C. briggsae and C. remanei. Both quantitative genetic analysis of chemosensory behaviour and molecular population genetic analysis of odr-3 show that there is little genetic variation among a worldwide collection of isolates of the primarily selfing C. elegans, whereas there is substantially more variation within a single population of the outcrossing C. remanei. Although there are a large number of substitutions at silent sites within odr-3 among the three species, molecular evolution at the protein level is extremely conserved, suggesting that odr-3 plays an important role in cell signalling during chemosensation and/or neuronal cilia development in C. remanei and in C. briggsae as it does in C. elegans. Our results suggest that C. remanei may be a more suitable subject for ecological and evolutionary genetic studies than C. elegans.