Sex, bugs and Haldane's rule: the nematode genus Pristionchus in the United States.
Sex, bugs and Haldane's rule: the nematode genus Pristionchus in the United States.
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DOI：
10.1186/1742-9994-3-14
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发表时间：
2006-09-12
影响因子：
2.8
通讯作者：
Sommer, Ralf J
中科院分区：
文献类型：
--
作者：
Herrmann, Matthias;Mayer, Werner E;Sommer, Ralf J
为了与秀丽隐杆线虫进行比较，在进化发育生物学中，太平洋拟线虫被发展为卫星生物。比较研究表明，太平洋毛圆线虫和秀丽线虫在发育过程的调控上存在重大差异。为了将进化发育生物学和观察到的物种之间的发育差异置于全面进化的背景下，这种研究必须与生态学方面相辅相成。对所涉有机体生态的了解可能表明可能导致发育适应的特定环境条件，并可能解释发育中的物种差异。为此，我们开始了对Pristionchus线虫的生态学研究。在最近对西欧的实地研究中，我们发现了六种与金龟子甲虫和科罗拉多州土豆甲虫密切相关的Pristionchus物种。这种Pristionchus-甲虫协会提供了将进化发育生物学的研究与生态学相结合的独特机会。然而，目前尚不清楚欧洲的这些发现在全球范围内有多普遍。在这里，我们描述了与美国东部的圣甲虫和科罗拉多州土豆甲虫有关的Pristionchus物种，并显示出显著的跨大西洋差异和意想不到的进化和生态模式。美国金龟子285个分离物中有2个(98%)属于5个种，这5个种都不同于欧洲种。我们将其中四种描述为Pristionchus新种。美国的五种Pristionchus属于一个单一的系统发育支系，具有雄性-雌性(雌雄配子体)繁殖模式，而大多数欧洲分离株是两性的。两个近缘关系最近的种间的杂交遵循霍尔丹法则，即异性配子的F1雄株是不能存活的。观察到空气假单胞菌和假单胞菌。在同一种金龟子上共存，并从野生甲虫中获得了两例F1杂交。最后，在美国和欧洲，科罗拉多州的马铃薯甲虫与同一种线虫--一致拟青霉--有关联。考虑到科罗拉多州马铃薯甲虫于1877年引入欧洲，我们的结果表明，一致拟青霉是与其甲虫媒介一起引入的。总而言之，Pristionchus-甲虫协会为在全球范围内研究生物多样性、生物地理、物种形成和物种入侵提供了一个强大的工具。
The nematode Pristionchus pacificus has been developed as a satellite organism in evolutionary developmental biology for comparison to Caenorhabditis elegans. Comparative studies have revealed major differences in the regulation of developmental processes between P. pacificus and C. elegans. To place evolutionary developmental biology and the observed developmental differences between species in a comprehensive evolutionary context, such studies have to be complemented with ecological aspects. Knowledge about the ecology of the organism in question might indicate specific environmental conditions that can result in developmental adaptations and could account for species differences in development. To this end, we have started to investigate the ecology of Pristionchus nematodes. In recent field studies in Western Europe we found six Pristionchus species that are closely associated with scarab beetles and the Colorado potato beetle. This Pristionchus – beetle association provides the unique opportunity to combine research in evolutionary developmental biology with ecology. However, it remains unknown how general these findings from Europe are on a global scale. Here, we describe the Pristionchus species associated with scarab and Colorado potato beetles in the Eastern United States and show striking transatlantic differences and unexpected evolutionary and ecological patterns. Twohundredeighty of 285 (98%) isolates from American scarab beetles belong to five Pristionchus species, all of which are different from the European species. We describe four of them as novel Pristionchus species. The five American Pristionchus species fall into a single phylogenetic clade and have a male-female (gonochoristic) mode of reproduction, whereas the majority of European isolates are hermaphroditic. Crosses between the two most closely related species, P. aerivorus and P. pseudaerivorus n. sp., follow Haldane's rule in that heterogametic F1 males are inviable. We observed P. aerivorus and P. pseudaerivorus n. sp. coexisting on the same scarab beetle and obtained two cases of F1 hybrids from wild beetles. Finally, the Colorado potato beetle is associated with the same nematode, P. uniformis in the United States and Europe. Given the introduction of the Colorado potato beetle to Europe in 1877, our results suggest that P. uniformis was introduced together with its beetle vector. Taken together, the Pristionchus – beetle association provides a powerful tool for studying biodiversity, biogeography, speciation and species invasion on a global scale.