Inheritance and diversification of symbiotic trichonymphid flagellates from a common ancestor of termites and the cockroach Cryptocercus
Inheritance and diversification of symbiotic trichonymphid flagellates from a common ancestor of termites and the cockroach Cryptocercus
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DOI：
10.1098/rspb.2008.1094
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发表时间：
2009-01-22
影响因子：
4.7
通讯作者：
Inoue, Tetsushi
中科院分区：
文献类型：
--
作者：
Ohkuma, Moriya;Noda, Satoko;Inoue, Tetsushi
隐尾蟑螂和低白蚁港口专性，多样性和独特的共生纤维素分解鞭毛虫在其后肠，被认为是在其主机的社会行为的发展至关重要。然而，关于这些共生鞭毛虫的起源一直存在争议。在这里，编码小亚基rRNA和甘油醛-3-磷酸脱氢酶的分子序列被确定在共生鞭毛虫的目的毛线虫（门Parabasalia）在肠道的Cryptocercus punctulatus和比较genetically相应的物种在白蚁。在每一个单系谱系，代表家庭层次的群体在毛螨，隐尾虫的共生体是强大的姐妹白蚁。结合最近关于宿主昆虫姐妹群关系的证据，这一首次比较共生体分子遗传学的综合研究强烈表明，一组代表现存多样性的共生鞭毛虫已经在隐尾虫和白蚁的共同祖先中建立，垂直传播给它们的后代，随后变得多样化到不同的水平，这取决于宿主和共生体的血统。
Cryptocercus cockroaches and lower termites harbour obligate, diverse and unique symbiotic cellulolytic flagellates in their hindgut that are considered critical in the development of social behaviour in their hosts. However, there has been controversy concerning the origin of these symbiotic flagellates. Here, molecular sequences encoding small subunit rRNA and glyceraldehyde-3-phosphate dehydrogenase were identified in the symbiotic flagellates of the order Trichonymphida (phylum Parabasalia) in the gut of Cryptocercus punctulatus and compared phylogenetically to the corresponding species in termites. In each of the monophyletic lineages that represent family-level groups in Trichonymphida, the symbionts of Cryptocercus were robustly sister to those of termites. Together with the recent evidence for the sister-group relationship of the host insects, this first comprehensive study comparing symbiont molecular phylogeny strongly suggests that a set of symbiotic flagellates representative of extant diversity was already established in an ancestor common to Cryptocercus and termites, was vertically transmitted to their offspring, and subsequently became diversified to distinct levels, depending on both the host and the symbiont lineages.