Molecular phylogeny of parabasalids inferred from small subunit rRNA sequences, with emphasis on the Devescovinidae and Calonymphidae (Trichomonadea)
Molecular phylogeny of parabasalids inferred from small subunit rRNA sequences, with emphasis on the Devescovinidae and Calonymphidae (Trichomonadea)
复制标题
DOI：
10.1016/s1055-7903(02)00300-7
复制
发表时间：
2002-12-01
影响因子：
4.1
通讯作者：
Viscogliosi, E
中科院分区：
文献类型：
--
作者：
Gerbod, D;Noël, C;Viscogliosi, E
小亚基rRNA序列通过聚合酶链反应从属于多鞭毛体Calonymphidae的白蚁的毛滴虫共生体中获得，包括Snyderella tabogae、Calapripha gracsii和Metacorphapha森塔。通过原位杂交，先前从白蚁Neotermes koshunensis中获得的尚未鉴定的序列Nk 9也已显示来自Devescovinidae Devescopus sp.。这些新的序列进行了分析的距离，简约性，和可能性的方法在一个广泛的同源性，包括所有确定的parabasalid序列数据库中。所有的分析表明，出现了一个非常好的支持Devescovinidae/Calonymphidae组，但表现出意想不到的二分法的Calonymphidae代表的“Corpuspha”和“Calpuspha”组。这有力地表明，在Calonymphidae中观察到的多鞭毛状态可能是由至少两个独立的进化事件来解释的。在第二个系统发育分析中，一些尚未确定的parabasalid序列可能来自Devescovinidae/Calonymphidae类群，被添加到我们的数据集。这一分析证实了Calonymphidae的多系性。一个试探性的识别提出了这些序列中的每一个，并讨论了Devescovinidae和Calonymphidae的起源假说。胎儿三毛滴虫或其近亲可能是Devescovinidae祖先的最佳候选者，这与基于形态学的假设相当一致。关于Calonymphidae，“Coronympha”组的起源可能是在Devescovinidae中发现的，与Foaina有关，而“Calonympha”组可能直接来自三毛滴虫或相关物种。(C)2002年由Elsevier Science（美国）出版。
Small subunit rRNA sequences were obtained by polymerase chain reaction from trichomonad symbionts of termites that belong to the polymastigont Calonymphidae, including Snyderella tabogae, Calonympha grassii, and Metacoronympha senta. The yet-unidentified sequence Nk9 previously obtained from the termite Neotermes koshunensis, has also been shown to derive from the Devescovinidae Devescovina sp. by in situ hybridization. These new sequences were analyzed by distance, parsimony, and likelihood methods in a broad phylogeny including all identified parabasalid sequences available in databases. All analyses revealed the emergence of a very well supported Devescovinidae/Calonymphidae group but showed an unexpected dichotomy of the Calonymphidae represented by the "Coronympha" and "Calonympha" groups. It strongly suggests that the polymastigont state observed in the Calonymphidae might be explained by at least two independent evolutionary events. In a second phylogenetic analysis, some yet-unidentified parabasalid sequences likely deriving from the Devescovinidae/Calonymphidae taxa, were added to our data set. This analysis confirmed the polyphyly of the Calonymphidae. A tentative identification is proposed for each of these sequences, and hypotheses on the origin of the Devescovinidae and Calonymphidae are discussed. Tritrichomonas foetus or a close relative might be the best candidate for the ancestor of the Devescovinidae, fairly consistent with morphology-based hypotheses. Regarding the Calonymphidae, the origin of the "Coronympha" group might be found within the Devescovinidae, related to Foaina, whereas the "Calonympha" group may directly descend from Tritrichomonas or related species. (C) 2002 Published by Elsevier Science (USA).