Merzlyak E, Yurchenko V, Kolesnikov A A, Alexandrov K, Podlipaev S A, Maslov D A
Department of Molecular Biology, Moscow State University, Russia.
J Eukaryot Microbiol. 2001 Mar-Apr;48(2):161-9. doi: 10.1111/j.1550-7408.2001.tb00298.x.
With the aim of further investigating phylogenetic relationships in insect trypanosomatids, we have determined the sequences of small subunit rRNA genes from ten isolates, which were originally classified as Leptomonas, Blastocrithidia, and Wallaceina based on their morphology in the hosts. The inferred maximum likelihood, parsimony, and distance trees indicate that the Leptomonas and Blastocrithidia are polyphyletic, and confirm the polyphyly of Herpetomonas and Crithidia. Blastocrithidia triatoma and Leptomonas collosoma were among the earliest branching lineages among the insect trypanosomatids, while most other isolates were found within a closely related terminal clade, which also included Crithidia fasciculata. This analysis has clearly demonstrated that the morphological classification system of insect trypanosomatids does not always reflect their genetic affinities warranting its revision in the future.
为了进一步研究昆虫锥虫的系统发育关系，我们测定了来自十个分离株的小亚基rRNA基因序列，这些分离株最初根据其在宿主体内的形态被归类为细滴虫属、杆状体虫属和华莱士虫属。推断的最大似然树、简约树和距离树表明，细滴虫属和杆状体虫属是多系的，并证实了赫氏锥虫属和短膜虫属的多系性。三锥杆状体虫和粗球细滴虫是昆虫锥虫中最早分支的谱系之一，而大多数其他分离株则位于一个密切相关的末端分支内，该分支还包括束状短膜虫。该分析清楚地表明，昆虫锥虫的形态分类系统并不总是反映它们的遗传亲缘关系，因此有必要在未来对其进行修订。
