Maslov D A, Podlipaev S A, Lukes J
Department of Biology, University of California, Riverside, CA 92521, USA.
Mem Inst Oswaldo Cruz. 2001 Apr;96(3):397-402. doi: 10.1590/s0074-02762001000300021.
To further investigate phylogeny of kinetoplastid protozoa, the sequences of small subunit (18S) ribosomal RNA of nine bodonid isolates and ten isolates of insect trypanosomatids have been determined. The root of the kinetoplastid tree was attached to the branch of Bodo designis and/or Cruzella marina. The suborder Trypanosomatina appeared as a monophyletic group, while the suborder Bodonina was paraphyletic. Among bodonid lineages, parasitic organisms were intermingled with free-living ones, implying multiple transitions to parasitism and supporting the 'vertebrate-first hypothesis'. The tree indicated that the genera Cryptobia and Bodo are artificial taxa. Separation of fish cryptobias and Trypanoplasma borreli as different genera was not supported. In trypanosomatids, the genera Leptomonas and Blastocrithidia were polyphyletic, similar to the genera Herpetomonas and Crithidia and in contrast to the monophyletic genera Trypanosoma and Phytomonas. This analysis has shown that the morphological classification of kinetoplastids does not in general reflect their genetic affinities and needs a revision.
为进一步研究动基体原生动物的系统发育，已测定了9株波豆虫分离株和10株昆虫锥虫分离株的小亚基（18S）核糖体RNA序列。动基体树的根部连接到德氏波豆虫和/或滨海克鲁氏鞭毛虫的分支上。锥虫亚目呈现为一个单系群，而波豆亚目则是并系群。在波豆虫谱系中，寄生生物与自由生活生物相互混杂，这意味着向寄生生活的多次转变，并支持“脊椎动物优先假说”。该树状图表明，隐鞭虫属和波豆虫属是人为分类单元。鱼类隐鞭虫和博氏锥浆虫作为不同属分开并不成立。在锥虫中，细滴虫属和短膜虫属是多系的，类似于动基体属和短膜虫属，与单系的锥虫属和植生滴虫属形成对比。该分析表明，动基体的形态分类总体上并不反映它们的遗传亲缘关系，需要进行修订。
