Allsopp M T, Cavalier-Smith T, De Waal D T, Allsopp B A
Onderstepoort Veterinary Institute, South Africa.
Parasitology. 1994 Feb;108 ( Pt 2):147-52. doi: 10.1017/s0031182000068232.
Small subunit ribosomal RNA (srRNA) genes of three Theileria species, one Cytauxzoon and four Babesia species were amplified using the polymerase chain reaction (PCR), cloned and sequenced. Our sequences were aligned with srRNA sequences previously published for eight species of Apicomplexa, one ciliate and one dinoflagellate, the last two being included as free-living outgroup species. Phylogenetic relationships between the organisms were inferred by four independent methods of phylogenetic tree construction using the ciliate Oxytricha nova to root the trees. Our trees fail to show a consensus branching order. They do, however, clearly indicate that the theilerias form a monophyletic taxon derived from a paraphyletic group which includes the species B. equi, C. felis and B. rodhaini. The distance trees indicate that the babesias sensu stricto (B. canis, B. caballi, B. bigemina and B. bovis) form another monophyletic taxon which diverged before the theilerias separated from the above-mentioned paraphyletic group. The parsimony and maximum likelihood trees suggest that the babesias and theilerias are sister taxa, both of which were derived from the paraphyletic group.
利用聚合酶链反应（PCR）扩增了三种泰勒虫属物种、一种嗜吞噬细胞无形体和四种巴贝斯虫属物种的小亚基核糖体RNA（srRNA）基因，并进行了克隆和测序。我们的序列与先前发表的八种顶复门物种、一种纤毛虫和一种甲藻的srRNA序列进行了比对，后两种作为自由生活的外类群物种被纳入。使用纤毛虫新奥xytricha nova作为树根，通过四种独立的系统发育树构建方法推断了这些生物体之间的系统发育关系。我们的树未能显示出一致的分支顺序。然而，它们确实清楚地表明，泰勒虫属形成了一个单系分类群，该分类群源自一个并系群，该并系群包括马巴贝斯虫、猫嗜吞噬细胞无形体和罗氏巴贝斯虫物种。距离树表明，狭义的巴贝斯虫属（犬巴贝斯虫、马巴贝斯虫、双芽巴贝斯虫和牛巴贝斯虫）形成了另一个单系分类群，该分类群在泰勒虫属与上述并系群分离之前就已经分化。简约树和最大似然树表明，巴贝斯虫属和泰勒虫属是姐妹分类群，两者均源自并系群。
