Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 370 05 České Budějovice (Budweis), Czech Republic.
Mol Phylogenet Evol. 2013 Oct;69(1):255-64. doi: 10.1016/j.ympev.2013.05.024. Epub 2013 Jun 7.
Widely distributed, highly prevalent and speciose, trypanosomatid flagellates represent a convenient model to address topics such as host specificity, diversity and distribution of parasitic protists. Recent studies dealing with insect parasites of the class Kinetoplastea have been focused mainly on trypanosomatids from true bugs (Heteroptera), even though flies (Diptera, Brachycera) are also known as their frequent hosts. Phylogenetic position, host specificity and geographic distribution of trypanosomatids parasitizing dipteran hosts collected in nine countries on four continents (Bulgaria, Czech Republic, Ecuador, Ghana, Kenya, Madagascar, Mongolia, Papua New Guinea and Turkey) are presented. Spliced leader (SL) RNA gene repeats and small subunit (SSU) rRNA genes were PCR amplified from trypanosomatids infecting the gut of a total of forty fly specimens belonging to nine families. While SL RNA was mainly used for barcoding, SSU rRNA was utilized in phylogenetic analyses. Thirty-six different typing units (TUs) were revealed, of which 24 are described for the first time and represent potential new species. Multiple infections with several TUs are more common among brachyceran hosts than in true bugs, reaching one third of cases. When compared to trypanosomatids from heteropteran bugs, brachyceran flagellates are more host specific on the genus level. From seven previously recognized branches of monoxenous trypanosomatids, the Blastocrithidia and "jaculum" clades accommodate almost solely parasites of Heteroptera; two other clades (Herpetomonas and Angomonas) are formed primarily by flagellates found in dipteran hosts, with the most species-rich Leishmaniinae and the small Strigomonas and "collosoma" clades remaining promiscuous. Furthermore, two new clades of trypanosomatids from brachyceran flies emerged in this study. While flagellates from brachyceran hosts have moderate to higher host specificity, geographic distribution of at least some of them seems to be cosmopolitan. Moreover, the genus Angomonas, so far known only from South America, is present on other continents as well.
广泛分布、高度流行且种类繁多的鞭毛原生动物代表了一个方便的模型，可以用来解决宿主特异性、寄生虫原生动物的多样性和分布等主题。最近研究昆虫寄生虫的 class Kinetoplastea 主要集中在原生动物从真正的虫子（半翅目），尽管苍蝇（双翅目，短角亚目）也被称为他们的常客。寄生在来自四大洲九个国家的双翅目宿主中的鞭毛原生动物的系统发育位置、宿主特异性和地理分布。拼接领导（SL）RNA 基因重复和小亚基（SSU）rRNA 基因从总共四十个蝇标本的肠道中感染的原生动物中 PCR 扩增，这些蝇标本属于九个科。虽然 SL RNA 主要用于条码，但 SSU rRNA 用于系统发育分析。揭示了 36 个不同的分型单位（TU），其中 24 个是首次描述的，代表潜在的新物种。在短角亚目宿主中，与半翅目昆虫相比，多重感染多个 TU 更为常见，达到三分之一。与来自半翅目昆虫的原生动物相比，短角亚目鞭毛原生动物在属级上更具宿主特异性。在单宿主原生动物的七个先前公认的分支中，Blastocrithidia 和“jaculum”分支几乎完全容纳了 Heteroptera 的寄生虫；另外两个分支（Herpetomonas 和 Angomonas）主要由在双翅目宿主中发现的鞭毛原生动物组成，其中物种最丰富的 Leishmaniinae 和小 Strigomonas 和“collosoma”分支仍然混杂。此外，本研究还出现了两个来自短角亚目蝇的新鞭毛原生动物分支。虽然来自短角亚目宿主的鞭毛原生动物具有中等至高宿主特异性，但它们中的至少一些的地理分布似乎是世界性的。此外，到目前为止仅在南美洲发现的 Angomonas 属也存在于其他大陆。
