Podlipaev Sergei A, Sturm Nancy R, Fiala Ivan, Fernandes Octavio, Westenberger Scott J, Dollet Michel, Campbell David A, Lukes Julius
Institute of Parasitology, Czech Academy of Sciences, Ceské Budĕjovice, Czech Republic.
J Eukaryot Microbiol. 2004 May-Jun;51(3):283-90. doi: 10.1111/j.1550-7408.2004.tb00568.x.
We have determined the sequences of 5S rRNA and spliced leader (SL) RNA genes, and adjacent intergenic regions for representatives of all known trypanosomatid genera parasitizing insects. The genetic loci have been analyzed separately as well as by a combined approach. Several isolates, assigned by morphology to different genera (Leptomonas spp., Blastocrithidia spp.), seem to belong to a single species with an unexpectedly wide host and geographical range. An unnamed trypanosomatid isolated from rats in Egypt was found to belong to the genus Herpetomonas, so far associated with insect hosts only. It is closely related to Herpetomonas ztiplika, a parasite of a blood-sucking biting midge. Apparently several different trypanosomatid species can infect one insect species, as exemplified by Leptomonas sp. PL and Wallaceina sp. Wsd, which were isolated from different specimens of Salda littoralis on the same locality and day. However, since the same species of Leptomonas was obtained from insect hosts belonging to different genera, some insect trypanosomatids may have low host specificity. Our data revealed additional discrepancies between molecular phylogenetic data and cell morphology, rendering current trypanosomatid taxonomy unreliable.
我们已经确定了寄生于昆虫的所有已知锥虫属代表的5S核糖体RNA（rRNA）和剪接前导序列（SL）RNA基因，以及相邻的基因间隔区的序列。这些基因位点已分别进行了分析，也采用了综合分析方法。一些根据形态学归为不同属（细滴虫属、短膜虫属）的分离株，似乎属于单一物种，其宿主和地理范围出人意料地广泛。从埃及大鼠体内分离出的一种未命名的锥虫被发现属于赫氏鞭毛虫属，该属迄今仅与昆虫宿主相关。它与吸血蠓的寄生虫兹氏赫氏鞭毛虫密切相关。显然，几种不同的锥虫物种可以感染同一种昆虫，例如从同一地点、同一天的不同海滨斧螳标本中分离出的细滴虫属PL种和沃氏鞭毛虫属Wsd种。然而，由于从属于不同属的昆虫宿主中获得了相同种类的细滴虫，一些昆虫锥虫可能宿主特异性较低。我们的数据揭示了分子系统发育数据与细胞形态之间的其他差异，使得当前的锥虫分类学不可靠。
