Kallert D M, Eszterbauer E, El-Matbouli M, Erséus C, Haas W
Institute for Zoology I, University of Erlangen, Erlangen, Germany.
J Fish Dis. 2005 Feb;28(2):71-9. doi: 10.1111/j.1365-2761.2004.00599.x.
The life cycle of the histozoic myxozoan parasite Henneguya nuesslini was investigated in two salmonid host species. Naive brown trout, Salmo trutta, and brook trout, Salvelinus fontinalis, were experimentally infected in two trials by triactinomyxon type actinospores from naturally infected Tubifex tubifex. In exposed common carp, Cyprinus carpio, no myxospore production was detected. The parasite formed cysts with mature myxospores in the connective tissue of the fish 102 days post-exposure. The morphology of both actinosporean and myxosporean stages was described by light microscopy and a 1417-bp fragment of the 18S rDNA gene was sequenced. Sequence analysis confirmed the absolute congruence of the two developmental stages and assisted in determining species identity. Host range, tissue specificity and myxospore measurements provided sufficiently distinctive features to confirm species validity and were thus crucial for identification. The triactinomyxon spores had 16 secondary germ cells, unique dimensions, a very opaque sporoplasm matrix and three conspicuously protruding, pyriform polar capsules. This is the first record of a Henneguya sp. life cycle with a triactinomyxon-type actinospore, which suggests a close relationship with the Myxobolus group and a polyphyletic origin of the genus Henneguya.
在两种鲑科宿主物种中研究了组织内寄生的粘孢子虫寄生虫努氏亨内粘体虫（Henneguya nuesslini）的生命周期。在两项试验中，用来自自然感染颤蚓（Tubifex tubifex）的三射孢子虫型放线孢子对未感染过的褐鳟（Salmo trutta）和溪鳟（Salvelinus fontinalis）进行了实验感染。在暴露的鲤鱼（Cyprinus carpio）中未检测到粘孢子产生。暴露后102天，寄生虫在鱼的结缔组织中形成了含有成熟粘孢子的囊肿。通过光学显微镜描述了放线孢子阶段和粘孢子阶段的形态，并对18S rDNA基因的1417 bp片段进行了测序。序列分析证实了两个发育阶段的完全一致性，并有助于确定物种身份。宿主范围、组织特异性和粘孢子测量提供了足够独特的特征来确认物种有效性，因此对于鉴定至关重要。三射孢子虫孢子有16个次生生殖细胞、独特的尺寸、非常不透明的孢子质基质和三个明显突出的梨形极囊。这是具有三射孢子虫型放线孢子的亨内粘体虫属物种生命周期的首次记录，这表明它与粘球虫类群关系密切，且亨内粘体虫属具有多系起源。
