Euplotespora binucleata n. gen., n. sp (Protozoa: Microsporidia), a parasite infecting the hypotrichous ciliate Euplotes woodruffi, with observations on microsporidian infections in Ciliophora
Euplotespora binucleata n. gen., n. sp (Protozoa: Microsporidia), a parasite infecting the hypotrichous ciliate Euplotes woodruffi, with observations on microsporidian infections in Ciliophora
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DOI：
10.1111/j.1550-7408.2008.00322.x
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发表时间：
2008-05-01
影响因子：
2.2
通讯作者：
Dini, Fernando
中科院分区：
文献类型：
--
作者：
Fokin, Sergei I.;Di Giuseppe, Graziano;Dini, Fernando
根据生活史特征、光镜和电镜特征以及小亚基（SSU）核糖体DNA （rDNA）测序，描述并定义了半咸水纤毛虫Euplotespora binucleata n. gen., n. sp., Euplotespora binucleata n., n. sp.。双核棘球绦虫的生命周期可能具有较短的分裂期和较长的孢子期。在实验感染的宿主细胞中发现了一些单核单体和孢子体，以及双核孢子母细胞和孢子。这样一个特殊的生命周期已经在Euplotes eurystomus和组成性无微孢子虫的木桐种群中被实验诱导。双核孢子为单形态，卵圆圆柱状，大小为3.44 +/- 0.17 × 1.65 +/- 0.22 μ m，具有双核形态和大后空泡的特征。极性管是等丝状的，弹出时长度为4.5-5.5 μ m，并且缺乏独特的卷曲区域（半卷曲）。极质体分为两个区域：前部有几个靠近锚定盘的片层；后部为圆形体（袋），约为孢子长度的四分之一。孢子看起来不会聚集成一组。每个孢子被紧挨着外孢子层的孢子膜所包围。用不同的方法对双核e.b nsp . SSU rDNA序列进行了系统发育分析，将其与微孢子虫属、囊孢子虫属和Vittaforma属的代表植物归为一个分支。鉴于纤毛虫门的微孢子虫感染频率，讨论了其他几种纤毛虫的微孢子虫观察。
A new microsporidian species, Euplotespora binucleata n. gen., n. sp., from the brackish-water ciliate Euplotes woodruffi is described and defined on the basis of life history characteristics, light and electron microscopic features, and small subunit (SSU) ribosomal DNA (rDNA) sequencing. The life cycle of E. binucleata n. sp. probably has rather short merogonic and relatively long sporogonic phases. Some uninuclear meronts and sporonts, along with diplokaryotic sporoblasts and spores, were found in experimentally infected host cells. Such a peculiar life cycle has been induced experimentally in Euplotes eurystomus and constitutively microsporidian-free stocks of E. woodruffi. Spores of E. binucleata n. sp. are monomorphic, ovoid-cylindrical in shape, 3.44 +/- 0.17 x 1.65 +/- 0.22 mu m in size, and characterized by a diplokaryotic condition and a large posterior vacuole. The polar tube is isofilar, 4.5-5.5 mu m in length when ejected, and lacking a distinctive coiled region (half-coiled). The polaroplast is divided into two regions: the anterior part has a few lamellae close to the anchoring disc; and the posterior part is a rounded body (sack), about one-quarter of the spore length. Spores do not appear to cluster together as a group. Each spore is surrounded by a sporophorous membrane closely adjacent to the exospore layer. A phylogenetic analysis of SSU rDNA sequences by different methods placed E. binucleata n. sp. in a clade with representatives of the microsporidian genera Cystosporogenes and Vittaforma. Observations of microsporidia in several other ciliates are discussed in view of the microsporidian infection frequency in the phylum Ciliophora.