Study on karyotype and genome size of entomopathogenic microsporidians

微孢子虫寄生虫的鉴定是基于光学和电子显微镜观察到的形态特征。脉冲场凝胶电泳不仅为小型单细胞生物染色体的研究提供了一种新的方法，而且也为微孢子虫的鉴定提供了一种新的方法。另一方面，这些研究中使用的微孢子虫不是克隆的。从病蚕中发现了微孢子虫的混合感染。本研究首先研究了混合感染条件下寄生虫在昆虫宿主和昆虫细胞培养物中的相互作用，并利用光学显微镜对克隆的微孢子虫进行了核型分析。在此基础上，对家蚕微孢子虫的脉冲场凝胶电泳结果进行了分析，并对家蚕微孢子虫的种内和种间变异进行了讨论。 关于我们 001对Nosema sp. NIS M11和Vairimorha sp. NIS M12的混合感染具有优势，但优势菌并不通过竞争消灭次要菌，微孢子虫可以在同一宿主中共存。用有限稀释法在昆虫细胞培养物中建立了几个微孢子虫克隆，并在Axioplan 2通用显微镜下对克隆微孢子虫营养细胞的染色体数目进行了估算。13条染色体被可视化的微孢子虫，变异形属物种NIS M12。在微孢子虫基因组DNA分析中，明确了巴西分离株基因组提取需要用碱性EDTA溶液处理孢子。不同种微孢子虫的脉冲场凝胶电泳带型不同，表明该方法可用于微孢子虫的鉴定。本报告中建立的方案适用于所有使用的分离株，这一结果证明了克隆的重要性。少

The identification of microsporidian parasites has been based on morphological characters observed with light and electron microscopy. Pulsed-field gel electrophoresis has recently provided an alternative for not only the investigation of chromosomes in small single-celled organisms but also the identification of microsporidians. On the other hand, microsporidians used in those studies were not cloned ones. Mixed infection of microsporidians has been known from the diseased silkworm larvae. In this study, the interaction of the parasites in insect hosts and insect cell cultures under mixed infection was investigated first and estimate of the karyotype of the cloned microsporidians was made by light microscopy. Then, we presented data from pulsed-field gel electrophoresis of cloned microsporidians and the intra- and inter-specific variations of entomophathogenic microsporidians was discussed.Both in the silkworm and in the Spodoptera frugiperda SF21AEII cell culture, Nosema bombycis NIS … More 001 dominated on the other microsporidians, Nosema sp. NIS M11 and Vairimorha sp. NIS M12, when it was involved in the mixed infections, However, the dominant did not eliminate the minor ones by competition and microsporidians could co-exist in the same host. It was, therefore, strongly suggested that cloning of microsporidians would be important when the characterization and identification of the parasites were discussed.Several clones of those microsporidians in insect cell cultures were established by a limiting dilution method and attempt to estimate the number of chromosomes for the vegetative cells of cloned microsporidians was made by an Axioplan 2 universal microscope. Thirteen chromosomes were visualizied for the microsporidian, Vairimorpha sp. NIS M12. In genomic DNA analysis of microsporidia, it was clarified that alkali EDTA solution treatment of spore was needed for genome extraction from Brazilian isolates. The banding patterns were different among the species of microsporidia in pulse-field gel electrophoresis, suggesting that this method useful tool for identification of microsporidia. Established protocol in this report could apply for all isolates used, and this restult demnonstrated the importance of cloning. Less