家蚕微孢子虫(Nosema bombycis)是蚕业生产上一种毁灭性病害—— 微粒子病的病原体。文章将安徽和重庆两地域来源的病原性家蚕微孢子虫分离株进行草地贪夜蛾Sf9细胞感染性检测, 结果显示二者对细胞的侵染能力存在显著差异。为进一步探讨不同家蚕微孢子虫分离株的种群多态性, 进行了孢子虫核糖体DNA序列的测定和系统聚类比较, 结果表明SSU rDNA(Small subunit ribosomal DNA)和ITS(Internal transcribed spacer)在不同地域的种群差异性并不显著。通过检索重庆株全基因组数据及其他地域株rDNA序列, 显示在家蚕微孢子虫rDNA元件的部分SSU rDNA结构复制子中存在MITE-like转座元件的插入, 表明家蚕微孢子虫rDNA结构的多样性。

Microsporidia Nosema bombycis is a fungal pathogen that causes epidemic pebrine disease in Bombyx mori. Two N. bombycis isolates were obtained from two areas in China and showed different pathogenicity after Spodoptera frugiperda Sf9 cell cultivation. The regions of rDNAs from different isolates were analyzed, suggesting no relationship between the genetic divergence and their geographic distributions. Further analysis showed that several copies of SSU rDNA units in N. bombycis were interrupted by a MITE-like transposon, indicating the complexity of genomic structure in Nosema bombycis.