家蚕微孢子虫假定膜蛋白基因NBO_32g0046的克隆及表达分析

Cloning and Expression Analysis of Hypothetical Membrane Protein Gene NBO_32g0046 of Nosema bombycis

家蚕微孢子虫(Nosema bombycis)感染家蚕引发家蚕微粒子病,对养蚕业造成巨大危害,其防治是蚕业生产的重大技术难题之一。家蚕微孢子虫的膜蛋白在侵染过程中发挥着重要作用,也是开展防治研究的重要候选靶标。从感染家蚕微孢子虫的家蚕中肠转录组数据中筛选到一个高量表达的家蚕微孢子虫假定膜蛋白基因NBO32g0046,生物信息学预测NBO32g0046蛋白的分子质量为24.9 kD,等电点为9.57,存在4个跨膜结构域,含有1个N-糖基化位点和2个O-糖基化位点,不具有信号肽和已知的功能域;同源分析发现,NBO32g0046在Encephalitozoon、Ordospora及Nosema属的多种微孢子虫中存在同源序列。转录分析表明,NBO32g0046基因在家蚕微孢子虫增殖的各个阶段均有表达。通过RNAi敲低NBO32g0046的表达,能有效抑制家蚕微孢子虫的增殖。上述结果表明NBO32g0046在家蚕微孢子虫的增殖过程中起重要作用,可作为开展家蚕抗性素材构建研究的潜在靶标。

Nosema bombycis can cause silkworm pebrinee disease,which is a devastating hazard to sericulture.The prevention and control of N.bombycis has become a key technical difficulty in the sericulture industry.The membrane proteins of N.bombycis play important roles in the infection process,and are also important candidate targets in the prevention and control research.A hypothetical membrane protein(NBO32g0046)with high expression level was screened out from the midgut transcriptome data of the silkworm infected with N.bombycis.According to bioinformatics prediction,NBO32g0046 has a molecular mass of 24.9 kD,theoretical pI of 9.57,four transmembrane domains,one N-glycosylation site and two O-glycosylation sites,whereas it has no signal peptide and known functional domains.Homology analysis revealed that NBO32g0046 has homologous sequences with various microsporidia of Encelphalitozoon,Ordospora and Nosema.The transcription profile analysis on NBO32g0046 showed that it was expressed at all stages of spore proliferation.Knock-down of NBO32g0046 by RNAi can effectively suppress the proliferation of N.bombycis.These results indicated that NBO32g0046 plays an important role in the proliferation of N.bombycis and can be used as a potential target for the construction of silkworm resistant materials.