家蚕应对球孢白僵菌感染的免疫应答基因表达差异分析

Analysis on Expression Difference of Silkw orm Im m une Response Genes Against Beauveria bassiana Infect ion

使用对家蚕Bombyx mori具有高、低毒力的球孢白僵菌Beauveria bassiana菌株侵染家蚕,分析家蚕应对球孢白僵菌浸染的免疫应答基因。采用新一代Illumina高通量测序技术对接种高、低毒力球孢白僵菌家蚕样品与未接种的家蚕样品分别进行转录组测序,筛选出差异表达基因,利用生物信息学软件分析差异表达基因的功能、分类及涉及的信号通路等。结果表明,接种高毒力菌株后诱导924个家蚕基因发生差异表达(FDR≤0.001,log2Ratio≥1),包括252个上调基因和672个下调基因;KEGG分析表明,557个差异表达基因被富集到31个功能通路。低毒力菌株侵染家蚕后诱导2697个基因显著差异表达(FDR≤0.001,log2Ratio≥1),包括778个上调基因和1919个下调基因;KEGG分析表明,1545个差异表达基因被富集到48个功能通路。分析发现,差异表达基因编码蛋白包括RNA聚合酶、丝氨酸蛋白酶、丝氨酸蛋白酶抑制剂以及ECM受体作用蛋白免疫相关蛋白等。另外,膜结合碱性磷酸酶样蛋白、E4酯酶、肽聚糖识别蛋白、黑芥子酶等的编码基因在球孢白僵菌侵染过程中也高表达,推测这些基因可能参与家蚕应对球孢白僵菌侵染的免疫反应。研究结果为进一步研究家蚕和其他昆虫相关免疫基因在抵抗病原物侵染中的功能奠定了基础。

Beauveria bassiana strain,which has high or low virulence against Bombyx mori,was used to infect Bombyx mori,and immune response genes of Bombyx mori against infection of B.bassiana were analyzed.New generation Illumina high-throughput sequencing technology was used to sequence the transcriptome of silkworm samples inoculated with B.bassiana with high or low virulence,and the samples without inoculation.Consequently,differentially expressed genes(DEGs)were screened out,and their functions,classification and signaling pathways were analyzed by bioinformatics.The results showed that 924 genes were differentially expressed(FDR≤0.001,log2 Ratio≥1)in silkworm after inoculation with B.bassiana with high virulence,including 252 up-regulated genes and 672 down-regulated genes.KEGG analysis showed that 557 DEGs were enriched to 31 functional approaches.Comparatively,2697 genes were significantly differentially expressed(FDR≤0.001,log2 Ratio≥1)after inoculation with B.bassiana with low virulence,including 778 up-regulated genes and 1919 down-regulated genes.KEGG analysis showed that 1545 DEGs were enriched to 48 functional approaches.It was found that DEG-encoded proteins included RNA polymerase,serine proteases,serine protease inhibitors and immune-related proteins of ECM receptor-acting proteins.Besides,genes of membrane-bound alkaline phosphatase-like,E4 esterase,peptidog-lycan recognition protein,and myrosinase were also highly expressed during the infection of B.bassiana,and it is speculated that these genes may be involved in the immune response of silkworm to B.bassiana infection.The results lay the foundation for further study on the function of immune response genes in silkworm and insects against pathogen infection.