CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Sci China Life Sci. 2017 Aug;60(8):839-851. doi: 10.1007/s11427-017-9101-3. Epub 2017 Jul 27.
The use of entomopathogenic fungi to control mosquitoes is a promising tool for reducing vector-borne disease transmission. To better understand infection stratagems of insect pathogenic fungi, we analyzed the global gene expression profiling of Beauveria bassiana at 36, 60, 84 and 108 h after topical infection of Anopheles stephensi adult mosquitoes using RNA sequencing (RNA-Seq). A total of 5,354 differentially expressed genes (DEGs) are identified over the course of fungal infection. When the fungus grows on the mosquito cuticle, up-regulated DEGs include adhesion-related genes involved in cuticle attachment, Pth11-like GPCRs hypothesized to be involved in host recognition, and extracellular enzymes involved in the degradation and penetration of the mosquito cuticle. Once in the mosquito hemocoel, the fungus evades mosquito immune system probably through up-regulating expression of β-1,3-glucan degrading enzymes and chitin synthesis enzymes for remodeling of cell walls. Moreover, six previous unknown SSCP (small secreted cysteine-rich proteins) are significantly up-regulated, which may serve as "effectors" to suppress host defense responses. B. bassiana also induces large amounts of antioxidant genes to mitigate host-generated exogenous oxidative stress. At late stage of infection, B. bassiana activates a broad spectrum of genes including nutrient degrading enzymes, some transporters and metabolism pathway components, to exploit mosquito tissues and hemolymph as a nutrient source for hyphal growth. These findings establish an important framework of knowledge for further comprehensive elucidation of fungal pathogenesis and molecular mechanism of Beauveria-mosquito interactions.
利用昆虫病原真菌来控制蚊子是减少媒介传播疾病的一种很有前景的工具。为了更好地了解昆虫病原真菌的感染策略，我们使用 RNA 测序（RNA-Seq）分析了在感染白纹伊蚊成蚊后 36、60、84 和 108 小时时球孢白僵菌的全球基因表达谱。在真菌感染过程中，共鉴定出 5354 个差异表达基因（DEGs）。当真菌在蚊子的外骨骼上生长时，上调的 DEGs 包括参与外骨骼附着的粘附相关基因、假设参与宿主识别的 Pth11 样 GPCR 以及参与蚊子外骨骼降解和穿透的细胞外酶。一旦进入蚊子血腔，真菌可能通过上调β-1,3-葡聚糖降解酶和几丁质合成酶的表达来逃避蚊子的免疫系统，以重塑细胞壁。此外，六个以前未知的 SSCP（小分泌半胱氨酸丰富蛋白）被显著上调，它们可能作为“效应子”来抑制宿主的防御反应。白僵菌还诱导大量的抗氧化基因来减轻宿主产生的外源性氧化应激。在感染后期，白僵菌激活了广泛的基因，包括营养降解酶、一些转运蛋白和代谢途径成分，以利用蚊子组织和血液作为菌丝生长的营养来源。这些发现为进一步全面阐明真菌发病机制和白僵菌-蚊子相互作用的分子机制奠定了重要的知识框架。
