Chai Wenmin, Mao Xianbing, Li Chunfeng, Zhu Liancai, He Zongyi, Wang Bochu
Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China.
Chongqing Xinstant Biotechnology Co., Ltd., Chongqing, China.
Front Microbiol. 2024 Aug 19;15:1411645. doi: 10.3389/fmicb.2024.1411645. eCollection 2024.
Parasites can facilitate their own spread and reproduction by manipulating insect hosts behavior, as seen in the interaction between and . Infection by leads to the mummification of larvae, but the underlying mechanisms remain mysterious.
The morphology of infected larvae and fungal growth were first observed. Subsequently, the metabolite changes in the larvae before and after infection with the fungus were analyzed by LC/MS and targeted metabolomics. The expression of mannitol-related genes was detected using RT-qPCR, and morphological changes in larvae were observed after injection of different concentrations of mannitol into the -infected larvae.
Significant changes were found in phenotype, fungal morphology in hemocoel, larval hardness, and mannitol metabolites in infected, mummified 0 h larvae and larvae 5 days after mummification behavior. Surprisingly, the occurrence of mummification behavior was accompanied by fungal dimorphism, as well as the absence of mannitol in both infected and non-infected larvae, until the initial accumulation of mannitol and the expression of mannitol-associated genes occurred at the time of mummification behavior. The presence of mannitol may promote fungal dimorphism to mediate changes in fungal toxicity or resistance, leading to the end of the fungus-insect coexistence period and the incidence of mummification behavior. Furthermore, mannitol injections increase the mummification rate of the infected larvae without significant difference from the normal mummification phenotype.
This finding suggests the importance of mannitol in the mummification of host larvae infected with .
寄生虫可通过操控昆虫宿主行为来促进自身传播和繁殖，就像[具体寄生虫]与[具体昆虫宿主]之间的相互作用那样。[具体寄生虫]感染会导致[具体昆虫宿主]幼虫木乃伊化，但其潜在机制仍不明晰。
首先观察[具体寄生虫]感染幼虫的形态及真菌生长情况。随后，通过液相色谱/质谱联用（LC/MS）和靶向代谢组学分析感染真菌前后幼虫的代谢物变化。利用逆转录定量聚合酶链反应（RT-qPCR）检测甘露醇相关基因的表达，并在向感染[具体寄生虫]的幼虫注射不同浓度甘露醇后观察幼虫的形态变化。
在感染并木乃伊化0小时的幼虫以及出现木乃伊化行为5天后的幼虫中，发现其表型、血腔中的真菌形态、幼虫硬度和甘露醇代谢物有显著变化。令人惊讶的是，木乃伊化行为的出现伴随着真菌的二态性，并且在感染和未感染的幼虫中均未检测到甘露醇，直到木乃伊化行为发生时才开始出现甘露醇的初始积累以及甘露醇相关基因的表达。甘露醇的存在可能促进真菌二态性，以介导真菌毒性或抗性的变化，从而导致真菌与昆虫共存期结束并引发木乃伊化行为。此外，注射甘露醇可提高感染幼虫的木乃伊化率，且与正常木乃伊化表型无显著差异。
这一发现表明甘露醇在感染[具体寄生虫]的宿主幼虫木乃伊化过程中具有重要作用。
