Antifungal innate immunity is an important defence used by insects against entomogenous fungi. However, the downstream target antifungal peptides of different immune signalling pathways are unknown. We found that the Toll, Janus kinase/signal transducer and activator of transcription (Jak/STAT) and Immunodeficiency (IMD) signalling pathways in the silkworm, Bombyx mori, can be activated by Beauveria bassiana. Inhibition of the Toll, IMD and Jak/STAT signalling pathways reduced the antifungal activities of silkworm haemolymph. We verified the target antifungal peptides of different immune signalling pathways. The expression patterns of five anti‐fungal peptide genes in silkworm larvae and BmN cells were detected after blocking or over‐expressing the immune signalling pathways. The Toll signalling pathways mediated the expression of Bmcecropin A, Bmattacin 1 and Bmgloverin 2; IMD signalling pathways mediated Bmenbocin 1, Bmgloverin 2 and Bmattacin 1; Jak/STAT signalling pathways mediated Bmstorage protein 30K‐19G1 (Bmsp 1), Bmattacin 1 and Bmcecropin A. These data indicated that anti‐microbial peptide genes in B. mori evolved through expansion and selection of existing genes to adapt to the challenge of invasive microorganisms such as fungi. This information provides insight into the antifungal immune responses in B. mori and aids understanding of insect immune regulation mechanisms.

中文翻译：

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以家蚕 Bombyx mori 免疫信号通路的抗真菌肽为靶点，对抗白僵菌

抗真菌先天免疫是昆虫对抗虫源真菌的重要防御手段。然而，不同免疫信号通路的下游靶标抗真菌肽尚不清楚。我们发现家蚕 Bombyx mori中的 Toll、Janus 激酶/信号转导和转录激活剂 (Jak/STAT) 和免疫缺陷 (IMD) 信号通路可以被白僵菌激活. Toll、IMD 和 Jak/STAT 信号通路的抑制降低了家蚕血淋巴的抗真菌活性。我们验证了不同免疫信号通路的目标抗真菌肽。在阻断或过表达免疫信号通路后，检测家蚕幼虫和 BmN 细胞中 5 种抗真菌肽基因的表达模式。Toll信号通​​路介导了Bmcecropin A、Bmattacin 1和Bmgloverin 2的表达；IMD 信号通路介导Bmenbocin 1、Bmgloverin 2和Bmattacin 1；Jak/STAT 信号通路介导的Bmstorage 蛋白 30K-19G1 ( Bmsp 1 )，Bmattacin 1和Bmcecropin甲。这些数据表明，家蚕中的抗菌肽基因是通过扩展和选择现有基因来适应真菌等入侵微生物的挑战而进化的。该信息提供了对家蚕抗真菌免疫反应的深入了解，并有助于了解昆虫免疫调节机制。