The common fruit fly Drosophila melanogaster is a powerful model for studying signaling pathway regulation. Conserved signaling pathways underlying physiological processes signify evolutionary relationship between organisms and the nature of the mechanisms they control. This study explores the cross-talk between the well-characterized nuclear factor kappa B (NF-κB) innate immune signaling pathways and transforming growth factor beta (TGF-β) signaling pathway in response to parasitic nematode infection in Drosophila. To understand the link between signaling pathways, we followed on our previous studies by performing a transcript-level analysis of different TGF-β signaling components following infection of immune-compromised Drosophila adult flies with the nematode parasites Heterorhabditis gerrardi and H. bacteriophora. Our findings demonstrate the requirement of NF-κB transcription factors for activation of TGF-β signaling pathway in Drosophila in the context of parasitic nematode infection. We observe significant decrease in transcript level of glass bottom boat (gbb) and screw (scw), components of the bone morphogenic protein (BMP) branch, as well as Activinβ (actβ) which is a component of the Activin branch of the TGF-β signaling pathway. These results are observed only in H. gerrardi nematode-infected flies compared to uninfected control. Also, this significant decrease in transcript level is found only for extracellular ligands. Future research examining the mechanisms regulating the interaction of these signaling pathways could provide further insight into Drosophila anti-nematode immune function against infection with potent parasitic nematodes.

中文翻译：

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转录本分析揭示了NF-κB转录因子参与线虫感染的果蝇中TGF-β信号的激活。

常见的果蝇果蝇是研究信号通路调控的强大模型。生理过程中保守的信号通路表明生物之间的进化关系及其控制机制的本质。这项研究探讨了果蝇中对寄生性线虫感染的应答，特征明确的核因子κB（NF-κB）先天性免疫信号通路与转化生长因子β（TGF-β）信号通路之间的相互影响。为了理解信号传导途径之间的联系，我们在进行先前的研究之后，通过对免疫功能低下的果蝇成年蝇感染了线虫寄生虫gerrardi和H.bacteriophora后，对不同的TGF-β信号传导成分进行了转录水平的分析。我们的发现表明，在寄生性线虫感染的情况下，果蝇中TGF-β信号通路的激活需要NF-κB转录因子。我们观察到玻璃底舟（gbb）和螺丝（scw），骨形态发生蛋白（BMP）分支以及Activinβ（actβ）的转录水平显着降低，而Activinβ（actβ）是TGF- β信号传导途径。与未感染的对照相比，这些结果仅在H. gerrardi线虫感染的果蝇中观察到。同样，仅在细胞外配体中发现转录水平的显着降低。今后研究调节这些信号传导途径相互作用的机制的研究可以为果蝇抗线虫的免疫功能提供进一步的见解，以抵抗强效寄生线虫的感染。