A mosaic analysis in Drosophila fat body cells of the control of antimicrobial peptide genes by the Rel proteins Dorsal and DIF
A mosaic analysis in Drosophila fat body cells of the control of antimicrobial peptide genes by the Rel proteins Dorsal and DIF
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DOI：
10.1093/emboj/18.12.3380
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发表时间：
1999-06-15
期刊：
影响因子：
11.4
通讯作者：
Lemaitre, B
中科院分区：
文献类型：
--
作者：
Manfruelli, P;Reichhart, JM;Lemaitre, B
编码抗真菌肽 Drosomycin 的基因在果蝇成虫中的表达受 Toll 信号通路控制，Rel 蛋白 Dorsal 和 DIF（Dorsal 相关免疫因子）可能是 Toll 通路中直接调节 Drosomycin 基因的反式激活蛋白的候选者。我们研究了幼虫脂肪体细胞（主要的免疫反应组织）中Dorsal和DIF对drosomycin表达的需求，使用酵母位点特异性flp/FRT重组系统生成纯合的细胞克隆，以发现dorsal和dif基因的缺陷。在这里，我们表明，在缺乏这两种基因的情况下，卓霉素的免疫诱导能力会丧失，但可以通过在热激启动子的控制下过度表达dorsal或dif来挽救。这一结果表明，两种Rel蛋白在控制果蝇幼虫中果霉素基因表达方面存在功能冗余，有趣的是，编码抗菌肽双翅目的基因在缺乏dorsal和dif基因的情况下仍然是完全可诱导的。最后，我们使用了各种突变纯合的脂肪体细胞克隆来表明线性激活级联Spaetzle-->Toll-->Cactus-->Dorsal/DIF导致在幼虫脂肪体细胞中诱导卓霉素基因。
Expression of the gene encoding the antifungal peptide Drosomycin in Drosophila adults is controlled by the Toll signaling pathway, The Rel proteins Dorsal and DIF (Dorsal-related immunity factor) are possible candidates for the transactivating protein in the Toll pathway that directly regulates the drosomycin gene. We have examined the requirement of Dorsal and DIF for drosomycin expression in larval fat body cells, the predominant immune-responsive tissue, using the yeast site-specific flp/FRT recombination system to generate cell clones homozygous for a deficiency uncovering both the dorsal and the dif genes. Here we show that in the absence of both genes, the immune-inducibility of drosomycin is lost but can be rescued by overexpression of either dorsal or dif under the control of a heat-shock promoter. This result suggests a functional redundancy between both Rel proteins in the control of drosomycin gene expression in the larvae of Drosophila, Interestingly, the gene encoding the antibacterial peptide Diptericin remains fully inducible in the absence of the dorsal and dif genes, Finally, we have used fat body cell clones homozygous for various mutations to show that a linear activation cascade Spaetzle-->Toll-->Cactus-->Dorsal/DIF leads to the induction of the drosomycin gene in larval fat body cells.