Transcriptional regulation of the mosquito vitellogenin gene via a blood meal-triggered cascade
Transcriptional regulation of the mosquito vitellogenin gene via a blood meal-triggered cascade
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DOI：
10.1016/s0378-1119(01)00602-3
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发表时间：
2001-08-22
期刊：
影响因子：
3.5
通讯作者：
Raikhel, AS
中科院分区：
文献类型：
--
作者：
Kokoza, VA;Martin, D;Raikhel, AS
在自体蚊子中，编码卵黄蛋白前体(YPP)的基因的激活需要血餐。卵黄蛋白原(Vg)是YPP的主要基因，在血餐激活后转录水平很高。它只在女性脂肪体中表达，这是产生蚊子血淋巴和免疫蛋白的组织。本文对埃及伊蚊VG基因的上游区域进行了分析，以确定其独特表达模式的调控元件。为了实现这一目标，我们使用转基因果蝇和伊蚊以及DNA结合试验对该基因进行了分析。这些分析揭示了VG基因2.1kb上游部分的三个调控区。包含ECR/USP、GATA、C/EBP和HNF3/FKH结合位点的近端区域是正确的组织和阶段特异性低水平表达所必需的。早期蜕皮激素反应因子E74和E75的中间区域携带部位是荷尔蒙促进VG表达的原因。最后，远端的GATA富集区是VG基因极高表达水平所必需的。本工作阐明了该基因血粉依赖表达的分子基础，为构建具有可预测阶段和组织特异性的蚊虫特异表达盒奠定了基础。(C)2001 Elsevier Science B.V.保留所有权利。
In anautogenous mosquitoes, a blood meal is required for activation of genes encoding yolk protein precursors (YPP). Vitellogenin (Vg), the major YPP gene, is transcribed at a very high level following blood meal activation. It is expressed exclusively in the female fat body, the tissue producing most of mosquito hemolymph and immune proteins. In this paper, we analyzed the upstream region of the Aedes aegypti Vg gene in order to identify regulatory elements responsible for its unique expression pattern. To achieve this goal, we analyzed the gene using transgenic Drosophila and Aedes as well as DNA-binding assays. These analyses revealed three regulatory regions in the 2.1 kb upstream portion of the Vg gene. The proximal region containing binding sites to EcR/USP, GATA, C/EBP and HNF3/fkh is required for the correct tissue- and stage-specific expression at a low level. The median region carrying sites for early ecdysone response factors E74 and E75 is responsible for hormonal enhancement of Vg expression. Finally, the distal GATA-rich region is necessary for extremely high expression levels characteristic of the Vg gene. The present work elucidates the molecular basis of blood meal-dependent expression of this mosquito gene, laying the foundation for mosquito-specific expression cassettes with predictable stage and tissue specificity. (C) 2001 Elsevier Science B.V. All rights reserved.