RNA interference-mediated knockdown of a GATA factor reveals a link to anautogeny in the mosquito Aedes aegypti
RNA interference-mediated knockdown of a GATA factor reveals a link to anautogeny in the mosquito Aedes aegypti
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DOI：
10.1073/pnas.2235649100
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发表时间：
2003-11-11
影响因子：
11.1
通讯作者：
Raikhel, AS
中科院分区：
文献类型：
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作者：
Attardo, GM;Higgs, S;Raikhel, AS
吸血严格调节自体蚊子的繁殖周期。卵黄发生（卵黄蛋白前体的合成）是蚊子繁殖周期中的一个关键事件，并在吸血后被激活。在吸血之前，埃及伊蚊处于繁殖停滞状态，在此期间卵黄蛋白前体基因（YPP）受到抑制。主要 YPP 基因卵黄原蛋白 (Vg) 的调控区具有该基因高表达水平所需的多个 GATA 结合位点。然而，GATA 因子 (AaGATAr) 可能充当阻遏物，阻止该基因在吸血前激活。在这里，我们报告了体内数据，证实了 AaGATAr 在卵黄发生前停滞状态下作为 Vg 基因阻遏物的作用。使用RNA干扰（RNAi）介导的技术与Sindbis病毒表达系统相结合，我们发现AaGATAr基因的敲低会导致Vg基因的基础表达水平增加，并提高处于逮捕状态的蚊子对类固醇激素20-羟基蜕皮激素的反应。这些实验揭示了埃及伊蚊维持自体发育的分子机制中的一个组成部分。
Blood feeding tightly regulates the reproductive cycle in anautogenous mosquitoes. Vitellogenesis (the synthesis of yolk protein precursors) is a key event in the mosquito reproductive cycle and is activated in response to a blood meal. Before blood feeding, Aedes aegypti is in a state of reproductive arrest during which the yolk protein precursor genes (YPPs) are repressed. The regulatory region of the major YPP gene vitellogenin (Vg) has multiple GATA-binding sites required for the high expression level of this gene. However, a GATA factor (AaGATAr) likely acts as a repressor, preventing activation of this gene before a blood meal. Here we report in vivo data confirming the role of AaGATAr as a repressor of the Vg gene at the state of previtellogenic arrest. Using an RNA interference (RNAi)-mediated technique in conjunction with the Sindbis viral expression system, we show that knockdown of the AaGATAr gene results in an increased basal level of expression of the Vg gene and an elevated response to the steroid hormone 20-hydroxyecdysone in mosquitoes in a state of arrest. These experiments have revealed a component in the molecular mechanism by which anautogeny is maintained in A. aegypti.