An insulin-like peptide regulates egg maturation and metabolism in the mosquito Aedes aegypti
An insulin-like peptide regulates egg maturation and metabolism in the mosquito Aedes aegypti
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DOI：
10.1073/pnas.0800478105
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发表时间：
2008-04-15
影响因子：
11.1
通讯作者：
Strand, Michael R.
中科院分区：
文献类型：
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作者：
Brown, Mark R.;Clark, Kevin D.;Strand, Michael R.
脊椎动物血液的摄入对于卵成熟和雌蚊传播致病寄生虫至关重要。先前对黄热病蚊子埃及伊蚊的研究表明，吸血通过触发蚊子大脑中的内侧神经分泌细胞释放激素来刺激产卵。牛胰岛素刺激类似反应的能力进一步表明该触发物是内源性胰岛素样肽（ILP）。A. aegypti编码8个预测的ILP。在这里，我们报告说，合成ILP3剂量依赖性地刺激卵母细胞的卵黄吸收和蜕皮激素的卵巢生产在较低的浓度比牛胰岛素。ILP3还通过增加碳水化合物和脂质储存而表现出代谢活性。使用卵巢膜的结合研究表明，ILP3的IC50值为5.9 nM，牛胰岛素的竞争性较差。放射自显影和免疫印迹研究表明，ILP3结合蚊子胰岛素受体（MIR），而功能丧失实验表明，ILP3的活性需要MIR的表达。总的来说，我们的研究结果确定ILP3是A.埃及人。
Ingestion of vertebrate blood is essential for egg maturation and transmission of disease-causing parasites by female mosquitoes. Prior studies with the yellow fever mosquito, Aedes aegypti, indicated blood feeding stimulates egg production by triggering the release of hormones from medial neurosecretory cells in the mosquito brain. The ability of bovine insulin to stimulate a similar response further suggested this trigger is an endogenous insulin-like peptide (ILP). A. aegypti encodes eight predicted ILPs. Here, we report that synthetic ILP3 dose-dependently stimulated yolk uptake by oocytes and ecdysteroid production by the ovaries at lower concentrations than bovine insulin. ILP3 also exhibited metabolic activity by elevating carbohydrate and lipid storage. Binding studies using ovary membranes indicated that ILP3 had an IC50 value of 5.9 nM that was poorly competed by bovine insulin. Autoradiography and immunoblotting studies suggested that ILP3 binds the mosquito insulin receptor (MIR), whereas loss-of-function experiments showed that ILP3 activity requires MIR expression. Overall, our results identify ILP3 as a critical regulator of egg production by A. aegypti.