Ovary ecdysteroidogenic hormone activates egg maturation in the mosquito Georgecraigius atropalpus after adult eclosion or a blood meal
Ovary ecdysteroidogenic hormone activates egg maturation in the mosquito Georgecraigius atropalpus after adult eclosion or a blood meal
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DOI：
10.1242/jeb.074617
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发表时间：
2012-11-01
影响因子：
2.8
通讯作者：
Brown, Mark R.
中科院分区：
文献类型：
--
作者：
Gulia-Nuss, Monika;Eum, Jai-Hoon;Brown, Mark R.
岩池蚊（Georgecraigius atropalpus）是一种兼性自生蚊种，在羽化后不久产生第一个卵窝，而不需要血餐。在产下这一窝卵几天后，雌性必须吃一顿血粉来产下第二窝卵。在出现后不久将雌性斩首或吸血会阻止卵成熟。在这里，我们报告说，一个单一的注射剂量的神经肽卵巢蜕皮甾体激素（OEH）完全恢复卵子成熟的断头女性在这两种情况下。这种神经肽和两种胰岛素样肽（ILP）是相关的黄热病蚊子埃及伊蚊中的有效促性腺激素。ILP3在断头的G. atropalpus和ILP4没有影响。非吸血和吸血G的卵子成熟。atropalpus是依赖于酶促动员氨基酸从存储的蛋白质或血粉的卵黄蛋白（卵黄蛋白原，VG）的合成和卵母细胞的吸收。我们进一步表明，OEH刺激丝氨酸蛋白酶活性的脂肪体的新羽化的女性或在中肠的血液喂养的，和蜕皮激素的生产由卵巢的女性。相比之下，只有20-羟基蜕皮激素刺激VG合成的脂肪体的非和血液喂养的女性。使用RNA干扰敲低胰岛素受体的表达，我们发现OEH仍然完全恢复了自体卵的成熟。总之，我们的研究结果确定OEH作为一个主要的调节卵子成熟的自体和血液喂养的G。atropalpus女性和建议的转变，从血餐依赖的血餐独立的释放OEH是在这个物种的自生进化的一个关键因素。
The rockpool mosquito, Georgecraigius atropalpus, is a facultatively autogenous species that produces its first egg clutch without a blood meal shortly after emergence. Several days after depositing this clutch, females must take a blood meal to produce a second egg clutch. Decapitation of females shortly after emergence or blood ingestion prevents egg maturation. Here, we report that a single injected dose of the neuropeptide ovary ecdysteroidogenic hormone (OEH) fully restored egg maturation in decapitated females in both circumstances. This neuropeptide and two insulin- like peptides (ILPs) are potent gonadotropins in the related yellow fever mosquito, Aedes aegypti. ILP3 was marginally restorative in decapitated G. atropalpus, and ILP4 had no effect. Egg maturation in non- and blood-fed G. atropalpus was dependent on the enzymatic mobilization of amino acids from stored protein or the blood meal for yolk protein (vitellogenin, VG) synthesis and uptake by oocytes. We further show that OEH stimulates serine protease activity in the fat body of newly eclosed females or in the midgut of blood-fed ones, and ecdysteroid hormone production by the ovaries of both females. In contrast, only 20-hydroxyecdysone stimulated VG synthesis in the fat body of non- and blood-fed females. Using RNA interference to knock down expression of the insulin receptor, we found that OEH still fully restored autogenous egg maturation. In summary, our results identify OEH as a primary regulator of egg maturation in both autogenous and blood-fed G. atropalpus females and suggest the shift from blood meal-dependent to blood meal-independent release of OEH is a key factor in the evolution of autogeny in this species.