Juvenile hormone mediates lipid storage in the oocytes of Dipetalogaster maxima.
Juvenile hormone mediates lipid storage in the oocytes of Dipetalogaster maxima.
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DOI：
10.1016/j.ibmb.2020.103499
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发表时间：
2020-11
影响因子：
3.8
通讯作者：
F. O. Ramos;J. Leyria;M. Nouzová;Leonardo L. Fruttero;F. G. Noriega;L. Canavoso
中科院分区：
文献类型：
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作者：
F. O. Ramos;J. Leyria;M. Nouzová;Leonardo L. Fruttero;F. G. Noriega;L. Canavoso
锥蝽是恰加斯病的媒介生物，也是昆虫生理学中重要的模式生物。“接吻虫”是必不可少的食血昆虫。卵发生过程主要由幼崽激素（JH）控制。为了进一步了解JH在卵黄发生和卵子发生中的调控作用，我们以双瓣胃为实验模型。特别关注的是JH控制卵母细胞的脂质和蛋白质募集的作用。血餐后jhiii跳过双环氧化物的血淋巴滴度升高。在血餐之后，脂肪体中蛋黄蛋白前体、卵黄原蛋白（Vg）和脂蛋白（Lp）的mrna水平以及它们在血淋巴中的蛋白质产物水平都有所增加；卵巢中Vg和Lp受体mrna （VgR和LpR）同时上调。局部给药JH可诱导卵黄前期雌鼠Lp/LpR和Vg/VgR基因的表达，促进Lp和Vg的摄取。通过RNA干扰敲低喂食雌性的LpR表达并没有损害Lp介导的脂质向卵母细胞的转移，这表明卵母细胞的大部分脂质获取是通过其他途径发生的，而不是通过内吞Lp/LpR途径。总之，我们的研究结果强烈表明，JH信号通过调节脂肪体中vgandlpgene的表达以及卵巢中flprandvgrgene的表达，对卵母细胞的脂质储存至关重要。
Triatomines are vectors of Chagas disease and important model organisms in insect physiology. “Kissing bugs” are obligatory hematophagous insects. A blood meal is required to successfully complete oogenesis, a process primarily controlled by juvenile hormone (JH). We usedDipetalogaster maximaas an experimental model to further understand the roles of JH in the regulation of vitellogenesis and oogenesis. A particular focus was set on the role of JH controlling lipid and protein recruitment by the oocytes. The hemolymph titer of JH III skipped bisepoxide increased after a blood meal. Following a blood meal there were increased levels of mRNAs in the fat body for the yolk protein precursors, vitellogenin (Vg) and lipophorin (Lp), as well as of their protein products in the hemolymph; mRNAs of the Vg and Lp receptors (VgR and LpR) were concomitantly up-regulated in the ovaries. Topical administration of JH induced the expression of Lp/LpR and Vg/VgR genes, and prompted the uptake of Lp and Vg in pre-vitellogenic females. Knockdown of the expression of LpR by RNA interference in fed females did not impair the Lp-mediated lipid transfer to oocytes, suggesting that the bulk of lipid acquisition by oocytes occurred by other pathways rather than by the endocytic Lp/LpR pathway. In conclusion, our results strongly suggest that JH signaling is critical for lipid storage in oocytes, by regulatingVgandLpgene expression in the fat body as well as by modulating the expression ofLpRandVgRgenes in ovaries.