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Abstract：
NPC intracellular cholesterol transporter 1 (NPC1) plays an important role in sterol metabolism and transport processes and has been studied in many vertebrates and some insects, but rarely in crustaceans. In this study, we characterized NPC1 from Macrobrachium nipponense (Mn-NPC1) and evaluated its functions. Its total cDNA length was 4283 bp, encoding for 1344 amino acids. It contained three conserved domains typical of the NPC family (NPC1_N, SSD, and PTC). In contrast to its role in insects, Mn-NPC1 was mainly expressed in the adult female hepatopancreas, with moderate expression in the ovary and heart. No expression was found in the embryo (stages CS-ZS) and only weak expression in the larval stages from hatching to the post-larval stage (L1-PL15). Mn-NPC1 expression was positively correlated with ovarian maturation. In situ hybridization showed that it was mainly located in the cytoplasmic membrane and nucleus of oocytes. A 25-day RNA interference experiment was employed to illustrate the Mn-NPC1 function in ovary maturation. Experimental knockdown of Mn-NPC1 using dsRNA resulted in a marked reduction in the gonadosomatic index and ecdysone content of M. nipponense females. The experimental group showed a significant delay in ovarian maturation and a reduction in the frequency of molting. These results expand our understanding of NPC1 in crustaceans and of the regulatory mechanism of ovarian maturation in M. nipponense.
摘要：
NPC细胞内胆固醇转运体1(NPC1)在甾醇代谢和转运过程中发挥重要作用,已在许多脊椎动物和一些昆虫中被研究,但在甲壳类动物中很少见。在这项研究中,我们对日本沼虾（Mn-NPC1）的NPC1进行了表征，并评估了其功能。其cDNA总长度为4283bp,编码1344个氨基酸。它包含NPC家族典型的三个保守域(NPC1_N，SSD,和PTC）。与它在昆虫中的作用相反，Mn-NPC1主要在成年女性肝胰腺中表达,在卵巢和心脏中中等表达。在胚胎（CS-ZS阶段）中未发现表达，而在从孵化到幼虫后阶段的幼虫阶段（L1-PL15）仅弱表达。Mn-NPC1表达与卵巢成熟度呈正相关。原位杂交表明，它主要位于卵母细胞的细胞质膜和细胞核中。采用25天的RNA干扰实验来说明Mn-NPC1在卵巢成熟中的功能。使用dsRNA对Mn-NPC1进行实验性敲除导致日本M.nipponense雌性的性腺指数和蜕皮激素含量显着降低。实验组显示卵巢成熟明显延迟，蜕皮频率降低。这些结果扩大了我们对甲壳类动物NPC1和日本支原体卵巢成熟调节机制的理解。
