The ridgetail white prawn Exopalaemon carinicauda has the potential to be used as a model organism in crustacean research because it has a transparent body, available draft genome, and short life cycle. However, their ovarian development pattern remains unclear under laboratory culture conditions. This study investigated the changes of ovarian external feature, ovarian histology, gonadosomatic index (GSI), and hepatosomatic index (HSI), as well as the expression and localization of vitellogenin in the ovary and the hepatopancreas during the first ovarian development cycle of E. carinicauda under laboratory-reared condition. The results demonstrated that (1) the first ovarian development cycle of E. carinicauda could be divided into 5 different stages in which the ovary changes its color from white to yellow during the vitellogenesis process in parallel with increasing GSI. (2) After pubertal molt, most females reached ovarian stage II while the females reached stage V after premating molt. (3) During the ovarian development, GSI increased smoothly and HSI relatively stable during the period of stages I to IV, while GSI increased but HSI decreased significantly from stages IV to V. (4) In situ hybridization (ISH) revealed that EcVg was slightly expressed in the oocyte cytoplasm of previtellogenic oocytes. The positive signal was mainly detected in hepatopancreatic fibrillar cells, and a strong signal was found in the hepatopancreas at stage IV. Moreover, the expression level of EcVg-mRNA in the hepatopancreas is stage-specific, and the hepatopancreas contributes majority of vitellin precursor protein to support the ovarian development of E. carinicauda.

中文翻译：

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脊尾白虾（Exopalaemon carinicauda）的卵巢发育模式和卵黄生成

脊尾白虾 Exopalaemon carinicauda 有可能被用作甲壳类研究的模式生物，因为它具有透明的身体、可用的基因组草图和较短的生命周期。然而，在实验室培养条件下，它们的卵巢发育模式仍不清楚。本研究探讨了大肠杆菌在第一个卵巢发育周期中卵巢外部特征、卵巢组织学、性腺体指数（GSI）和肝体指数（HSI）的变化，以及卵黄蛋白原在卵巢和肝胰腺中的表达和定位。在实验室饲养条件下的carinicauda。结果表明：（1）E的第一个卵巢发育周期。carinicauda 可以分为 5 个不同的阶段，其中在卵黄生成过程中，随着 GSI 的增加，卵巢的颜色从白色变为黄色。(2) 青春期蜕皮后，大部分雌性达到卵巢II期，而雌性在交配前蜕皮后达到V期。(3)在卵巢发育过程中，I-IV期GSI升高平稳，HSI相对稳定，而IV-V期GSI升高但HSI显着降低。(4)原位杂交(ISH)显示EcVg在卵黄前卵母细胞的卵母细胞质中轻微表达。阳性信号主要在肝胰腺原纤维细胞中检测到，IV期肝胰腺中检测到强信号。此外，肝胰腺中 EcVg-mRNA 的表达水平具有阶段特异性，