Ruan Yao, Wong Nai-Kei, Zhang Xin, Zhu Chunhua, Wu Xiaofen, Ren Chunhua, Luo Peng, Jiang Xiao, Ji Jiatai, Wu Xugan, Hu Chaoqun, Chen Ting
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
University of Chinese Academy of Sciences, Beijing, China.
Front Physiol. 2020 May 15;11:485. doi: 10.3389/fphys.2020.00485. eCollection 2020.
Oocyte maturation and ovarian development are sequentially coordinated events critical to reproduction. In the ovaries of adult oviparous animals such as birds, bony fish, insects, and crustaceans, vitellogenin receptor (VgR) is a plasma membrane receptor that specifically mediates vitellogenin (Vg) transport into oocytes. Accumulation of Vg drives sexual maturation of the female crustaceans by acting as a pivotal regulator of nutritional accumulation within oocytes, a process known as vitellogenesis. However, the mechanisms by which VgR mediates vitellogenesis are still not fully understood. In this study, we first identified a unique () and characterized its genomic organization and protein structural domains in , a predominant cultured shrimp species worldwide. This newly identified phylogenetically forms a group with VgRs from other crustacean species within the arthropod cluster. Duplicated LBD/EGFD regions are found exclusively among arthropod VgRs but not in paralogs from vertebrates and nematodes. In terms of expression patterns, transcripts are specifically expressed in ovaries of female shrimps, which increases progressively during ovarian development, and rapidly declines toward embryonic development. The cellular and subcellular locations were For analyzed by hybridization and immunofluorescence, respectively. The mRNA was found to be expressed in the oocytes of ovaries, and Lv-VgR protein was found to localize in the cell membrane of maturing oocytes while accumulation of the ligand Vg protein assumed an even cytoplasmic distribution. Silencing of transcript expression by RNAi was effective for stunting ovarian development. This present study has thus provided new insights into the regulatory roles of in crustacean ovarian development.
卵母细胞成熟和卵巢发育是对生殖至关重要的一系列有序协调的事件。在成年卵生动物如鸟类、硬骨鱼、昆虫和甲壳类动物的卵巢中，卵黄蛋白原受体（VgR）是一种质膜受体，它特异性地介导卵黄蛋白原（Vg）转运到卵母细胞中。Vg的积累通过作为卵母细胞内营养积累的关键调节因子来驱动雌性甲壳类动物的性成熟，这一过程称为卵黄发生。然而，VgR介导卵黄发生的机制仍未完全了解。在本研究中，我们首先在全球主要养殖虾种凡纳滨对虾中鉴定出一种独特的（），并对其基因组组织和蛋白质结构域进行了表征。这种新鉴定的（）在系统发育上与节肢动物群中其他甲壳类物种的VgR形成一个组。重复的LBD/EGFD区域仅在节肢动物VgR中发现，而在脊椎动物和线虫的旁系同源物中未发现。就表达模式而言，（）转录本在雌性凡纳滨对虾的卵巢中特异性表达，在卵巢发育过程中逐渐增加，并在胚胎发育时迅速下降。分别通过（）杂交和免疫荧光分析了细胞和亚细胞定位。发现（）mRNA在卵巢的卵母细胞中表达，并且发现凡纳滨对虾VgR蛋白定位于成熟卵母细胞的细胞膜，而配体Vg蛋白的积累呈现均匀的细胞质分布。通过RNAi沉默（）转录本表达对阻碍卵巢发育有效。因此，本研究为（）在甲壳类动物卵巢发育中的调节作用提供了新的见解。
