Niu Jingjing, Song Weihao, Li Rui, Yu Haiyang, Guan Jian, Qi Jie, He Yan
MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
BMC Ecol Evol. 2021 Mar 17;21(1):44. doi: 10.1186/s12862-021-01774-0.
Black rockfish (Sebastes schlegelii) is a viviparous teleost. We proposed that the rockfish ovarian wall had a similar function to the uterus of mammals previously. In the present study, the well-developed vascular system was observed in the ovarian wall and the exterior surface of the egg membrane. In gestation, adaptation of the ovary vasculature to the rising needs of the embryos occurs through both vasodilation and neovascularization. Bdkrb2, encoding a receptor for bradykinin, plays a critical role in the control of vasodilatation by regulating nitric oxide production.
Eight Bdkrb2 genes were identified in the black rockfish genome. These genes were located on chromosome 14, which are arranged in a tandem array, forming a gene cluster spanning 50 kb. Protein structure prediction, phylogenetic analysis, and transcriptome analysis showed that eight Bdkrb2 genes evolved two kinds of protein structure and three types of tissue expression pattern. Overexpression of two Bdkrb2 genes in zebrafish indicated a role of them in blood vessel formation or remodeling, which is an important procedure for the viviparous rockfish getting prepared for fertilization and embryos implantation.
Our study characterizes eight Bdrkb2 genes in the black rockfish, which may contribute to preparation for fertilization and embryo implantation. This research provides a novel view of viviparity adaptation and lays the groundwork for future research into vascular regulation of ovarian tissue in the breeding cycle in black rockfish.
黑鲪是一种卵胎生硬骨鱼。我们之前提出，鲪鱼的卵巢壁具有与哺乳动物子宫类似的功能。在本研究中，在卵巢壁和卵膜外表面观察到了发育良好的血管系统。在妊娠期，卵巢血管系统通过血管舒张和新生血管形成来适应胚胎不断增加的需求。Bdkrb2编码一种缓激肽受体，通过调节一氧化氮的产生在血管舒张控制中起关键作用。
在黑鲪基因组中鉴定出8个Bdkrb2基因。这些基因位于14号染色体上，呈串联排列，形成一个跨越50 kb的基因簇。蛋白质结构预测、系统发育分析和转录组分析表明，8个Bdkrb2基因进化出两种蛋白质结构和三种组织表达模式。在斑马鱼中过表达两个Bdkrb2基因表明它们在血管形成或重塑中发挥作用，这是卵胎生鲪鱼为受精和胚胎着床做准备的重要过程。
我们的研究对黑鲪中的8个Bdrkb2基因进行了表征，它们可能有助于受精和胚胎着床的准备。本研究为卵胎生适应性提供了新的视角，并为今后研究黑鲪繁殖周期中卵巢组织的血管调节奠定了基础。
