PDF(Pubmed)
Abstract：
The estrogen receptor signaling pathway plays an important role in vertebrate embryonic development and sexual differentiation. There are four major estrogen receptors in zebrafish: esr1, esr2a, esr2b and gper. However, the specific role of different estrogen receptors in zebrafish is not clear. To investigate the role of esr2b in zebrafish development and reproduction, this study utilized TALENs technology to generate an esr2b knockout homozygous zebrafish line. The number of eggs laid by esr2b knockout female zebrafish did not differ significantly from that of wild zebrafish. The embryonic development process of wild-type and esr2b knockout zebrafish was observed, revealing a significant developmental delay in the esr2b knockout zebrafish. Additionally, mortality rates were significantly higher in esr2b knockout zebrafish than in their wild-type counterparts at 24 hpf. The reciprocal cross experiment between esr2b knockout zebrafish and wild-type zebrafish revealed that the absence of esr2b resulted in a decline in the quality of zebrafish oocytes, while having no impact on sperm cells. The knockout of esr2b also led to an abnormal sex ratio in the adult zebrafish population, with a female-to-male ratio of approximately 1:7. The quantitative PCR (qPCR) and in situ hybridization results demonstrated a significant downregulation of cyp19ab1b expression in esr2b knockout embryos compared to wild-type embryos throughout development (at 2 dpf, 3 dpf and 4 dpf). Additionally, the estrogen-mediated induction expression of cyp19ab1b was attenuated, while the estradiol-induced upregulated expression of vtg1 was disrupted. These results suggest that esr2b is involved in regulating zebrafish oocyte development and sex differentiation.
摘要：
雌激素受体信号通路在脊椎动物胚胎发育和性分化中起重要作用。斑马鱼中有四种主要的雌激素受体：esr1，esr2a，esr2b和gper.然而,不同雌激素受体在斑马鱼中的具体作用尚不清楚。探讨esr2b在斑马鱼发育繁殖中的作用,本研究利用TALENs技术产生esr2b敲除纯合斑马鱼系。esr2b敲除雌性斑马鱼产卵的数量与野生斑马鱼没有显着差异。观察野生型和esr2b基因敲除斑马鱼的胚胎发育过程,揭示了esr2b敲除斑马鱼的显着发育延迟。此外,在24hpf时，esr2b基因敲除斑马鱼的死亡率明显高于野生型斑马鱼。esr2b基因敲除斑马鱼和野生型斑马鱼的相互交叉实验表明，缺乏esr2b会导致斑马鱼卵母细胞质量下降，同时对精子细胞没有影响。esr2b的敲除还导致成年斑马鱼种群的性别比异常，男女比例约为1:7。定量PCR（qPCR）和原位杂交结果表明，在整个发育过程中，与野生型胚胎相比，esr2b敲除胚胎中的cyp19ab1b表达显着下调（在2dpf，3dpf和4dpf)。此外,雌激素介导的cyp19ab1b诱导表达减弱，而雌二醇诱导的vtg1上调表达被破坏。这些结果表明esr2b参与调节斑马鱼卵母细胞发育和性别分化。
