Neurokinin B (NKB) plays a pivotal role in the regulation of reproduction in vertebrates. However, whether this neuropeptide is dispensable for reproduction in teleosts remains unknown. In order to reveal its authentic functions in fish, in this study, two tachykinin 3 (tac3) genes encoding Nkbs were functional mutated in zebrafish using the Transcription Activator-like Effector Nucleases (TALEN) technology. We established tac3a^−/−, tac3b^−/− and tac3a^−/−;tac3b^−/− mutant lines, and investigated their reproductive performance and ontogeny. According to our study, spermatogenesis and folliculogenesis were not impaired in tac3a^−/−, tac3b^−/− and tac3a^−/−;tac3b^−/− mutant lines, but changes in the expression of genes related to reproductive axis were observed after loss of Tac3, suggesting that possible compensatory response was activated to maintained the reproductive function in zebrafish. In summary, our results indicate that mutation of tac3 genes do not disrupt the reproduction in zebrafish unlike in mammals, revealing the plasticity of reproductive neuroendocrine system in the brain of zebrafish.

神经激肽 B (NKB) 在脊椎动物的繁殖调节中起关键作用。然而，这种神经肽对于硬骨鱼的繁殖是否是可有可无的仍然未知。为了揭示其在鱼类中的真实功能，在本研究中，使用转录激活因子样效应核酸酶 (TALEN) 技术在斑马鱼中对编码 Nkbs 的两个速激肽 3 ( tac3 ) 基因进行了功能突变。我们建立了tac3a ^-/-、tac3b ^-/-和tac3a ^-/-；tac3b ^-/-突变系，并研究了它们的繁殖性能和个体发育。根据我们的研究，精子发生和卵泡发生在tac3a ^-/- , tac3b ^-/-和tac3a ^-/- ; tac3b ^-/-突变系，但在 Tac3 缺失后观察到与生殖轴相关的基因表达的变化，这表明可能的补偿反应被激活以维持斑马鱼的生殖功能。总之，我们的研究结果表明，与哺乳动物不同，tac3基因的突变不会破坏斑马鱼的繁殖，揭示了斑马鱼大脑中生殖神经内分泌系统的可塑性。