Paternal effects in a wild-type zebrafish implicate a role of sperm-derived small RNAs

While the importance of maternal effects has long been appreciated, a growing body of evidence now points to the paternal environment having an important influence on offspring phenotype. Indeed, research on rodent models suggests that paternal stress leaves an imprint on the behaviour and physiology of offspring via non-genetic information carried in the spermatozoa, however fish have been understudied with regard to these sperm-mediated effects. Here we investigated whether the zebrafish was subject to heritable influences of paternal stress by exposing males to stressors (conspecific-derived alarm cue, chasing, and bright light) before mating and assessing the behavioural and endocrine responses of their offspring, including their behavioural response to conspecific-derived alarm cue. We found that after males are exposed to stress, their larval offspring show weakened responses to stressors. Small RNA sequencing subsequently revealed that the levels of several small noncoding RNAs, ...尽管母体效应（maternal effects）的重要性早已得到学界认可，但越来越多的研究证据表明，父本环境对子代表型（offspring phenotype）具有关键调控作用。事实上，针对啮齿类动物模型（rodent models）的研究显示，父本应激可通过精子（spermatozoa）携带的非遗传信息，对子代的行为与生理特征留下印记；然而，目前针对鱼类的这类精子介导效应的相关研究仍较为匮乏。本研究以斑马鱼（zebrafish）为实验对象，探究其是否会受到父本应激的可遗传影响：具体方法为在交配前将雄性个体暴露于三类应激源（同种来源告警信息素、追逐刺激与强光），并评估其子代的行为与内分泌反应（endocrine responses），包括子代针对同种来源告警信息素的行为应答。研究结果显示，当雄性斑马鱼暴露于应激环境后，其子代幼鱼对应激源的应答反应显著减弱。后续的小RNA测序（small RNA sequencing）分析显示，多种小型非编码RNA（small noncoding RNAs）的表达水平发生了变化……