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

A growing body of evidence points to the paternal environment pre-fertilisation having an important influence on offspring phenotype, mediated via noncoding RNA (e.g. microRNA) transmitted in spermatozoa. Here we investigated whether the zebrafish was subject to heritable influences of paternal stress by exposing males to stressors before mating and assessing the behavioural and endocrine responses of their offspring. We found that after males are exposed to stress, their larval offspring show weakened responses to stressors. We subsequently applied small RNA sequencing to ascertain whether stress affected patterns of small RNA abundance in paternal sperm, which may in turn have influenced offspring development.