Non-genomic transmission of paternal behaviour between fathers and sons in the monogamous and biparental California mouse

Maternal behaviour has profound, long-lasting implications for the health andwell-being of developing offspring. In the monogamous California mouse(Peromyscus californicus), care by both parents is critical foroffspring survival. We tested the hypothesis that similar to maternal care inrodents, paternal huddling and grooming (HG) behaviour can be transmitted to futuregenerations via behavioural mechanisms. In California mice, testosterone maintainspaternal HG behaviour. In the present study, we randomly assigned a group of maleCalifornia mice to castration or sham-operated conditions and allowed them to raisetheir offspring normally. Adult sons of these males were paired with a female, andthey were observed interacting with their own offspring. We found that like theirfathers, the sons of castrated males huddled and groomed their young at lower levelsthan the sons of sham-operated fathers. The sons of castrates also retrieved pupsmore frequently. When both parents were present, the sons of castrates also showed atrend towards engaging in less exploratory behaviour. These data support thehypothesis that paternal behaviour, like maternal behaviour, can be transferred tofuture generations via epigenetic mechanisms and suggest that in a biparental speciesboth parents contribute to offspring behavioural development.