Maternal genetic and non-genetic effects on the development of exploration and anxiety-like behaviours in a native Australian rodent, the fawn-footed mosaic-tailed rat Melomys cervinipes

Abstract

Personality in non-human animals has been a popular area of research; however, it is still unknown how genetic and non-genetic factors influence the development of personality in many species. Therefore, we investigated how maternal genetic and non-genetic effects influenced adult offspring personality (exploration and anxiety) in the fawn-footed mosaic-tailed rat Melomys cervinipes. We first measured the amount of maternal care mothers provided to their offspring. Later, we assessed mothers and adult offspring over two testing sessions for exploratory behaviour using open field and novel object tests, and anxiety behaviour in a light/dark test. We calculated repeatability of behaviours and used parent–offspring regressions to assess heritability of behaviours. No measure of maternal care significantly influenced offspring personality. However, exploration of new spaces was constrained by maternal genetic effects. In contrast, anxiety and exploration of novel objects was more flexible, suggesting these behaviours may be more influenced by an individual’s experiences during development.