All a mother's fault? Transmission of stereotypy in striped mice Rhabdomys

Environmentally induced stereotypy is the most common abnormal behaviour in captive animals. However, not all animals housed in identically impoverished environments develop stereotypy, possibly because of differences in genetic predisposition. To investigate the transmission of stereotypy in striped mice, Rhabdomys, we established four breeding treatments (non-stereotypic parents; stereotypic mother and non-stereotypic father; non-stereotypic mother and stereotypic father; stereotypic parents), and recorded offspring stereotypy prevalence. The prevalence of stereotypy was five times greater in the offspring of stereotypic than those of non-stereotypic females, regardless of whether the sire was stereotypic, and three times greater in offspring sired by stereotypic males paired with non-stereotypic females than in offspring from non-stereotypic parents. Our data show that stereotypy has a strong genetic component. However, the greater maternal than paternal contribution to stereotypy prevalence in offspring indicates that genetics alone cannot explain the observed transmission pattern. As previous work has excluded social influences on the development of stereotypy, we suggest that maternally mediated prenatal factors (e.g. gestational stress) might also predispose the stereotypic phenotype in striped mice.