UC Davis

The effects of early stress may not be limited to the exposed generation, but are sometimes passed on to subsequent generations. Such non-genetic transgenerational inheritance is a potentially important developmental and evolutionary force. We compared the transgenerational effects of maternal and paternal line early stress on anxiety- and health-related traits in three non-exposed generations (F1, F2 and F3) of semi-naturalistically raised rhesus macaques. As infants, F0 macaques were exposed to nursery rearing (NR) or semi-naturalistic social conditions (CONTROL). Three hundred forty non-exposed F1-F3 descendants were CONTROL reared and physiological and behavioral measures were collected during standardized assessment at 3-4 months of age. Paternal line NR was significantly associated with greater nervousness in F1-F3 and lower immune cell counts in F1-F2. Maternal-line NR effects were not observed. This study suggests that acquired stress-related traits may be "inherited" across generations in primates, through complex social or germ-line mechanisms.