Meeting Abstract
Energy intake, storage, and expenditure can be programmed by the energetic status of the mother. Maternal programming is often studied in the context of human obesity, but may play a role in adaptive traits – especially plastic traits which may influence survival. Pregnant Syrian hamsters fail to increase food intake and lose ~40% of body lipid stores, so offspring may be highly susceptible to programming from the maternal environment. We hypothesized that variation in adult ingestive behaviors – intake and hoarding – may be due to programming effects that are not controlled for. To test the effects of maternal energy availability on offspring traits, pregnant hamsters were either fed ad libitum throughout gestation or limited to 90% of pre-pregnant daily intake for the final 2/3 of gestation. Postpartum maternal care and litter size can affect pup growth and development, so we attempted to control litter size and cross-fostered all pups to get 4 treatment groups. Based on the literature, we expected lowered birth weight, catch-up growth, and altered adult behaviors in restricted groups. Pilot studies showed significantly lowered birth weight; this effect was not replicated. Pups from restricted dams fostered to control dams exhibited catch-up growth and substantial sex differences in food hoarding as adults. The underlying neuroendocrine correlates of this effect will be discussed. We show that subtle differences in a pregnant mother’s energy expenditure during food acquisition can have long term effects on offspring ingestive behaviors. Programming effects may lead to inter-individual differences in adult responses to energetic challenge in laboratory and wild populations.
