Meeting Abstract
The environment that an individual experiences early in life can have long-lasting impacts on its physiological phenotype. These adjustments are hypothesized to be adaptive. That is, if the developmental environment is predictive of later life conditions, the physiological changes associated with this adaptation are predicted to improve subsequent reproductive performance and survival for that individual. Thus, although there is an ontological program during the fetal and neonatal periods, there is also the capacity for the individual to adjust their phenotype in order to maximize future reproductive success. Small rodents, such as mice (Mus musculus), are particularly useful models for understanding how maternal investment shapes offspring because allocation to reproduction is high and likely pushes females to their physiological limits. Here, we used outbred laboratory mice to investigate the impact of maternal immune challenge with KLH (keyhole limpet hemocyanin, a non-replicating antigen) on physiological characteristics of offspring. Mothers were placed in three experimental groups based on their reproductive intensity and whether or not they received an immune challenge including 1) control and lactating (PBS+L), 2) immune-challenged and lactating (KLH+L) and 3) immune-challenged and concurrently gestating and lactating (KLH+PL). Body and organ masses of the pups were recorded, and gene expression for glucocorticoid and mineralocorticoid receptors, growth hormone and insulin-like growth factor 1 receptors, and pro-inflammatory cytokines were quantified. Our results support that maternal immune challenge and maternal reproductive intensity impact offspring physiology. Together, this study provides empirical evidence in mammals that is critical to furthering our understanding of factors that contribute to offspring life-history variation.
