Meeting Abstract
Artificial selection has been used to increase the expression of desirable traits in the lab mouse. Associated with this procedure, hundreds of well-characterized phenotypic variants (strains) are now available for use in research. Although these strains are typically used in biomedical research models, we propose that data from lab mice can be used to identify pleiotropic traits that contribute to life-history variation. We used the publicly available Mouse Phenome Database by the Jackson Laboratory to investigate correlations among life-history traits and between life-history and physiological variables in adult female mice. We used fitness-related variables in a principal component analysis, which resulted in two principal components (breeding frequency and reproductive performance) that describe the variance in reproductive traits. Scores from this analysis were then regressed against life-history associated traits (body mass, body composition, lifespan, and allocation to self-maintenance) and physiological variables (metabolism, mean serum IGF-1) in non-reproductive adult females. Interestingly, we found that lifespan did not significantly correlate with individual fitness-related variables (total number of offspring, litter size, or litters per dam), but did have a significant negative correlation with interval between consecutive litters. Further, we found that reproductive performance and longevity were not significantly correlated, as we had initially hypothesized. Our analysis of physiological variables supports the hypothesis that IGF-1 may contribute to variation in reproductive performance. Together, these results help understand what drives individual variation in life-history, as well as the phenotypic and physiological correlates that accompany this variation.
