Poster 31
Presenter: Melissa Gray
Wednesday, 3:00 – 5:00pm
Melissa M. Gray*, Michelle Parmenter*, Peter Ryan**, and Bret Payseur* *University of Wisconsin, Madison, Laboratory of Genetics, Wisconsin **University of Cape Town, Percy FitzPatrick Institute of African Ornithology, South Africa
Laboratory house mice (Mus musculus) are the leading mammalian model system for understanding genetic variation in complex phenotypes. Body size has been especially well studied, mostly due to its pervasive correlations with morphological, physiological, and life-history traits, and the underlying pleiotropy of the genes regulating body size. For example, many of the same genetic factors that contribute to variation in body size have been implicated in human diseases, ranging from coronary disease to obesity and cancer. Although most research on the genetic basis of body size in house mice has focused on the classical inbred strains or their derivatives, wild house mice also show substantial variation in body size across a wide range of habitats. Studying wild populations can connect phenotypic variation to the natural environment in which it evolved. This combination of genetic tools and natural variation provides a practical platform for dissecting the genetic underpinnings of complex trait variation. House mice from Gough Island provide an especially dramatic example of extreme body size evolution: they are larger than any other wild population and most inbred strains. Here, we present body mass data from our study which aims to identify the genomic regions responsible for large body size in Gough Island mice. Analyses are reported for weekly weights, growth curves, and growth rate variation within and between the four crosses and two sexes. Gough Island mice are born heavier and grow faster at many ages compared to a wild-derived inbred strain (WSB) from the same subspecies. F2 body weights from intercrosses between semi-inbred Gough Island mice and WSB are normally distributed. Our results suggest that multiple loci contribute to extreme body size in Gough Island mice and motivate genetic mapping to identify these loci.