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Show COLLEGE OF SCIENCE Wayne Potts PARENT SPECIFIC EPIGENETIC INHERITANCE OF BODY SIZE IN WILD MICE DUE TO A DYNAMIC SOCIAL ENVIRONMENT Joseph W. Cauceglia, Adam Nelson, (Wayne Potts) Department of Biology University of Utah Epigenetic inheritance is defined as inheritance that is independent of D N A sequence. It is thought that epigenetic inheritance can result from environmental signals or disturbances and allows rapid adaptation to environmental problems, largely through changes in gene expression. Epigenetic inheritance can be mediated by maternal or paternal effects (or both). While evidence is accumulating that environmental disturbances or toxin exposures can induce epigenetic inheritance of gene expression differences, none of these responses have been shown to be functional (adaptive) in natural systems. W e have discovered what appears to be an adaptive response to social competition that is epigenetically inherited. Using wild mice, we simulate high social competition by housing 10 males and 20 females together in large enclosures with microhabitats that range in quality to stimulate resource and mate competition. These enclosures are referred to as "the barn" because they mimic natural mouse populations. W e discovered that parent mice who experience social competition in the barn produce offspring with lower body mass than those produced by parents from the non-competitive cage treatment. Using a one-generation reciprocal breeding design of animals exposed to either social treatment (barn or cage), w e were able to isolate and identify parent of origin effects while effectively ruling out genetic mechanisms. The breeding design revealed that sons of barn fathers weigh significantly less than sons from caged fathers. In addition, daughters of barn females weighed less than daughters from caged mothers. These effects have been highlighted as parent specific due to the observation that the parental treatment had no effect on the weight of opposite sex offspring. W e hypothesize that this decrease in weight is an adaptation to the competitive and dietary stressors found in "barn life" (i.e. nature). This story is particularly interesting in light of the trends found in American obesity caused in part by diet and inactivity. 62 |