Kathleen Grogan

KATHLEEN GROGAN, University of Cincinnati, Cincinnati, Ohio, was awarded funding in April 2018 to aid research on ‘Functional Epigenomics of Growth and Development in Human Hunter-gatherers and Agriculturalists.’ The epigenome is one mechanism through which sociocultural processes and environmental variation may influence human biology and even evolution. Because epigenetic marks can modify gene expression, they are an important contributor to human phenotypic variation. Epigenetic patterns are affected by inherited genetic variation and dynamically responsive to the ecological or social environment. By studying patterns of epigenomic variation among human populations, we can contextualize human variation and evolution within the framework of major differences in environmental factors and/or lifestyles. For example, subsistence strategy differences, e.g. between hunting and gathering versus agricultural societies, result in major habitat, activity level, and nutritional intake differences that could affect phenotypic variation. Compared to neighboring agriculturalist (AGR) populations, rainforest hunter-gatherers (RHGs) have significantly shorter mean adult stature. Although the environment plays a role, this height difference has a major heritable component. Furthermore, RHG and AGR populations have epigenetic differences near genes involved in growth. To study the interaction between the genome, epigenome, and environment, the project will quantify how gene expression and methylation patterns of cells from Batwa RHG and Bakiga AGR from southwest Uganda: 1) differ at baseline; and 2) change in response to growth hormones. By describing baseline epigenomic variation and its response to growth hormone treatment, we may better understand gene expression differences play a role in stature differences between populations. This project represents a unique opportunity to investigate evolutionary and ecological influences on epigenetic regulation of growth and development as well as the flexibility of the mechanisms regulating these pathways.