A Bio-Cultural Investigation of Intergenerational Epigenetic Mechanisms

Western Michigan University, Kalamazoo MI

Investigators

Abstract

The new science of epigenetics holds a promising pathway for understanding how maternal experiences, including nutrition, environmental crises, and traumatic events, affect fetal development and infant outcomes. The biocultural research supported by this award is focusing on one epigenetic mechanism, DNA methylation, because it is dynamically responsive to environmental conditions, including climate, diet, toxins, and traumatic events. The research team will investigate the intergenerational, biological effects of drought and food shortages on mothers and their infants in a rural population. This research is relevant to all human populations, and critically important because the impacts on the fetus can be lifelong, including altered growth trajectories, obesity risk, impaired immune response, and risk for psychological illness. Knowing how extreme environmental events impact mechanisms for gene expression will aid in developing needed tools for resilience in the United States and elsewhere. The project will train university students, including those from groups underrepresented in STEM fields, and foster international collaborations and science education. Project findings will be shared with parents and the research community, in addition to dissemination through academic publications and presentations. The research will be undertaken by anthropologist Dr. Bilinda Straight (Western Michigan University) and her interdisciplinary team. They will focus on the effects of climate extremes in a context of rural poverty and persistent conflict, to clarify the connections between exposures and developmental outcomes. The research site is in northern Kenya, where an extreme drought in 2008-2009 devastated rural populations. This is an ideal setting for the study because the lead researcher has worked in the target communities since 1992, so essential baseline data and research infrastructure are already in place. This makes possible a degree of longitudinal depth that is rarely available and it also makes the project cost-effective. The team will focus on the Samburu, livestock herders who keep cattle, goats, and sheep, as well as camels in some communities. A 2008-2009 drought, which killed over half of Samburu cattle, resulted in widespread hunger, and may have escalated the violent conflicts between Samburu and ethnic neighbors. The study will employ a sibling-pair design, comparing children whose mothers were in their first trimester of pregnancy during the drought to their same-sex siblings conceived and born after full recovery from the drought. Data collection from mothers and other caregivers will include interviews about their experiences during the disaster, stress and trauma questionnaires focused on mothers' recollections of stress and trauma during the drought, and caregiver perceptions of child wellbeing. Data collection from children will include activity observations; birth weight, height, weight, dietary, and illness data; and saliva samples for the DNA methylation analysis.