1Anthropology, University of Florida, 2Genetics and Genomics Graduate Program, University of Florida, 3Biochemistry and Molecular Biology, University of Florida
Saturday 4:15-4:30, Parlors
Adaptation is a complex process involving genetic, physiological, and behavioral mechanisms. There is growing evidence that epigenetic modifications may serve as an intermediate adaptive mechanism that mediates between the rapidly changing environment and our slowly evolving genome and, thus, may provide a possible mechanism for phenotypic plasticity during fetal development. We test the idea that epigenetic modifications may create heritable changes in response to extreme environmental stressors that affect infant health in a multigenerational manner.
Maternal blood and umbilical cord blood samples were collected from 25 mother-infant dyads in the eastern Democratic Republic of Congo. Detailed ethnographic interviews and peri-natal trauma surveys were administered to all mothers. Medical histories of mothers were accessed and birth weights and gestational age of infants were recorded. DNA was extracted and treated with sodium bisulfite. A 321 bp promoter of NR3C1 with 39 CpG sites was amplified, cloned and sequenced. An average of 21.5 clones per sample was sequenced. NR3C1 is a glucocorticoid receptor that was previously implicated in methylation-mediated changes in gene expression associated with differences in childhood trauma. When treating maternal stress exposures as categorical variables, our preliminary results show increased methylation in stressed mothers (material deprivation, emotional stress, recent rape, war stressors). In contrast, infants of less stressed mothers (material deprivation, emotional stressors, war stress) show increased methylation with respect to their mothers and with respect to infants of stressed mothers. Our results suggest that methylation patterns differ between mothers and infants and may correlate with specific maternal stress exposures.
This research was supported by grants from the University of Florida and the National Institutes of Health.