1School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA, 2Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA, 3Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
March 28, 2015 , Gateway Ballroom 2/3/4/5
Epigenetic regulation, including DNA methylation, can impact the development and maintenance of complex skeletal traits and thereby contribute to morphological diversity in primate evolution. Knowledge and appreciation of normal epigenetic variation in primates and skeletal tissues is a necessary first step towards understanding the role of epigenetics in the evolution of skeletal variation. We investigated the relationship between epigenetic variation and skeletal variation in one species and identified DNA methylation patterns in bone and cartilage from age- and sex-matched baboons, six with and six without knee osteoarthritis (OA). Genomic DNA was extracted from right distal femur bone (n=12) and cartilage samples (n=12), and genome-wide methylation was detected using the Illumina HumanMethylation 450K BeadChip. Several loci were significantly differentially methylated between normal and OA individuals, between bone and cartilage, and between the four groups based on tissue type and OA status. Specifically, out of over 450,000 positions, approximately 2.06% were differentially methylated between the OA and control groups, 1.94% between tissue types, and 1.32% among the four combinations of tissue type and OA status. From an evolutionary perspective, these results begin to give us an appreciation for normal methylation variation in one species and in two skeletal tissues. They also give us insight into the degree to which a common skeletal condition (OA) affects that variation. Expansion of this sample set and more focused testing of specific genes will advance our knowledge of the degree to which the epigenetic phenomenon of DNA methylation may regulate complex skeletal traits in primate evolution.
Funding for this work was provided by the Max and Minnie Tomerlin Voelcker Foundation, William and Ella Owens Foundation for Biomedical Research, SNPRC, and ASU Chapter of Sigma Xi.