1Human Evolution Research Center, University of California, Berkeley, 2Center for Neurobehavioral Genetics, University of California, Los Angeles, 3Department of Human Genetics, University of California, Los Angeles, 4Department of Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine
March 26, 2015 9:45, Grand Ballroom A/B
There are known maternal effects on obesity outcomes in humans and nonhuman primates, but few have investigated these effects on obesogenic growth throughout the lifespan. To investigate the impact of maternal effects on the genetic underpinnings of obesogenic growth we used growth curve analysis on measures taken thrice yearly from 2000 to 2013 on body size and composition in a captive population of 641 vervet monkeys (Chlorocebus spp). Of these, 38 were defined as chronically obese, having had an adult waist circumference above 40.5 cm for three successive measurements. Growth was modeled using three-parameter logistic growth curves in nonlinear mixed models, with parameters modeled as fixed and subject and sex/obesity status modeled as random effects. We assessed heritability of individual growth parameters using SOLAR, with the variance attributed to maternal ID (c2) partitioned from environmental variance to determine maternal effects. We found significant heritability and maternal effects on all static measures of adult body condition (e.g., BW, h2=0.86, p=6.52x10-10 and c2=0.11, p=0.04; BMI, h2=0.77, p=1.39x10-09 and c2=0.12, p=0.05), and high heritability but no significant maternal effects on parameters of growth (e.g., BW, asymptote of growth, h2=0.77, p=4.93x10-21 and c2=0.05, p=0.11). This study suggests that although adult obesity is a developmental process driven in part by heritable obesogenic trajectories resulting in larger adult size, those trajectories do not appear to be influenced by maternal effects. A better understanding of how growth can be decoupled from maternal effects on adult obesity will be necessary to assess early obesity risks.