1Department of Anthropology, University of Washington, 2Center for Studies in Demography and Ecology, University of Washington, 3USC-Office of Population Studies Foundation, Inc., University of San Carlos, Cebu City, Philippines, 4Division of Endocrinology, Metabolism and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, 5Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, 6Department of Anthropology, Northwestern University, 7Institute for Policy Research, Northwestern University
April 16, 2020 30, Platinum Ballroom
Telomeres are comprised of DNA repeats located at chromosomal ends that shorten with cellular replication and with age in most human tissues, and thus are biomarkers of aging. In contrast, spermatocyte telomeres lengthen with age. These changes in telomere length (TL) appear to be heritable, as older paternal ages of conception (PAC) predict longer offspring TL. Mouse studies suggest that paternal factors like smoking, inflammation and DNA damage can influence sperm TL and thus offspring TL, pointing to possible heritable genetic effects of paternal experience. Here, we test whether similar human paternal environmental experiences predict offspring TL as well as the pace of age-related change in TL with PAC. Using data from metropolitan Cebu, the Philippines, we tested if smoking, psychosocial stressors, and/or shorter knee height (a measure of early life adversity) predicted shorter offspring TL. We also tested if these variables modified the PAC-related increase in offspring TL.While we did not find the predicted associations, we observed a trend towards fathers with shorter knee height having offspring with longer TL, and a significant interaction between knee height and PAC in predicting offspring TL. Specifically, offspring of fathers with shorter knee heights experienced a stronger positive effect of PAC on their TL. While the reasons for these associations remain uncertain, shorter knee height is characteristic of earlier puberty. Since spermatocyte TL increases with sperm production, we speculate that individuals with earlier puberty, who therefore experienced an earlier onset of sperm production, had more time to accumulate longer sperm telomeres.
Funding from NSF (BCS-1519110 and BCS-0962282), the Wenner-Gren Foundation (Gr. 8111), and NIH (TW05596, DK078150, RR20649, ES10126, and DK056350).