About the speakers
Ann-Karin Olsen, Nur Duale and Kristine B. Gutzkow are Molecular Biologists and Toxicologists working as senior researchers and risk assessors at the Department of Molecular Biology, Norwegian Institute of Public Health. Topics they work with are exposures to environmental agents including radiation leading to DNA-damage, mutations, epigenetic changes and different reproductive outcomes, including transgenerational outcomes.
About the presentation
Exposure to different environmental chemicals may affect the human sperm genome, and resulting mutations or epigenetic changes in the sperm may be transferred to the unborn child with the probability of developing health problems later in life. In a highly exposed population of Chernobyl-survivors and their children, paternal exposure caused heritable germline minisatellite mutations. Similarly, we studied two of the most commonly used minisatellite loci (CEB1 and B6.7) to identify germline mutations in blood samples of complete mother-father-child triads from the Norwegian Mother and Child Cohort Study (MoBa). We looked for correlations between mutation rates and lifestyle factors, with the hypotheses that paternal smoking before the partner became pregnant would lead to increased mutation rates in offspring. The hypothesis was based on our previous studies in mice exposed to a chemical in cigarette smoke (BaP, benzo(a)pyrene), where we demonstrated increased de novo mutations in sperm as well as altered gene expression in the developing embryo after fertilisation with sperm from exposed males. We found a dose dependent increase in paternally derived mutations in one of the two minisatellite loci were when the father smoked in the 6 month-period prior to pregnancy.
In a follow up study, our goal is to study families with fathers that are heavy smokers or non-smokers to identify new germline mutations by whole genome sequencing. Moreover, we will analyse changes to the epigenome with focus on miRNAs and DNA methylation in children since changes in gene expression may lead to adverse effects on a child’s development and health.