Paternal under and over nutrition modify semen composition and preimplantation embryo developmental kinetics in mice

Poor parental health can influence the development and eventual health outcomes of their offspring. Many studies have detailed the maternal role yet a father’s health requires further examination as his poor nutritional status has also been shown to have negative consequences on fetal development and impact the long-term health of his offspring. The present study examined how preimplantation embryo development was altered by sub-optimal paternal diet, with specific focus on sperm- and seminal plasma-mediated mechanisms. To address this, male mice were fed a diet to model either under (low protein diet (LPD)) or over (high fat/sugar ‘Western’ diet (WD)) nutrition, LPD or WD supplemented with methyl-donors or a control diet (CD) before mating. Embryo development was assessed using in vitro time-lapse imaging of preimplantation embryos which revealed a significant increase in embryo development rates in all experimental groups when compared to CD embryos. Further analysis of the semen revealed a significant number of differentially expressed seminal plasma proteins in all groups (LPD: 13, MD-LPD: 27, WD: 24, MD-WD: 19) when compared to control. This study highlights a role for paternal nutritional status influencing embryonic development and the maternal reproductive tract via changes to his metabolic and reproductive health. These findings demonstrate potential direct (sperm-mediated) and indirect (seminal plasma-mediated) pathways in which a father's poor diet could shape the long-term health of his offspring