Impact of Different Standard Chow Diet Exposures on the Epigenome of Mouse Sperm

Different standard chow diets contain varying quantities of macro- and micronutrients, which have been shown to drive variability mouse model phenotypic outcomes. However, the impact of different chow diets on mouse model epigenetic outcomes and male reproductive health is not yet well characterized. This study tested the effects of lifetime exposure (LE) to four standard chow diets (5V5M, 2920X, 5058, 5V0G) on  the DNA methylome of mouse sperm. It also tested diet switch exposure (DE), to assess if switching mice onto a uniform chow (5V5M) at weaning could mitigate diet-driven variability. Our finding demonstrate that different standard chows drive differences in sperm epigenetic outcomes. Switching to a common diet did not mitigate diet-driven variability, instead, it may cause greater methylation variation due to the dietary shift stressing the mouse. This study is important in demonstrating how standard chow diets affect the rigor and reproducibility of mouse model research.