Australian researchers have found that the sperm of overweight fathers appears to carry a molecular signal that causes their offspring to inherit obesity. This may be more severe in female children and males they add.
The work by the Robinson Institute Research Centre for Reproductive Health, at the University of Adelaide, has so far focused on microRNA expression on the sperm of laboratory mice. They plan to look for similar mechanisms in humans as well. The research was presented at the World Congress on Human Reproduction in Melbourne, which has been running since Wednesday and finishes on Sunday.
Researcher Maria Ohlsson Teague said the sperm microRNAs identified are molecular regulators of gene expression in several biological processes, including embryonic development. The researchers included two groups - one of mice fed a high-fat diet, the other fed a good nutritional diet - with screening of the microRNA profile of sperm in both groups.
“In the group fed the high-fat diet, we discovered that male obesity alters the microRNA profile of sperm, resulting in poor embryo quality as well as obesity in offspring,” Dr Ohlsson Teague said. “This is the first evidence that a father's nutrition can affect the epigenome of his sperm, a non-genetic mechanism to inform the next generation of environmental change. We don't yet understand how this occurs and are particularly interested in why it appears to have a greater impact on the female offspring.”
The research adds that since transfer of the obesity factor is a biological process, not a genetic one, a father who loses weight and gets fit is less likely to pass on obesity to his children.
Research explores how moms' obesity reprograms babies