Carl Engelking in Discover:
You may have inherited your mother’s eyes, but, genetically speaking, you use more DNA passed down from your father. That’s the conclusion of a new study on mice that researchers say likely applies to all mammals. We humans get one copy of each gene from mom and one from dad (ignoring those pesky sex chromosomes) – that hasn’t changed. The same is true for all mammals. But that doesn’t necessarily mean that mom and dad genes are equally active in creating who we are. Researchers now report that thousands of mouse genes show parent-specific effects, and that on balance, the scales are tipped in favor of dads. Studying whether this imbalance exists in humans could give scientists insights into the causes of inherited conditions like diabetes and heart disease.
…Scientists interbred three strains of these mice to create nine different types of offspring. When these mice reached adulthood, scientists measured the level of gene expression in a variety of bodily tissues. They then quantified how much gene expression was derived from the mother and the father for every single gene in the genome. Overall, they found that most genes showed parent-of-origin effects in their levels of expression, and that paternal genes consistently won out. For up to 60 percent of the mouse’s genes, the copy from dad was more active than the copy from mom. This imbalance resulted in mice babies whose brains were significantly more like dad’s, genetically speaking.