Though you inherited about half your DNA from your mother and half from your father, you're more likely to express DNA you've gotten from your dad, says Carl Engelking at the D-brief blog, noting that that's if you're a mouse, anyway.
As they report in Nature Genetics, researchers from the University of North Carolina at Chapel Hill and elsewhere turned to a collection of mice called the Collaborative Cross to examine gene expression across various mouse tissues in a three-way diallel and, through this, uncovered parent-of-origin effects, including classical imprinting and a global allelic imbalance that favored paternal alleles.
That is, Engelking says, for up to 60 percent of the mouse genes, the paternal allele was more active than the maternal one.
"We now know that mammals express more genetic variance from the father," UNC's Fernando Pardo-Manuel de Villena tells Engelking. "So imagine that a certain kind of mutation is bad. If inherited from the mother, the gene wouldn't be expressed as much as it would be if it were inherited from the father. So, the same bad mutation would have different consequences in disease if it were inherited from the mother or from the father."