Research from the University of North Carolina has revealed that all mammals, humans included, have more in common genetically with their fathers than their mothers.
This is because although we inherit equal amounts of genetic material from each parent, we end up expressing more of the DNA we get from our father.
The scientists made the discovery by breeding three different strains of inbred mice to create nine different types of hybrid offspring. This allowed them to distinguish easily which original strain the expressed genes came from in the offspring's brain tissue, and therefore whether they came from the mother or father mouse.
The results, published in the journal Nature Genetics, show that in each case the child mouse ended up expressing more of its father's genes.
"We discovered a new, genome-wide expression imbalance in favour of the dad in several hundred genes,” explained Fernando Pardo-Manuel de Villena, lead researcher of the study. “This imbalance resulted in offspring whose brain gene expression was significantly more like their fathers'."
Better disease monitoring
As well as providing us with an interesting fact about ourselves, the finding could help in the study of human diseases using mammalian research models - it shows that inheriting a mutation has different consequences in mammals depending on whether it is inherited from the mother or the father.
Hereditary diseases it could have implications for include type-2 diabetes, heart disease, schizophrenia, obesity, and cancers.
"This is an exceptional new research finding that opens the door to an entirely new area of exploration in human genetics," said Pardo-Manuel de Villena.
"We've known that there are 95 genes that are subject to this parent-of-origin effect. They're called imprinted genes, and they can play roles in diseases, depending on whether the genetic mutation came from the father or the mother.”