Even if you look just like you're mother and have her laugh, you're still probably genetically closer to your father.
Researchers found mammals are generally genetically closer to their dads, even though they inherit equal amounts of genetic mutations from both parents, University of North Carolina Health Care reported. The recent findings show we tend to "use" more of the DNA we inherit from our fathers.
The findings could have important implications in the study of disease. In many mouse models that look at gene expression researchers fail to take into account whether a gene expression originated in the mother or father. The recent research shows inheriting genes have very different consequences depending on which parent they were inherited from.
"This is an exceptional new research finding that opens the door to an entirely new area of exploration in human genetics," said Fernando Pardo-Manuel de Villena, PhD, professor of genetics and senior author of the paper. "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. Now we've found that in addition to them, there are thousands of other genes that have a novel parent-of-origin effect."
Genetic mutations passed down from parents play roles in a number of common diseases, including "type-2 diabetes, heart disease, schizophrenia, obesity, and cancers." Taking into account which parent a genetic mutation was inherited from in mouse models could provide insight into the root causes of some of these diseases.
Researchers at the university bred together a number of types of wild mice to create a genome with a wide range of diversity comparable to what is seen in the human genome. The study allowed the researchers to look at gene expression (which connects DNA to proteins, carrying out different functions within cells) for every gene in every kind of tissue.
In this specific study the researchers looked at three genetically diverse inbred strains of mice that came from ancestors that evolved on different continents. The mice from these strains were bred to produce nine different types of hybrid offspring. Once these hybrid mice reached adulthood, the researchers measured gene expression in four different types of tissue, and pinpointed whether it was attributed to the mother or father.
"We found that the vast majority of genes - about 80 percent - possessed variants that altered gene expression," said first author James Crowley, assistant professor of genetics. "And this was when we discovered a new, genome-wide expression imbalance in favor of the dad in several hundred genes. This imbalance resulted in offspring whose brain gene expression was significantly more like their father's."
The findings reveal mammals' expression level relies on the mother and father, and individuals express more genetic variance from their fathers.
"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," Pardo-Manuel de Villena said.
The findings were published in a recent edition of the journal Nature Genetics.
