Parenting is not the only way moms and dads impact the behavior of their offspring—genes matter, too. And although most of our genes are inherited in pairs with one copy from each parent, moms and dads exert their genetic influence in different ways. According to new research led by scientists at University of Utah Health, each parent has their own impact on hormones and other chemical messengers that control mood and behavior.
“We’re really intrigued that there is this untapped area of biology that controls our decisions,” says Christopher Gregg, principal investigator and associate professor of neurobiology. Gaining a clearer picture of the genetic factors that shape behavior is a crucial step toward developing better diagnoses and treatments for psychiatric disorders, he says.
Gregg’s research team found that certain groups of cells in the brains of mice rely exclusively on the mother’s copy of a gene that is needed to produce essential chemical messengers in the brain called neurotransmitters. In those cells, the father’s copy of the gene remains switched off. However, in a different organ, the adrenal gland, certain cells favor the father’s copy of the same gene. There, the gene is involved in producing the stress hormone adrenaline.
After identifying this unexpected switch in parental control of a single gene, Gregg’s team went on to demonstrate that it had consequences for behavior. They found that each parent’s gene affected sons and daughters differently: certain decisions in sons were controlled by their mother’s gene, whereas fathers had control over some decision-making in daughters.
Evolutionarily speaking, this form of genetic regulation may reflect different parental priorities, says Gregg. “Not everybody has the same sort of interests, outcomes, and selective effects,” he explains. “Daughters need to rear offspring. Sons often disperse and will go to new environments.” Consequently, it may be in parents’ interest to influence behavior differently in their sons and daughters.
This finding is a first step toward understanding how a parent’s genes may affect more behaviors and health conditions in people, from mental illnesses and addiction to cancer and Alzheimer’s disease, Gregg notes.