It has long been thought that each copy - one inherited from mom and one from dad - is treated the same. A new study from scientists at the University of Utah School of Medicine shows that it is not uncommon for cells in the brain to preferentially activate one copy over the other.
The finding suggests new ways in which genetic mutations might cause brain disorders.
Copying mom's or dad’s genes
The research shows that in at least one region of the newborn mouse brain, inequality seems to be the norm.
About 85 per cent of genes in the dorsal raphe nucleus, known for secreting the mood-controlling chemical serotonin, differentially activate their maternal and paternal gene copies.
Ten days later in the juvenile brain, the landscape shifts, with both copies being activated equally for all but 10 per cent of genes.
More than an oddity of the brain, the disparity also takes place at other sites in the body, including the liver and muscle. It also occurs in humans.
