It had been thought that each copy of DNA- one inherited from the mother and one from the father- was treated the same. While most kids don’t want to pick between their parents, a new study from the University of Utah School of Medicine shows brain cells may preferentially activate one copy over the other. The finding breaks basics of classic genetics and suggests new ways in which genetic mutations might cause brain disorders.
The research led by Christopher Gregg Ph.D., assistant professor of Neurobiology and Anatomy and senior author of the paper reveals that 85 percent of the genes located in the dorsal raphe nucleus of a newborn mouse brain deferentially activate their maternal and paternal gene copies.
Breaking fundamentals of genetics
This study suggests that at times, the dorsal raphe nucleus can activate the maternal gene copies over the paternal ones or the other way around. The dorsal raphe nucleus is also the area in the brain where the mood-controlling chemical serotonin is secreted. This disparity also takes place at other sites in the body, including liver and muscle of the mouse, as well as in humans.
“We customarily consider of traits in terms of a whole person, or animal. We’re anticipating that when we demeanour during a turn of cells, genetics is most some-more difficult than we thought,” says Christopher Gregg in Neuron on February 23.
What does that mean to our health?
What the genetic imbalance could mean for our health remains to be determined, but results suggest that it could shape vulnerabilities to disease, explains Gregg. Normally, having two copies of a gene acts as a protective buffer in case one is defective. Activating a gene copy that is mutated and silencing the healthy copy – could be disruptive enough to cause trouble in specific cells.
“activating a gene copy that is mutated could be disruptive”
In humans, there is a gene called DEAF1 and is implicated in autism and intellectual disability. This specific gene shows several preferential expressions in different regions of the brain. This further indicates gene types that are linked to other mental illnesses like the Huntington’s Disease, schizophrenia, bipolar disorder, and attention deficient disorder.
The research method
To conduct the study, scientists screened thousands of genes, quantifying the relative levels of activation for each maternal and paternal gene copy. It was discovered that expression of the two is different for many genes.The research team developed statistical methods to test their validity and determine that they were not due to technical artifacts, nor genetic noise.
Results of the study expand the scenario on how genes work and play favorites. Imprinted genes and X-linked genes are activated differently depending on their maternal and paternal gene copies. Silencing one gene copy may help in tune fining. “Our new findings reveal a new landscape of diverse effects that shape the expression of maternal and paternal gene copies in the brain according to age, brain region, and tissue type,” Gregg stated.
“findings reveal a new landscape of effects that shape the expression of maternal and paternal gene copies”
Images taken from the Creative Commons