Divisive gene splits brain and brawn

CARDIFF U. (UK) — A newly discovered gene defies conventional rules, with the copies inherited from the mother and father working in different ways.

In most cases, both copies are active, but in some one copy is switched off, a process called imprinting.

A gene called Grb10 takes things a step further with the copy from the father only active in the brain and the maternal copy active in all other parts of the body.

The study, published in the journal Nature, shows the two copies also have very different functions: the maternal copy is involved in fetal growth, metabolism and fat storage, and the paternal one regulates social behavior in adults.

The research is expected to give scientists a better understanding of how genes involved in metabolism work, shedding light on the causes of obesity in humans.

“This is the first example of where the copy of a gene has two very different functions depending on which parent it is inherited from,” says Anthony Isles, who led the research at Cardiff University.

“It seems that the mother and father are using different strategies to influence their offspring, one focused on the body and the other on the brain. Imprinted genes are proving to be important for many aspects of human health, and are very important for brain function.

“Here is a single gene that may link growth in the womb with both physical and mental health in later life. In future research we’d like to investigate how this single gene might have evolved to serve such distinct purposes.”

“Grb10 is the first example of an imprinted gene that regulates social behavior in adults,” says Alastair Garfield, who carried out the work at Bath and Cardiff but is now working at the University of Cambridge.

“Asserting your dominance over others in your social group can be risky behavior, and this gene appears to keep that behavior in check. Many genes that are imprinted in mice are also similarly imprinted in humans, so we predict Grb10 could work in a similar way in people.”

The work was funded in part by the Biotechnology & Biological Sciences Research Council (BBSRC), Medical Research Council, and a Wellcome Trust “Value in People” award.

More news from Cardiff University: www.cardiff.ac.uk/news/