An example of physical traits varying as a result of difference in epigenetics (Source: Wikipedia)
In America, where obesity is currently an epidemic, pinpointing and attacking the causes of weight gain are central to the world of public health. While it has long been established that weight gain is determined by more than just culture and decision-making, a clear molecular basis for obesity has eluded researchers. But recently, Andrew Pospisilik, a physiologist at the Max Planck Institute, and his colleagues discovered an epigenetic “on and off switch” for obesity (1).
Epigenetics is the study of factors that alter gene expression without changing the DNA sequence itself. While changes in an individual’s gene expression were already thought to impact health conditions such as obesity, the specific mechanisms by which this occurred were unknown (1).
Working with mice that were missing one copy of the gene TRIM28, Pospisilik noticed that the mice tended to become either obese or thin (1). To find out why, Pospisilik and his team measured gene expression in the mice and found that, among obese mice, expression of certain genes typically active in fat cells and the hypothalamus, the area of the brain that controls hunger, was decreased (1). Based on this information, Pospisilik and his colleagues hypothesized that the TRIM28 gene serves as an epigenetic switch that can turn genes that affect obesity on and off (1).
To test that hypothesis, they removed fat samples from children and found that, in the cells of the obese children, TRIM28 activity was substantially lower, indicating that they had, indeed, found an epigenetic switch for obesity (1).
Going forward, Pospisilik hopes that this information can be applied to find the “trigger” that flips the switch, causing obesity (1). If this “trigger” can be identified, one day physicians may be able to better treat obesity and alleviate the current epidemic.
References:
1. Leslie, M. (2016, January 28). Fat? Thin? Molecular switch may turn obesity on or off. Science. Retrieved from: http://www.sciencemag.org/news/2016/01/fat-thin-molecular-switch-may-turn-obesity-or