Madhuri Raman
Mr. Mathieu
Period 2
January 14th, 2014
Author: Gina Kolata
Published: July 18th, 2013
Article: http://www.nytimes.com/2013/07/19/health/overweight-maybe-you-really-can-blame-your-metabolism.html?smid=pl-share
Summary
This article is about the discovery of a gene called MRAP2 that controls weight gain and how quickly calories are burned. It is a helper gene, sending signals from the brain to another gene that control's an individual's appetite. However, there are rare mutations of this gene that cause it to get "turned off" and leads to the organism gaining a lot of weight, even while on a normal diet. In one experiment, scientists kept two groups of mice on the same diet in order to compare their weights at the end of a given period of time. The first group of mice had the gene for the control of weight gain removed from their cells, but the other group of mice still possessed the gene. The scientists found that the group without the gene was getting fat, while the other group was not. This led them to believe that the presence of the MRAP2 gene determines a person's general weight, much more than the person's diet. Other researchers conducted a similar experiment in which they found that children without the gene gained weight, but still had normal appetites. But once the children matured into adults, their appetites grew tremendously. Now the question is, is this the cause of obesity?
Connection
This article directly relates to our studies of Heredity and Molecular Genetics throughout Term 2. In class, we learned a lot about inherited traits, and the article discusses how obesity and weight gain are a result of genes that have been passed down from generation to generation, not poor dietary habits. We also learned about the dangers that one could possibly face from having a gene mutation, although mutations are not always harmful. The rare mutation of the MRAP2 gene explained in the article is an excellent example of that. It was most probably the factor that has led to many cases of obesity in children, one of whom has already been found to have the mutation. All in all, the discovery of the gene controlling weight gain is important in understanding the actual causes of obesity.
How could scientists test for this gene in humans to see if it is the gene or the diet that is causing the obesity?
ReplyDeleteScientists have been conducting various experiments in order to test for the presence and function of this gene mutation. They have already tested with mice to see if diet or mutation is causing major weight gain. Since both groups of mice were on the same diet, and the group lacking the mutation stayed normal, they were able to rule out the diet as a cause for obesity. Therefore, scientists believe that this gene mutation is the most probable cause for obesity. However, many more experiments need to be run in order to confirm these results.
DeleteDo you know the reason why when humans without this gene mature into an adult their appetite increases?
ReplyDelete