In a revolutionary movie, scientists have apparently identified what they believe is the gene linked to obesity, according to a new study.
Geneticists have said that they narrowed down to the gene that was believed to be most strongly associated with obesity, and said that this discovery could aid efforts to find drug-based treatment for the fast-spreading problem, as well as for diabetes.
The study, conducted on mice by scientists from the University of Chicago, shows that those mice that we bred without the IRX-3 gene were on an average, almost a third lighter than mice bred with the gene. The presence of this gene was thus linked to obesity.
Those researching this gene said that there exists a similar gene in humans as well, and that the results of the study could lead to the creation of a drug that would successfully treat obesity, as well as diabetes – a disease sometimes linked to the former.
According to Marcelo Nobrega of the University of Chicago, who headed the investigation, the data in the study results strongly suggested that the gene controls body mass and controls body composition by regulating metabolism.
The discovery of the method in which the IRX-3 gene functions could finally explain to geneticists why some people were more prone to obesity than others.
To verify the role of the gene in obesity, scientists had two sets of mice for experimentation. While the first set was normal, the second set was engineered without the IRX-3 gene. Both sets ate the same diet and were exposed to the same exercise.
They then found that those mice without the gene weighed 30 percent less than those with it, due to a reduced amount of fat in their bodies. They were also found to be resistant to obesity as well as diabetes, and burned energy more efficiently.
The findings stated that the mice without the IRX-3 gene were thus completely resistant to ‘high-fat, diet-induced’ obesity, and could also handle glucose much better which led to protection against diabetes.
Prior to this study, previous research had identified a gene, FTO, as the cause for obesity after an apparent link between mutations in the gene and excess body fat was observed. However, this could not be proved, and FTO on its own had a minor effect on obesity.
The scientists then used mouse and zebrafish embryos, as well adult mouse brains, and human cells that included brain cells, to show a laboratory-controlled interaction between the genes FTO and IRX-3. It was found that instead of affecting the FTO gene itself, the mutations inside it triggered a reaction in the IRX-3 gene. This led to the overproduction of IRX-3 in the brain and could probably affect the hypothalamus, which controls metabolism and appetite. This meant, according to the study, the genetic tendency to be obese was wired in the brain.
The study thus demonstrated the previously ignored role of IRX-3 in regulating body weight, and would now focus on identifying which cell functions were being altered by the gene. However, though the study established a link between the gene and obesity, it did not specifically conclude that the former was a cause of the latter. Also, the findings from animals trials could not merely be replicated with humans.
Obesity and related diseases like diabetes have become epidemics in developed countries today. Many causes are known to contribute to this state, and before this study, experts were not too positive on an immediate pharmaceutical solution for the same. It is estimated that at least 2.8 million adults die each year due to obesity, according to the UN.