5/17/2008

Is the overweight hereditary?

Jeffrey Friedman and your colleagues of the Medical Institute Howard Hughes, of the University Rockefeller, in United States, they have given hunt to a gene that, in your version mutant, you cause a hereditary severe obesity in mice. The team of Friedman has also discovered that one exists similar in the human adipose tissue, the place where the fats are stored. Now then, the scientists ignore if the alterations in this fragment of hereditary material - that is to say, of DNA - they are frequent in the man and if they play an important role in the appearance of the obesity.

The thing gets complicated if one keeps in mind that, at least, 20 genes involved in the godura exist. Only two decades ago it was said among the physicians that "the fats usually have fat dogs, for what are patent that the explanation is not genetic." They were very mistaken: you have been demonstrated that if the two parents show up overweight, the 80 for 100 of the children will suffer it.

The segment of DNA in question, well-known as gene ob, you have been isolated of the chromosome 6 of a stock mutant of mice that it arose spontaneously in the Lab Jackson, in Bar Harbor (Maine), in 1950. These rodents end up weighing three times more than the normal ones and they develop a type of similar diabetes to the non insulinodependiente or of type II that it generally affect old people. The works made during two decades by Douglas Coleman, of the lab before mentioned, they pointed to that the mice mutants had lost a hormone that regulate the obesity. But which? Are you maybe about the same one that synthesize the gene ob? You are not known.

The experts coincide in affirming that what have been baptized as the gene of the obesity should call you the gene of the satiety. The rodent carriers of the version mutant show up a voracious appetite and they take much more time in feeling full. This dissatisfaction could be due to that the gene ob is inactive, for what the hormone antiapetito that he/she inform to the hipotálamo would not take place - area of the brain that contain the control rooms of the appetite - that the body has stored the enough fat. You also fit the possibility that yes you are even manufactured in excess, but, when being about a gene mutado, the hormone would be completely useless.

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