A gene responsible for feelings of fullness, drowsiness and physical activity has been discovered in a worm. It would also be present in humans.
Worms may well hold a key to obesity. A gene responsible for the feeling of fullness has been discovered in C. elegans by Australian and Danish researchers. In their study published in PNAS, they explain that this gene, called ETS-5, would limit food excess and encourage movement more. A similar version would be present in humans, paving the way for the development of new drugs.
In the nematode, this gene seems to control exchanges between the brain and the intestines. Professor Roger Pocock of the Monash Institute of Biomedicine (Australia) explains that once the intestines have absorbed enough fat, they send a signal to the brain to warn it. The latter then triggers a phase of drowsiness, and the worm stops moving and begins a good nap. “On the other hand, if they have not eaten enough, they continue to crawl in search of food”, specifies the scientist.
Therapeutic target
With his Danish colleagues, Prof. Pocock was able to pinpoint ETS-5 by analyzing the neurological reactions of the brain of worms to food. They then discovered that, like mammals, these responses are different depending on the quality of the diet. A diet high in fat and sugar stimulates appetite and leads to overeating, which can lead to obesity. So when they are fed this low quality diet they keep looking for food.
The research team points out that ETS-5 is the first appetite regulator gene to be discovered. “This family of genes is present in humans and a link with obesity has been suggested. Now that we know that it controls food intake via exchanges with the brain, it represents a credible therapeutic target for the treatment of obesity, ”concludes Professor Pocock.
80% of genes in common with humans
The nematode Caenorhabditis elegans, better known as C. elegans is a small transparent worm is very popular with researchers because its brain is very easy to study. It has only 302 neurons and about 8,000 neural connections, compared to a hundred billion neurons in humans and 100 billion billion synapses.
Despite these huge differences, these two species share nearly 80% of their genome, including more than half of genes involved in human diseases. “These worms are therefore a very good model for exploring and better understanding the biological mechanisms behind metabolic disorders and diseases in humans,” says the Australian researcher.
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