Fruit flies have 2,000 muscle genes

Fly muscles of the insects are among the strongest in the animal kingdom

Side view of Drosophila melanogaster (left: head): A genetic program is responsible for the development of various muscle cells in the fruit fly. © Frank Schnorrer
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Scientists have identified all genes of the fruit fly Drosophila that play a role in the development and function of muscles - a total of 2, 000 pieces. In the end, they make sure that the flight muscles of the insects are among the strongest muscles in the animal kingdom.

The human body consists of ten to a hundred trillion cells. Not every cell is the same: 200 different cell and tissue types make up the human body. During its development, each of these cell types undergoes a specific genetic program, at the end of which red blood cells carry oxygen, neurons relay electrical signals, and muscles can generate mechanical forces.

"It's fascinating how the genetic program of an organism can produce such different cell types from identical progenitor cells, " says Frank Schnorrer from the Max Planck Institute of Biochemistry in Martinsried near Munich in the science journal "Nature".

In search of the muscle genes

Together with the team of Barry Dickson from the Research Institute of Molecular Pathology (IMP) in Vienna, the researchers around Schnorrer have for the first time systematically examined all 12, 000 genes of the fruit fly Drosophila melanogaster for their role in muscle development and muscle function. Similar to humans, the fruit fly has different types of muscles. Muscles that, for example, crawl fly larvae slowly or let the adult fly's wings strike with lightning speed.

25, 000 flight tests

Through more than 25, 000 flight tests, researchers have identified around 2, 000 genes that function in the muscles of the flies. "Some of these genes are needed in all muscles, " explains Schnorrer, "another part only in the very fast, very powerful flight muscles." Display

The flight muscles of insects are among the strongest muscles in the animal kingdom. "They can produce up to 100 watts per kilogram of muscle mass over a long period of time, " says the biochemist. "Bodybuilders or Tour de France drivers can only dream of that." They permanently generate about 30 watts per kilogram of muscle mass.

Many genes are also present in humans

Many of the genes found are also present in humans and are probably also needed for normal muscle function. According to the researchers, a change in these genes often leads to muscle diseases. For example, it is known that mutations in the laminin genes are responsible for some form of degenerative muscle disease, muscular dystrophy.

"Knowing about such connections could help in the future to recognize muscle diseases earlier and treat them individually", hopes Schnorrer.

(idw - Max Planck Institute for Biochemistry, 11.03.2010 - DLO)