Researchers have identified a protein in fruit flies that affects locomotion in cold environments. This protein is related to human irisin and plays a role in locomotor efficacy and cold adaptation. This study highlights the evolutionary importance of this gene family in both invertebrates and mammals and suggests its important role in repairing muscle damage during intense exercise.
This gene, called Iditarod, appears to be responsible for the ability of movement to repair damaged cells.
As the days get shorter and colder in the Northern Hemisphere, those who decide to exercise in the morning may find it difficult to get up and run. A new study in PNAS has identified a protein whose deficiency makes exercise in the cold more difficult, at least in fruit flies.
While studying the effects of stress on metabolism and the body, a team from the University of Michigan Medical School and Wayne State University School of Medicine discovered a fly protein called the Iditarod, named after the famous long-distance dogsled ride across Alaska. It was named.
The link between autophagy and the Iditarod
They were particularly interested in a physiological process called autophagy, in which damaged parts of cells are removed from the body. By screening the fly genome, researchers discovered candidates that regulate key housekeeping procedures.
They demonstrated a link between autophagy and the Iditarod. fool, by tweaking the genetic makeup of some flies to overactivate autophagy in their eyes. Flies with too much autophagy had massive cell death and visible degeneration.Inactivating fool Genetic restoration of normal eye structure means fool Genes are involved in the process of autophagy.
Benefits of connecting with others and exercising
The next step for the research team was to look for similar genes, or homologues, in humans.
“When we looked at this gene in the human genome, the top hit was a gene called FNDC5, which is the precursor to the protein irisin,” said Dr. Jun Hee Lee of UM’s Department of Molecular and Integrative Physiology.
Previous research has shown that irisin is an important hormone involved in producing the musculoskeletal and other benefits of exercise in mammals, and also plays a role in cold adaptation.
Lee’s lab has long been interested in exercise as a mild form of physical stress.
“We realized that this gene may also be important for exercise. If so, we should be able to detect similar physiological effects in flies,” Lee said.
Working with Dr. Robert Wessels’ team at Wayne State University, which has developed a new method of training fruit flies, the researchers used a type of fly cliff climber that harnesses the insect’s instinct to climb out of a test tube.
They discovered that the flies had been bred to be defective. fool This gene was impaired in exercise endurance and did not show the improvements typically seen after training. Additionally, mammalian irisin is known to upregulate thermogenic processes important for cold tolerance. Interestingly, it flies without doing anything. fool I couldn’t stand the cold either.
What this tells us, Lee says, is that this gene family exists on Earth. invertebrates As in mammals, it appears to have been conserved throughout evolution and serves important functions.
“We believe that exercise helps clean the cellular environment through autophagy,” Lee said. “When you exercise intensely, your muscles get damaged and some of your mitochondria become dysfunctional,” Lee says. “The process of autophagy is activated to remove damaged organelles and toxic byproducts. fool Genes appear to be important in this process. ”
Lee next hopes to connect this research to previous research on exercise and physiological stress.
reference: “Iditarod, Drosophila Homolog of irisin precursor FNDC5is important for exercise performance and cardiac autophagy.” Tyler Cobb, Eileen Hwang, Michael Souker, Nam-Kung Shim, Eun-Soo Cho, Mariam Safdar, Myung-Jin Kim, Robert J. Wessels, Jun Hee・Written by Lee, September 18, 2023, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2220556120
Other authors include Tyler Cobb, Irene Hwang, Michael Soukar, Sim Namkoong, Uhn-Soo Cho, and Myungjin Kim.
