Altering genes

Spending long periods at low gravity may alter genes, suggests a new experiment involving a magnet-powered trick used on Earth to simulate weightlessness in space.

Subjected to magnetic levitation that generated an effect similar to microgravity experienced by astronauts orbiting Earth, fruit flies experienced changes in crucial genes.

Humans won’t necessarily respond like fruit flies, but the system is considered an useful model for probing the effects of permanent free-fall on biology. However, it’s also possible that the gene disruption was caused by magnetism, not low gravity.

"We have tried to separate the effects of microgravity and magnetism, but we’ve learned it’s not so easy," said molecular biologist Raul Herranz of Centro de Investigaciones Biológicas in Spain, leader of the upcoming study in BMC Genomics. "We don’t know yet what is causing what — the magnetism or the microgravity?"

Sending anything into space is expensive. The cost to launch an experiment into low-Earth orbit can exceed as $10,000 per pound. Yet as the United States, Russia, China and other nations eye a human future off-Earth, understanding what will happen to our bodies is crucial.

NASA already knows that astronauts in space lose as much bone each month as they would in a year on Earth, where resisting gravity keeps muscles strong. But rigorously studying the molecular mechanisms behind those changes in humans — a large, highly complex creature — isn’t easy or ethical. As a result, researchers look to animal models in an Earth-based weightless environment.

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