Human genes may be altered when in outer space

A study in the journal BMC Genomics subjected fruit flies to microgravity (similar to the kind experienced by astronauts) for 22 days. The flies in microgravity reproduced less, and upon inspection, their genes had been substantially altered (some of the changes were attributable to the magnetism used to simulate microgravity, but some 200 gene changes seemed due to weightlessness alone). These changes involved genes regulating stress, temperature and immune responses, effects that could potentially become magnified over time -- particularly, for example, on a multiple-year mission to Mars.