Compare a normal mouse with a “twice-muscled” mouse. The “mighty mouse” was developed at the University of Connecticut School of Medicine. (AP)

Compare a normal mouse with a “twice-muscled” mouse. The “mighty mouse” was developed at the University of Connecticut School of Medicine. (AP)

The International Space Station, where the mice spent time (AP)

The International Space Station, where the mice spent time (AP)

The astronaut mice returned to Earth in a type of re-entry called a splashdown. (AP)

The astronaut mice returned to Earth in a type of re-entry called a splashdown. (AP)

The muscle-bound mice held on to their muscle mass during a one-month space mission. (AP)

The muscle-bound mice held on to their muscle mass during a one-month space mission. (AP)

Mighty Mice in Space

Posted: November 1, 2020

Splash!

Mutant “mighty mice” parachute into the Pacific Ocean . . . on their way back from outer space!

The mighty mice spent a month on the International Space Station. What made them so mighty? Scientists changed their genes. A pair of proteins keep muscles from growing and growing and growing. Scientists blocked these proteins in the mice. The mighty mice developed twice as much muscle as regular mice.

In outer space, muscle—both mouse and human—loses mass. But the super-gene mice didn’t lose muscle mass during their journey. That’s a triumph for science . . . and a boon for astronauts too. The breakthrough could keep astronauts from losing muscle and bone on long space trips like Mars missions. It could also help people on Earth who can’t get out of bed or who need wheelchairs because of weak muscles.

Forty young female black mice rocketed to the space station in December. Twenty-four of these were just regular mice. During their journey, these lost a lot of muscle and bone mass—just what scientists expected. But the eight genetically engineered “mighty mice” kept their bulk. Their muscles remained similar to those of other “mighty mice” that stayed behind at NASA’s Kennedy Space Center.

Eight normal mice received the mighty mouse treatment in space. They returned to Earth with bigger muscles than they left with. A SpaceX capsule brought all 40 mice back in good condition in January.

When will the new muscle tech be used on people? Not for a long time. Scientists have to make sure it will work on humans without harming them.