Sign up for our daily briefing
Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.
Stay on top of the latest market trends
Subscribe to Axios Markets for the latest market trends and economic insights. Sign up for free.
Sports news worthy of your time
Binge on the stats and stories that drive the sports world with Axios Sports. Sign up for free.
Tech news worthy of your time
Get our smart take on technology from the Valley and D.C. with Axios Login. Sign up for free.
Get the inside stories
Get an insider's guide to the new White House with Axios Sneak Peek. Sign up for free.
Catch up on coronavirus stories and special reports, curated by Mike Allen everyday
Catch up on coronavirus stories and special reports, curated by Mike Allen everyday
Want a daily digest of the top Denver news?
Get a daily digest of the most important stories affecting your hometown with Axios Denver
Want a daily digest of the top Des Moines news?
Get a daily digest of the most important stories affecting your hometown with Axios Des Moines
Want a daily digest of the top Twin Cities news?
Get a daily digest of the most important stories affecting your hometown with Axios Twin Cities
Want a daily digest of the top Tampa Bay news?
Get a daily digest of the most important stories affecting your hometown with Axios Tampa Bay
Want a daily digest of the top Charlotte news?
Get a daily digest of the most important stories affecting your hometown with Axios Charlotte
The International Space Station over Earth. Photo: NASA via Getty Images
Genetically enhanced mice retained or increased muscle mass after spending a month on the International Space Station.
Why it matters: The findings of the study, published Monday in the journal Proceedings of the National Academy of Sciences, suggest that muscle and bone loss could be mitigated for astronauts on space flights as well as for people on Earth who experience muscle degeneration.
What they did: The nonprofit Jackson Laboratory provided 40 black, female mice that were placed on a SpaceX rocket that traveled to the space station for the "Rodent Research-19" experiment.
What they found: 24 mice that were left untreated experienced muscle and bone mass loss of up to 18%.
- But eight "mighty mice" lost none of their brawn after being modified to lack the protein myostatin, which blocks a molecular signaling pathway.
- The muscles increased noticeably in eight other mice given the "mighty mouse" treatment in space after they returned to Earth in a SpaceX Dragon capsule on Jan. 7.
What they're saying: Lead researcher Se-Jin Lee, of the Jackson Laboratory, and wife Emily Germain-Lee, of Connecticut Children's Medical Center, who also took part in the study, told AP the results were encouraging.
- But Germain-Lee added researchers were "years away" from testing the drug in people without concerns about "serious side effects."
- Lee said they were looking at possibly sending more "mighty mice" to space for a longer duration.
Of note: NASA astronauts Andrew Morgan and Jessica Meir and Christina Koch — who made history with the first female spacewalk last October — cared for the mice on the ISS, and they're listed as study co-authors.