Health

Buff Rodents

Knocking out a gene endows mice with an unusually muscular physique.

Newsletter

Sign up for our email newsletter for the latest science news
 

The shoulder in the bottom photo belongs to a knockout mouse, so named only partly because of its brawny good looks. The one on top is from a normal mouse. Molecular biologists Se-Jin Lee and Alexandra McPherron at Johns Hopkins University School of Medicine knocked out a gene from the big mouse’s DNA. Mice without the gene doubled, and in some cases tripled, their muscle mass. Lee and McPherron discovered the gene about five years ago while examining genes known to regulate embryonic growth and development. To see exactly what the gene did, McPherron bred a line of mice that lacked it. We didn’t really know what would happen, she says. We thought maybe they would have no muscle at all. But then we saw the mutants had this funny body shape. Their shoulders and hips were very bulky. Underneath the skin, McPherron found rippling muscles. The muscle fibers were larger and more numerous than in normal mice, and even after a year the mutant mice show no other abnormalities. McPherron and Lee think their research can lead to meatier, leaner livestock, and possibly a treatment for people afflicted with muscle-wasting diseases like muscular dystrophy.

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Magazine Examples
Want more?

Keep reading for as low as $1.99!

Subscribe

Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 70% off the cover price when you subscribe to Discover magazine.

Copyright © 2021 Kalmbach Media Co.