Creative Minds: Can Salamanders Show Us How to Regrow Limbs?

Jessica Whited

Jessica Whited /Credit: LightChaser Photography

Jessica Whited enjoys spending time with her 6-year-old twin boys, reading them stories, and letting their imaginations roam. One thing Whited doesn’t need to feed their curiosity about, however, is salamanders—they hear about those from Mom almost every day. Whited already has about 1,000 rare axolotl salamanders in her lab at Harvard University and Brigham and Women’s Hospital, Cambridge, MA. But caring for the 9-inch amphibians, which originate from the lakes and canals underlying Mexico City, certainly isn’t child’s play. Axolotls are entirely aquatic–their name translates to “water monster”; they like to bite each other; and they take 9 months to reach adulthood.

Like many other species of salamander, the axolotl (Ambystoma mexicanum) possesses a remarkable, almost magical, ability to grow back lost or damaged limbs. Whited’s interest in this power of limb regeneration earned her a 2015 NIH Director’s New Innovator Award. Her goal is to discover how the limbs of these salamanders know exactly where they’ve been injured and start regrowing from precisely that point, while at the same time forging vital new nerve connections to the brain. Ultimately, she hopes her work will help develop strategies to explore the possibility of “awakening” this regenerative ability in humans with injured or severed limbs.

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Copying and Reading the Book of Life Inside One Cell, Accurately

Microwell strip

Caption: The genome researchers collaborated with materials science engineers to create the arrays of microwells or compartments that each capture a single cell.
Credit: UC San Diego Jacobs School of Engineering

Decoding the complete DNA genome in a single cell has been a major goal of technology developers. But the methods aren’t quite able to deal with that yet.  So, for scientists to do this, they first need to make multiple copies of the DNA inside. Until now, the copying technology hasn’t been as accurate as scientists would like. If you think of the genome like a book, then our current copiers replicate certain chapters thousands of times, others just a few, and some not at all. As you can imagine, if you tried to read one of these copies, you’d be quite confused—and you certainly couldn’t rely on your reading for any medical purposes.

Now, NIH-funded researchers at the University of California, San Diego, have developed a new molecular technique that can accurately and uniformly copy the DNA inside a single cell [1]. Using this technique, they’ve already made some surprising discoveries.

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