Imagine losing an arm or leg and thinking “No problem! It will grow back.” Now, imagine finding a bump on your big toe one day, only to have it grow into a complete clone of you that buds off and walks away. Laughable, right?
But that’s exactly what earthworms and their aquatic cousins can do. Duygu Özpolat, a fellow at the Marine Biological Laboratory, wants to know how, and why not all animals can do the same.
Özpolat hasn’t always worked with worms. She started with chicken embryos.
“They are actually terrible at regenerating,” Özpolat explained. “But the idea there was to see if we can induce regeneration in an organism that's not good at it.”
It worked, at least partially. She couldn’t make a chicken regrow its wing, but she could get it to start re-growing part of its elbow joint. And that provides clues as to what regeneration requires.
“I would say we're getting close to understanding what are the permissive situations, environments, or contexts that allow regeneration to happen,” she said. “But I think we have still a lot of ways to go to understand complete mechanisms of regeneration. It's not an easy thing to deal with.”
Özpolat is currently trying to develop methods for editing genes in the adult animals – a challenge, but one which could open a lot of doors when it comes to testing how regeneration works.
“It's going to allow us to test gene function during regeneration, right in the place that it's happening,” Özpolat said.
Özpolat’s work could someday help humans, who are distinctly regeneration-challenged. We can regrow liver tissue and, as children, we can regrow fingertips (if they aren’t stitched, which has its own risks).
Regeneration is something that has been gained and lost multiple times in the course of animal evolution, and it’s not entirely clear why humans lost the ability, according to Özpolat. It may have to do with a trade-off between regeneration and a stronger, adaptive immune system. Or there may just not have been enough evolutionary pressure to maintain the resource-intensive capability.
But Özpolat’s primary interest is the basic biology of regeneration, and she finds it beautiful. Since she was a child, Özpolat has been both a scientist and an artist. Today, her two passions are interwoven, as she creates drawings, embroidery, and ceramics based on what she sees under the microscope in the lab.
“There is a big cross-talk between art and science for me,” Özpolat said. “I get artistic inspiration from my science work. But then my artistic work makes me a better scientist.”