Using Salamanders to Study Regeneration
by Jessica Driscoll
Dr. James Monaghan, an assistant professor of regeneration biology at Northeastern University, has been studying the Mexican axolotl salamander’s amazing regenerative properties to discover the cellular and genetic basis of tissue regeneration — findings that could have a huge impact on regenerative medicine.
The axolotl, a species indigenous to Lake Xochimilco near Mexico City, has the ability to regenerate many different tissues — from its limbs to parts of its brain, its heart, its lower jaw and even its spinal cord — according to Monaghan.
“They can regenerate all the essential new neurons and connections, allowing them to walk again after being paralyzed,” said Monaghan.
The long-term goal, he said, is to use the genetic findings of the axolotl to impact the work of regenerative clinicians and bioengineers.
The axolotl is known to retain its juvenile, or larval, features throughout its life — a condition called neoteny — so it remains aquatic and keeps its gills.
Animals like the axolotl — with the ability to regenerate the spinal cord — seem to maintain and activate their progenitor neural stem cells throughout their lives which differs from species like humans, according to Monaghan, that have a limited number of these neural cells.
“It is thought that certain fish, and these salamanders, have spinal cords kind of like ours when we were embryos,” he said.
Species like the zebrafish, Xenopus frog and axolotl are the primary vertebrate models being used for regeneration studies, and they’ve been investigated more over the last decade since tools have been created to locate and test the genes in these animals. Researchers can actually graft tissue from one axolotl to another, according to Monaghan, and then track what cells do during regeneration.
According to various sources, axolotls can grow up to a foot long — though most remain smaller — and can be black, brown or white, especially when bred in captivity. Due to water pollution and other factors, the axolotl has become an endangered species in Mexico. They are bred frequently in captivity, and even kept as pets, and can have a lifespan of about 15 years.
Monaghan said the axolotl, and its amazing regenerative properties, has recently become a much more mainstream topic of study.
Thanks to Northeastern’s cooperative education program, four undergraduate students will be joining Monaghan in the lab next semester to assist in his axolotl research.
“I really like the idea of co-op learning in terms of undergraduates,” he said. “Part of the reason I got into science was because my undergraduate education had internships, which led to the lab, which led me to graduate school and got me here today. It’s a learning platform that’s really effective for training students in science.”
December 21, 2012 EDIT: news@Northeastern published a story about Monaghan and his work with salamanders. The article can be found here.