The Axolotl (Ambystoma mexicanum), also known as the “Mexican salamander,” is a superhero of regeneration. Axolotls can functionally regenerate multiple body parts—including limbs, spinal cord, and parts of the brain and heart—without forming scar tissue. They are native to only one lake (Lake Xochimilco) in Mexico.
Axolotls are unusual among amphibians in that they reach adulthood without going through metamorphosis. When the axolotl genome was sequenced in 2018 it was the largest genome ever fully sequenced! (Scientists have since discovered two larger genomes). Axolotls have 32 billion base pairs compared to about 3 billion in humans.
Range: Lake Xochimilco in Mexico
Life Span in the Wild: 10 to 15 years
Size: Up to 12 inches
Weight: 2.11 to 8 ounces
Diet: Carnivorous: Worms, insect larvae, small crustaceans, fish
Status: Critically endangered in the wild
In the MBL’s Echeverri Lab, scientists studying these animals hope to decipher how the cells of axolotls respond to injury in the spinal cord, limbs, and skin at the cellular and molecular level, and how that process differs from healing in humans, who can’t regenerate. MBL Associate Scientist Karen Echeverri and her lab are identifying critical molecules, regulatory pathways and cellular processes in the axolotls underlying scar-free regeneration.