Previous studies suggest that nerves play a role in limb regeneration. Wells et al. hypothesized that larger animals have more nerves, and that blastemas from a smaller animal grafted onto a large animal would cause the new limb to grow to the same size as the animal’s existing limb. Large (top; pink) and small (bottom; pink) axolotls were grafted with blastemas from small (top; green) and large (bottom; green) individuals, respectively. Regardless of the size of the blastema they received, the animals grew limbs matching their body size, suggesting that the number of nerves could play a role in determining the size of the regenerate limb.
Image credit: The figure was generated using BioRender.