Integration failure of regenerated limb tissue is associated with incongruencies in positional information in the Mexican axolotl.

Little is known about how the newly regenerated limb tissues in the Mexican axolotl seamlessly integrate with the remaining stump tissues to form a functional structure, and why this doesn't occur in some regenerative scenarios. In this study, we evaluate the phenomenological and transcriptional characteristics associated with integration failure in ectopic limb structures generated by treating anterior-located ectopic blastemas with Retinoic Acid (RA) and focusing on the "bulbus mass" tissue that forms between the ectopic limb and the host site. We additionally test the hypothesis that the posterior portion of the limb base contains anterior positional identities.

Algae on the brain in bioengineering.

Özugur et al. recently pushed the boundaries of augmented physiology through artificial symbioses. They microinjected algal cultures into tadpole (Xenopus laevis) hearts.