While movement of Fgf-signaling to the limb mesenchyme accompanied a shift in function, the ultimate outcome remains a convergent tetrapod limb phenotype.
CRISPR-based lineage tracing in the axolotl shows that regenerated limbs are composed of the same cell lineages in the same frequencies as those that gave rise to the original limb.
Both gill musculature and the evolutionarily conserved cucullaris muscle are derived from unsegmented mesoderm adjacent to the first 3 somites, extending the posterior limit of cranial mesoderm.
The endosymbiosis between an alga and the spotted salamander shows several parallels to invertebrate-algal symbioses as well as to pathogen associations in vertebrate animals.
Upon injury, the regeneration of the adult axolotl brain rebuilds neuronal diversity, but alters the original long-distance circuitry and tissue architecture.
Homology of vertebrate skull structures should be based on evolutionary continuity and an appreciation of germ layer origins and inductive signaling in the embryonic head.
Experimental manipulation of a core DNA damage response factor and cell-cycle checkpoint regulators reveals a key role for these processes in the progenitor cells that fuel limb regeneration.
Elucidation of the molecular basis of early wound epidermis dependence during salamander limb regeneration reveals midkine as a key modulator of wound epidermis development and wound-healing resolution.