University of California, Berkeley

Why do embryos form limbs while postnatal humans form scar tissue? This fundamental question remains elusive under existing medical research paradigms. Current knowledge of amphibian limb regeneration cannot explain the lack of functional tissue re-growth in adult mammals. Although limb regeneration via blastema has been observed in neonatal mice, little is known in cellular or molecular terms. Consequently, controlling and enhancing postnatal organogenesis for therapeutic ends appears to be an intractable challenge. Thus, the researchers seek to transform present understanding of the dramatic decline in regenerative capacity after birth by inventing technology capable of probing cellular and molecular determinants of regeneration in single mammalian cells. Their combined efforts will develop: 1) a novel cell-sorting tool to isolate from tiny tissue clusters the single cells that are pivotal to mammalian tissue regeneration; 2) new tools to study molecular mechanisms orchestrating the regenerative behavior at single cell levels; and 3) 3D ex-vivo systems to recreate the regenerative processes biosynthetically, thereby identifying molecular cues driving tissue regeneration. This single-cell approach may surmount prevailing limitations, thus advancing the frontiers of biomedicine and engineering.