John L. Loeb Associate Professor of the Natural Sciences
Curator in Invertebrate Zoology
Department of Organismic & Evolutionary Biology
Museum of Comparative Zoology
All animals undergo embryonic development, the process by which a single cell produces a multicellular organism, to establish their body plans. Many, but not all, animals can recapitulate parts of this process after the completion of embryogenesis, when they undergo regeneration as adult animals. My research group focuses on the mechanisms of whole-body regeneration, the striking phenomenon where animals can regrow entire bodies from small fragments, often via the use of large populations of adult stem cells. The widespread but variable occurrence of regeneration across the tree of animal life raises the question of how regeneration evolved, and we seek to determine whether any fundamental, unifying molecular and cellular principles operate during regeneration and stem cell regulation in distantly related animals. Over the last several years, we have focused on our newly established model system, the three-banded panther worm Hofstenia miamia, to develop frameworks for identifying these mechanisms.
In this talk, I will focus on two major advances from our research: 1) We developed an approach to build gene regulatory networks for regeneration, which identified the mechanism for how an embryonic process for patterning is activated during regeneration and revealed a potentially conserved principle of regeneration. 2) We used transgenic worms to determine how the adult stem cells that power regeneration in H. miamia are made in embryos, knowledge that is further enabling us to construct a regulatory network for stem cells. The approaches we have developed in H. miamia have revealed new insights into mechanisms of regeneration and stem cells, and they can now be applied to other research organisms, fueling comparative studies.