The pancreas is a complex organ derived from the endoderm that is composed of two different cell populations, exocrine and endocrine. Work in the lab is interested in elucidating the molecular signals underlying specification of the pancreas. The lab uses the amphibian, Xenopus laevis, as its model organism to identify the master switch genes involved in endodermal organ development. It has been commonly assumed that as embryogenesis proceeds cells become irreversibly restricted in their cell fates. Recent work, however, has shown that there is much more plasticity in cellular differentiation, such that transdifferentiation between cell types is possible. The main goals of my research program are to define in detail the molecular lineage of the beta cell pathway from endocrine progenitors (directed differentiation), define the molecular lineage of liver to pancreas conversion (transdifferentiation), and elucidate how endodermal progenitor cells regulate proliferation and differentiation (regeneration).
Dr. Marko Horb
Director, National Xenopus Resource
7 MBL Street
Woods Hole, MA