Meeting Abstract
Vertebrates interact directly with their environment largely through their epithelia. To enhance these interactions, most vertebrates deploy various accessory structures in these high-contact regions of their bodies, called epithelial appendages. These include scales, hair, feathers, teeth, and many other organs. Despite their vastly different shapes and compositions as mature organs and structures, epithelial appendages begin development by relying on a surprisingly conserved set of signals and cell-cell interactions, and exhibit curiously similar histogeneses. Another character shared by most epithelial appendages is their capacity to regenerate. In most cases, this process is undergone constantly throughout the life of an organism, either in a facultative or obligate manner (i.e. prompted by damage or constant renewal). Given the recently published evidence for the conservation, and perhaps homology, of epithelial appendage development, we hypothesized that the regenerative process would also be conserved between disparate organs such as teeth and hair, namely that the stem cells contributing to this process would be marked by similar sets of gene expression. Using previously published information on gene expression during mammalian hair regeneration, we assayed the expression of stem cell markers during tooth replacement in two fish species: zebrafish (Danio rerio) and the threespine stickleback (Gasterosteus aculeatus). We find expression overlap consistent with a conserved regeneration process in these distantly-related epithelial appendages.
