Investigating Dynamics of Tissue Regeneration via Live Imaging of Zebrafish Scales

Regeneration occurs throughout the animal kingdom and is a well-studied

feature of many model organisms, yet the field lacks a fundamental understanding of

the real-time dynamics of cell behavior during regeneration. I discuss how existing

knowledge of regeneration may be used to inform efforts to translate these remarkable

feats of animals to human regeneration and present research that uses live imaging to

improve understanding of cell origins and diversification during regeneration in the

scale, focusing specifically on osteoblasts the matrix-depositing cells that divide and heal

bone injuries. I developed an imaging platform to monitor and quantify individual and

collective behaviors of osteoblasts in adult zebrafish scales. I show that a founder pool

of osteoblasts emerges through de novo differentiation within one day of scale plucking,

then diversifies across the primordium by two days after injury, with region-specific

changes in proliferation, cell shape, and cell death rates coincident with acquisition of

mature scale morphology. I also demonstrate a role for Fgf signaling in scale

regeneration and present tools for high resolution imaging studies of basal epidermal

cells during skin and scale injury. These findings demonstrate the value of live imaging

in revealing novel biology and gaining a more complete picture of the many complex

processes that must be elegantly choreographed to achieve tissue regeneration.