In vivo cytoskeletal dynamics of living fish embryos

In collaboration with Pat Wadsworth at UMass Amherst I have been studying the dynamics of the tiny fibers within each and every cell that gives the cell its shape, provides "railroad tracks" for the movement of vesicles from one part of a cell to another, and are involved in cell movements. Our approach has been to try to create embryos with fluorescent microtubules (panels A, B above) or microfilaments (panels C,D above) by injecting newly-fertilized eggs with a DNA plasmid for the tubulin or actin gene attached to the gene for green fluorescent protein (GFP). If and when the cells then express this DNA, their cytoskeleton will glow, allowing us to visualize these fibers. What is unique about our study is that we will be watching cells in an intact embryo. The killifish embryo is so exquisitely transparent that we can achieve images of a quality and resolution that used to be possible only with isolated cells crawling on glass.

 

Research Videos

For the following movies, we injected the GFP-actin plasmid to label microfilaments. Using a Perkin-Elmer spinning disc laser confocal microscope, we followed individual deep cell migration (for differential interference contrast sequences of migrating deep cells, see video pages linked here), as well as protrusive activity on the apical surface of epithelial enveloping layer cells.
Note: These movies should only take a short time (5-30 seconds) to load and play. You can click on links below, or listed at left.

INDIVIDUAL MIGRATING DEEP CELLS

Movie #1: Turning Deep Cell
Movie #2: Deep Cell Circus Movements
Movie #3: Actin Retrograde Flow in Migrating Deep Cell

ENVELOPING LAYER EPITHELIAL CELLS
Movie #4: Apical Ridge Dynamics
Movie #5:Apical Protrusive Activity