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Movies Prepared by Students in the Course:
Keratocyte Motility: Migrating goldfish epidermal keratocytes in culture. Keratocytes are amongst the fastest migrating metazoan cells and originate from the protective epithelial layer surrounding fish scales.
GFP-Actin: Drosophila S2 cells expressing GFP-actin were imaged using a spinning disk confocal microscope (Solamere Technologies). Retrograde flow of actin from the leading edge is seen.
Squid Kinesin: Students prepared a kinesin preparation from squid nervous tissue and then tested it using an in vitro motility assay. Movie shows fluorescently microtubules gliding over a glass surface coated with kinesin in the presence of ATP.
Pho84 Endocytosis: Pho84 endocytosis in response to increased intracellular phosphate levels in S. cerevisiae.
Symmetry Breaking: Dual-channel imaging of symmetry breaking in in vitro motility system assembled from purified protein components. ActA-coated 5µm polystyrene beads were first incubated in a mixture of Arp2/3, capping protein, and Alexa488-labeled actin, then transferred into an equivalent mixture containing TMR-labeled actin and visualized using wide-field illumination. The use of a trace amount of TMR-labeled actin—approximately 1 fluorophore for 20,000 actin monomers—produces fluorescent speckles, which can be used as fiducial marks to study network dynamics. This experiment shows that new actin growth on the surface of the bead pushes older layers outward, and the speckles can be tracked to confirm the presence of elastic strain in the shell before symmetry breaking (not shown).
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