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Publications in VIVO

Tamm, Sidney Whitman Center Scientist, Whitman Center


We take advantage of the experimental virtues of comb jellies (ctenophores) and termite protozoa to investigate basic problems in cell biology and motility. We work on ctenophores at various marine stations to study the mechanism and coordination of ciliary motion, as well as the ionic and nervous control of cilia. By injecting fluorescent calcium probes and using high-sensitivity video microscopy, we image the pattern of stimulus-induced calcium flux into cilia that causes them to reverse beat direction and propel the ctenophore backwards. Some ctenophores keep their mouths closed by reversible cell-cell adhesion that disappears upon contact with prey and feeding. We use this novel system to study the dynamic control of cell actin-based junctions regulated by a newly discovered net of giant neurons. We also use symbiotic protozoa from the hindgut of American and Australian termites to investigate the mechanism of a unique rotary motor that continuously turns one part of the protozoan relative to the re of the cell (providing direct evidence for fluidity in cell membranes). Other termite flagellates possess remarkable arrays of microtubules and motile ectosymbiotic bacteria that are advantageous for studying cytoskeleton development and prokaryotic-eukaryotic relationships.

selected publications