• Title Professor Emeritus of Biology
  • Education PhD, University of Chicago, 1966
  • Phone 617-353-1734
  • Area of Interest cell biology and motility; cytoskeleton, nervous, and ionic control of cilia; protozoan motility; cell junctions


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

  • Tamm, SL (2008). Views Article: Unsolved Motility Looking for Answer. Cell Motility and the Cytoskeleton65: 435-440.
  • Tamm SL, Tamm S. (2002). Novel bridge of axon-like processes of epithelial cells in the aboral sense organ of ctenophores. J Morphol. 254, 99-120.
  • Tamm SL. (1999). Locomotory waves of Koruga and Deltotrichonympha: flagella wag the cell. Cell Motil Cytoskeleton. 43(2), 145-58.
  • Tamm SL. (1999). Dynamic control of reversible cell adhesion and actin cytoskeleton in the mouth of Beroe. Microsc Res Tech 44, 293-303.
  • Tamm SL. (1999). Locomotory waves of Koruga and Deltotrichonympha: flagella wag the cell. Cell Motil Cytoskeleton 43, 145-158.
  • Tamm S, Tamm SL. (1995). A giant nerve net with multi-effector synapses underlying epithelial adhesive strips in the mouth of BeroĆ« (Ctenophora). J. Neurocytol. 24, 711-723.
  • Tamm SL. (1994). Calcium channels and signaling in cilia and flagella. Trends Cell Bio. 4, 305-310.
  • Tamm SL, Terasaki M. (1994). Imaging of calcium transients controlling orientation of ciliary beat. J. Cell Bio. 125, 1127-1135.

Courses Taught:

  • BI 118 Honors Biology
  • BI 485/685 Single Cell Eukaryotes
  • BI 544 Cell Motility
  • BI 555 Advanced Cell Techniques Lab
  • BI 735 Advanced Cell Biology

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