Peter A. V. Anderson
(Ph.D. University of California, Santa Barbara, 1976)

Director of the Whitney Laboratory; Professor of Physiology and Functional Genomics, Neuroscience and Zoology

paa@whitney.ufl.edu

Regulation of Cellular Excitablitly

Over the years, our research has been on the factors that control the electrical excitability of nerve cells, particularly ion channels. Ion channels are proteins that control the movement of sodium, calcium and potassium through cell membranes, thereby producing nerve spikes and other electrical events.

Recently we broadened our focus somewhat and now work predominantly on the factors that regulate the excitability of one of the most fascinating cells in biology: the sting cells (cnidocytes) of jellyfish and other cnidarians (jellyfish, sea anemones and corals). Since cnidocytes, or sting cells, are arguably the most complex cells of any animal, they are likely to be energetically very expensive for the animals to produce. The investment the animal makes in producing these cells is intensified by the fact that they can only be used once. Not surprisingly, therefore, the discharge or firing of these cells is tightly regulated to ensure that they do not discharge at the wrong time. This work is being carried out using several jellyfish species, most notably the Portugese Man of War, Physalia.

Current Projects

The business end of a sting cell is a large capsule (the cnidocyst) that occupies most of the volume of the cell and envelops a tubule which, in nature, acts as a microscopic hypodermic needle to inject toxin into the animal’s prey. We are exploring the possibility of using sting cells as delivery systems for therapeutic agents such as pharmaceuticals or antidotes. We are working on a project that seeks, ultimately, to re-engineer cnidocytes so that instead of injecting toxins, they inject drugs or other chemicals of choice.

To achieve this goal we must understand the pathways and mechanisms by which the toxins are normally produced by the sting cell and then transported into the cnidocyst. The best way to do this is to identify all the genes that are active during the development and maturation of a cnidocyte. we are currently using high-throughput DNA sequencing technologies to sequence genes obtained from developing and mature cnidocytes. In addition, this approach has the benefit of providing important information about the synthesis and packaging of toxins. It will also provide a great deal of other useful information; most notably identification of all the toxins produced by the sting cells and a better understanding of the various mechanisms used to regulate cnidocyte discharge.

At the same time, we are exploring ways to isolate and culture interstitial cells, the stem cells that differentiate into cnidocytes. These stem cells will then be genetically re-engineered so that they synthesize and package the drug of choice into the cnidocyst and, hence, be used as a source of cnidocysts for microscale delivery devices.

Personnel

Peter A. V. Anderson, Professor
Christelle Bouchard, Postdoctoral Associate

Selected Publications

Anderson, P.A.V. and Bouchad, C.M. (In press) The regulation of cnidocyte discharge. Toxicon.

Price, R. B. and Anderson, Peter A. V. (2006) Chemosensory pathways in the capitate tentacles of the hydroid Cladonema. Invert. Neuroscience,6, 23-32.

Bouchard, C., Price, R. B., Money penny, C. G., Thompson, L. F., Zillhardt, M., Stalheim, L. and Anderson, Peter A. V. (2006) Cloning and functional expression of voltage-gated ion channel subunits from cnidocytes of the Portuguese Man O’War, Physalia physalis. J. Exp. Biol. 209, 2979-2989.

Kohn, A.B., Roberts-Misterly, J.M., Anderson, P.A.V., Khan, N., and Greenberg, R.M. (2003). Specific residues in the Beta Interaction Domain of a schistosome Ca2+ channel [beta] subunit are key to its role in sensitivity to the antischistosomal drug praziquantel. Parasitology 127: 349-356.

Anderson, Peter A. V. (2004). Cnidarian Neurobiology: what does the future hold? Hydrobiologia, in press.
Anderson, Peter A. V., Roberts-Misterly, J. and Greenberg, R. M. (In press) The evolution of voltage-gated sodium channels: were algal toxins involved? Harmful Algae.

Kohn, A.B., Anderson, P.A.V., Roberts-Misterly, J.M., and Greenberg, R.M. (2002) Schistosome calcium channel ß subunits. Unusual modulatory effects and potential role in the action of the antischistosomal drug praziquantel. J. Biol. Chem. 276: 36873-36876.

Anderson, Peter A. V. and Greenberg, R.M. (2001). Phylogeny of Ion Channels: Clues to Structure and Function. Comp. Physiol. Biochem. 129B, 17-28.

Kohn, A.B., Lea, J.M., Roberts-Misterly, J.M., Anderson, P.A.V., and Greenberg, R.M. (2001). Structure of three high voltage-activated calcium channel alpha₁ subunits from Schistosoma mansoni. Parasitology 124: 489-497.

Kohn, A.B., Anderson, P.A.V., Roberts-Misterly, J.M., and Greenberg, R.M. (2001). Schistosome calcium channel ß subunits. Unusual modulatory effects and potential role in the action of the antischistosomal drug praziquantel. J. Biol. Chem. 276: 36873-36876.

Jeziorski, M.C., Greenberg, R.M. and Anderson, Peter A. V. (2000). The molecular biology of invertebrate voltage-gated Ca²⁺ channels, J. exp. Biol., 203: 841-856

Jeziorski, M.C., Greenberg, R.M. and Anderson, Peter A. V. (1999). Cloning and expression of a jellyfish calcium channel beta subunit reveal functional conservation of the alpha₁ - beta interaction. Receptors and Channels, 6: 375-386.

White, G.B, Pfahnl, A., Haddock, S., Lamers, S., Greenberg, R.M. and Anderson, Peter A.V. (1998). Structure of a Putative Sodium Channel from the Sea Anemone Aiptasia pallida. Invert. Neurosci., 3: 317-326.

Jeziorski, M.C., Greenberg, R.M., Clark, K.S. and Anderson, Peter A. V. (1998). Cloning and functional expression of a voltage-gated calcium channel alpha₁ subunit from jellyfish. J. Biol. Chem., 273: 22792-22799.

Blair, K.L. and Anderson, Peter A.V. (1996). Physiology and pharmacology of turbellarian neuromuscular systems. Parasitology 113: S73-S82.

Blair, K.L. and Anderson, Peter A.V. (1994). Physiology and pharmacology of muscle cells isolated from the flatworm Bdelloura candida. Parasitology 109: 325-335.

Anderson, Peter A.V., Holman, M. A. and Greenberg, R.M. (1993). Deduced amino acid structure of a putative sodium channel from the scyphozoan jellyfish Cyanea capillata. Proc. Natl. Acad. Sci. 90: 7419-7423.

Blair, K.L. and Anderson, Peter A.V. (1993). Properties of voltage-activated ionic currents in cells from the brains of the triclad flatworm Bdelloura candida. J. exp. Biol. 185: 267-286.

Anderson, Peter A.V., A. Moosler and C.J.P. Grimmelikhuijzen (1992). The distribution of AnthoRF-amide-like immunoreactivity in scyphomedusae. Cell Tiss Res. 267: 67-74.

Holman, M. and Anderson, Peter A.V. (1991). Voltage-activated ionic currents in myoepithelial cells from the sea anemone Calliactis tricolor. J. exp. Biol. 161: 333-346.

Anderson, Peter A.V. (1990). Evolution of the First Nervous Systems, Peter A. V. Anderson (Ed.). Plenum Press, New York. 423p.

Anderson, Peter A.V. and M. C. McKay (1987). The electrophysiology of cnidocytes. J. exp. Biol. 133: 215-230.

Anderson, Peter A.V. (1987). Properties and pharmacology of a TTX-insensitive Na⁺ current in neurones of the jellyfish Cyanea capillata. J. exp. Biol. 133: 231-248.