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ABLE 2007: University of Kentucky, Lexington, KY June 5-9. Host: Ruth Beattie
E-mail: rebeat1@uky.edu
Mini Workshop
Friday June 9
Johnson, Daniel A.
Oh where shall I go? What shall I do? Using Chlaymdomonas in
signal transduction experiments
Chlamydomonas reinhardtii is a biflagellate algae found in fresh water
and damp soil worldwide. It is an exceptional model for demonstrating
many principles of cell biology. Additionally, students can use them
to conduct a range of experiments they have designed. Participants in
this mini-symposium will learn how we use it for a two-week, inquiry-based
lab that teaches principles of signal transduction.
Chlamydomonas has several behaviors that students can measure easily in a teaching lab. One such behavior is binary phototaxis; at low illumination cells are positively phototactic, but above a certain brightness they abruptly switch and become negatively phototactic. This behavior depends on an eyespot that is linked to two distinct signal transduction pathways. Other behaviors such as flagellar growth and repair, and mating of compatible strains, etc. also are controlled by known signaling pathways. Students can manipulate these paths experimentally just by adding chemical agonists or blockers to the algal culture medium.
In our labs, students spend the first week learning how to quantify phototactic responses, and how to measure flagellar formation and regeneration. In a subsequent week, students conduct an experiment they have designed to test some aspect of signal transduction.
Participants will receive a copy of the complete sequence of exercises that we conduct, along with supplemental instructional and preparatory notes describing how we grow bulk cultures of vegetative cells and mating-competent gametes. They will also receive a list of the signaling activators and blockers that we let students use. I will show short videos of algal cells engaged in various behaviors, describe the most common types of experiments our students conduct, and point out resources and some other potential uses of this robust model system.