A steep thermal gradient thermotaxis assay far the nematode Caenorhabditiselegans

The nematode Caenorhabditis elegans with its well-described nervous system is one of the multicellular organisms of choice to study thermotaxis. The n euronal circuitry for thermosensation has been analyzed at the level of ind ividual cells. Two methods have previously been described to study the beha vior of C. elegans with respect to temperature: 1) isothermal tracking assa ys and 2) linear thermal gradients (Hedgecock and Russell, 1975). Here we p resent a short linear thermal gradient assay which is faster and which allo ws statistical evaluation of different populations using a thermotaxis inde x. Thin agar plates are used on which a temperature gradient from about 10 degrees to 30 degrees is induced over the distance of about 5 cm. The short linear thermal gradient uses inexpensive materials so that multiple tests can be performed in parallel in a short period of time. genesis 27:141-144, 2000, (C) 2000 Wiley-Liss, Inc.