Figure 1.

Evolutionary neuronal remodeling between nematode strains. (a) In C. elegans three sets of neurons, ASH, FLP and OLQ, mediate aversion to light mechanical stimulation of the nose (top). The same response was found to require ASH alone in C. sp. 3 (bottom). (b) In C. elegans, only the ASH neurons are necessary for sensing high osmotic stress (top). This response was sensed in P. pacificus by the ADL neurons in addition to the ASH neurons (bottom). Arrows indicate the direction of the response.