Further evidence for changes in the level of palmitoyl-CoA desaturase during thermal adaptation in Tetrahymena pyriformis.

Palmitoyl-CoA desaturase activity in microsomes was increased up to about 4-fold within 2 h after temperature shift from 39.5 to 15 degrees C. Compared with control cells, cycloheximide-treated cells indicated no induction of palmitoyl-CoA desaturase by a decrease in temperature. The results suggest that temperature acclimation requires an increase in the level of the desaturase enzyme content.