Fig. 3. Effects of FK506 on the incorporation of [3H]deoxythymidine into the acid-insoluble fraction from cells of Suberites domuncula. Single cells were incubated in sea water for 2 days and subsequently exposed to different concentrations of FK506 for 24h, as described in Materials and methods. The acid-insoluble fraction was examined and the incorporation of 3H correlated with the protein content of the sample. Values are means ± S.D. of eight experiments.