Inverse affects on thymidine incorporation in dissociated blastula cells of the sea urchin Paracentrotus lividus induced by butanol treatment and Fab addition.

When dissociated blastula cells of the sea urchin Paracentrotus lividus were prevented from aggregating by extracting them with 2.5% n-butanol in sea water, they became unable to incorporate labelled thymidine, like over-diluted dissociated cells. If, however, cells were prevented from aggregating by the addition of Fab against plasma membranes, thymidine incorporation was not blocked, but increased compared to that of spontaneously aggregating cells. At the same time amino acid incorporation also increased.