Trimethyltin inhibits the chemotaxis of Dictyostelium discoideum amoebae

The effect of trimethyltin (TMT) on the chemotaxis of Dictyostelium discoid eum amoebae in developing concentration gradients of folic acid (FA), CAMP, Ca2+, and Mg2+ has been studied with quantitative, computer-assisted metho ds. A "U" shaped pocket-like chamber, permitting the monitoring of the loco motion of individual cells, was used to observe the chemotactic response of amoebae. We found that TMT slightly affected the motile activity of cells but completely inhibited the chemotactic response of Dictyostelium discoide um cells towards all the tested chemoattractants. Moreover, the treatment o f Dictyostelium amoebae with TMT caused the disruption of microtubules, sug gesting that they have a role in the polarization and directional movement of these cells.