Chemotaxis in tetrahymena.

Chemotaxis - that is oriented locomotion of single cells - was shown by motion analysis of Tetrahymena thermophila. An electronic registration of swimming tracks was carried out in gradients of chemoattractant established in a modified Zigmond chamber. The attractants used were proteose peptone, platelet extract and fibroblast growth factor. From 5 to 55 minutes after addition of the chemoattractant, 65% of the cells are oriented within the 180° angle segment towards the attractant compared to 51% in the control, containing no attractant. The figures are based on the measurement of 1567 and 499 tracks, respectively. Under the conditions used, cell migration towards the attractant is caused, solely, by an oriented movement (Chemotaxis) since the swimming speed was unaffected by the presence of the attractant. Similar results were obtained using T. pyriformis cells.