The effect of starvation on the rate of food vacuole formation in Tetrahymena thermophila

Abstract

The objectives of the study were to determine if starvation has an effect on food vacuole formation in Tetrahymena thermophila and also to see if the effect from starvation on food vacuole formation is different in the mutant versus the wild-type. We began by placing mutant and wild-type T. thermophila into starvation medium (10mM Tris-HCl pH 7.5) and regular culture medium for 17 hours, and then reintroducing both into nutrient medium (SPP). India ink (1%) was then added to both the mediums to make the food vacuoles more easily visible. Glutaraldehyde (1%) was added to samples taken at the given time intervals as a fixative and to make counting food vacuoles less difficult. Food vacuoles were then counted at 5 different time intervals. The mean rate of food vacuole formation found was 0.911±0.142, 1.406±0.257, 0.760±0.195 and 2.742±0.789 in starved wild-type cells, wild-type control cells, starved mutant cells, and for mutant control cells respectively. Our results suggest the controls have an increased mean number of food vacuoles over time compared to starved cells. Further, another trend seen was that the controls generally have a higher rate of food vacuole production compared to the starved wild-type and starved mutant as indicated by the mean rate of food vacuole formation. The three factors that contributed to the results include sexual immaturity, uptake via pinocytosis and the inefficiency of phagocytosis of the mutant. In conclusion, we found that with our data we reject our H_O1, H_O2 and H_O3 and provide support for our H_a1, H_a2, H_a3