Table 1.

Comparison of cell cycle parameters of CNS cells from larvae reared on erg2Δ or wild-type (WT) yeast

Yeast fed, time dissected Mitotic index* % G1 %BrdU label
WT 1.16 69.85 9.97
erg2Δ day 1 1.36 73.14 8.39
erg2Δ day 2 0.99 72.20 4.48
  • * The mitotic index in the CNS of larvae reared on WT yeast dissected at 110-116 hours. AED was compared to larvae fed erg2Δ yeast dissected at 110-116 hours AED (day 1) and at 130-136 hours (day 2). For each set, data was collected from 12-15 larvae and 4-10 fields were studied per larva. All nuclei in the field were counted. The mitotic index was computed by calculating the percentage of cells undergoing mitosis. The difference in the mitotic index for each set was not found to be statistically significant as calculated by G-test for goodness of fit.

  • In a separate experiment, larvae were fed BrdU laced food for 3 hours and immediately dissected. Quantitation of DNA content based on DAPI fluorescence intensity allowed us to categorize the cells in G1 or S/G2 phase of the cell cycle. Nine to ten larvae were used for each time point per yeast fed and at most five fields were scored per larva. As shown in the table, an increase in the proportion of cells in G1 phase was observed in larvae reared on erg2Δ yeast (P value <0.01 computed by G-test). A decrease in the proportion of cells labeled with BrdU was seen in larvae fed erg2Δ yeast at 136 hours AED (P value <0.001 computed by G-test) when compared to larvae dissected at 110-116 hours irrespective of the yeast fed.