Figure 3. nprl2-mutant flies displayed GI tract motility defects. Fifteen-day-old yw and nprl21 males were used for the following analyses. (A) CAFE assay to quantify food ingestion. Error bars represent the SD from eight independent experiments. (B) Defecation rate assay to quantify food expulsion. Error bars represent the SD from five independent experiments. (C and D) Flies were starved in complete starvation medium (PBS with 1% agarose) for 10 hours and then fed dyed food for 30 min. The dyed food concentration in crops and guts was determined using a spectrophotometer. (E) The contraction rate of the crop was measured in dissected flies. Error bars represent the SD of the indicated number of data points. **P < 0.01, ***P < 0.001. N is the total number of flies used.