D. Quantification of three categories of midguts treated with the pH indicator Bromophenol Blue in Drosophila carrying esgts-GAL4-driven UAS-lacZ (control), Las RNAi, or Las RNAi with ALA administration. The numbers of quantified guts from left to right are 90, 90, and 90. Error bars show SD of three independent experiments. Data information: The statistical tests used in other panels were student's t-tests. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, and non-significant (NS) represents p > 0.05. 