Figure 6.

MC fails to rescue Punch mutants due to dysregulation of nitric oxide synthase catalytic function. (a) Effect of 1 mM MC co-fed with 10 mM PQ on DA regulatory mutants, Catsup ²⁶/+, Pu ^Z22/+ and ple ²/+. Catsup and ple mutant flies showed extension of life span, while Pu mutants did not. NS = not significant. ** = P < 0.005 and represents significant differences between PQ and PQ with MC. (b) After 24 hr of PQ, or PQ with MC exposure, suppression of NOS was detected in wild type heads but not in Punch mutants where NO levels of non-PQ-treated Pu mutants assayed are significantly lower than NO levels of non-PQ-treated wild type heads. * or ^ϕ P = <0.05 and ** or ^## P = <0.005. (c) Co-feeding of L-NAME with 1 mM PQ reduced NO production in wild type and Pu mutants. ** = P < 0.005. (d) The survival of Pu mutants was improved by co-feeding PQ with L-NAME, but not with MC when compared with survival of Pu mutants on PQ alone. * represents significant differences between control and PQ-exposed flies, while ^# represents significant differences between flies fed PQ only and PQ with MC. ** = P < 0.005 and ^### = P < 0.001. NS = not significant. Error bars represent standard error of the mean and n = 100–120 fly heads for NOS assays and 50–60 flies for survival where experiments were replicated thrice with the same sample size.