MUL1 and infection: N-Acetyl-d-galactosamine supplementation fully restored RNAi mul-1 nematode survival to the level of control nematode survival on nonsupplemented plates while having no effect on RNAi control nematode survival (Fig. 4D), which suggests that P. aeruginosa may specifically require N-acetyl-d-galactosamine from MUL-1 during infection and that MUL-1 is the predominant source from which P. aeruginosa obtains N-acetyl-d-galactosamine.