Fig. 2. The Con phenotype of Exp mutants. Nomarski images of the tail region of wild-type and Exp mutant hermaphrodites (A-D) and their male counterparts (E-H). Arrows indicate the width of the intestinal lumen. N2 hermaphrodites and males are neither expulsion defective (Exp) nor Constipated (Con). dsc-1(qm133) (B) exp-1(sa6) (C) and unc-25(e156) (D) hermaphrodites are Exp and, as a result, exhibit the Con phenotype, as the gut lumen fills with bacterial debris and becomes distended. Neither dsc-1 (F) nor exp-1 (G) males are Con, indicating that they are not expulsion defective. By contrast, unc-25(e156) males are Exp, and as a result are severely Con (H). Scale bar: 10 µm.