Fig. 4. ncr-1 and ncr-2; ncr-1 mutants are hypersensitive to progesterone. Synchronized populations of N2, ncr-1, ncr-2, or ncr-2; ncr-1 strains (Gen 1, see Materials and methods) were cultured on NGM plates with (+) or without (–) 5 µg/ml cholesterol and 20 µg/ml progesterone. The development of wild-type and mutant worms were scored after 72 hours at 20°C. The results from duplicate experiments were pooled together and expressed as a percent value (n>50).