In the in vivo experiment, 20 intermolt males (mean wet mass of 30±2·g) were divided into three groups (of seven, seven and six). In the first group, the XO–SG complexes were surgically
removed from seven males, and four of these were repeatedly injected with 20E to a maximum concentration of 1000·pg·l–1. The other three crayfish were sham-injected with carrier. The crayfish were sacrificed 1·day after ecdysis, and hepatopancreatic RNA was extracted. In the second group, four of the intermolt males were repeatedly injected with 20E as