Expression in male-specific structures is directed by all three promoters. Promoter pA directs expression in the spicule protractor muscles of the proctodeum and in a single male-specific neuron that is likely to be CP8 or CP9. Promoter pB directs expression in the spicule retractor muscles, gubernaculum retractor muscles, posterior oblique muscles, diagonal muscles, and the vas deferens. Promoter pC also directs expression in the vas deferens, as well as the seminal vesicle and the valve that separates the seminal vesicle and vas deferens. Thus
itr-1 is expressed widely in the sex-associated muscles and somatic gonad of males.