Fshb expression is abolished in pituitaries of cKO mice. Pituitaries were collected from 10-week-old control and cKO mice (n = 11 or 15 for control and cKO males. A, (n = 12) genotype for females; B, mRNA levels of gonadotropin subunits (Fshb, Lhb, and Cga), GnRH receptor (Gnrhr), Smad3, and Smad4 were measured by RT-qPCR. mRNA levels were normalized to the housekeeping gene Rpl19. Bars reflect group means (±S.E.). The data were analyzed by Student's t test. ***, p < 0.0001; **, p = 0.0004. n.s., not statistically significant.