Thyroid Hormone and Follicle-Stimulating Hormone Regulate Müllerian-Inhibiting Substance Messenger Ribonucleic Acid Expression in Cultured Neonatal Rat Sertoli Cells**This work was supported by NIH Grant HD-29376 (to P.S.C.). Portions of this work were presented in abstract form at the 23rd Annual Meeting of the American Society of Andrology, Long Beach, CA, March 1998.