Cellular localization of müllerian inhibiting substance messenger ribonucleic acid during human ovarian follicular development

Müllerian inhibiting substance is expressed in the human reproductive system and has been associated with oocyte meiotic arrest. In situ hybridization was used to selectively localize ovarian cells containing high levels of müllerian inhibiting substance messenger ribonucleic acid, a müllerian inhibiting substance precursor, during different stages of human follicular development. Müllerian inhibiting substance transcript was noted in the granulosa cells of primordial, primary, and antral follicles. Surprisingly, transcript was also identified within the cytoplasm of oocytes and throughout the ovarian stroma. Controls included sense oligoprobe, positive and negative tissue controls, and treatments minus the detection antibody. Localization of transcript within the cytoplasm demonstrates that active transcription of müllerian inhibiting substance messenger ribonucleic acid occurs within both fetal and adult human female gonads. The presence of müllerian inhibiting substance messenger ribonucleic acid within oocyte cytoplasm could implicate an autocrine role for müllerian inhibiting substance-derived peptides in the establishment of oocyte competence. (AM J OBSTET GYNECOL 1991;165:1881-6.)