PROOPIOMELANOCORTIN (POMC) EXPRESSION AND IMMUNOLOCALIZATION OF POMC-RELATED PEPTIDES IN THE OVARY OF PROTOPTERUS ANNECTENS, AN AFRICAN LUNGFISH

Antisera against adrenocorticotropic hormone (ACTH), alpha-melanocyte- stimulating hormone (alpha MSH) and beta-endorphin were used to locali ze pro-opiomelanocortin (POMC)-derived peptides in the ovary of the Af rican lungfish Protopterus annectens by immunohistochemistry. Immunore activity was observed in the granulosa and the internal theca of the v irellogenic follicles. No immunoreactivity was observed in immature fo llicles. Using human POMC cDNA as the hybridization probe, POMC-like m RNA was identified in situ in cells of the granulosa and internal thec a of the vitellogenic follicles. No labeling was observed in primordia l follicles. The demonstration in the same cells of POMC mRNA and POMC -related peptides immunoreactivity indicates a local production of the opiate hormones. (C) 1997 Elsevier Science Inc.