The presence of proopionmelanocortin (POMC)-like mRNA has been demonstrated
in a variety of extrapituitary tissues including hypothalamus,1 placenta,2 ovary,2 and
testis.3 In amphibians, the POMC gene is actively expressed in the pituitary, both in
melanotrope cells of the pars intermedia and in corticotrope cells of the pars distalis.
4–6 POMC gene expression in peripheral organs has also been investigated in
Rana esculenta,7 indicating that POMC is actually synthetized in the ovary. Previous
studies have shown that POMC-derived peptides are involved in local control of
ovarian function and display seasonal changes.8,9 The aim of the present work was
to develop a competitive reverse transcriptase polymerase chain reaction (RT-PCR)
method using a synthetic, deletion mutant of POMC cRNA as an internal standard
in order to quantify the amount of POMC mRNA in the ovary of Rana esculenta
