GENE-EXPRESSION AND PEPTIDE LOCALIZATION FOR EPIDERMAL GROWTH-FACTOR RECEPTOR AND ITS LIGANDS IN PORCINE LUTEAL CELLS

The present study was undertaken to determine the expression of the ge nes for epidermal growth factor receptor (EGF-R), and two of its ligan ds, epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) in isolated large (LLC) and small (SLC) porcine luteal ce lls by reverse transcription-polymerase chain reaction (RT-PCR), and t o localize their peptides in whole corpora lutea (CL) as well in isola ted UC and SLC by immunocytochemistry. RT-PCR revealed strong cDNA sig nals for EGF-R and EGF in both LLC and SLC, and for TGF-alpha in LLC. The signal for TGF-alpha message in SLC was relatively weaker but dete ctable. Immunocytochemistry revealed intense EGF-R staining in LLC and SLC in both isolated and intact CL preparations. On the other hand, i mmunoreactive EGF and TGF-alpha appeared to be present only in LLC in intact CL sections, and isolated luteal cell preparations confirmed th eir presence in LLC and absence in SLC. These results suggest an autoc rine/paracrine role for EGF and TGF-alpha in luteal functions.