EXPRESSION OF THE GENES FOR THE EPIDERMAL GROWTH-FACTOR RECEPTOR AND ITS LIGANDS IN PORCINE CORPORA-LUTEA

Using reverse transcription-polymerase chain reaction (RT-PCR), transcripts for EGF receptor and for EGF, transforming growth factor-alpha (TGFalpha), amphiregulin (AR) and heparin binding-EGF (HB-EGF) were detected in porcine corpora lutea at day 4, 10 and 20 of the estrous cycle. No cycle-dependent changes were apparent in the expression of the receptor, AR or TGFalpha. In contrast, HB-EGF mRNA levels appeared highest on day 4 during luteal growth and development, whereas EGF mRNA levels appeared highest on day 20 when the corpora lutea undergo luteolysis. These results suggest that luteal function may be subject to regulation by members of the EGF family acting in an autocrine, paracrine or intracrine manner.