Abstract
This study was carried out to examine, by the reverse transcription-polymerase chain reaction (RT-PCR), whether growth factor mRNAs [epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), transforming growth factor-α (TGF-α), basic fibroblast growth factor (bFGF) and platelet-derived growth factor A chain (PDGF-A)] express in porcine cumulus-oocytes complexes (COCs) during maturation in vivo and in vitro. Porcine oocytes or their surrounding cumulus cells were analyzed immediately after collection (0 h), at 12, 24, 36 and 42 h of in vitro maturation, and at 42 h of hCG injection in eCG primed gilts, respectively. EGF, IGF-I, bFGF and PDGF-A mRNAs were detectable in both oocytes and cumulus cells at all stages of in vitro maturation. TGF-α mRNA was detectable in cumulus cells at all stages of in vitro maturation, whereas TGF-α mRNA in oocytes was not detected throughout in vitro maturation. In addition, the expression patterns of those genes in COCs matured in vivo were entirely consistent with those in COCs matured in vitro. These results provide the evidence that several growth factor mRNAs are present in both oocytes and cumulus cells during maturation and support the concept that those factors are involved in the regulation of porcine oocyte maturation.
