|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1995 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1994 : ¥1,400,000 (Direct Cost : ¥1,400,000)
This study was carried out examine, 1) by the reverse transcription-polymerase chain reaction (RT-PCR), whether cytokine mRNAs [epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), insulin-like growth factor-I (IGF-I), platelet derived growth factor-A (PDGF-A) and transforming growth factor-a (TGF-a)] and cytokine-receptor (R) mRNAs (EGF-R,bFGF-R,IGF-I-R,PDGF-Ra) express in porcine ova during maturation and after fertilization in vitro, 2) the effect of inhibitors for receptor-tyrosine kinase (genistein and herbimycin A) on cumulus mass expansion (CME) and nuclear maturation of porcine cumulus-oocytes complexes (COCs) in vitro, and 3) the effect of delayd insemination in vitro on the developmental capacity to blastocyst in porcine embryos derived from in vitro maturation and fertilization. The results are as follows ; EGF,bFGF,IGF-I and PDGF-A mRNAs were detectable at all stages of maturation and fertilization, but were not detected at 8-to 16-cell stages. TGF-a mRNA was only dctectable after 2-cell stage of development. IGF-I-R and PDGF-Ra mRNAs were detectable at all stages of maturation, fertilization and development. EGF-R and bFGF-R mRNAs were detectable at all stages of maturation and development, but were not detected at early stage of fertilization. The addition of genistein or herbimycin A to maturation medium significantly decreased the rates of CME and oocytes with metaphase II in dose-dependent fashion. The delayd insemination in vitro was effective for the increase of rate of embryos developed to the blastocyst stage. These results indicate that porcine ova show the temporal and stage-specific expression patterns of cytokine and its receptor mRNAs during in vitro maturation and after fertilization, and that the signal transduction pathway for induction of CME and the progression of oocytes to metaphase II involve cytokine-sensitive process.