We analyzed the expression of mRNAs for growth factor receptors with receptor tyrosine kinases [ErbB3 (a member of the EGF-R subfamily), insulin-like growth factor-I receptor (IGF-I-R), basic fibroblast growth factor receptor (bFGF-R) and platelet-derived growth factor receptor α (PDGF-Rα)] by reverse transcription-polymerase chain reaction during in vitro development (10 to 168 h of in vitro insemination: zygotes to blastocysts) of porcine ova matured and fertilized in vitro. Transcripts for IGF-I-R, bFGF-R and PDGF-Rα were detectable in ova at all stages of in vitro development. Transcripts for ErbB3 were present in embryos from the late pronucleate stage onward. The results provide evidence that several growth factor receptor mRNAs are present in porcine ova during development in vitro.