Introduction & Objective: During oogenesis, mRNA is actively transcribed and accumulated in the growing oocytes, and then the transcription stops. Transcription silencing will continue during early embryonic stages at least up to the time when the embryonic genome is activated. Thus the earliest stages of embryogenesis in mammals and other animal species are depending on stored maternal RNAs and proteins. Degradation of maternal mRNAs is a way to control their translation. The aim of this study was investigation of the degradation pattern of some of these mRNAs.

Materials & Methods: In this experimental study, some oocyte specific genes including H1oo, c-mos, tPA and Gdf9 were selected and relative amounts of these transcripts were examined in oocyte(metaphase II) and one-cell mouse embryos, 3, 6, 9 and 12 hours after insemination using Real-time PCR, and compared with Cyclin A2 and Hprt mRNAs.

Results: The results showed that oocyte specific mRNAs had low stability and degraded in 12 hour embryo and excluded from oocyte cytoplasm while Cyclin A2 and Hprt mRNAs did  not.

Conclusion: These results indicated different stability of mRNAs in oocyte and embryo.