Specific Inhibition of Transient and Stable EGFP Gene Expression by Double Stranded RNA Interference in Mouse Preimplantation Embryos

Double stranded RNA （dsRNA） interference is a useful tool for interfering with gene function by promoting the sequence－dependent degradation of targeted mRNA in several organisms. In the present study, in order to confirm and improve the effect of dsRNA, we investigated an inhibitory effect of dsRNA on both transient and stable gene expression of enhanced green fluorescent protein （EGFP） in mouse primplantation embryos. In the transient expression system, the rates of fluorescent embryos were significantly decreased by co－injection of EGFP dsRNA and EGFP expression vector fragment into the pronucleus of zygotes. In the stable expression system, EGFP expression in transgenic embryos was significantly decreased by injection of EGFP dsRNA into both the pronucleus and cytoptasm of zygotes, but, Cytoplasmic injection caused a more significant EGFP inhibition than pronuclear injection . In quantitative PCR analysis, the expression of the EGFP gene was also inhibited by dsRNA injection, whereas the endogenous gene expression was not affected. These data suggest that dsRNA can inhibit the specific gene expression without affecting the de velopment and expression of other genes.