Regulation of gene expression in mouse embryos and its embryonic cells through RNAi.

The ability to direct cell differentiation of embryo-derived cells should have considerable practical applications. A prerequisite for success is the availability of robust tools that allows efficient knockdown of specific genes to elucidate gene function and direct differentiation. Loss-of-function studies in the mouse have traditionally been carried out using gene knockout animals to obtain mutant embryonic cells. Despite improvements in this technology, it still remains a laborious method. In addition, the use of knockout for studying preimplantation embryonic cells is limited due to maternal contributions. RNA interference (RNAi) is a powerful genetic approach for specific gene silencing of target genes in which 21-23 nt small interfering RNAs work as sequence-specific RNAi mediators. Using RNAi approaches, gene function has been eliminated in mouse embryonic stem cells and carcinoma cells to direct cell differentiation. In mouse oocytes and embryos, RNAi eliminated both maternal and zygotic transcripts and disturbed normal development.