Silencing in mice

In an Advanced Online Publication in Nature Genetics, Lewis et al. describe a simple technique for silencing gene expression in postnatal mice using RNA interference (RNAi) (Nature Genetics 29 July 2002, doi:10.1038/ng944). The authors exploited a 'high-pressure delivery' technique to deliver siRNA (short interfering RNA) to the organs of postnatal mice. They injected plasmid solutions into the tail vein and monitored expression of co-injected constructs encoding a firefly luciferase reporter gene. They achieved up to 90% inhibition levels in the liver, spleen, kidney, lung and pancreas. Inhibition of gene expression in the liver was dose-dependent - as little as 0.05 μg siRNA caused a 36% reduction in luciferase gene expression. Lewis et al.also show that injecting siRNA could effectively inhibit transgene expression.