Here we report a versatile mammalian expression vector called pRIGHT11 for production of small interfering RNA (siRNA) in cells. This vector uses opposing eukaryotic RNA polymerase III promoters U6 and H1 to drive the expression of short siRNA. We have demonstrated the effectiveness of pRIGHT11-generated siRNA in sequence-specific inhibition of transfected reporter genes and endogenous genes. Furthermore, this retrovirus-based vector can carry a random library of siRNA, and thus can be applied to rapid screening of novel genes involved in specific cellular responses.
