High-efficiency gene knockdown using chimeric ribozymes in fish embryos

We report an effective gene knockdown technique in rainbow trout embryos using additional RNA components combined with ribozymes (R zs). Chimeric R zs (tR zCs) containing tRNA Val, R z against GFP, and a constitutive transport element were microinjected into transgenic embryos. tR zCs induced greater gene interference than R zs alone. Control tR zCs did not affect unpaired bases of target RNA, and the tR zC did not interfere with non-relevant gene expression, suggesting that the tR zC-mediated gene-interference effects were sequence-specific. Furthermore, the tR zC-containing expression vector specifically suppressed target GFP expression in transgenic trout. tR zCs enhance R z cleavage and could therefore be powerful tools for studying unknown gene function in vertebrates.