Recent developments in the hammerhead ribozyme field

Developments in the hammerhead ribozyme field during the last two years ape reviewed here. New results on the specificity of this ribozyme, the mechan ism of its action and on the question of metal ion involvement in the-cleav age reaction are discussed. To demonstrate the potential of ribozyme techno logy examples of the application of this ribozyme for the inhibition of gen e expression in cell culture, in animals, as well as in plant models are pr esented. Particular emphasis is given to critical steps in the approach, in cluding RNA site selection, delivery, Vector development and cassette const ruction.