Antisense gene expression in yeast.

The use of antisense and ribozyme RNA to modulate gene expression is emerging as an effective genetic technique. A compilation of successful antisense gene suppression experiments reveals the absence of reports on the use of the yeast Saccharomyces cerevisiae as a host. We examine the field of antisense and ribozyme use in S. cerevisiae and discuss that this result is not due to any lack of attempts and may reflect unique features of S. cerevisiae biology. In an attempt to learn from cellular RNA physiology we review evidence for naturally occurring antisense RNA regulation. Although there are many examples of well characterised overlapping RNA transcripts there is, as yet, no clear evidence suggesting complementary RNA-dependent gene regulation in S. cerevisiae. The application of artificial antisense and ribozyme genes is then discussed with an emphasis on the role of yeast as a model system for the systematic and genetic analysis of antisense and ribozyme RNA function. In addition, potential reasons for the lack of attempts to use antisense or ribozyme genes to create pseudogenetic mutants are considered. We conclude that the application of successful antisense and ribozyme strategies in yeast may have to address features of S. cerevisiae RNA biology and offer experimental approaches that may identify some of these features.