NATURAL ANTISENSE TRANSCRIPTS OF THE S-LOCUS RECEPTOR KINASE GENE ANDRELATED SEQUENCES IN BRASSICA-OLERACEA

Gene expression can be inhibited by antisense RNA transcripts. Althoug h this phenomenon is widely used to analyse gene function in plants, t he molecular mechanisms involved are poorly understood. One approach t o improving our understanding of antisense gene regulation is to analy se the function of endogenous antisense transcripts. To date, only a s mall number of plant genes have been shown to be transcribed in both d irections and limited information is available concerning the role of natural antisense transcripts in plants. In this study, we have identi fied several natural antisense transcripts which hybridise to probes d erived from the S locus receptor kinase gene (SRK). The RNase protecti on assay and reverse trancriptase-PCR were used to demonstrate that a proportion of the antisense transcripts are encoded directly by SRK. U sing different RNase protection probes, regions of the promoter, exon I (which encodes the S domain) and intron I of SRK were shown to be tr anscribed in an antisense direction. An antisense SRK transcript was s hown to inhibit translation of a sense transcript in vitro. The possib le role of antisense SRK transcripts in vivo is discussed.