Poster: Genomics Resources

Abs # 953: Sage analysis of UV- and g-ray-irradiated arabidopsis reveals the presence of polyadenylated antisense RNAs

Presenter:	Du, Zeji , zdu@noble.org
Authors	Du, Zeji  (A)   Scott, Angela D. (A)   May, Gregory D. (A)
Affiliations:	(A): The Samuel Roberts Noble Foundation

Recent reports indicate that much attention is being paid to RNAs as versatile molecules, including antisense RNA, micro-RNA (miRNAs), and RNA interference (RNAi). Antisense RNAs have similar effects as miRNAs and RNAi on gene expression regulation and the silencing of sequence-specific genes at the mRNA level by the introduction of the cognate double-stranded RNAs. Endogenous antisense RNAs can be found for up to 30% of mammalian genes. However, in plants no naturally occurring antisense RNAs have been found so far. As a genome wide gene expression analysis technique, serial analysis of gene expression (SAGE) is able to detect antisense RNAs since the orientation of the SAGE tag on the transcripts can be readily determined. In Arabidopsis, our study showed that among 577 differentially expressed SAGE tags responded to UV-B and g-ray irradiation, with 29 SAGE tags identified only in the antisense orientation. We have performed 5' and 3’-RACE on four of the antisense tags with strand specific primers. The results validate the presence of endogenous antisense transcripts in Arabidopsis predicted by SAGE. One complete antisense RNA (PR-1-like, At2g14610) has been sequenced, it is a 277-bp polyadenylated RNA and overlaps with the 5’-end of the sense transcript. Further investigation including identification of more full-length sequences of antisense transcripts, primary regulatory functions and gene silencing is in progress. The relationship between the endogenous antisense RNAs, RNAi and miRNA will be demonstrated and discussed.