MicroRNAs and Transcriptional Control

Background: MicroRNAs are small non-coding transcripts that have regulatory roles in the genome. Cis natural antisense transcripts are transcripts overlapping a sense transcript at the same loci in the genome, but at the opposite strand. Such antisense transcripts are thought to have regulatory roles in the genome, and the hypothesis is that miRNAs might bind to such antisense transcripts and thus activate the overlapping sense transcript. Aim of study: The following two aims have been identified during this project: (1) investigate whether the non-coding transcript of cis-NATs show significant enrichment for conserved miRNA seed sites, and (2) to correlate miRNA expression with expression of the sense side of targeted cis-NAT pairs. Results: Seed sites within such antisense transcripts gave significant enrichment, suggesting that miRNAs might actually bind to such antisense transcripts. There is a significant negative correlation between the expression of mir-28 and the expression of its targeted antisense transcripts, whereas the other miRNAs have no significant correlations. Also, the 3 UTR of the sense side of cis-NAT pairs is longer and more conserved than random transcripts. Conclusion: This work has strengthened the hypothesis that miRNAs might bind to such antisense transcripts