Abstract
MicroRNAs (miRNA) act as triggers of post-transcriptional regulation of target genes. Some miRNA sequences are conserved among all lineages of land plants. In contrast, others exist only in a single or related species. This is because miRNAs evolve through relatively simple mechanism in which they originate from recently emerged local inverted repeats. Thus, it is possible that those miRNAs confer unique gene expression profile in certain species.
In an effort to identify such miRNAs from rice, we found one miRNA, miRJ, whose target is de novo DNA methyltransferase. miRJ is originated from recently produced inverted repeats of a part of a gene encoding de novo DNA methyltransferase. Interestingly, these inverted repeats seem to locate within the CACTA DNA transposons dispersed at 4 loci in rice genome. In this presentation, we discuss the biological significance of transposon derived miRNA that regulates the expression of de novo DNA methyltransferase.
