Are ta-siRNAs only originated from the cleavage site of miRNA on its target RNAs and phased in 21-nt increments?

作者：Yu, Lan; Meng, Yijun^*; Shao, Chaogang; Kahrizi, Danial

来源：Gene, 2015, 569(1): 127-135.

DOI：10.1016/j.gene.2015.05.059

• RNA
• Small interfering
• MicroRNAs
• Gene regulatory networks
• Arabidopsis
• Biogenesis

Trans-acting siRNAs (ta-siRNAs) are a class of small RNAs playing crucial roles in the regulation of plant gene expression. According to the canonical model, specific miRNA-guided cleavage of a TAS transcript triggers and sets the registry for the subsequent production of ta-siRNAs at 21-nt increments from the cleavage site. However, a previously validated 22-nt ta-siR2140 indicated that ta-siRNAs might be initiated from other phase increments and registers, which res\ulted in massive ta-siRNAs missing in the canonical model. To test this hypothesis, we employed high-throughput sequencing data to thoroughly identify the miR173-triggered ta-siRNAs from TAS1/TAS2 transcripts. As a result, thousands of phased siRNAs not generated through the canonical pathway were identified and 110 novel siRNA-target interactions were further validated based on degradome sequencing data. Based on these results, we propose that the canonical biogenesis model of ta-siRNAs should be modified in order to recruit the previously unidentified ta-siRNA candidates.

• 出版日期2015-9-10
• 单位杭州师范大学