genome-wide identification of reverse complementary microrna genes in plants全基因组反向互补的microrna基因在植物的识别.pdfVIP

Genome-Wide Identification of Reverse Complementary microRNA Genes in Plants 1. 2. 1 2 2 Chaogang Shao , Xiaoxia Ma , Xiufang Xu , Huizhong Wang *, Yijun Meng * 1 College of Life Sciences, Huzhou Teachers College, Huzhou, The People’s Republic of China, 2 College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, The People’s Republic of China Abstract MicroRNAs (miRNAs) are ,21-nucleotide small RNAs (sRNAs) with essential regulatory roles in plants. They are generated from stem-loop-structured precursors through two sequential Dicer-like 1 (DCL1)-mediated cleavages. To date, hundreds of plant miRNAs have been uncovered. However, the question, whether the sequences reverse complementary (RC) to the miRNA precursors could form hairpin-like structures and produce sRNA duplexes similar to the miRNA/miRNA* pairs has not been solved yet. Here, we interrogated this possibility in 16 plant species based on sRNA high-throughput sequencing data and secondary structure prediction. A total of 59 RC sequences with great potential to form stem-loop structures and generate miRNA/miRNA*-like duplexes were identified in ten plants, which were named as RC-miRNA precursors. Unlike the canonical miRNAs, only a few cleavage targets of the RC-miRNAs were identified in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), and none in Soybean (Glycine max) based on degradome data. Surprisingly, the genomic regions surrounding some of the RC-miRNA target recognition sites were observed to be specifically methylated in both Arabidopsis and rice. Taken together, we reported a new class of miRNAs, called RC-miRNAs, which were generated from the antisense strands of the miRNA precursors. Based on the resul