姝︿寒甯堝厔鍏充簬miRNA鐨勫張涓绡囨枃绔
鍘诲勾鐨勪竴绡嘝lant Cell瑙杩欏効锛屼粖骞村湪Molecular Cell鍙堝彂涓绡囷紝甯堝厔浣犳槸鎴戜滑鐨勫伓鍍忋
DNA Methylation Mediated by a MicroRNA Pathway [鍏ㄦ枃] [鎰熻阿绾㈠啗闀垮緛璁哄潧鐨刴hl]
In plants, the known microRNAs (miRNAs) are produced as 锝21 nucleotide (nt) duplexes from their precursors by Dicer-like 1 (DCL1). They are incorporated into Argonaute 1 (AGO1) protein to regulate target gene expression primarily through mRNA cleavage. We report here the discovery of a class of miRNAs in the model monocot rice (Oryza sativa). These are 24 nt in length and require another member of the Dicer family, DCL3, for their biogenesis. The 24 nt long miRNAs (lmiRNAs) are loaded into AGO4 clade proteins according to hierarchical rules, depending on the upstream biogenesis machinery and the 5鈥-terminal nucleotide. We demonstrated that lmiRNAs direct DNA methylation at loci from which they are produced as well as in trans at their target genes and play roles in gene regulation. Considered together, our findings define a miRNA pathway that mediates DNA methylation.

娣卞彈鎵撳嚮锝烇綖 鍝綅濂藉績浜哄府鎴戜笅杞戒竴涓 澶氳阿澶氳阿锛