title: Rice germline-specific Argonaute MEL1 protein binds to phasiRNAs generated from more than 700 lincRNAs.
abstract: Small RNAs that interact with Argonaute (AGO) proteins play central roles in RNA-mediated silencing. MEIOSIS ARRESTED AT LEPTOTENE1 (MEL1), a rice AGO, has specific functions in the development of pre-meiotic germ cells and the progression of meiosis. Here, we show that MEL1, which is located mostly in the cytoplasm of germ cells, associates preferentially with 21-nucleotide phased small interfering RNAs (phasiRNAs) that bear a 5'-terminal cytosine. Most phasiRNAs are derived from 1171 intergenic clusters distributed on all rice chromosomes. From these clusters, over 700 large intergenic, non-coding RNAs (lincRNAs) that contain the consensus sequence complementary to miR2118 are transcribed specifically in inflorescences, and cleaved within the miR2118 site. Cleaved lincRNAs are processed via DICER-LIKE4 (DCL4) protein, resulting in production of phasiRNAs. This study provides the evidence that the miR2118-dependent and the DCL4-dependent pathways are both required for biogenesis of 21-nt phasiRNAs associated with germline-specific MEL1 AGO in rice, and over 700 lincRNAs are key factors for induction of this biogenesis during reproductive-specific stages.
authors.affiliation: Experimental Farm, National Institute of Genetics (NIG), Mishima, Shizuoka, 411-8540, Japan.
authors.forename: Reina
authors.initials: R
authors.lastname: Komiya
authors.forename: Hajime
authors.initials: H
authors.lastname: Ohyanagi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Niihama
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Nakano
authors.forename: Nori
authors.initials: N
authors.lastname: Kurata
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Nonomura
mesh_terms: D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism*; D032461:Chromosomes, Plant; D018506:Gene Expression Regulation, Plant; D008540:Meiosis; D012275:Oryza / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D062085:RNA, Long Noncoding; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism*
chemical_list: D060565:Argonaute Proteins; D010940:Plant Proteins; D062085:RNA, Long Noncoding; D018749:RNA, Plant; D034741:RNA, Small Interfering
keywords: Argonaute; lincRNA; phasiRNA; reproduction; rice