title: Two small regulatory RNAs establish opposing fates of a developmental axis.
abstract: Small RNAs are important regulators of gene expression. In maize, adaxial/abaxial (dorsoventral) leaf polarity is established by an abaxial gradient of microRNA166 (miR166), which spatially restricts the expression domain of class III homeodomain leucine zipper (HD-ZIPIII) transcription factors that specify adaxial/upper fate. Here, we show that leafbladeless1 encodes a key component in the trans-acting small interfering RNA (ta-siRNA) biogenesis pathway that acts on the adaxial side of developing leaves and demarcates the domains of hd-zipIII and miR166 accumulation. Our findings indicate that tasiR-ARF, a ta-siRNA, and miR166 establish opposing domains along the adaxial-abaxial axis, thus revealing a novel mechanism of pattern formation.
authors.affiliation: Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
authors.forename: Fabio T S
authors.initials: FT
authors.lastname: Nogueira
authors.forename: Shahinez
authors.initials: S
authors.lastname: Madi
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Chitwood
authors.forename: Michelle T
authors.initials: MT
authors.lastname: Juarez
authors.forename: Marja C P
authors.initials: MC
authors.lastname: Timmermans
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D019521:Body Patterning; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000196:embryology* / Q000235:genetics / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D016415:Sequence Alignment; D003313:Zea mays / Q000196:embryology* / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D035683:MicroRNAs; D010940:Plant Proteins; D018749:RNA, Plant; D034741:RNA, Small Interfering