title: Conservation and diversification of the miR166 family in soybean and potential roles of newly identified miR166s.
abstract: microRNA166 (miR166) is a highly conserved family of miRNAs implicated in a wide range of cellular and physiological processes in plants. miR166 family generally comprises multiple miR166 members in plants, which might exhibit functional redundancy and specificity. The soybean miR166 family consists of 21 members according to the miRBase database. However, the evolutionary conservation and functional diversification of miR166 family members in soybean remain poorly understood.
  
  
  
  We identified five novel miR166s in soybean by data mining approach, thus enlarging the size of miR166 family from 21 to 26 members. Phylogenetic analyses of the 26 miR166s and their precursors indicated that soybean miR166 family exhibited both evolutionary conservation and diversification, and ten pairs of miR166 precursors with high sequence identity were individually grouped into a discrete clade in the phylogenetic tree. The analysis of genomic organization and evolution of MIR166 gene family revealed that eight segmental duplications and four tandem duplications might occur during evolution of the miR166 family in soybean. The cis-elements in promoters of MIR166 family genes and their putative targets pointed to their possible contributions to the functional conservation and diversification. The targets of soybean miR166s were predicted, and the cleavage of ATHB14-LIKE transcript was experimentally validated by RACE PCR. Further, the expression patterns of the five newly identified MIR166s and 12 target genes were examined during seed development and in response to abiotic stresses, which provided important clues for dissecting their functions and isoform specificity.
  
  
  
  This study enlarged the size of soybean miR166 family from 21 to 26 members, and the 26 soybean miR166s exhibited evolutionary conservation and diversification. These findings have laid a foundation for elucidating functional conservation and diversification of miR166 family members, especially during seed development or under abiotic stresses.
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors.forename: Xuyan
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Xie
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.affiliation: Agriculture and Agri-Food Canada, London Research and Development Centre, London, ON, Canada.|Department of Biology, Western University, London, ON, Canada.
authors.forename: Yuhai
authors.initials: Y
authors.lastname: Cui
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Hou
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Zhai
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Fu
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China.
authors.forename: Ranran
authors.initials: R
authors.lastname: Liu
authors.affiliation: College of Plant Science, Jilin University, Changchun, Jilin, China. shmbian@jlu.edu.cn.
authors.forename: Shaomin
authors.initials: S
authors.lastname: Bian
mesh_terms: D001483:Base Sequence; D032461:Chromosomes, Plant; D017124:Conserved Sequence; D019143:Evolution, Molecular; D020440:Gene Duplication; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics* / Q000502:physiology; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic; D038621:Regulatory Sequences, Ribonucleic Acid; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D013025:Glycine max / Q000235:genetics* / Q000502:physiology; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D035683:MicroRNAs; D010940:Plant Proteins; D038621:Regulatory Sequences, Ribonucleic Acid
keywords: Evolutionary conservation and diversification; Gene expression pattern; Promoter analysis; Soybean; miR166 family