title: Evolution of plant microRNAs and their targets.
abstract: MicroRNAs (miRNAs) are a specialized class of small silencing RNAs that regulate gene expression. They have a limited phylogenetic distribution among eukaryotes, suggestive of at least two independent origins from an ancestral small RNA-producing pathway. A set of 21 abundantly expressed miRNAs are clearly conserved among the angiosperms; many of these function to regulate transcription factors involved in developmental control. Recent experiments have uncovered a much larger set of weakly expressed, less conserved miRNAs in plants, and this group has provided insights into the origins of miRNAs and their targets. These data have provided a coherent set of hypotheses explaining the birth, selection and death of miRNAs in land plants.
authors.affiliation: Department of Biology and Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Axtell
authors.forename: John L
authors.initials: JL
authors.lastname: Bowman
mesh_terms: D019143:Evolution, Molecular; D035683:MicroRNAs / Q000145:classification / Q000235:genetics*; D008957:Models, Genetic; D010802:Phylogeny; D018749:RNA, Plant / Q000145:classification / Q000235:genetics*
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant