title: The regulatory activity of microRNA* species has substantial influence on microRNA and 3' UTR evolution.
abstract: During microRNA (miRNA) biogenesis, one strand of a approximately 21-22-nucleotide RNA duplex is preferentially selected for entry into a silencing complex. The other strand, known as the miRNA* species, has typically been assumed to be a carrier strand. Here we show that, although Drosophila melanogaster miRNA* species are less abundant than their partners, they are often present at physiologically relevant levels and can associate with Argonaute proteins. Comparative genomic analyses revealed that >40% of miRNA* sequences resist nucleotide divergence across Drosophilid evolution, and at least half of these well-conserved miRNA* species select for conserved 3' untranslated region seed matches well above background noise. Finally, we validated the inhibitory activity of miRNA* species in both cultured cells and transgenic animals. These data broaden the reach of the miRNA regulatory network and suggest an important mechanism that diversifies miRNA function during evolution.
authors: Sloan-Kettering Institute, Department of Developmental Biology, 521 Rockefeller Research Laboratories, 1275 York Ave, Box 252, New York, New York 10065, USA.
authors: Katsutomo
authors: K
authors: Okamura
authors: Michael D
authors: MD
authors: Phillips
authors: David M
authors: DM
authors: Tyler
authors: Hong
authors: H
authors: Duan
authors: Yu-ting
authors: YT
authors: Chou
authors: Eric C
authors: EC
authors: Lai
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D030801:Animals, Genetically Modified; D004331:Drosophila melanogaster / Q000235:genetics; D019143:Evolution, Molecular; D047468:Immunoprecipitation; D035683:MicroRNAs / Q000737:chemistry / Q000502:physiology*; D009690:Nucleic Acid Conformation
chemical_list: D020413:3' Untranslated Regions; D035683:MicroRNAs