<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Grimson, Andrew</style></author><author><style face="normal" font="default" size="100%">Srivastava, Mansi</style></author><author><style face="normal" font="default" size="100%">Fahey, Bryony</style></author><author><style face="normal" font="default" size="100%">Woodcroft, Ben J</style></author><author><style face="normal" font="default" size="100%">Chiang, H Rosaria</style></author><author><style face="normal" font="default" size="100%">King, Nicole</style></author><author><style face="normal" font="default" size="100%">Degnan, Bernard M</style></author><author><style face="normal" font="default" size="100%">Rokhsar, Daniel S</style></author><author><style face="normal" font="default" size="100%">Bartel, David P</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Early origins and evolution of microRNAs and Piwi-interacting RNAs in animals.</style></title><secondary-title><style face="normal" font="default" size="100%">Nature</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Nature</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Base Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Eukaryotic Cells</style></keyword><keyword><style  face="normal" font="default" size="100%">Evolution, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">MicroRNAs</style></keyword><keyword><style  face="normal" font="default" size="100%">Phylogeny</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA, Small Interfering</style></keyword><keyword><style  face="normal" font="default" size="100%">Sea Anemones</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Analysis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008 Oct 30</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">455</style></volume><pages><style face="normal" font="default" size="100%">1193-7</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In bilaterian animals, such as humans, flies and worms, hundreds of microRNAs (miRNAs), some conserved throughout bilaterian evolution, collectively regulate a substantial fraction of the transcriptome. In addition to miRNAs, other bilaterian small RNAs, known as Piwi-interacting RNAs (piRNAs), protect the genome from transposons. Here we identify small RNAs from animal phyla that diverged before the emergence of the Bilateria. The cnidarian Nematostella vectensis (starlet sea anemone), a close relative to the Bilateria, possesses an extensive repertoire of miRNA genes, two classes of piRNAs and a complement of proteins specific to small-RNA biology comparable to that of humans. The poriferan Amphimedon queenslandica (sponge), one of the simplest animals and a distant relative of the Bilateria, also possesses miRNAs, both classes of piRNAs and a full complement of the small-RNA machinery. Animal miRNA evolution seems to have been relatively dynamic, with precursor sizes and mature miRNA sequences differing greatly between poriferans, cnidarians and bilaterians. Nonetheless, miRNAs and piRNAs have been available as classes of riboregulators to shape gene expression throughout the evolution and radiation of animal phyla.</style></abstract><issue><style face="normal" font="default" size="100%">7217</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/18830242?dopt=Abstract</style></custom1></record></records></xml>