title: The microRNA toolkit of insects.
abstract: Is there a correlation between miRNA diversity and levels of organismic complexity? Exhibiting extraordinary levels of morphological and developmental complexity, insects are the most diverse animal class on earth. Their evolutionary success was in particular shaped by the innovation of holometabolan metamorphosis in endopterygotes. Previously, miRNA evolution had been linked to morphological complexity, but astonishing variation in the currently available miRNA complements of insects made this link unclear. To address this issue, we sequenced the miRNA complement of the hemimetabolan Blattella germanica and reannotated that of two other hemimetabolan species, Locusta migratoria and Acyrthosiphon pisum, and of four holometabolan species, Apis mellifera, Tribolium castaneum, Bombyx mori and Drosophila melanogaster. Our analyses show that the variation of insect miRNAs is an artefact mainly resulting from poor sampling and inaccurate miRNA annotation, and that insects share a conserved microRNA toolkit of 65 families exhibiting very low variation. For example, the evolutionary shift toward a complete metamorphosis was accompanied only by the acquisition of three and the loss of one miRNA families.
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim 37, 08003 Barcelona, Spain.
authors.forename: Guillem
authors.initials: G
authors.lastname: Ylla
authors.affiliation: Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Nydalen, N-0424, Oslo, Norway.
authors.forename: Bastian
authors.initials: B
authors.lastname: Fromm
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim 37, 08003 Barcelona, Spain.
authors.forename: Maria-Dolors
authors.initials: MD
authors.lastname: Piulachs
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim 37, 08003 Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Belles
mesh_terms: D000818:Animals; D005075:Biological Evolution; D007313:Insecta / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D010802:Phylogeny; D014786:Vision Disorders / Q000235:genetics
chemical_list: D035683:MicroRNAs