title: Survey of sugar beet (Beta vulgaris L.) hAT transposons and MITE-like hATpin derivatives.
abstract: Genome-wide analyses of repetitive DNA suggest a significant impact particularly of transposable elements on genome size and evolution of virtually all eukaryotic organisms. In this study, we analyzed the abundance and diversity of the hAT transposon superfamily of the sugar beet (B. vulgaris) genome, using molecular, bioinformatic and cytogenetic approaches. We identified 81 transposase-coding sequences, three of which are part of structurally intact but nonfunctional hAT transposons (BvhAT), in a B. vulgaris BAC library as well as in whole genome sequencing-derived data sets. Additionally, 116 complete and 497 truncated non-autonomous BvhAT derivatives lacking the transposase gene were in silico-detected. The 116 complete derivatives were subdivided into four BvhATpin groups each characterized by a distinct terminal inverted repeat motif. Both BvhAT and BvhATpin transposons are specific for species of the genus Beta and closely related species, showing a localization on B. vulgaris chromosomes predominantely in euchromatic regions. The lack of any BvhAT transposase function together with the high degree of degeneration observed for the BvhAT and the BvhATpin genomic fraction contrasts with the abundance and activity of autonomous and non-autonomous hAT transposons revealed in other plant species. This indicates a possible genus-specific structural and functional repression of the hAT transposon superfamily during Beta diversification and evolution.
authors.affiliation: Institute of Botany, Dresden University of Technology, 01062 Dresden, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Menzel
authors.forename: Carmen
authors.initials: C
authors.lastname: Krebs
authors.forename: Mercedes
authors.initials: M
authors.lastname: Diez
authors.forename: Daniela
authors.initials: D
authors.lastname: Holtgräwe
authors.forename: Bernd
authors.initials: B
authors.lastname: Weisshaar
authors.forename: André E
authors.initials: AE
authors.lastname: Minoche
authors.forename: Juliane C
authors.initials: JC
authors.lastname: Dohm
authors.forename: Heinz
authors.initials: H
authors.lastname: Himmelbauer
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmidt
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D027461:Beta vulgaris / Q000235:genetics*; D022202:Chromosomes, Artificial, Bacterial; D032461:Chromosomes, Plant; D004251:DNA Transposable Elements; D015723:Gene Library; D018745:Genome, Plant; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D010802:Phylogeny; D020161:Physical Chromosome Mapping; D019895:Transposases / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements; D019895:Transposases