title: Dramatic amplification of a rice transposable element during recent domestication.
abstract: Despite the prevalence of transposable elements in the genomes of higher eukaryotes, what is virtually unknown is how they amplify to very high copy numbers without killing their host. Here, we report the discovery of rice strains where a miniature inverted-repeat transposable element (mPing) has amplified from approximately 50 to approximately 1,000 copies in four rice strains. We characterized 280 of the insertions and found that 70% were within 5 kb of coding regions but that insertions into exons and introns were significantly underrepresented. Further analyses of gene expression and transposable-element activity demonstrate that the ability of mPing to attain high copy numbers is because of three factors: (i) the rapid selection against detrimental insertions, (ii) the neutral or minimal effect of the remaining insertions on gene transcription, and (iii) the continued mobility of mPingelements in strains that already have > 1,000 copies. The rapid increase in mPing copy number documented in this study represents a potentially valuable source of population diversity in self-fertilizing plants like rice.
authors.affiliation: Department of Plant Biology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Naito
authors.forename: Eunyoung
authors.initials: E
authors.lastname: Cho
authors.forename: Guojun
authors.initials: G
authors.lastname: Yang
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Campbell
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yano
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Okumoto
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Tanisaka
authors.forename: Susan R
authors.initials: SR
authors.lastname: Wessler
mesh_terms: D001483:Base Sequence; D003198:Computer Simulation; D018556:Crops, Agricultural / Q000235:genetics*; D004251:DNA Transposable Elements / Q000235:genetics; D005784:Gene Amplification; D018628:Gene Dosage; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D012275:Oryza / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements