title: Characterization of active miniature inverted-repeat transposable  elements in the peanut genome.
abstract: Miniature inverted-repeat transposable elements (MITEs), some of which are known as active nonautonomous DNA transposons, are found in the genomes of plants and animals. In peanut (Arachis hypogaea), Ah-MITE1 has been identified in a gene for fatty-acid desaturase, and possessed excision activity. However, the AhMITE1 distribution and frequency of excision have not been determined for the peanut genome. In order to characterize AhMITE1s, their genomic diversity and transposition ability was investigated. Southern blot analysis indicated high AhMITE1 copy number in the genomes of A. hypogaea, A. magna and A. monticola, but not in A. duranensis. A total of 504 AhMITE1s were identified from the MITE-enriched genomic libraries of A. hypogaea. The representative AhMITE1s exhibited a mean length of 205.5 bp and a GC content of 30.1%, with AT-rich, 9 bp target site duplications and 25 bp terminal inverted repeats. PCR analyses were performed using primer pairs designed against both flanking sequences of each AhMITE1. These analyses detected polymorphisms at 169 out of 411 insertional loci in the four peanut lines. In subsequent analyses of 60 gamma-irradiated mutant lines, four Ah-MITE1 excisions showed footprint mutations at the 109 loci tested. This study characterizes AhMITE1s in peanut and discusses their use as DNA markers and mutagens for the genetics, genomics and breeding of peanut and its relatives.
authors.affiliation: Department of Plant Genome Research, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan. shirasaw@kazusa.or.j
authors.forename: Kenta
authors.initials: K
authors.lastname: Shirasawa
authors.forename: Hideki
authors.initials: H
authors.lastname: Hirakawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Makoto
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kiyoshima
authors.forename: Sigeru
authors.initials: S
authors.lastname: Suzuki
authors.forename: Sigemi
authors.initials: S
authors.lastname: Sasamoto
authors.forename: Akiko
authors.initials: A
authors.lastname: Watanabe
authors.forename: Tsunakazu
authors.initials: T
authors.lastname: Fujishiro
authors.forename: Sachiko
authors.initials: S
authors.lastname: Isobe
mesh_terms: D010367:Arachis / Q000235:genetics*; D001483:Base Sequence; D003433:Crosses, Genetic; D004247:DNA / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004251:DNA Transposable Elements; D017343:Genes, Plant; D018745:Genome, Plant; D023281:Genomics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic; D012689:Sequence Homology, Nucleic Acid
chemical_list: D017931:DNA Primers; D004251:DNA Transposable Elements; D004247:DNA