title: A major non-LTR retrotransposon of Bombyx mori, L1Bm.
abstract: Repetitive sequences with oligo A tails were observed in Dra1 fragments of Bombyx mori genomic DNA. The full sequence of the element, an abundant non-LTR retrotransposon of B. mori, was determined by assembling inner restriction fragments. This element, designated L1Bm, contained two ORFs encoding a gag-like protein and reverse transcriptase (RT), respectively. An endonuclease domain was identified at the N-terminus of the RT sequence. The homology search of the amino acid sequences revealed that L1Bm belongs evolutionally to the same family as various other non-LTR retrotransposons of Drosophila and Mosquito. On the other hand, L1Bm resembles the L1 element of human genome in its high copy number and its frequent truncation at the 5'-side. Some units of the histone gene repeat in B. mori possess complete L1Bm elements in a 3'-flanking region of H2b.
authors.affiliation: Division of Biology and Oncology, National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba-shi, 263, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Ichimura
authors.forename: K
authors.initials: K
authors.lastname: Mita
authors.forename: K
authors.initials: K
authors.lastname: Sugaya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D012194:RNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D018626:Retroelements / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018626:Retroelements; D012194:RNA-Directed DNA Polymerase