title: Transposon-like sequences in extrachromosomal circular DNA from mouse thymocytes.
abstract: Small polydisperse circular (spc) DNA was isolated from mouse thymocytes and cloned into the HindIII site of lambda vector Charon 7. Fifty-six recombinants from this spc DNA library were analyzed. R repeats, which were originally found near immunoglobulin genes, were enriched in spc DNA clones relative to their representation in the chromosome. In one clone, the R sequence was linked to Bam and MIF sequences and the contiguous arrangement was truncated from both ends. In another clone, composite Bam/R and R repeats existed as a pair in inverted repeat orientation. Truncation occurred from the 5' side without affecting the 3' ends. In both clones, short direct repeats flanked the repeated sequences. The possible role of R sequences in transposition and circular formation is discussed.
authors.forename: S
authors.initials: S
authors.lastname: Fujimoto
authors.forename: T
authors.initials: T
authors.lastname: Tsuda
authors.forename: M
authors.initials: M
authors.lastname: Toda
authors.forename: H
authors.initials: H
authors.lastname: Yamagishi
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004270:DNA, Circular / Q000032:analysis*; D007136:Immunoglobulins / Q000235:genetics; D051379:Mice; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D013601:T-Lymphocytes / Q000032:analysis
chemical_list: D004251:DNA Transposable Elements; D004270:DNA, Circular; D007136:Immunoglobulins