Signal joint of immunoglobulin Vλ1‐Jλ and novel joints of chimeric V pseudogenes on extrachromosomal circular DNA from chicken bursa

Tokukazu Kondo, Hiroshi Arakawa, Hiroyuki Kitao, Yoshikazu Hirota, Hideo Yamagishi

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17 Citations (Scopus)


We isolated extrachromsomal circular DNA from the bursa of 18‐day chick embryos and cloned their BamHI fragments into a phage vector. We found examples of the signal joint fused by Vλ1‐Jλ, rearrangement and the sequences homologous to Vλ1 segments that showed: (1) clustered V pseudogene (ΨV) germ‐line segments containing new ΨV26, (2) a head‐to‐tail duplication of ΨV13‐ΨV12 region and (3) chimeric structures composed of 5′‐Vλ1 and 3′‐ΨV segments. Both intrachromosomal tandem duplications and extrachromosomal circles may be generated by unscheduled DNA synthesis and recombination. The chimeric structure of Vλ1 joined with upstream ΨV segments suggests the involvement of V gene replacement for somatic diversification of the immunoglobulin genes in addition to a mechanism of segmental gene conversion.

Original languageEnglish
Pages (from-to)245-249
Number of pages5
JournalEuropean Journal of Immunology
Issue number1
Publication statusPublished - Jan 1 1993
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Immunology and Allergy
  • Immunology

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