title: Preferential usage of JH2 in D-J joinings with DQ52 in murine lymphocytes.
abstract: Southern blot analysis of genomic DNA of normal mouse thymocytes with a JH4 probe, a probe for JH4 of Igh genes, consistently showed a second band in addition to a germline band. The same band was also observed in analysis with a 5' DQ probe, a 5'-flanking sequence of DQ52, thus suggesting the use of DQ52. By analyzing EcoRI- and PvuII-digested genomic DNA, the above-observed band was demonstrated to be the result of DQ52-JH2 joining. This was further confirmed utilizing a T cell leukemia line with known DQ52-JH joinings. We then quantitatively estimated the frequencies of JH segment usages in joining with DQ52, through plaque hybridization assays. Three hundred and fifty JH4-positive clones were obtained from 7 x 10(5) plaques by plaque hybridization. Forty-eight randomly selected non-germline clones were purified and the use of JH segments was determined through Southern blot analysis. Nine clones used JH1, 29 used JH2, 9 used JH3, and 1 used JH4, thus indicating an apparent preferential usage of JH2 segment. Southern blot analysis of genomic DNA of progenitor B cells in culture showed a dominant band of DQ52-JH2 joining 1 week after initiation of culture. This may indicate that the dominant DQ52-JH2 joining in thymocytes is representative of early D-J joinings in progenitor B cells.
authors.affiliation: Department of Oncology, Nagasaki University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Abe
authors.forename: S
authors.initials: S
authors.lastname: Nishikawa
authors.forename: E
authors.initials: E
authors.lastname: Nakayama
authors.forename: H
authors.initials: H
authors.lastname: Shiku
mesh_terms: D000818:Animals; D015342:DNA Probes; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D015329:Gene Rearrangement, T-Lymphocyte; D005803:Genes, Immunoglobulin; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D015342:DNA Probes