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Immunoglobulin heavy chain switch region recombination within a retroviral vector in murine pre‐B cells.
Author(s) -
Ott D.E.,
Alt F.W.,
Marcu K.B.
Publication year - 1987
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1987.tb04793.x
Subject(s) - recombination , microbiology and biotechnology , biology , thymidine kinase , immunoglobulin heavy chain , immunoglobulin light chain , gene , antibody , v(d)j recombination , physics , immunoglobulin class switching , virology , genetics , b cell , virus , herpes simplex virus
We have employed a retroviral vector, ZN(Smu/S gamma 2b)tk1, as a substrate for detecting the presence of immunoglobulin heavy chain constant region (CH) gene switch (S) recombination activity in murine pre‐B cells. ZN(Smu/S gamma 2b)tk1 contains a neomycin (neo) resistance gene in addition to the herpes simplex virus thymidine kinase (Htk) gene which is positioned between murine Smu and S gamma 2b sequences. Stable acquisition of the ZN(Smu/S gamma 2b)tk1 vector was selected in G‐418 and switch region recombination within these proviruses was selected by resistance to the drug bromodeoxyuridine (BUdR). Fluctuation analyses of ZN(Smu/S gamma 2b)tk1 infected 18‐8tk‐ and 38B9tk‐ pre‐B lines revealed Htk gene inactivations with apparent frequencies of 5 X 10(‐5) and 1 X 10(‐5) events/cell/generation, respectively, while G‐418 resistant Ltk‐ fibroblasts lost the HTK phenotype at an apparent rate of 4 X 10(‐8). Southern blot analysis demonstrated that switch recombination caused the deletion of the Htk gene in all pre‐B clones examined while the loss of Htk in Ltk‐ clones was not mediated by S region recombination. In 21 out of 24 pre‐B clones, the recombinations involved the tandemly repetitive portions of the Smu and S gamma 2b sequences. These results demonstrate that the CH gene S region segments inserted into ZN(Smu/S gamma 2b)tk1 are sufficient for B‐cell‐specific recombination/deletion within the S region tandem repeats.