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Somatic hypermutation of immunoglobulin κ transgenes: Association of mutability with demethylation
Author(s) -
Jolly Christopher J,
Neuberger Michael S
Publication year - 2001
Publication title -
immunology and cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0818-9641
DOI - 10.1046/j.1440-1711.2001.00968.x
Subject(s) - somatic hypermutation , biology , genetics , demethylation , transcription (linguistics) , immunoglobulin gene , microbiology and biotechnology , gene , antibody , dna methylation , b cell , gene expression , linguistics , philosophy
Following antigen encounter, immunoglobulin genes are diversified by somatic hypermutation. The mechanism by which this mutational process preferentially targets immunoglobulin genes is not known, but is likely linked to transcription. However, transcription is not sufficient to ensure mutability. Here, by polymerase chain reaction amplification of bisulfite‐modified DNA, the pattern of demethylation within the Igκ mutation domain is analysed and transgenes are used to identify an association between demethylation and mutability. In mice carrying an Igκ transgene that is well transcribed but only poorly targeted for hypermutation, the mutated transgene copies have been demethylated within the mutation domain, whereas the methylated copies remain unmutated. Thus, the hypermutation mechanism only acts on immunoglobulin gene targets that are demethylated as well as transcribed, although transcription and demethylation do not themselves guarantee mutability.