Transcripts of the immunoglobulin C(μ) gene vary in structure and splicing during lymphoid development

Abstract

Two classes of transcripts of the mouse immunoglobulin μ constant region (Cμ) gene can be distinguished. Whereas B cells contain μ mRNAs of 2.4 and 2.7 kilobases (kb),many T lymphoma, Abelson pre-B lymphoma, and myeloid tumor cell lines contain polyadenylylated RNA species bearing Cμ sequences (CμRNAs) of 1.9, 2.1, 2.3, and 3.0 kb. Production of CμRNAs, unlike μ mRNAs, does not require recombination within the joining region (J(H)) locus. To define the structure of CμRNAs, RNA from representative cell lines was fractionated by gel electrophoresis, transferred to diazobenzyloxymethyl paper, and tested for hybridization with 23 DNA fragments that collectively span a chromosomal μ gene, cloned ..