Generation of long mRNA for membrane immunoglobulin γ2a chains by differential splicing

Abstract

Immunoglobulin may be secreted by a lymphocyte or bound to the cell membrane as an antigen receptor1. The most common classes of membrane immunoglobulin (mIg) are IgM and IgD, but some B lymphocytes, thought to be involved in immunological memory2,3, bear other classes such as mIgG and mIgA4. In mice, the μm heavy chain of mIgM bears a hydrophobic C-terminus whereas in the secreted (μs) chain it is hydrophilic. There are distinct μs and μm mRNAs with different 3′ termini, which are produced by alternative splices of transcripts of the active rearranged μ gene5-7. There also seem to be alternative C-termini and distinct mRNAs for δs and δm chains8-11. The murine B-lymphoma cell line 2PK-3 (re..