Variable and constant parts of the immunoglobulin light chain gene of a mouse myeloma cell are 1250 nontranslated bases apart.

Abstract

A DNA fragment carrying an immunoglobulin gene coding for variable (V) and constant (C) regions of a mouse .lambda. L chain was enriched about 15-fold from a total [Escherichia coli] endonuclease EcoRI digest of a plasmacytoma (HOPC 2020) DNA by preparative agarose gel electrophoresis. The DNA fraction was used for cloning of a .lambda. chain gene in the phage .lambda.gtWES vector. After screening of about 70,000 plaques, each arising from an independent transfection event, clone (Ig 303) was isolated that contained a V.lambda. and a C.lambda. DNA sequence. EM of R-loops formed between the cloned DNA and purified .lambda. chain mRNA (HOPC 2020) revealed that the V.LAMBDA. and C.lambda. DNA sequences are separated by a 1250-base DNA fragment.