ISOLATION OF NEW NONSENSE AND FRAMESHIFT MUTANTS IN THE IMMUNOGLOBULIN-MU HEAVY-CHAIN GENE OF HYBRIDOMA CELLS

In order to expand the experimental material available for genetic and biochemical analyses of the natural immunoglobulin genes, we have iso lated a variety of mutant mouse hybridoma cell lines. Some of these mu tants have partial or complete deletions of the mu gene. Other mutants have nonsense or frameshift mutations in the exons encoding the varia ble and the second and third constant region domains of the mu heavy c hain. When combined with earlier mutant data, this collection of genot ypically and phenotypically tight mutants of known sequence spans most of the 10 kb of the A gene, providing material for a variety of studi es of genetic recombination and mRNA metabolism.