STRUCTURE OF MINK IMMUNOGLOBULIN GAMMA-CHAIN CDNA

Two cDNA clones, encoding mink Ig gamma chains were characterized. The pIGG47 clone contains a part of the leader segment, VDJ and C regions , and pIGG14 contains a part of the J and a complete C region. The clo nes differ by only four nucleotides in the C region, and they most pro bably represent allelic variants of the same gene. The V gene segment of pIGG47 was found to be highly similar to human VHIII subgroup seque nces; there was 86-87% similarity for the whole V gene segment and 91% for the VHIII specific regions (codons 65-87). Southern blot analysis demonstrated that a high proportion of mink VH genes is VHIII related . The V gene segment used as a probe revealed 19-23 bands in mink DNA under stringent conditions, This is in agreement with our previous dat a showing that a high proportion of mink Ig contains an 'alternative' binding site for protein A, a feature common to VHIII-related molecule s. According to Southern blot analysis there may be 5-7 C gamma genes at the mink IgH locus. Copyright (C) 1996 Elsevier Science Ltd.