Genetic Marker in the Variable Region of Kappa Chains of Mouse Anti-phosphorylcholine Antibodies

A newly discovered genetic marker in the kappa light chains of mouse immunoglobulins is described. This marker, designated kappa-PC8, is located in the L chains of those anti-phosphorylcholine (PC) antibodies which show the same functional and idiotypic characteristics as a PC-binding myeloma protein, HOPC 8 (H8). Analytical isoelectric focusing of these L chains revealed two phenotypes whose strain distribution pattern suggested a genetic association with genes that determine the T lymphocyte surface antigen(s) Ly-2/Ly-3. In four strains , AKR/J, C58/J, RF/J and PL/J (AKR-type, A) the H8-like L chains have a slightly lower isoelectric point than those of C57L/J and 12 other strains (C57L-type, B). Breeding experiments showed that the kappa-PC8-A phenotype is preferentially expressed. The most probable location of the marker is the variable region since other idiotypically related kappa-chains in C57L/J and AKR/J do not show differences in their electrophoretic mobility.