Idiotype of inulin-binding antibodies and myeloma proteins controlled by genes linked to the allotype locus of the mouse.

The serum from non-immunized mice of strains BALB/c, C58, A/He, and RIII contained hemagglutinins for stearoyl inulin-coated SRBC. Immunization with bacterial levan slightly elevated these titers. These same sera also carried cross-specific idiotypic determinants (IdX) that are associated only with inulin-binding myeloma proteins (INBMP) of BLAB/c mice. Three InuldX specificities, A, B, and G, were identified. The InuIdX phenotypes of strains BALB/c, C58, and A/He were InuIdXA+B+G+; strain RIII was InuIdX A+B-G+; strain C57BL/6, C57BL/10, DBA/2, AKR and NH were A-B-G-. Strains CBA, C3H, PL, and C57L could not be typed because of low and inconsistent levels of InuIdX and anti-inulin hemagglutinins. The InuIdXA+B+G+ phenotype was used as a genetic marker in immunoglobulin congenic strains CB-20, BAB-14, and BC-8 and in Bailey RI strains which are derived from crosses of BALB/c (InuIdXA+B+G+) and C57BL/ka or C57BL/6, respectively (InuldXA-B-G-). Linkage of the IdXA+B+G+ to the BALB/c a allotype locus was demonstrated. In addition, the InuldXA+B+G+ marker was used as a phenotype in an analysis of 168 first generation backcorss progeny (C57BL X (C57BL X BALB/c) F). Linkage of the marker to the BALB/c allotype was found again. Two proven recombinant mice having the C57BL a allotype and the InuIdxA+B+G+ markers were identified and progeny tested. Four other potential crossover types are still being progeny-tested.