Inheritance of antibody specificity. II. Anti-(4-hydroxy-5-bromo-3-nitrophenyl) acetyl in the mouse.

Mice of 17 inbred strains produced anti-(4-hydroxy-5-bromo-3-nitrophenyl)-acetyl (NBrP) of three different fine specificity types. Anti-NBrP antibodies of all allotype b mice (five strains tested) had a high relative affinity for (4-hydroxy-3.5-dinitrophenyl) acetyl (NNP) but low for (4-hydroxy-5-cloro-3-nitrophenyl) acetyl (NCP). Another category was characterized by high relative affinity for NCP but low for NNP. This category included most of the tested strains. The third category (CBA and C3H strains) had an intermediate fine specificity. Associated with fine specificity characteristics were anti-NBrP titers, mice of allotype b had lower titers than the other mice. Studies of congenic, recombinant inbred, F1 and backcross mice showed that both fine specificity and the magnitude of the anti-NBrP response of tbalb/C MICE WERE CONTROLLED BY AN ALLOTYPE-LINKED GENE. This gene was dominant over the C57BL/6 ALLELE. Lack of recombinant mice in the backcross generatioterns on the other suggest close linkage between the two genes.