The genetic control of antibody production. A study of isoimmune antibodies in cattle twins

Abstract

1. The antibody response was studied in twenty-five monozygous (MZ) and ten dizygous (DZ) pairs o f cattle twins, which were inoculated with red cells from one cattle donor carrying the M, V and U′ antigens. These red cell antigens are controlled by genes at three different loci. Most o f the recipients lacked two or all of these antigens. All had passed puberty at the onset of the experiment.2. The antibody response against the three antigens differed markedly. Anti-U′ appeared on the average 11 days after the 1st injection and the maximum titre values were high. The V antibodies were produced at a slow rate, while anti-M was intermediate.3. There was some influence of age on the rate and intensity of antibody production. Older animals gave a faster response and, with regard to anti-M, also higher titres.4. Twins belonging to the same MZ pair usually produced v e r y similar antibody curves. However, there was at least one noticeable exception, which is given special consideration in the Discussion. The differences between MZ pairs accounted for a considerable portion of the variance in the different measures of antibody response and in most cases this portion remained significant also after the elimination of the influence o f age and sex. The DZ pairs were more variable.5. The simultaneous response o f two or three antibodies in the same animal was studied. There was a significant positive association between antibody types which suggests the existence o f individual (probably genetic) differences in the general antibody-producing ability.