[Non-specific polygenic regulation of antibody synthesis]

Four two-way genetic selections of outbred mice for the quantitative character "agglutinin production" to heterologous erythrocytes and flagellar or somatic antigens of Salmonella are briefly described. The principal genetic parameters regulating the quantitative antibody response are the following: 1) the character is polygenic; the number of independent loci is estimated between 7 and 16; 2) the heritability of the character (h2) is comprised between 0.17 and 0.21; 3) the maximal interline separation RT (4.8-7.8 log2) is reached after about 15 consecutive generations of selective breeding; (4) the rate of interline separation/generation RG is 0.32-0.48 log2. 5) The phenotypic variance V(P) of the foundation populations is due for 52%-63% to genetic factors V(G) and for 37%-48% to environmental factors V(E); 6) The effect of the selective breeding is essentially non-specific; it modifies the antibody responsiveness to many unrelated complex immunogens.