Immune response genes in chickens: the multifarious responsiveness to (T,G)-A--L.

Immune response in chickens to the multichain copolymer (T,G)-A--L 2030 is analysed. Previous work has shown that responsiveness is not linked to the B-complex. Three different antibody specificities could be distinguished. From the data it is proposed that the response to the backbone of (T,G)-A--L (poly-DL-alanine) influences the responses to the side chain determinants (primarily the (T,G)-determinant). Thus the anti-(T,G) response in chickens is determined by at least two different loci, the B-complex, and another, as yet unidentified locus which determines the response to the poly-DL-alanine determinant. A third antibody specificity is directed against G-A--L and is only detectable in chickens which are high responders to poly-DL-alanine.