Further evidence for two separate loci (H-2D and H-2L) in the D region of the H-2 complex.

The differential redistribution method was used to analyze the relationships between the antigens of the H-2.1 and H-2.28 families and the K- and D-region H-2 specificities on the lymphocyte surface. The experiments were performed on T peripheral lymphocytes of B10. AKM mice (H- 2m), where the H-2.28 specificity is controlled by theD region; C3H.OL mice (H- 20l), where the H-2.28 specificity is controlled by theK region and the H-2.1 specificity by theD region; and B10.A mice (H- 2a) where the H-2.1 specificity is controlled by theK region. The results show the following: 1. In the D-region products, the redistribution of the private specificities fails to induce the redistribution of the H-2.1 or H-2.28 specificity. Antibodies against the H-2.1 or H-2.28 specificity provoke the redistribution of the D-region private specificities. 2. In the K-region products, the H-2.1 or H-2.28 specificity cocaps with the private specificities. 3. In both K- and D-region products, the public specificity H-2.5 always cocapped by antibodies against the private specificity.