Chromosome 4 Jt gene controls murine T cell surface I-J expression.

Data are presented suggesting a resolution to the paradox concerning the murine response subregion I-J, which encodes a suppressor T cell marker. The controversy arose when sequences corresponding to I-J DNA were not found in the central immune response region described by immunogeneticists. New evidence is presented that T cell surface I-J expression results from the action of at least two complementing genes. One gene is within the H-2 region on chromosome 17; the second gene, termed Jt, is on chromosome 4. The two recombinant mouse strains B10.A(3R) and B10.A(5R) originally used to define the I-J subregion apparently differ not within the H-2 region but elsewhere.