Effect of the BXSB Y chromosome accelerating gene on autoantibody production

The Y chromosome of the BXSB mouse is able to accelerate and adversely alter the autoimmune disease of inbred BXSB mice and in male F₁ hybrids. In order to further study the effects of the BXSB Y chromosome, we developed three inbred congenic strains, each bearing the BXSB Y: CBA J.BXSB-Y, NZW.BXSB-Y, and NZB.BXSB-Y. The BXSB Y did not induce anti-DNA or anti-red blood cell (RBC) autoantibodies in either CBA J or NZW congenic strains. Thus, it is an accelerating rather than an inducing factor. NZB.BXSB-Y congenic mice had accelerated anti-RBC but not anti-DNA. Studies of recombinant inbred by BXSB F₁ mice indicated that the BXSB Y did not act to promote the activity of the NZB gene underlying anti-DNA. These and studies of (BXSB × NZB.BXSB-Y) F₁ mice suggested that BXSB autosomal genes are required for the full anti-DNA accelerating activity of the BXSB Y. These mice provide a basis for future molecular genetic studies of the BXSB Y.