GENETIC LINKAGE RELATIONSHIPS OF LOCI SPECIFYING DIFFERENTIATION ALLOANTIGENS IN THE MOUSE

Abstract

Data concerning the linkage relationships of loci determining cell surface differentiation alloantigens in the mouse are reported. The order of the loci theta antigen (θ), dilute (d), and malic enzyme (Mod-1) in genetic linkage group (LG) II is θ-d-Mod-1. Recombination between θ and d is 15.0 \Pm 4.0%. The lymphocyte antigen C locus (Ly-C) and the lymphocyte antigen B locus (Ly-B) are closely linked; no recombinants were observed among 370 backcross segregants. The provisional symbols, Ly-A and Ly-B,C, therefore, provide a useful descriptive notation for the loci of the Ly series so far recognized. Recombination between the lactic dehydrogenase regulatory locus (Ldr-1) and the Ly-B,C locus is 37.5 \Pm 5.4% and between Ly-B,C and the microphthalmia locus (mi), 7.3 \Pm 2.2% in linkage group XI. The tentative order of the three loci is Ly-B,C-mi-Ldr-1. Other (negative) linkage data, involving biochemical, serological, and other markers, are summarized.