We have already reported antigenic polymorphism in a serum protein detected by reciprocal immunizations between the BALB/c and MOL-ANJ mouse strains (Harada et al. 1986). This protein migrates electrophoretically in the c~ region and has been called alphaprotein-1 (APH-1). In this investigation, we describe yet another antigenic polymorphism and its genetic control in the serum protein that migrates close to APH-1. Methods for preparation of sera, reciprocal immunizations, and immunoelectrophoresis were similar to those described previously (Harada et al. 1986).
Immunoelectrophoretie pattern
BALB/c and MOM mouse strains were used for allo'immunization. MOM is derived from Mus musculus molossinus. The original MOM mice were captured in Mizuhoku, Nagoya City, in 1972, and were inbred for 25 generations by full-sib matings at the Laboratory of Animal Genetics, Faculty of Agriculture, Nagoya University. The strain was then given to the National Institute of Genetics, Mishima, where these mice have been inbred for more than seven generations.
MOM mice immunized with BALB/c serum exhibited two precipitin lines with BALB/c serum in the immunoelectrophoretic pattern as shown in Figure 1. One line was found in the o~ region, the other in the/3 region. Serum components for these precipitin lines have been reported previously; the component in the o~ region is APH-1A (Harada et al. 1986) and that in the/3 region is SAS-2A (Harada et al. 1987). BALB/c mice immunized with MOM serum produced four precipitin lines with MOM serum. The serum component for the precipitin line in the /3 region is SAS-2B and that in the 3, region is immunoglobulin. Two precipitin lines have been observed in the c~ region. The anodic one is APH-1B, which has