MGI:98450This locus controls multi-band electrophoretic variation in a secreted seminal vesicle protein. Three alleles are known: the a allele occurs in C57BL/6; the b allele in AKR and CBA; the c allele in C3H/He, DBA/2 and BALB/c. Heterozygotes have patterns resembling mixtures of the parental types.