Components of major urinary proteins (MUP's) in the mouse. Sex, strain, and subspecies differences

The differences in electrophoretic patterns of major urinary proteins (MUP's) due to sex, strain, and subspecies of the mouse (Mus musculus) were examined by the combined methods of agarose gel electrophoresis and immunofixation. The MUP's from the male of common laboratory inbred mice (M. m. domesticus) showed a component that was absent in females of the same strain, in addition to a strain-specific component that was determined by the Mup-1 allele carried by the strain. In MOA mice, an inbred strain from M. m. molossinus (Japanese wild mice), there was no apparent sex difference in the constitution of the components. The MUP's from this strain contained a major component that was virtually absent in those from laboratory mice, but lacked the strain-specific components of laboratory mice. In addition, the present methods revealed that both liver and serum contained MUP's consisting of components similar to those found in the urine from the same sex and strain.