Microsatellite genotyping for four expected inbred mouse strains from KM mice

Chinese Kun Ming (KM) mouse, an outbreed strain of laboratory animal, has been widely utilized in related pharmaceutical and genetic studies throughout China. However, the value of KM mice to the research community has been severely limited, partially due to the fact that well-characterized inbred strain of KM mice is not available. Several expected inbred strains from KM mice have been bred, but their genetic purity remains uncertain. In this study, four expected inbred strains of KM mice (A1, T2, N2, and N4) were chosen and their inbred degree were compared with two classical inbred mouse lines (BALB/c and C57BL/6) by analyzing the genotypes of about 30 microsatellite markers. In the four strains, A1 and N4 were homozygous at all genotyped loci, but N2 and T2 were only heterozygous at locus D15Mit16. These results indicate that the level of genetic purity/homozygousity of A1, N4, N2, and T2 inbred line is comparable to those of BALB/c and C57BL/6. This study provided the first and solid evidence for genetic purity of four expected inbred strains of KM mice. These 4 inbred mice strains should be well maintained for further characterization and utilization in genetic studies.