Strain Code 01CQ4 [Cr:NIH-BL(S)]
Origin and Characteristics
Developed at the NIH Genetic Resource by Dr. Carl Hansen. N:NIH Swiss outbred mice were crossed to C57BL/6N mice to generate a hybrid black mouse that was heterozygous for the agouti loci. Through a series of test matings and backcrosses (N10) to the N:NIH(S) strain the agouti gene was eliminated. Received by NCI in 2000. Black Swiss females nurture foster young well, better than other pigmented strains. It is homozygous for the same coat color loci as the C57BL/6 and has litter sizes approximately double that of the C57BL/6. The N:NIH-BL(S) is useful for germline test mating of knockout chimeras created using 129 agouti ES cell lines implanted in C57BL/6 blastocysts. Black Swiss females also make ideal pseudopregnant female recipients for embryo transfers of albino lines.