Ctsk^tm1(cre)Ska

A cre recombinase gene and a downstream frt-flanked kanamycin/neomycin resistance gene was inserted into the endogenous ATG start site of the gene, replacing the first four exons. Chimeric mice were crossed with a deleter strain to remove the selection cassette. Cre expression in heterozygotes was detected in mature osteoclasts but not osteoblasts when crossed with a tester strain. (J:127179)