Cr2^tm3.1Jhws

This mutant allele was engineered to remove the alternative splice site required for the expression of the Cr2 isoform but leave the Cr1 isoform intact. A construct containing a cDNA fusion of the SCRs 18 (thus removing the alternative splice junction) was ligated to the testes specific self-deleting pACN neomycin resistance gene and flanked by Cr2 homologous DNA. This construct replaced exons 1-8 of the endogenous gene. The neomycin selection cassette was removed in the germline. This allele expresses Cr1 on B cells but is deficient for the full length Cr2 protein. An alternative splice within the Cr2 gene created a truncated product that encoded a novel protein termed iCr2 that was expressed on the surface of these cells. (J:223195)