Ifnb1^tm1Lky

A bicistronic reporter cassette containing a loxP-flanked neomycin cassette, an encephalomyocarditis virus (EMCV) IRES element, and enhanced yellow fluorescent protein (EYFP) was introduced immediately after the Ifnb1 STOP codon. The use of 129 background embryonic stem (ES) cells expressing cre under the control of the germline-specific protamine (Prm) promoter allowed for the cre-mediated excision of the floxed neomycin gene from the male germline. The line was backcrossed to C57BL/6 to breed cre out of the line. (J:152138)