Ewsr1 The L1L2_Bact_P cassette was inserted at position 5041734 of Chromosome 11 upstream of the critical exon(s) (Build GRCm39). The cassette is composed of an FRT site followed by lacZ sequence and a loxP site. This first loxP site was followed by a neomycin resistance gene under the control of the human beta-actin promoter, SV40 polyA, a second FRT site and a second loxP site. A third loxP site was inserted downstream of the targeted exon(s) at position 5042321. The critical exon(s) were thus flanked by loxP sites. A "conditional ready" (floxed) allele was created by flp recombinase expression in mice carrying this allele. Subsequent cre expression resulted in a knockout mouse.
