Dll1^tm15.1Gos

The transcribed region of the endogenous gene was replaced with a Dll1 minigene derived from a cDNA fragment encompassing exon 1 through the 5' part of exon 9 joined to a genomic DNA fragment containing the remainder of exon 9 through the polyadenylation signal, followed by a reverse-oriented, loxP-flanked neomycin selection cassette. Before the vector was used for gene targeting, the fourth and fifth cysteine codons (TGT or TGC) of the seventh EGF repeat (EGF7) were replaced by glycine codons (GGT or GGC) to prevent formation of the disulfide bridge. The neo cassette was later deleted in vivo by Cre recombinase. (J:230819)