Ikzf1^tm1Kge

An 8.5 kb genomic fragment containing part of exon 3 and exon 4 was replaced with a neomycin cassette. The mutation deletes zinc fingers 1, 2, and 3, which mediate the high affinity binding domain of the protein. Mutant mRNA was detected by RT-PCR analysis. Low amounts of mutant protein were detected by western analysis. Gel retardation assays using nuclear extracts from spleen and thymus showed no binding activity in homozygous mutant animals. A subsequent study suggested this allele generates a dominant-negative protein. (J:20671, J:40023)