Ciita^tm1Wrth

The gene was specifically inactivated in non-bone marrow antigen presenting cells by deleting the pIV promoter and its associated exon 4. A loxP site was introduced upstream of pIV and a floxed neo cassette was introduced downstream of exon 4. Transient expression of cre recombinase in correctly targeted ES cells removed the entire floxed region (800 bp) containing the pIV promoter and exon 4. Ablation of type IV mRNA in Ifng-stimulated MEFs (mouse embyronic fibroblasts) derived from homozygous mutant animals was confirmed by RNase protection assay. Gene expression from the pI and pIII promoters was not affected by the pIV deletion. (J:71102)