| Primary Identifier | MGI:4850023 | Allele Type | Targeted |
| Attribute String | Null/knockout | Gene | Ighg1 |
| Transmission | Germline | Strain of Origin | 129P2/OlaHsd |
| Is Recombinase | false | Is Wild Type | false |
| description | The ES cells targeted to create this allele were heterozygous for Ighg1 |
| molecularNote | A 1.7 kb sequence directly upstream of the IgG1 switch region and containing all known IL-4 inducible elements in this region was replaced with a neomycin selection cassette in reverse orientation and the human metallothionein II promoter. The splice donor site of the I exon was retained. |