| Primary Identifier | MGI:2158307 | Allele Type | Targeted |
| Attribute String | Null/knockout | Gene | Igh-J |
| Transmission | Germline | Strain of Origin | 129S7/SvEvBrd-Hprt1<+> |
| Is Recombinase | false | Is Wild Type | false |
| description | Homozygous mutant mice do not develop mature B cells (J:97700). |
| molecularNote | A ~2.3 kb genomic fragment encompassing the four J-H segments and a flanking D-Q52 segment was replaced with a neomycin selection cassette. Homozygous mice do not produce rearranged immunoglobulin heavy chains. |