| Primary Identifier | MGI:1934014 | Allele Type | Targeted |
| Attribute String | Null/knockout | Gene | Ighm |
| Transmission | Germline | Strain of Origin | 129S4/SvJae |
| Is Recombinase | false | Is Wild Type | false |
| molecularNote | A targeting vector was constructed in which the exon encoding the secreted form of the immunoglobulin mu (IgM) heavy chain and its three downstream poly(A) sites were replaced by a cDNA fragment encoding the constant region mu4 exon and the exon encoding the membrane-bound form of IgM. The resultant homozygous mutant mice had B cells that did not secrete IgM, but did express membrane-bound IgM. |