| Primary Identifier | MGI:2388157 | Allele Type | Targeted |
| Attribute String | Null/knockout | Gene | Top3b |
| Transmission | Germline | Strain of Origin | 129S6/SvEvTac |
| Is Recombinase | false | Is Wild Type | false |
| molecularNote | A region of the gene spanning nucleotides 777 to 1490 of the coding sequence was replaced with a PGK-neo cassette. This region includes the active site tyrosine 336. Gene expression was undetectable by RT-PCR analysis of liver mRNA from homozygous mutant animals. |