Homozygotes: Mice that are homozygous for the targeted mutation are viable and normal in size. Although testes appear normal at 2.5 months, by 9 months homozygous males exhibit testicular atrophy and empty, degenerated seminiferous tubules, although no decrease in Leydig cells is observed. Submaxillary and parotid salivary glands develop abnormally large and swollen cell nuclei and binucleate cells. Large nuclei and binucleate cells also are observed in the exocrine portion of the pancreas. Body weights are normal until 12 to 15 months of age when many mice develop dramatic weight loss. Spontaneous tumors develop in 19% to 34% of mice between 8 and 18 months of age suggesting a function for E2f1 in tumor suppression. Tumor types include, in order of frequency, reproductive tract sarcomas, lung tumors, lymphomas and other tumor types at lower frequencies.
This mutant mouse strain may be useful in studies of cancer and cell cycle research.

Heterozygote: Normal phenotype, although several heterozygotes develop rare reproductive tract sarcomas and lung adenocarcinomas.

These E2f1 (E2F transcription factor 1) knockout mice exhibit late onset testicular atrophy, degenerated seminiferous tubules, abnormal submaxillary and parotid salivary glands, abnormal cells in the pancreas, late-onset weight loss and spontaneous tumors in 19% to 34% of mice. 
This mutant mouse strain may be useful in studies of cancer and cell cycle research.

This strain is hosted by NIH's MMRRC, which partners with JAX for the distribution of this and other strains. For additional information and to purchase, please visit the MMRRC site.