Experimental Animal Division

  The Ink4a-Arf tumor suppressor locus encodes two proteins, p19Arf and p16Ink4, and influences key physiological processes such as replicative senescence, apoptosis, and stem cell self renewal. The Lck-p19Arf transgenic mice carry the gene encoding p19Arf under the control of the Lck proximal promoter. Two independently generated these transgenic mice showed that the number of total thymocytes and percentage of CD4/CD8 double positive (DP) cells was dramatically reduced, whereas the percentage of γδT cells was increased. The overexpression of p19Arf results in thymocyte cell death and inhibits the CD4/CD8 double negative (DN) to DP transition in a p53-dependent manner. In the lineage-negative CD4/CD8 double negative (DN) population, the percentage of DN4 cells was markedly decreased. These transgenic mice are useful for investigating p19Arf function in early T-cell development.