Trp53 Conditional Knockout mouse models

Trp53, the mouse ortholog of human TP53, encodes the tetrameric transcription factor whose central DNA-binding core reads p53 response elements at Cdkn1a, Mdm2, Bbc3, Pmaip1, and Zmat3, coupling ATM and ATR phosphorylation of the amino-terminal transactivation domains to arrest, senescence, and mitochondrial apoptosis while MDM2 and MDM4 impose continuous ubiquitin-dependent turnover. Because most human alleles are missense rather than deleted, the design fork is decisive: conditional or germline nulls model pure suppressor loss and yield thymic lymphoma and sarcoma, whereas structural and contact hotspot knockins such as R172H and R270H (human R175H and R273H) confer dominant-negative and gain-of-function metastatic behavior that a null never reproduces. Lox-stop-lox and restorable alleles interrogate reactivation therapeutics, and humanized TP53 supports MDM2 inhibitor and mutant-reactivator pharmacology. Note that Trp63 and Trp73 share response elements and can buffer apoptotic output, so match allele class to tumor spectrum, latency, and drug response endpoints deliberately.

Trp53 conditional knockout mice carry a floxed allele so you delete function only where Cre is active. The germline allele stays intact until you cross to a tissue specific Cre. Labs reach for this design when a global knockout is lethal, when they need adult onset loss, or when regional redundancy hides a whole body phenotype.