Mice homozygous for this caspase-2 targeted mutation are viable and fertile. As the mutation deletes the QACRG active site and the caspase-2S sequence of the endogenous enzyme, this deletion was shown to inactivate both the long and short form of caspase-2. As such, homozygous mice exhibit defects in regulation of apoptosis; including an enlarged oocyte reserve attributed to a germ cell-intrinsic death defect during prenatal ovarian development (resistance to oocyte cell death following complete cytokine starvation or exposure to an anticancer drug), as well as accelerated motor neuron cell death and defective B lymphoblast apoptosis. In addition, caspase-2-deficient mice exhibit characteristics of premature aging (including shortened maximum lifespan, impaired hair growth, increased bone loss, reduced body fat content, and higher hepatic levels of oxidized proteins). As caspase-2 acts as an upstream regulator of cell death in many cell types, caspase-2-deficient mice may be useful in studying negative and positive regulation of apoptosis, as well as oxidatively damaged cell clearance and aging. The Jackson Laboratory 2024, used with permission.