Probing the Physiological Role of CPR

8-9 days and display a number of defects including neural tube, cardiac, eye, and limb abnormalities, and generalized defects in cell adhesion . 

One of the remarkable aspects of the hepatic CPR deletion in mice was the fact that they live and reproduce normally. This means that in adult mice at least, the hepatic P450 system is not essential for life, and indicates most strongly a fundamental role in providing protection against toxic environmental agents. The data from these transgenic models also demonstrate that potential alternative electron transfer pathways for P450s, such as the cytochrome b /b reductase systems that are discussed later, play only a minor role, if any, in vivo. 

The earliest CPR gene deletions were of course carried out with yeast, and the data offer some interesting contrasts with mammalian deletions - . The deletion of the CPR gene in 

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