In an effort to better understand the role of cholesterol in humans, scientists have created cholesterol-free mice. The researchers bred mice with a genetic mutation that caused cholesterol to be replaced by another sterol, desmosterol - a sterol found in some shellfish. These cholesterol-free mice are smaller than normal mice and also are infertile (because cholesterol is needed in the production of sex hormones), but they are otherwise healthy.
Reporting inScience (December 19, 2003), lead researcher Elena Feinstein, MD, PhD, said that it was possible to create these mice because during gestation mice receive their cholesterol from their mother, unlike humans, where the fetus must rely on its own production of cholesterol. Whereas cholesterol is essential for development in humans, in adult life cholesterol appears to be interchangeable with desmosterol, added Dr. Feinstein. Although the discovery might not have immediate clinical importance, another expert in the field said that it is possible that the discovery may lead to new cholesterol-lowering drugs that eliminate some of the side effects of statins, but what other consequences it might have are unknown.