Defective regulation of cholesterol biosynthesis and plasma membrane fluidity in a Chinese hamster ovary cell mutant

A Chinese hamster ovary cell mutant resistant to killing by 25-hydroxycholesterol is shown to be defective in the regulation of cholesterol synthesis by exogenous cholesterol. When grown with various cholesterol supplements in delipidized serum, the mutant cell exhibits a variation in cholesterol content and plasma membrane fluidity that is not observed in the parental cell type.