Abstract
Orotic aciduria is a rare autosomal recessive disease. The homozygous patients have megaloblastic anemia and pancytopenia. The patients also excrete large quantities of orotic acid in urine. Most and perhaps all of the disease symptoms respond to dietary supplementation of uridine. We undertook a search for auxotrophic variants in mammalian cells in vitro, as a possible model system for inherited human biochemical diseases. The present study reports on the induction and isolation of variant Chinese hamster cells requiring uridine for in vitro growth.
