RANDOM NUCLEOTIDE SUBSTITUTIONS IN PRIMATE NONFUNCTIONAL GENE FOR L-GULONO-GAMMA -LACTONE OXIDASE, THE MISSING ENZYME IN L-ASCORBIC ACID BIOSYNTHESIS

Abstract Humans and other primates have no functional gene for l -gulono-γ-lactone oxidase that catalyzes the last step of l -ascorbic acid biosynthesis. The 164-nucleotide sequence of exon X of the gene was compared among human, chimpanzee, orangutan, and macaque, and it was found that nucleotide substitutions had occurred at random throughout the sequence with a single nucleotide deletion, indicating that the primate l -gulono-γ-lactone oxidase genes are a typical example of pseudogene.