title: Inactivation dates of the human and guinea pig vitamin C genes.
abstract: The capacity to biosynthesize ascorbic acid has been lost in a number of species including primates, guinea pigs, teleost fishes, bats, and birds. This inability results from mutations in the GLO gene coding for L-gulono-γ-lactone oxidase, the enzyme responsible for catalyzing the last step in the vitamin C biosynthetic pathway. We analyzed available primate and rodent GLO gene sequences to determine their evolutionary history. We used a method based on sequence comparisons of lineages with and without functional GLO genes to calculate inactivation dates of 61 and 14 MYA for the primate and guinea pig genes, respectively. These estimates are consistent with previous phylogeny-based estimates. An analysis of transposable element distribution in the primate and rodent GLO sequences did not reveal conclusive evidence that illegitimate recombination between repeats has contributed to the loss of exons in the primate and guinea pig genes.
authors.affiliation: Département de biologie et Centre de recherche avancée en génomique environnementale, Université d'Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada.
authors.forename: Marc Y
authors.initials: MY
authors.lastname: Lachapelle
authors.forename: Guy
authors.initials: G
authors.lastname: Drouin
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000235:genetics*; D001483:Base Sequence; D019143:Evolution, Molecular; D005091:Exons; D016368:Frameshift Mutation; D017353:Gene Deletion; D006168:Guinea Pigs; D006801:Humans; D050544:L-Gulonolactone Oxidase / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D011544:Pseudogenes; D012689:Sequence Homology, Nucleic Acid
chemical_list: D050544:L-Gulonolactone Oxidase; D001205:Ascorbic Acid