Multiple independent L-gulonolactone oxidase (GULO) gene losses and vitamin C synthesis reacquisition events in non-Deuterostomian animal species

Abstract

Background L-ascorbate (Vitamin C) is an important antioxidant and co-factor in eukaryotic cells, and in mammals it is indispensable for brain development and cognitive function. Vertebrates usually become L-ascorbate auxothrophs when the last enzyme of the synthetic pathway, an L-gulonolactone oxidase ( GULO ), is lost. Since Protostomes were until recently thought not to have a GULO gene, they were considered to be auxothrophs for Vitamin C. Results By performing phylogenetic analyses with tens of non-Bilateria and Protostomian genomes, it is shown, that a GULO gene is present in the non-Bilateria Placozoa, Myxozoa (here reported for the first time) and Anthozoa groups, and in Protostomians, in the Araneae family, the Gastropoda class, the Acari subclass (here reported for the first time), and the Priapulida, Annelida (here reported for the first time) and Brachiopoda phyla lineages. GULO is an old gene that predates the separation of Animals and Fungi, although it could be much older. We also show that within Protostomes, GULO has been lost multiple times in large taxonomic groups, namely the Pancrustacea, Nematoda, Platyhelminthes and Bivalvia groups, a pattern similar to that reported for Vertebrate species. Nevertheless, we show that Drosophila melanogaster seems to be capable of synthesizing L-ascorbate, likely through an alternative pathway, as recently reported for Caenorhabditis elegans . Conclusions Non-Bilaterian and Protostomians seem to be able to synthesize Vitamin C either through the conventional animal pathway or an alternative pathway, but in this animal group, not being able to synthesize L-ascorbate seems to be the exception rather than the rule. Electronic supplementary material The online version of this article (10.1186/s12862-019-1454-8) contains supplementary material, which is available to authorized users.

Pretreatment serum vitamin level predicts severity of radiation‐induced oral mucositis in patients with nasopharyngeal carcinoma

“…24,25 Vitamin C, also known as ascorbic acid, is also an essential water-soluble vitamin in humans. Vitamin C cannot be synthesized in humans due to the loss of a functional L-gulonolactone oxidase (GULO) gene, 26 so we must obtain vitamin C from food. In addition to participating in the regulation of the immune system, vitamin C participates in various metabolic processes as a coenzyme, is involved in tissue repair, and has anti-oxidant properties, 27 besides, vitamin C may also exhibit a prooxidative effect antitumor at high doses.…”

Vitamin C Enema Advances Induction of Remission in the Dextran Sodium Sulfate-Induced Colitis Model in Rats

“…However, humans do not express l-gluconolactone oxidase, an important enzyme in the biosynthetic pathway of VC. Therefore, humans cannot biosynthesize VC, even though VC is an essential nutrient for humans (8,9). VC has a characteristic chemical structure of an enediol group (HO-C5C-OH), which is a free radical such as a superoxide anion radical (O2 2 ) and hydroxyl radical (-OH), and the function of an electron donor to supply electrons to radicals (9).…”

“…Therefore, humans cannot biosynthesize VC, even though VC is an essential nutrient for humans (8,9). VC has a characteristic chemical structure of an enediol group (HO-C5C-OH), which is a free radical such as a superoxide anion radical (O2 2 ) and hydroxyl radical (-OH), and the function of an electron donor to supply electrons to radicals (9). By this action, VC has a strong antioxidant activity such as protecting important biomolecules, including proteins, lipids, and nucleic acids, from damage by oxidants.…”

Bombyx mori can synthesize ascorbic acid through the l‐gulose pathway to varying degrees depending on developmental stage

“…Studies on fruit‐eating Rousettus leschenaultii , insectivorous Hipposideros armiger (Cui et al, 2011a; 2011b) and Passeriformes birds (Drouin et al, 2011) have confirmed that the VC synthesis ability of animals may not be associated with their food habits and may instead be associated with evolutionary neutral selection pressure. The results of molecular evolution analysis of 11 animals with Gulo gene deletion also support this view (Henriques et al, 2019). Therefore, some insects may also have the ability to synthesize VC, a pathway that has the potential for genetic evolutionary selection.…”