Evolution and the Biosynthesis of Ascorbic Acid

Chatterjee, I. B.

doi:10.1126/science.182.4118.1271

Cited by 401 publications

(227 citation statements)

References 30 publications

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“…Most vertebrates synthesize ascorbic acid endogenously, because of its important antioxidant functions, but anthropoid primates, fruit bats, guinea pigs, and many birds have lost this capacity (52). Among the primates, all prosimians except Tarsiers also synthesize ascorbic acid endogenously.…”

Section: Case 2 External Redundancymentioning

confidence: 99%

A role for relaxed selection in the evolution of the language capacity

Deacon

2010

Proc. Natl. Acad. Sci. U.S.A.

108

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Explaining the extravagant complexity of the human language and our competence to acquire it has long posed challenges for natural selection theory. To answer his critics, Darwin turned to sexual selection to account for the extreme development of language. Many contemporary evolutionary theorists have invoked incredibly lucky mutation or some variant of the assimilation of acquired behaviors to innate predispositions in an effort to explain it. Recent evodevo approaches have identified developmental processes that help to explain how complex functional synergies can evolve by Darwinian means. Interestingly, many of these developmental mechanisms bear a resemblance to aspects of Darwin's mechanism of natural selection, often differing only in one respect (e.g., form of duplication, kind of variation, competition/cooperation). A common feature is an interplay between processes of stabilizing selection and processes of relaxed selection at different levels of organism function. These may play important roles in the many levels of evolutionary process contributing to language. Surprisingly, the relaxation of selection at the organism level may have been a source of many complex synergistic features of the human language capacity, and may help explain why so much language information is “inherited” socially.

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Section: Case 2 External Redundancymentioning

confidence: 99%

A role for relaxed selection in the evolution of the language capacity

Deacon

2010

Proc. Natl. Acad. Sci. U.S.A.

108

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“…This is supported by location on the same chromosome as SAP and CRP. Functionality of human Mptx may subsequently be lost in the human lineage, as has been described for vitamin C synthesis [6]. It was shown that in humans, other primates and guinea pigs, L-gulono-c-lactone oxidase, which catalyzes the terminal step in L-ascobic acid biosynthesis, is lacking [22].…”

Section: Discussionmentioning

confidence: 90%

Dietary modulation and structure prediction of rat mucosal pentraxin (Mptx) protein and loss of function in humans

et al. 2007

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Mucosal pentraxin (Mptx), identified in rats, is a short pentraxin of unknown function. Other subfamily members are Serum amyloid P component (SAP), Creactive protein (CRP) and Jeltraxin. Rat Mptx mRNA is predominantly expressed in colon and in vivo is strongly (30-fold) regulated by dietary heme and calcium, modulators of colon cancer risk. This renders Mptx a potential nutrient sensitive biomarker of gut health. To support a role as biomarker, we examined whether the pentraxin protein structure is conserved, whether Mptx protein is nutrientsensitively expressed and whether Mptx is expressed in mouse and human. Sequence comparison and 3D modelling showed that rat Mptx is highly homologous to the other pentraxins. The calcium-binding site and subunit interaction sites are highly conserved, while a loop deletion and charged residues contribute to a distinctive ''top'' face of the pentamer. In accordance with mRNA expression, Mptx protein is strongly down-regulated in rat colon mucosa in response to high dietary heme intake. Mptx mRNA is expressed in rat and mouse colon, but not in human colon. A stop codon at the beginning of human exon two indicates loss of function, which may be related to differences in intestinal cell turnover between man and rodents.

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“…We tested for the occurrence of the fluorescent band on gels with the microsomal preparations of 324 tissues of various animals. The microsomes of rabbit liver, chicken kidney and bullfrog kidney, which are known to contain L-gulono-y-lactone oxidase [8], all gave a fluorescent band. The migration distance of each band was the same within the experimental error.…”

Section: Resultsmentioning

confidence: 99%

“…The microsomal preparations of carp hepatopancreas and kidney gave no fluorescent band, either. Since all these microsomal preparations that did not give the fluorescent band are reported to have no enzymic activity [8], localization of L-gulono-ylactone oxidase on SDS-polyacrylamide gels by its intrinsic fluorescence seems to provide a means of detecting the enzyme with crude preparations.…”

Section: Resultsmentioning

confidence: 99%