Please use this identifier to cite or link to this item: https://doi.org/10.1371/journal.pone.0066691
Title: Ascorbic Acid Biosynthesis and Brackish Water Acclimation in the Euryhaline Freshwater White-Rimmed Stingray, Himantura signifer
Authors: Wong, S.Z.H.
Ching, B.
Chng, Y.R.
Wong, W.P.
Chew, S.F.
Ip, Y.K. 
Issue Date: 18-Jun-2013
Source: Wong, S.Z.H., Ching, B., Chng, Y.R., Wong, W.P., Chew, S.F., Ip, Y.K. (2013-06-18). Ascorbic Acid Biosynthesis and Brackish Water Acclimation in the Euryhaline Freshwater White-Rimmed Stingray, Himantura signifer. PLoS ONE 8 (6) : -. ScholarBank@NUS Repository. https://doi.org/10.1371/journal.pone.0066691
Abstract: L-gulono-γ-lactone oxidase (Gulo) catalyzes the last step of ascorbic acid biosynthesis, which occurs in the kidney of elasmobranchs. This study aimed to clone and sequence gulonolactone oxidase (gulo) from the kidney of the euryhaline freshwater stingray, Himantura signifer, and to determine the effects of acclimation from freshwater to brackish water (salinity 20) on its renal gulo mRNA expression and Gulo activity. We also examined the effects of brackish water acclimation on concentrations of ascorbate, dehydroascorbate and ascorbate + dehydroascorbate in the kidney, brain and gill. The complete cDNA coding sequence of gulo from the kidney of H. signifer contained 1323 bp coding for 440 amino acids. The expression of gulo was kidney-specific, and renal gulo expression decreased significantly by 67% and 50% in fish acclimated to brackish water for 1 day and 6 days, respectively. There was also a significant decrease in renal Gulo activity after 6 days of acclimation to brackish water. Hence, brackish water acclimation led to a decrease in the ascorbic acid synthetic capacity in the kidney of H. signifer. However, there were significant increases in concentrations of ascorbate and ascorbate + dehydroascorbate in the gills (after 1 or 6 days), and a significant increase in the concentration of ascorbate and a significant decrease in the concentration of dehydroascorbate in the brain (after 1 day) of fish acclimated to brackish water. Taken together, our results indicate that H. signifer might experience greater salinity-induced oxidative stress in freshwater than in brackish water, possibly related to its short history of freshwater invasion. These results also suggest for the first time a possible relationship between the successful invasion of the freshwater environment by some euryhaline marine elasmobranchs and the ability of these elasmobranchs to increase the capacity of ascorbic acid synthesis in response to hyposalinity stress. © 2013 Wong et al.
Source Title: PLoS ONE
URI: http://scholarbank.nus.edu.sg/handle/10635/100123
ISSN: 19326203
DOI: 10.1371/journal.pone.0066691
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
2013-ascorbic_acid_biosynthesis_brackish_water-pub.pdf1.01 MBAdobe PDF

OPEN

PublishedView/Download

SCOPUSTM   
Citations

5
checked on Jan 15, 2018

WEB OF SCIENCETM
Citations

4
checked on Jan 15, 2018

Page view(s)

21
checked on Jan 12, 2018

Download(s)

4
checked on Jan 12, 2018

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.