Maternally derived yolk antioxidants buffer the developing avian embryo against oxidative stress induced by hyperoxia

Watson, H., Salmón, P. and Isaksson, C. (2018) Maternally derived yolk antioxidants buffer the developing avian embryo against oxidative stress induced by hyperoxia. Journal of Experimental Biology, 221(13), jeb179465. (doi: 10.1242/jeb.179465) (PMID:29748217)

Abstract

In oviparous animals, maternally transferred antioxidants protect the embryo from oxidative damage from high rates of reactive oxygen species (ROS) production incurred by rapid growth. Elevated ROS exposure - beyond that incurred by normal growth - can occur as a result of exposure to exogenous factors (e.g. pollutants, toxins, radiation), increasing the risk of oxidative damage, with potentially adverse consequences for embryonic development and long-term fitness. The capacity of the avian embryo's antioxidant protection system to counter an increased exogenous oxidative threat is poorly understood. We induced an external oxidative challenge via experimental increase in ambient oxygen concentration throughout incubation of wild great tit eggs in the laboratory. At day 11 of incubation, brain tissue revealed no consistent differences in oxidative stress status - as measured by antioxidant levels (superoxide dismutase and total glutathione), lipid peroxidation and telomere length - between control (21% oxygen) and hyperoxic (40% oxygen) embryos. However, the level of vitamin E was significantly lower and lipid peroxidation was significantly higher in yolks of eggs reared under elevated oxygen concentrations. The results suggest that maternally derived yolk antioxidants successfully buffer developing embryonic tissues against an increased exogenous oxidative threat. Furthermore, vitamin E plays a more important role in protecting the embryo than carotenoids. However, the depletion of antioxidants and increased peroxidation of lipids in the yolk could have negative consequences for embryonic development - in particular for the brain and heart that require highly unsaturated fatty acids - and protection against the oxidative burst following hatching.

• Item Type: Articles
• Additional Information: H.W. was funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 659643. We are grateful for additional financial support from the Swedish Research Council (Vetenskapsrådet, grant no. C0361301 to C.I.), Crafoord Foundation (grant no. 20150506 to C.I.), Marie Curie Career Integration Grant no. 322217 (to C.I.), Lunds Djurskyddsfond (to H.W.) and Kungliga Fysiografiska Sällskapet i Lund (to H.W.).
• Keywords: Antioxidant, hyperoxia, lipid peroxidation, oxidative stress, prenatal development, vitamin E.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Watson, Miss Hannah and Salmon, Dr Pablo
• Authors: Watson, H., Salmón, P., and Isaksson, C.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Journal of Experimental Biology
• Publisher: Company of Biologists
• ISSN: 0022-0949
• ISSN (Online): 1477-9145
• Published Online: 10 May 2018
• Copyright Holders: Copyright © 2018 The Company of Biologists Ltd
• First Published: First published in Journal of Experimental Biology 221(13): jeb179465
• Publisher Policy: Reproduced in accordance with the publisher copyright policy
• Data DOI: 10.6084/m9. figshare.6216293