Water mould exposure induces enzymatic antioxidant defences in embryos of Elachistocleis bicolor (Anura: Microhylidae)

GHIRARDI R.; CAZENAVE J.; LOPEZ J.; ANTONIAZZI C. E.; PEROTTI MG

CANADIAN JOURNAL OF ZOOLOGY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2020 vol. 98 p. 411 - 416

0008-4301

Water moulds are pathogens of amphibian eggs and embryos. However, little is known aboutoxidant or antioxidant status of amphibians in response to stress caused by water moulds. Weexposed embryo stages of two-coloured oval frogs Elachistocleis bicolor (Guérin-Méneville,1838) to Saprolegnia-like sp. water mould in order to explore homeostatic adjustments by theshifting of oxidative stress markers. We also tested whether water mould infection affectedsurvivorship and hatching time and morphology of hatching embryos. We found thatSaprolegnia-like sp. is a genuine stressor and substantially altered the physiological state ofE. bicolor embryos. Among antioxidant defences, superoxide dismutase (SOD) andglutathione S-transferase (GST) activity increased in embryos exposed to Saprolegnia-like sp.However, no difference in lipid peroxidation levels was found between treatments, whichmight indicate that SOD and GST activation could be enough to prevent oxidative damage.Finally, we found higher mortality and number of malformations in the water mouldtreatment. We showed the stressful effect of water moulds on amphibian embryos, evidencedby the activation of their antioxidant system, and reveal the importance of consideringphysiological stress markers as key information when studying the potential consequences ofdisease outbreaks in the ecology and conservation of amphibians.