Polar and non-polar species of the protozoan ciliate Euplotes behave differently in response to environmental oxidative stress

Polar coastal seawaters are saturated by high oxygen concentrations, which impose very effective adaptive strategies to strive against a continuous environmental oxidative stress. We studied these strategies in Euplotes nobilii (Ciliophora: Spirotrichea), a ciliate species dwelling in Antarctic and...

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Bibliographic Details
Published in:Italian Journal of Zoology
Main Authors: DOBRI, NICOLETA, ALIMENTI, Claudio, VALLESI, Adriana, E. E. Ngueng Oumarou
Other Authors: Dobri, Nicoleta, E. E., Ngueng Oumarou, Alimenti, Claudio, Vallesi, Adriana
Format: Article in Journal/Newspaper
Language:English
Published: 2014
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Online Access:http://hdl.handle.net/11581/333991
https://doi.org/10.1080/11250003.2014.947337
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Summary:Polar coastal seawaters are saturated by high oxygen concentrations, which impose very effective adaptive strategies to strive against a continuous environmental oxidative stress. We studied these strategies in Euplotes nobilii (Ciliophora: Spirotrichea), a ciliate species dwelling in Antarctic and Arctic coastal seawaters, in comparison with Euplotes raikovi, a sister species living in temperate seawaters. Cell samples of the two species were exposed to hydrogen peroxide (H2O2)-induced oxidative stress and analyzed for their survival rates and levels of expression of the genes encoding the enzyme methionine-sulfoxide reductase (Msr) A, which restores oxidized methionines (in their S form) of damaged proteins to the status of functional methionines. While 6 h of exposure to a 750-μM concentration of H2O2 did not affect E. nobilii viability, these conditions were lethal to E. raikovi. In correlation with this inter-specific difference in the cell survival to oxidative stress, the MsrA-coding genes of the two species showed different mechanisms of expression: constitutive in E. nobilii, elicited by induction in E. raikovi.