ABSTRACT
As the world's climate changes, life faces an evolving thermal environment. Mitochondrial oxidative phosphorylation (OXPHOS) is critical to ensure sufficient cellular energy production, and it is strongly influenced by temperature. The thermally induced changes to the regulation of specific steps within the OXPHOS process are poorly understood. In our study, we used the eurythermal species of planarian Dugesia tigrina to study the thermal sensitivity of the OXPHOS process at 10, 15, 20, 25 and 30°C. We conducted cold acclimation experiments where we measured the adjustment of specific steps in OXPHOS at two assay temperatures (10 and 20°C) following 4 weeks of acclimation under normal (22°C) or low (5°C) temperature conditions. At the low temperature, the contribution of the NADH pathway to the maximal OXPHOS capacity, in a combined pathway (NADH and succinate), was reduced. There was partial compensation by an increased contribution of the succinate pathway. As the temperature decreased, OXPHOS became more limited by the capacity of the phosphorylation system. Acclimation to the low temperature resulted in positive adjustments of the NADH pathway capacity due, at least in part, to an increase in complex I activity. The acclimation also resulted in a better match between OXPHOS and phosphorylation system capacities. Both of these adjustments following acclimation were specific to the low assay temperature. We conclude that there is substantial plasticity in the mitochondrial OXPHOS process following thermal acclimation in D. tigrina, and this probably contributes to the wide thermal range of the species.
FOOTNOTES
Competing interests
The authors declare no competing or financial interests.
Author contributions
Conceptualization: H.L.; Methodology: K.Y.S., M.S., H.L.; Validation: H.L.; Formal analysis: K.Y.S., R.M., J.W., M.S., H.L.; Investigation: K.Y.S., R.M., J.W., M.S., H.L.; Resources: H.L.; Data curation: K.Y.S., H.L.; Writing - original draft: H.L.; Writing - review & editing: K.Y.S., R.M., J.W., M.S., H.L.; Visualization: H.L.; Supervision: H.L.; Project administration: H.L.; Funding acquisition: H.L.
Funding
This study was supported by the following grants to H.L.: a discovery grant from the Natural Sciences and Engineering Research Council of Canada (RGPIN 402636), a research grant and a startup grant from Campus Saint-Jean, and an equipment grant from the Canadian Foundation for Innovation.
Data availability
All datasets supporting this manuscript are available from the Dryad Digital Repository (Scott et al., 2019): dryad.727r289
Supplementary information
Supplementary information available online at http://jeb.biologists.org/lookup/doi/10.1242/jeb.207951.supplemental
- Received May 28, 2019.
- Accepted August 14, 2019.
- © 2019. Published by The Company of Biologists Ltd
Log in using your username and password
Log in through your institution
Pay Per Article - You may access this article (from the computer you are currently using) for 1 day for US$30.00 .
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.
Keywords
Article navigation
Related articles
Cited by...
More in this TOC section
Similar articles
Other journals from The Company of Biologists
Editorial - The changing of the guard
In his Editorial, Hans Hoppeler announces that he will be stepping down as Editor-in-Chief of JEB in July 2020. He reflects on the history of JEB, why he has enjoyed his tenure as JEB’s Editor-in-Chief and the recent developments in the publishing world.
Editors’ choice – Ontogeny of effective mechanical advantage in eastern cottontail rabbits (Sylvilagus floridanus)
Jesse Young and his team show that young eastern cottontail rabbits have shorter limbs relative to their size than older rabbits. These shorter limbs amplify forces more, allowing the youngsters to accelerate faster during getaways, and thus promote survival.
Motor neurons relay signals from the brain and spinal cord to muscles that perform behaviours. In their Review, Charlotte Barkan and Erik Zornik discuss an additional function of motor neurons: their contribution to the function of pattern-generating circuits.
Gall midge larvae don't have legs, but that doesn't stop them leaping when they need a quick getaway. Sheila Patek and her team show that larvae latch their front ends to their rears and press down on the back half to push off for a spectacular leap. Read their full research article here.
The Peter Baker Fellowship is for post-doctoral scientists interested in marine biology research, especially physiological research. It will provide living and travel expenses (up to £3,000) to spend approximately two months working at the Laboratory of the Marine Biological Association, Plymouth, at any time of the year. Bench fees will be waived and a small sum may be available to assist with research expenses. This fund is held in trust by the Physiological Society, The Company of Biologists and the Marine Biological Association. Application deadline: 31 January 2020.
Journal of Experimental Biology is pleased to announce a new partnership with Publons! This allows reviewers to easily track and verify every review by choosing to add the review to their Publons profile when completing the review submission form. Publons also makes it simple for reviewers to showcase their peer review contributions in a format that can be included in job and funding applications (without breaking reviewer anonymity). Read the official announcement here!
The Company of Biologists provides grants to fund scientific meetings, workshops and conferences in the fields covered by our journals. Typically, meetings with fewer than 100 people may be granted up to £2,000, increasing up to £6,000 for about 400 people. The next deadline to apply is 28 November 2019.
preLights - Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver
Charlotte Nelson highlights a preprint from Brant Isakson’s lab, who tested whether low iron availability may have influenced speciation in Antarctic icefish of the family Channichthyidae.