Details

Autor(en) / Beteiligte

• Kake-Guena, S.A.
• Touisse, K.
• Warren, B.E.
• Scott, K.Y.
• Dufresne, F.
• Blier, P.U.
• Lemieux, H.

Titel

Temperature-related differences in mitochondrial function among clones of the cladoceran Daphnia pulex

Ist Teil von

• Journal of thermal biology, 2017-10, Vol.69, p.23-31

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2017

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• This study assessed the thermal sensitivity of mitochondrial respiration in the small crustacean Daphnia pulex. More specifically, we wanted to determine if clones that inhabit different latitudes and habitats showed differences in the thermal sensitivity of their mitochondrial function. The experimental design included two clones from temperate environments (Fence from Ontario and Hawrelak from Alberta) and two clones from subarctic environments (A24 from Manitoba and K154 from Quebec). The integrated mitochondrial function was measured with high-resolution respirometry following whole-animal permeabilization. Mitochondrial respiration was performed under six different temperatures (10, 15, 20, 25, 30, and 35°C) in the clone Hawrelak and at two temperatures (10 and 20°C) in the three other clones. In the clone Hawrelak, complexes I and II respiration showed higher sensitivity to temperature variation compared to complex IV respiration. Interestingly, the threshold plot showed no excess capacity of complex IV at 20°C in this clone. The clones showed significant divergence in the ability to oxidize the complex I and complex IV substrates relative to the maximal oxidative phoshorylation capacity of mitochondria. More importantly, some of the clonal divergences were only detected under low assay temperatures, pointing toward the importance of this parameter in comparative studies. Future and more complex studies on clones from wider environmental gradients will help to resolve the link between mitochondrial function and adaptations of organisms to particular conditions, principally temperature. •The present study applies our previously developed method in order to study the mitochondrial functions and their thermal sensitivity in D. pulex clones.•We clearly show that divergences in mitochondrial function among clones are more important at a low temperature assay and mainly target Complexes I and IV capacities.•This measurable phenotypic variability in mitochondrial function in D. pulex makes it an ideal model to study how the genetic background is linked to bioenergetics of organisms and their ability to exploit different thermal environments.