Water availability and temperature induce changes in oxidative status during pregnancy in a viviparous lizard

Andréaz Dupoué (1) , Pauline Blaimont (2) , David Rozen‐rechels (3) , Murielle Richard (1) , Sandrine Meylan (4, 3) , Jean Clobert (1) , Donald B. Miles (5) , Rémi Martin (1) , Beatriz Decencière (6) , Simon Agostini (6) , Jean‐françois Le Galliard (6, 7)

1 SETE - Station d'écologie théorique et expérimentale
2 UC Santa Cruz - University of California [Santa Cruz]
3 iEES Paris - Institut d'écologie et des sciences de l'environnement de Paris
4 Laboratoire Ecologie et évolution
5 Ohio University
6 CEREEP-Ecotron Ile de France (UMS 3194)
7 iEES Paris - Institut d'écologie et des sciences de l'environnement de Paris

Reproduction involves considerable reorganization in an organism's physiology that incurs potential toxicity for cells (e.g., oxidative stress) and decrease in fitness. This framework has been the cornerstone of the so‐called ‘oxidative cost of reproduction’, a theory that remains controversial and relatively overlooked in non‐model ectotherms. Here, we used two complementary approaches in natural and controlled conditions to test whether altered access to climate conditions (water and temperature resources) alters oxidative status and mediates reproductive trade‐offs in viviparous populations of the common lizard (Zootoca vivipara). First, we examined whether access to free‐standing water and differences in ambient temperature across 12 natural populations could be related to variation in oxidative status, reproductive effort and reproductive success. Second, we determined whether an experimental restriction to water triggers higher oxidative cost of reproduction and correlates with fitness measures (reproductive success, future survival rate and probability of future reproduction). Pregnant females exhibited higher sensitivity than males to natural or experimental limitations in temperature and water access. That is, in restricted environments, pregnant females with higher reproductive effort exhibited stronger oxidative damage despite enhanced non‐enzymatic antioxidant capacity. Enhanced antioxidant defensive capacity in pregnant females was positively correlated with higher reproductive success, whereas elevated oxidative damage negatively correlated with offspring annual survival. Altogether, our results revealed a context‐dependent oxidative cost of reproduction that was concomitant with a conflict in water demand from offspring. These new insights should be critical for understanding ectotherm responses to heat waves and summer droughts that are increasing in frequency and duration.

Mots clés: antioxidant capacity; ectotherm; fitness; pregnancy; reactive oxygen metabolites; temperature; water

Domaines: Biodiversité et Ecologie; Milieux et Changements globaux; Zoologie des vertébrés

Andréaz Dupoué, Pauline Blaimont, David Rozen‐rechels, Murielle Richard, Sandrine Meylan, et al.. Water availability and temperature induce changes in oxidative status during pregnancy in a viviparous lizard. Functional Ecology, 2019, 34 (2), pp.475-485. ⟨10.1111/1365-2435.13481⟩. ⟨hal-02480583⟩