Université de Neuchâtel

Oxidative stress as a life history constraint : pespectives from a bat species with alternative reproductive tactics

Meniri, Magali ; Helfenstein, Fabrice (Dir.) ; Fasel, Nicolas (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2018.

Au cours de cette thèse, j’ai étudié le rôle du stress oxydant en tant que contrainte pour les traits d’histoire de vie, en utilisant les chauves-souris Fer de lance à lunettes (Carollia perspicillata) comme modèle d’étude. Chez cette espèce, les mâles présentent trois tactiques de reproduction alternatives qui ont des succès reproducteurs différents, et dont...

Université de Neuchâtel

Social dominance explains within-ejaculate variation in sperm design in a passerine bird

Rojas Mora, Alfonso ; Meniri, Magali ; Ciprietti, Sabrina ; Helfenstein, Fabrice

In: BMC Evolutionary Biology, 2017, vol. 17, no. 66, p. 1-10

Comparative studies suggest that sperm competition exerts stabilizing selection towards an optimal sperm design – e.g., the relative size and covariation of different sperm sections or a quantitative measure of sperm shape - that maximizes male fertility, which results in reduced levels of within-male variation in sperm morphology. Yet, these studies also reveal substantial amounts of...

Université de Neuchâtel

Badge Size Reflects Sperm Oxidative Status within Social Groups in the House Sparrow Passer domesticus

Rojas Mora, Alfonso ; Meniri, Magali ; Glauser, Gaëtan ; Vallat, Armelle ; Helfenstein, Fabrice

In: Frontiers in Ecology and Evolution, 2016, vol. 4, no. 67, p. 1-10

The phenotype-linked fertility hypothesis proposes that male ornaments reflect male fertility. Male ornaments could honestly signal sperm quality due to the high susceptibility of sperm to free radicals on the one hand and the negative impact of oxidative stress on ornament elaboration on the other hand. Thus, only males with superior antioxidant defences could bear the cost of more elaborated...