Biology subjects

Daufresne, M.

Publications and source records attributed to Daufresne, M..

3 recordsLinked to original sources

bioRxiv2025

A century of allopatry: plasticity and rapid selection shape phenotypic trait variability under contrasting environments.

Allopatric isolation under contrasting environments can drive rapid phenotypic divergence, even over contemporary timescales. Rapid changes in morphology or physiology can allow organisms to adapt to biotic and abiotic characteristics of their habitats. While studying metabolism, growth and resources needs may allow to understand adaptation to several selective pressures, these traits are rarely jointly considered. We investigated morphological, growth, and metabolic divergence in two allopatric populations of Arctic charr (Salvelinus alpinus) sharing a common evolutionary origin but inhabiting contrasting environments. We combined field observations, common garden and quantitative genetic approaches to disentangle contributions of genetic divergence and plasticity to phenotypic variability. Wild adults differed in body shape and growth trajectories, potentially reflecting plasticity related to resource availability and temperature variations. Under common garden conditions, juveniles displayed inter-population differences in routine metabolic rate, its allometric scaling with body mass. These patterns suggest divergent selection on physiological traits. Despite low neutral genetic differentiation, phenotypic divergence unfolded in fewer than 100 years, suggesting that plasticity and selection can promote rapid multi-trait changes. These findings highlight that considering changes in physiological, growth and morphological traits can reveal the adaptive potential of small, isolated populations facing rapid environmental change.

evolutionary biology↗

bioRxiv2025

Multigenerational effects of temperature exposure on upper thermal limit and mitochondrial functioning in Medaka (Oryzias Latipes) brain

Determining the mechanisms underpinning the thermal limits of organisms is essential to anticipate the impact of climate change on their survival. As mitochondrial activity is key for cellular ATP production, we aimed at investigating the link between mitochondrial dysfunction and the upper thermal limit (CTmax) at which neuromuscular functions are lost. We reared medaka fish (Oryzias latipes) over generations at 20{degrees}C (COLD) and 30{degrees}C (WARM) during five years and measured their CTmax and their mitochondrial oxygen consumption rates (OCRs) at 25{degrees}C and at their CTmax. We found that multigenerational exposure at elevated temperature increases the CTmax by 13%. We observed for all fish a general decrease in the OCRs and for the RCR of complex-I between 25{degrees}C and their CTmax suggesting a link between CTmax and cerebral mitochondrial performance. Finally, we found an increase in the contribution of the mitochondria complex II to OCRs at elevated temperature suggesting that this complex underlie the plasticity in mitochondrial functioning at high temperature. Our study highlights the link between whole organism thermal tolerance and mitochondrial dysfunction and that multigenerational exposure can modify mitochondrial and thermal performance.

ecology↗

bioRxiv2023

No model to rule them all: a systematic comparison of 83 thermal performance curve models across traits and taxonomic groups

In ectotherms, the performance of physiological, ecological and life-history traits universally increases with temperature to a maximum before decreasing again. Identifying the most appropriate thermal performance model for a specific trait type has broad applications, from metabolic modelling at the cellular level to forecasting the effects of climate change on population, ecosystem and disease transmission dynamics. To date, numerous mathematical models have been designed, but a thorough comparison among them is lacking. In particular, we do not know if certain models consistently outperform others and how factors such as sampling resolution and trait or organismal identity influence model performance. To fill this knowledge gap, we compile 2,739 thermal performance datasets from diverse traits and taxa, to which we fit a comprehensive set of 83 existing mathematical models. We detect remarkable variation in model performance that is not primarily driven by sampling resolution, trait type, or taxonomic information. Our results reveal a surprising lack of well-defined scenarios in which certain models are more appropriate than others. To aid researchers in selecting the appropriate set of models for any given dataset or research objective, we derive a classification of the 83 models based on the average similarity of their fits.

ecology↗