Environmental Stressors

Le réchauffement climatique et les invasions biologiques représentent des menaces croissantes pour la biodiversité et les habitats des régions subantarctiques. Les îles subantarctiques constituent des environnements sentinelles des changements pouvant être assimilés à des laboratoires à ciel ouvert pour l’étude des synergies entre changements climatiques et invasions biologiques sur la biodiversité polaire. Nos recherches sont centrées sur la faune et la flore terrestres et aquatiques, avec pour objectif d’accroître nos connaissances de l'écologie et de distribution des espèces subantarctiques (activités observatoires de la biodiversité, et approches expérimentales en conditions contrôlées). Ces connaissances sont ensuite employées pour prédire la manière dont la biodiversité polaire pourrait évoluer dans le futur, et suggérer des mesures d'atténuation des impacts des changements globaux. Nos recherches visent également à améliorer les connaissances des mécanismes écologiques et physiologiques qui régissent la distribution et les assemblages d'espèces, des échelles locales aux échelles régionales, dans les Îles Crozet et Kerguelen. Les plantes et les invertébrés constituent des modèles d’études privilégiés, en raison de leur sensibilité aux variations microclimatiques. Ces modèles biologiques constituent par ailleurs des espèces clés qui structurent les réseaux écologiques, et leur sensibilité aux changements globaux pourrait ainsi avoir des effets en cascade sur les interactions écologiques. En démêlant la complexité des processus dirigeant la redistribution de la biodiversité dans les îles subantarctiques, les données produites constitueront un socle de connaissances pour le développement de stratégies de conservation des Îles Crozet et Kerguelen, deux archipels protégés et classés au patrimoine mondial de l'UNESCO.

Funding: ANR

Ecobio collaborators: Hervé COLINET, Romain GEORGES, Stéphanie LLOPIS, Emmanuel LE ROUZIC, David RENAULT, Nathalie LEBRIS, Brea SIMOES-BERTON

Partners: UMR Ecobio, UMR IRBI, UMR EDYSAN, UMR LBBE

Dates/period/years: 01/10/2020 to 30/09/2025

The Spotted Wing Drosophila fly (SWD), Drosophila suzukii, is an invasive fruit pest native to Southeast Asia. The main goal of ANR DroThermal is to fill key knowledge gaps on SWD thermal ecology using multidisciplinary, integrative and ecologically-relevant approaches. By considering different levels of variation across relevant spatio-temporal scales, we aim to elucidate the thermal responses and adaptations of SWD, and thus, better predict population persistence and dynamics. DroThermal has also the applied objective of generating data for the development of innovative population predictive models that could be useful for sustainable management programs against SWD.

Link to external website: https://www.drothermal.cnrs.fr/

Funding: MOPGA 2022 - Ministère de l’Europe et des affaires étrangères

Ecobio collaborators: Hervé COLINET, Fatemeh SAEIDI

Partners:  UMR ECOBIO,

Dates/period/years: 01/12/2022 au 01/12/2023

Cell death, occurring through apoptosis, autophagy and necrosis, is supposed to be a consequence of thermal stress. However, the causes, consequences as well as the molecular mechanisms and specific molecular pathways of thermal-induced cell death are unknown in insects. Understanding when, where, and how cell death occurs in insects following chill & heat stress is critical to understand how insects die under thermal stress and modulate their thermal tolerance within their lifetime (e.g. acclimation) or over evolutionary time. The project will focus on the fruit fly Drosophila melanogaster to study thermal-induced cell death.

Keywords: climate change, thermal ecology, thermal stress, physiology, insects, cell death

Partners/collaborators: Hervé Colinet, Valentin Cabon, Benjamin Bergerot (ECOBIO, Université de Rennes),  Sylvain Pincebourde (IRBI, Université de Tours), Hervé Quénol et Vincent Dubreuil (LETG, université Rennes 2)

Funding: OSUR

Dates/period/years: 2022

Urban and peri-urban areas are subject to strong urbanization pressures. Faced with these pressures, taking nature and biodiversity into account is now an important issue linked to the questions of living environment and ecosystem services. The challenges of global change, and more particularly of climate change, are putting ecology back at the heart of the city and its management policies. Numerous studies report on climate variations related to urban heat islands (UHI) and their biological and physiological consequences on flora, but more rarely on fauna (e.g. birds, arthropods). Few studies focus on fauna because few cities are instrumented to characterize local temperatures (i.e. at a fine resolution). Since 2021, Rennes Métropole has been equipped with numerous sensors that allow local characterization of temperature variations. This makes Rennes a relatively unique study site in France. The objectives of this project at the interface between climatology and ecology are to provide knowledge by collecting along a thermal gradient of living arthropods (objective 1) in order to measure their thermal preferences (objective 2) in the laboratory allowing the adaptation of individuals to local climates (objective 3). This innovative scientific project (fauna/ICU relationship) aims at reinforcing the research initiated since October 2021 by Valentin Cabon's thesis officially co-directed between LETG and ECOBIO, two research units of OSUR.

Other theme: Paysabio

Funding: Ecophyto - Maturation

Ecobio collaborators: Hervé COLINET, Romain GEORGES, Melissa ANNE

Partners:  UMR ECOBIO, UMR CBGP INRAE, CTIFL, UMR GREDEG, UMR SADAPT INRAE

Dates/period/years: 01/02/2022 to 30/09/2024

The Spotted Wing Drosophila fly (SWD), Drosophila suzukii, is an invasive fruit pest native to Southeast Asia. In SuzuKIISS:ME, we will maturate the Sterile Insect Technique (SIT) targeting SWD. The SIT has shown great efficacy to control many insects in many countries. It prevents reproduction by wild females through their mating with sterile males of the same species, which are mass-produced, sterilised and regularly released in large numbers. Females that mate with them produce non-viable eggs, hence reducing the population over generations. SIT will be deployed in semi-enclosed environments such as greenhouses and netted orchards in France. This project will mature the technology to TRL7.

Link to external website: https://ecophytopic.fr/recherche-innovation/piloter/projet-suzukiissme

Funding: ECOBIO – Boost’Europe

Ecobio collaborators: Claire Mérot – Hervé Colinet – Léa Nicolas

Species occupying a wide geographical range face important thermic variation, further amplified by climate change. Natural selection may lead to the evolution of phenotypic variation across populations, for instance in their ability to handle cold and warm temperatures. Such local adaptation is predicted to be favoured by peculiar genetic architecture such as chromosomal inversions.

In Coelopa frigida, a seaweed fly living from Brittany to polar latitude, three inversions vary in frequency along a North-South gradient. This clinal pattern suggest that inversions may be involved in adaptation to thermal stress. We aim to test this hypothesis by experiments, and more generally describe the thermal tolerance of this non-model species.

The physiology of response to cold and heat stress in C. frigida is measured by key parameters and behaviours (supercooling point, minimal and maximal critical temperature, chill/heat coma recovery, etc). Those phenotypes are quantified in two populations from the South and two populations from the North on both the American and European coasts in order to test the hypothesis of  parallel local adaptation. Individual measurements are analysed in the light of inversion genotypes (PCR marker) to test the role of inversions in response to cold/heat stress.

This project presently involves a master student, Léa Nicolas. We welcome future internships, PhD candidates, and post-doc collaborators. If you are interested, please get in touch.

Other theme: EVO-ADAPT