Post-doctoral researcher in Population Modelling for Assessing Amphibian Vulnerability to Endocrine Disruptors

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INRAE presentation

The French National Research Institute for Agriculture, Food, and Environment (INRAE) is a major player in research and innovation. It is a community of 12,000 people with 272 research, experimental research, and support units located in 18 regional centres throughout France. Internationally, INRAE is among the top research organisations in the agricultural and food sciences, plant and animal sciences, as well as in ecology and environmental science. It is the world’s leading research organisation specialising in agriculture, food and the environment. INRAE’s goal is to be a key player in the transitions necessary to address major global challenges. Faced with a growing world population, climate change, resource scarcity, and declining biodiversity, the Institute has a major role to play in building solutions and supporting the necessary acceleration of agricultural, food and environmental transitions.

Work environment, missions and activities

-This 6-month contract will be welcomed in the laboratoire d’écotoxicologie (INRAE RiverLy ; Villeurbanne) is part of the research activities conducted within the ANR-funded MACDONALD project (2023–2027; ANR-22-CE34-0008), coordinated by the LECA laboratory (Grenoble, France) under the supervision of Dr. S. Reynaud.- The MACDONALD project investigates the hypothesis that transgenerational metabolic impairments induced by exposure to obesogenic endocrine disruptors (EDs) (Regnault et al., 2018; Usal et al., 2021) may constitute a key driver of amphibian population decline by altering individual fitness. To address this question, the project examines the effects of a mixture of six obesogenic EDs at environmentally relevant concentrations across three generations of Xenopus tropicalis (F0 exposed, F1/F2 unexposed). The effects of this contaminant mixture have been assessed in this amphibian model species at each generation through the measurement of growth, developmental, reproductive, thyroidal and neurodevelopmental parameters, metabolic impairments, and patterns of transgenerational inheritance. A major remaining question is: to what extent can delayed alterations in life-history traits among progeny compromise the long-term demographic persistence of amphibian populations?

To address this challenge, the ecotoxicology team at INRAE RiverLy will contribute its expertise in stage-structured population modelling (Caswell, 2001) to investigate how interspecific variation in life-history traits may influence population viability under ED exposure, particularly when exposure induces transgenerational disruption of physiological functions. The overall objective is to develop a population-level ecological risk assessment framework that integrates amphibian life-history characteristics to determine whether specific demographic strategies confer greater resilience or vulnerability to endocrine disruptor exposure. 

Building on the methodology previously developed for aquatic invertebrates (Prudhomme et al., 2017; Cribiu et al., 2020), your mission will be to implement deterministic and stochastic population models to translate experimentally observed alterations in life-history traits across F0, F1, and F2 generations (growth, survival, fertility, developmental timing, etc.) into projected demographic consequences.

-You will be more specifically in charge of:

1. Development of population models based on experimental data in Xenopus

The postdoctoral researcher will: (i) Develop a stage-structured population model integrating developmental and reproductive parameters obtained during the multigenerational MACDONALD experiment; (ii) Project the demographic impacts of ED exposure across F0, F1, and F2 Xenopus generations using deterministic and stochastic indicators (e.g., asymptotic growth rate, extinction risk) and population viability analyses incorporating both demographic and environmental stochasticity; (iii) Perform sensitivity and elasticity analyses to identify which life-history traits most strongly determine population vulnerability; (iv) Test the hypothesis of demographic compensation mechanisms between direct and transgenerational effects associated with ED-induced metabolic disorders

2.  Extension of the modelling framework to European amphibian species

Using the extensive literature on amphibian population ecology and available life-history trait databases, the postdoctoral researcher will: (i) Adapt the population modelling framework to three European amphibian species; (ii) Examine species-specific demographic elasticity patterns and identify the life-history determinants underlying interspecific and interpopulation variability in vulnerability to metabolic disruption caused by EDs.

Perspectives :

This initial 6-month contract is conceived as a first step in a broader research programme. Several funding applications are currently under review to extend this modelling framework by (i) Integrating mechanistic descriptions of the energetic and physiological processes underlying transgenerational transmission of altered life-history traits; and (ii) Incorporating additional environmental drivers that may shape intraspecific life-history variation in amphibian populations. These future developments aim to establish an integrative predictive framework linking physiological disruption, life-history evolution, and population-level responses to the combination of multiple environmental stressors.

REFERENCES: 

Caswell H (2001) Matrix population models. Sunderland, USA: Sinauer Associates Publishers.

Cribiu P, et al. (2020) A "Population Dynamics" Perspective on the Delayed Life-History Effects of Environmental Contaminations: An Illustration with a Preliminary Study of Cadmium Transgenerational Effects over Three Generations in the Crustacean Gammarus. Int J Mol Sci 21(13).

Prud'homme SM, Chaumot A, Cassar E, David JP, & Reynaud S (2017) Impact of micropollutants on the life-history traits of the mosquito Aedes aegypti: On the relevance of transgenerational studies. Environ Pollut 220(Pt A):242-254.

Regnault C, et al. (2018) Unexpected metabolic disorders induced by endocrine disruptors in Xenopus tropicalis provide new lead for understanding amphibian decline. Proc Natl Acad Sci U S A 115(19):E4416-E4425.

Usal M, et al. (2021) Exposure to a mixture of benzo[a]pyrene and triclosan induces multi-and transgenerational metabolic disorders associated with decreased female investment in reproduction in Silurana (Xenopus) tropicalis. Environ Pollut 292(Pt B):118418.

Training and skills

-Recommended training: A PhD in ecotoxicology/ecology modelling

-Appreciated experience: physiological models (energétic budget)

-Skills: autonomy, integrative vision

INRAE's life quality

By joining our teams, you benefit from (depending on the type of contract and its duration):

- up to 30 days of annual leave + 15 days "Reduction of Working Time" (for a full time);
- parenting support: CESU childcare, leisure services;
- skills development systems: training, career advise;
- social support: advice and listening, social assistance and loans;
- holiday and leisure services: holiday vouchers, accommodation at preferential rates;
- sports and cultural activities;
- collective catering.

How to apply

I send my CV and my motivation letter