TrEMIT
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Transgenerational Effects of MIT in Aquatic Ecosystems |
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Research
Context and Issues
Emerging contaminants represent a particular challenge for management and risk assessment given the inherent lack of data regarding their effects on natural systems. One such class of compounds are synthetic biocides in the isothiazolinone family. These are extensively used in commercial and domestic applications, typically in mixtures of methylisothiazolinone (MIT) and methylchloroisothiazolinone (CMIT), and thus are likely routinely discharged to the environment. Currently under scrutiny for their link to contact dermatitis, their potential impact on aquatic ecosystems has received considerably less attention. This project aims to address this lacuna, using Daphnia, model invertebrates that are also a keystone species for healthy ecosystem functioning in lentic environments.Objectives
This project has two broad goals: to evaluate MIT toxicity and to assess its epigenetic/transcriptional effects. To achieve these ends, the project is built around the following specific objectives:
- to extend the LC50 model of acute MIT toxicity to incorporate broad-sense genetic variance for resistance
- to test for epigenetic effects of MIT at the global and gene-specific levels
- to characterize the transcriptome-wide response to MIT exposure
- to disentangle the relative effects of direct versus transgenerational exposure to MIT, and to quantify their associated transcriptional responses
Methodology
Acute toxicity will be evaluated by a 48h LC50 test, using multiple independent clonal lines established from an outbred natural population, thereby providing insights into the potential for genetically based variation in MIT resistance. Next Generation sequencing will be used to quantify epigenetic and transcriptional effects of CMIT/MIT exposure. Specifically, whole genome bisulfite sequencing will provide site-specific data of genome-wide methylation; RNA-Seq will be used to quantify transcriptome-wide RNA abundance as a proxy for expression. These will be measured in clonal lines that have been subjected to both direct and/or maternal exposure to CMIT/MIT; measures taken in descendant generations unexposed to the xenobiotic will provide a test for transgenerational effects.Expected Results
This project will address the current lacuna regarding the potential impacts of MIT in the aquatic environment. One aspect will explore variation in MIT toxicity as a function of evolutionary history and inherent genetic diversity within a natural population, yielding data essential for policy makers. In addition to providing data for ecological risk assessment, results will also help to address a broader fundamental question regarding the role of methylation as a regulator of dynamic gene expression in a model invertebrate.Partners
- INRA, Unité Expérimentale d'Ecologie et d'Ecotoxicologie U3E, Rennes
- INRA Plateforme génome et transcriptome (GeT PlaGe), Toulouse
- Université de Séoul, Corée du Sud, Prof. Jinhee Choi, School of Environmental Engineering
People involved
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COLLINET Marc, Technician Phone : +33 2 23 48 55 29 Email : marc.collinet@inrae.fr |
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COUTELLEC Marie-Agnès, Scientist Phone : +33 2 23 48 52 48 Email : marie-agnes.coutellec@inrae.fr |
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MCCAIRNS Scott, Scientist Phone : +33 2 23 48 52 37 Email : scott.mccairns@inrae.fr |
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VASSAUX Danièle, Technician Phone : +33 2 23 48 56 69 Email : daniele.vassaux@inrae.fr |
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WAGNER Margot, Ph.D. Student Phone : +33 2 23 48 70 38 Email : margot.wagner@inrae.fr |
Funding and Support
This project is funded by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES; grant no: 2017/1/093) under the National Research Programme on Environmental and Occupational Health (PNREST).