PLAYLYST
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Properties and ligand affinity of endocrine disruptor-binding receptors in <i>Lymnaea stagnalis</i> (Mollusc, Gastropod) |
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Research
Context and Issues
The Great Pond Snail Lymnaea stagnalis has been selected as a test species for the development of an OECD Guideline for reprotoxicity testing in molluscs. The test protocol was pre-validated in 2012, and the validation ring test started in October 2013. This in vivo test appears as a Mollusc Partial Life-Cycle Assay at Level 4 of the OECD Conceptual Framework for Testing and Assessment of Endocrine Disrupters (EDs). It is meant to provide data about adverse effects on endocrine-relevant endpoints related to reproduction.
For such an apical test, endpoints can be sensitive to more than one mechanism and may be due to non-ED mechanisms. However, in L. stagnalis and other mollusc species, the existence, properties and ligand-affinity of ED-binding receptors are poorly documented and even controversial, thus the endocrine origin of adverse effects on individuals cannot be ascertained.
Objectives
The main general goal of PLAYLYST is to develop tools for in silico prediction and in vitro screening of the effects of EDs that specifically bind to mollusc receptors.
Too meet this goal, the scientific objective of the project is to characterize the properties and ligand- binding affinity of ED-binding receptors, namely the estrogen receptor (ER) (or estrogen-related receptor, ERR) and the retinoid-X receptor (RXR), of L. stagnalis.
Methodology
Genomic resources recently acquired in the Great Pond Snail and available in other molluscs will be used to:
- sequence L. stagnalis ER and RXR genes (LymER and LymRXR, respectively)
- synthesize expression vectors of these genes, using transient and stable transfection
- test their inducibility by ligands known to bind to human receptors, i.e. hER (e.g., E2, EE2,…) and hRXR (e.g., TBT, 9-cis retinoic acid)
- model the ligand-binding domains of LymER and LymRXR order to virtually screen a larger number of ligands.
Besides pesticides, other compounds of primary interest in research on endocrine disruption will be used. Among them, bisphenol A and its possible substitutes, phthalates, parabens will be tested on both LymER and LymRXR.
Expected results
This in vitro approach will contribute to filling the knowledge gap on ED-binding receptors in molluscs and strengthen interpretation of mechanisms underlying adverse reproductive effects of chemicals in L. stagnalis in the context of the forthcoming OECD Guideline.
This project will form the basis for the development of in silico prediction methods and in vitro assays which could be respectively implemented as levels 1 and 2 tests for non-mammalian animals in the OECD Conceptual Framework for Testing and Assessment of Endocrine Disrupters.
People involved
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BESNARD Anne-Laure, Technician Phone : +33 2 23 48 54 43 Email : anne-laure.besnard(at)inrae.fr |
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COUTELLEC Marie-Agnès, Scientist Phone : +33 2 23 48 52 48 Email : marie-agnes.coutellec@inrae.fr |
Partners
Funding and Support
This project is funded and supported by PNRPE (French National Research Program on Endocrine Disruptors)