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THE AMPHIBIAN SHORT TERM ASSAY (ASTA): EVALUATION OF A NEW ECOTOXICOLOGICAL METHOD FOR AMPHIBIANS USING TWO ORGANOPHOSPHATE PESTICIDES COMMONLY FOUND IN NATURE. ASSESSMENT OF BIOCHEMICAL, MORPHOMETRICAL AND BEHAVIORAL TRAITS.

 

Neurotoxic pesticides are used worldwide to protect crops from insects. Developed at the beginning of the 20th century, they now represent a threat to non-target organisms that live in areas surrounded by treated crops. Many biochemical and cell-based solutions have been developed for testing insecticide neurotoxicity. Nevertheless, such solutions provide a partial assessment of the impact of neurotoxicity, neglecting important phenotypic components such as behavior.

During my PhD, I enjoyed developping a 8-day method for assessing the impacts of organophosphate insecticides (OPI) on early stage of X. laevis, a model species for amphibians. This promising method implies the measurement of biochemical (AChE activity), morphometrical (lengths and shape) and locomotor traits. For measuring the latter, I conceived a home-made device for recording larvae swimming behavior. I also developed a Python application for tracking larvae trajectories and computing different locomotor speed- and direction-related components.

The home-made device for recording the larvae swimming behavior.

For evaluating the efficiency of the method, I used two OPIs, the diazinon and the chlorpyrifos insecticide.

The Python application tracking a larvae trajectory.

The results of this work are numerous:

  • I was able to prove the efficiency of the method for highlighting the impact of these OPIs on AChE activity, body length and shape, growth rate and locomotor components,
  • 4-day old embryos were less sensitive to OPIs than to 8-day old larvae,
  • the impact of exposure on locomotor performance was time-dependent with day 6 as the most critical time.

I am confident that this method would be a good candidate for standardization after implementing improvement and leading few investigation about its repeatability and reproducibility.

2023

Boualit, L., Cayuela, H., Ballu, A. , Cattin, L., Reis, C. & Chèvre, N. The Amphibian Short Term  Assay (ASTA): Evaluation of a New Ecotoxicological Method for Amphibians Using Two Organophosphate Pesticides Commonly Found in Nature. Assessment of of behavioral traits. Submitted to Environmental Toxicology and Chemistry.

2022

Boualit, L., Cayuela, H., Cattin, L., & Chèvre, N. (2022). The Amphibian Short‐Term Assay: Evaluation of a New Ecotoxicological Method for Amphibians Using Two Organophosphate Pesticides Commonly Found in Nature—Assessment of Biochemical, Morphological, and Life‐History Traits. Environmental Toxicology and Chemistry, 41(11), 2688-2699.

2021