NRP50

15: Endocrine disruption in soil invertebrates: assessing multigeneration effects and developing a proteomic biomarker approach.

Impact of endocrine disruptors on soil invertebrates.

Soil invertebrates play an important role in the functioning and fertility of soil. This project focuses on the effect of endocrine-disrupting insecticides on collembola (springtails) and on the development of a biomarker, which would facilitate the detection of endocrine disruption in invertebrates.

Tarradellas Joseph, ENAC-ISTE, Ecole polytechnique fédérale de Lausanne

Background

Research in the area of endocrine disruption is mainly focused on vertebrates or aquatic invertebrates. Although soil constitutes an essential resource in our environment, very little research work is done in this field. Pollutants and natural chemicals can have an impact on soil organisms which are essential to maintain the fertility and functioning of the soil. So there is an increasing need for methods to assess the effects of these chemicals on soil ecosystems. As early warning systems they should provide a biological response able to predict adverse effects before they occur and should help us to evaluate the endocrine-disrupting potential of substances.

In this project we work with the primitive insects Folsomia candida (parthenogenic reproduction) and Folsomia fimetaria (sexual reproduction), two springtail species (collembola) which do not have the same endocrine system as vertebrates. They live in the top layer of the soil where they degrade organic material and serve as prey for other important soil invertebrates.

Aim

In the first phase of this project, we look at the effect of pesticides on the reproduction of springtails. These chemicals are known to interact with insect hormones. The aim is to define toxic levels of these insecticides and to look at their effect on several generations of springtails.
In the second phase, we focus on subtle changes inside the organisms by looking at protein patterns. The aim is to find a biomarker indicating an effect on the endocrine system before it becomes evident in reproduction. Such a biomarker would simplify the evaluation of endocrine disruptors and could be applied to different kinds of invertebrates.

Significance

This project will enable us to develop a soil invertebrate model for the study of developmental and endocrin effects. These effects will be observed over several generations, as endocrine disruptors may induce effects in the second or even the third generation. It will allow us to detect the disruption of endocrine systems in invertebrates which have no mammalian correlate. The biomarkers developed in this project could be used as an early warning system for endocrine effects in soil invertebrates.