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Many priority pollutants are concentrated in the environment due to human activity. Most are highly toxic to various organisms, including endocrine disruptors EDCs, aromatic polycyclic hydrocarbons PAHs, pesticides. While the effects of single and binary exposure have been widely explored, several pollutants can be simultaneously present at the same time in the environment, in in more or less polluted matrices. Effective pollution control requires the presence and sources of contamination to be identified. Previously we used Drosophila melanogaster to investigate metal pollution. Here, we re-used Drosophila to identify the biomarkers of pollution, and to determine if they can be used for specific types of pollution. Single and combined exposure of Bis(2-ethylhexyl) phthalate (DEHP), bisphenol A, nonylphenol, benzo(a)pyrene, and glyphosate was investigated. The impact of these pollutants on post-embryonic development and the expression pattern of 38 molecular targets were examined using qPCR. During single exposure, different profiles were observed at the molecular level. In complex mixtures, the expression profile resembled that of bisphenol A. In contrast, relatively specific gene expression profiles were obtained for the effects of each pollutant separately. While direct pollutant-gene profiling remains difficult in mixtures, molecular biology analyses enhance pollution monitoring, and should be incorporated in toxicological studies. [Display omitted] • Single and combined exposure of Bis(2-ethylhexyl) phthalate (DEHP), bisphenol A, nonylphenol, benzo(a)pyrene, and glyphosate was investigated on Drosophila melanogaster model. • Correlations on the impact of these pollutants were made between effects on the post-embryonic development and the expression pattern of 38 molecular targets. • Relatively specific gene expression profiles were obtained for the effects of each pollutant separately whereas in the complex mixtures, the expression profile resembled that of bisphenol A. • Drosophila melanogaster offers great potential as a bioassay models for wastewater pollutions. [ABSTRACT FROM AUTHOR]

Abstract: In the honeybee Apis mellifera, multiple-trial olfactory conditioning of the proboscis extension response specifically leads to long-term memory (LTM) which can be retrieved more than 24h after learning. We studied the involvement of nicotinic acetylcholine receptors in the establishment of LTM by injecting the nicotinic antagonists mecamylamine (1mM), α-bungarotoxin (α-BGT, 0.1mM) or methyllycaconitine (MLA, 0.1mM) into the brain through the median ocellus 20min before or 20min after multiple-trial learning. The retention tests were performed 1, 3, and 24h after learning. Pre-training injections of mecamylamine induced a lower performance during conditioning but had no effect on LTM formation. Post-training injections of mecamylamine did not affect honeybees’ performances. Pre-training injections of MLA or post-training injection of α-BGT specifically induced LTM impairment whereas acquisition as well as memory retrieval tested 1 or 3h after learning was normal. This indicates that brain injections of α-BGT and MLA did not interfere with learning or medium-term memory. Rather, these blockers affect the LTM. To explain these results, we advance the hypothesis that honeybee α-BGT-sensitive acetylcholine receptors are also sensitive to MLA. These receptors could be essential for triggering intracellular mechanisms involved in LTM. By contrast, medium-term memory is not dependent upon these receptors but is affected by mecamylamine. [Copyright &y& Elsevier]

Heavy metals, like many other chemical elements, are naturally present in the environment; however, the concentrations of these metals in various environmental matrices have increased through their intensive use in many human activities (such as industry, mining and agriculture). Among the heavy metals, cadmium (Cd) and mercury (Hg) induce a wide variety of defects in animals. While the effects of these heavy metals have been widely documented, a single exposure paradigm is typically used. Few studies have focused on evaluating combined exposure to these metals. However, in the environment, animals are confronted with a plethora of substances simultaneously; thus, the presence and origin of such substances must be determined to reduce the sources of contamination. Using the model of the fruit fly Drosophila melanogaster , for which many tools are readily available, we investigated how different concentrations of Cd and Hg in single and combined exposures impact post-embryonic development. In parallel, we evaluated the extended expression pattern of 38 molecular targets used as potential biomarkers of exposure through qPCR. Our results showed that both metals caused developmental delays and mortality in dose-dependent responses. Both metals were able to deregulate genes involved in hormonal control, general stress, and oxidative stress. Importantly, we confirmed synergistic interactions between Cd and Hg. Our results indicate the importance of assessing several biomarkers and their kinetics in mixtures. Drosophila represents a useful model for monitoring the toxicity of substances in polluted environments. [Display omitted] • Cd and Hg in single or mixtures caused developmental delays and mortality in dose-dependent responses. • Both metals were able to deregulate genes involved in hormonal control, general stress, and oxidative stress. • Synergistic interactions between Cd and Hg was observed. [ABSTRACT FROM AUTHOR]

The behavioural lateralization observed in several invertebrate species appears to parallel the phenomenon seen in vertebrates. However, it is not yet clear whether lateralization in invertebrates varies within an individual across development as it does in vertebrates. We examined when during postembryonic development juvenile cuttlefish begin to show side-turning preferences in a T-shaped apparatus. We also determined whether or not the direction of turning was stimulus dependent by providing, or not providing, shelters in the two choice arms of the apparatus. We found that as the animals aged from 3 to 45days posthatch they progressively developed a left-turning bias but only when shelters were provided in the apparatus. We suggest that left-turning biases in cuttlefish result from an eye use preference. Emergence of visual lateralization at the time of dispersal may afford juveniles greater behavioural efficiency by enabling them to look out for escape routes while hunting. The left visual field may be associated with rapid responses as in many species of vertebrates. Determining the role of the right visual field of cuttlefish when looking for prey may provide evidence for homology between lateralization in invertebrates and vertebrates. [Copyright &y& Elsevier]

Bis(2-ethylhexyl) phthalate (DEHP) is a widely produced plasticizer that is considered to act as an endocrine-disrupting chemical in vertebrates and invertebrates. Indeed, many studies have shown that DEHP alters hormonal levels, reproduction and behavior in vertebrates. Few studies have focused on the effects of DEHP on insects, although DEHP is found almost everywhere in their natural habitats, particularly in soils and plants. Here, we investigated the effects of DEHP on the sexual behavior and physiology of a pest insect, the noctuid moth Spodoptera littoralis. In this nocturnal species, olfaction is crucial for sexual behavior, and ecdysteroids at the antennal level have been shown to modulate sex pheromone detection by males. In the present study, larvae were fed food containing different DEHP concentrations, and DEHP concentrations were then measured in the adults (males and females). Hemolymphatic ecdysteroid concentrations, the antennal expression of genes involved in the ecdysteroid pathway (nuclear receptors EcR , USP , E75 , and E78 and calmodulin) and sexual behavior were then investigated in adult males. The success and latency of mating as well as the hatching success were also studied in pairs consisting of one DEHP male and one uncontaminated female or one DEHP female and one uncontaminated male. We also studied the offspring produced from pairs involving contaminated females to test the transgenerational effect of DEHP. Our results showed the general downregulation of nuclear receptors and calmodulin gene expression associated with the higher concentrations of DEHP, suggesting peripheral olfactory disruption. We found some effects on male behavior but without an alteration of the mating rate. Effects on offspring mortality and developmental rates in the N + 1 generation were also found at the higher doses of DEHP. Taken together, the results of the study show for the first time that larval exposure to DEHP can induce delayed endocrine-disruptive effects in the adults of a terrestrial insect as well as effects on the next generation. To date, our study is also the first description of an impact of endocrine disrupter on olfaction in insects. • Larval exposure to DEHP induced delayed effects on adults and the next generation. • The expression of ecdysteroid responsive genes in male antennae was reduced. • DEHP altered some male sexual behavior's items, but not the mating rate. • The observed effects on mating duration and hatching success were sex-dependent. • The duration of larval stages and adult lifespan of offspring were altered. [ABSTRACT FROM AUTHOR]