Adaptive trade-offs between vertebrate defence and insect predation drive Amazonian ant venom evolution.

Stinging ants have diversified into various ecological niches, and selective pressures may have contributed to shape the composition of their venom. To explore the drivers underlying venom variation in ants, we sampled 15 South American rainforest species and recorded a range of traits, including ecology, morphology and venom bioactivities. Principal component analysis of both morphological and venom bioactivity traits reveals that stinging ants display two functional strategies where species have evolved towards either an exclusively offensive venom or a multi-functional venom.

MRGPRB2/X2 and the analogous effects of its agonist and antagonist in DSS-induced colitis in mice.

The mast cell receptor Mrgprb2, a mouse orthologue of human Mrgprx2, is known as an inflammatory receptor and its elevated expression is associated with various diseases such as ulcerative colitis. We aimed to elucidate the role of Mrgprb2/x2 and the effect of its ligands on a chemically induced murine colitis model. We showed that in Mrgprb2 mice, there is a differential regulation of cytokine releases in the blood plasma and severe colonic damages after DSS treatment.

The genome of the ant Tetramorium bicarinatum reveals a tandem organization of venom peptides genes allowing the prediction of their regulatory and evolutionary profiles.

Background: Venoms have evolved independently over a hundred times in the animal kingdom to deter predators and/or subdue prey. Venoms are cocktails of various secreted toxins, whose origin and diversification provide an appealing system for evolutionary researchers. Previous studies of the ant venom of Tetramorium bicarinatum revealed several Myrmicitoxin (MYRTX) peptides that gathered into seven precursor families suggesting different evolutionary origins.

Discovery of an Insect Neuroactive Helix Ring Peptide from Ant Venom.

Ants are among the most abundant terrestrial invertebrate predators on Earth. To overwhelm their prey, they employ several remarkable behavioral, physiological, and biochemical innovations, including an effective paralytic venom. Ant venoms are thus cocktails of toxins finely tuned to disrupt the physiological systems of insect prey.

Optimization and calibration of behavioural tests on different species of planaria for ecotoxicological studies.

Freshwater planarian are emerging as a valuable in vivo model for (eco) toxicological studies, but the lack of harmonization of procedures between laboratories remains a challenge. This study aimed to optimize, automate and select the best behavioural tests and analyse the potential of different planarian species as models for toxicological assessment. We implemented four tests: exploration, photomotor response, Tapping and Planarian Light Dark Test, on different planaria species using the DanioVision system.

Ant venoms contain vertebrate-selective pain-causing sodium channel toxins.

Stings of certain ant species (Hymenoptera: Formicidae) can cause intense, long-lasting nociception. Here we show that the major contributors to these symptoms are venom peptides that modulate the activity of voltage-gated sodium (Na) channels, reducing their voltage threshold for activation and inhibiting channel inactivation. These peptide toxins are likely vertebrate-selective, consistent with a primarily defensive function.

The mechanism underlying toxicity of a venom peptide against insects reveals how ants are master at disrupting membranes.

Hymenopterans represent one of the most abundant groups of venomous organisms but remain little explored due to the difficult access to their venom. The development of proteo-transcriptomic allowed us to explore diversity of their toxins offering interesting perspectives to identify new biological active peptides. This study focuses on U function, a linear, amphiphilic and polycationic peptide isolated from ant venom.

Venomics survey of six myrmicine ants provides insights into the molecular and structural diversity of their peptide toxins.

Among ants, Myrmicinae represents the most speciose subfamily. The venom composition previously described for these social insects is extremely variable, with alkaloids predominant in some genera while, conversely, proteomics studies have revealed that some myrmicine ant venoms are peptide-rich. Using integrated transcriptomic and proteomic approaches, we characterized the venom peptidomes of six ants belonging to the different tribes of Myrmicinae.

A carvacrol-based product reduces Campylobacter jejuni load and alters microbiota composition in the caeca of chickens.

Aim: This study was conducted to test the ability of a carvacrol-based formulation (Phodé, France) to decrease the C. jejuni caecal load in inoculated broiler chickens and to study the impact of the C. jejuni inoculation alone or combined with the product, on the caecal microbiota.

Long-term exposure to environmental diclofenac concentrations impairs growth and induces molecular changes in Lymnaea stagnalis freshwater snails.

As pharmaceutical substances are highly used in human and veterinary medicine and subsequently released in the environment, they represent emerging contaminants in the aquatic compartment. Diclofenac (DCF) is one of the most commonly detected pharmaceuticals in water and little research has been focused on its long-term effects on freshwater invertebrates. In this study, we assessed the chronic impacts of DCF on the freshwater gastropod Lymnaea stagnalis using life history, behavioral and molecular approaches.

Effects of the anxiolytic benzodiazepine oxazepam on freshwater gastropod reproduction: a prospective study.

Psychoactive drugs have emerged as contaminants over the last few decades. These drugs are frequently prescribed and poorly eliminated by wastewater treatment plants, and many are present at non-negligible concentrations in surface waters. Several studies have investigated the non-target organism toxicity of one such drug, oxazepam, a benzodiazepine anxiolytic frequently detected in rivers.

P17 induces chemotaxis and differentiation of monocytes via MRGPRX2-mediated mast cell-line activation.

Background: P17, a peptide isolated from Tetramorium bicarinatum ant venom, is known to induce an alternative phenotype of human monocyte-derived macrophages via activation of an unknown G protein-coupled receptor (GPCR).

Objective: We sought to investigate the mechanism of action and the immunomodulatory effects of P17 mediated through MRGPRX2 (Mas-related G protein-coupled receptor X2).

Methods: To identify the GPCR for P17, we screened 314 GPCRs.

Low concentrations of oxazepam induce feeding and molecular changes in Radix balthica juveniles.

Psychotropics, especially benzodiazepines, are commonly prescribed worldwide. Poorly eliminated at wastewater treatment plants, they belong to a group of emerging contaminants. Due to their interaction with the GABA receptor, they may affect the function of the nervous system of non-target organisms, such as aquatic organisms.

Comparative study of the effects of ziram and disulfiram on human monocyte-derived macrophage functions and polarization: involvement of zinc.

Ziram, a zinc dithiocarbamate is widely used worldwide as a fungicide in agriculture. In order to investigate ziram-induced changes in macrophage functions and polarization, human monocytes-derived macrophages in culture were treated with ziram at 0.01-10 μmol.

The Peptide Venom Composition of the Fierce Stinging Ant (Formicidae: Pseudomyrmecinae).

In the mutualisms involving certain pseudomyrmicine ants and different myrmecophytes (i.e., plants sheltering colonies of specialized "plant-ant" species in hollow structures), the ant venom contributes to the host plant biotic defenses by inducing the rapid paralysis of defoliating insects and causing intense pain to browsing mammals.

Deciphering the Molecular Diversity of an Ant Venom Peptidome through a Venomics Approach.

The peptide toxins in the venoms of small invertebrates such as stinging ants have rarely been studied due to the limited amount of venom available per individual. We used a venomics strategy to identify the molecular diversity of the venom peptidome for the myrmicine ant Tetramorium bicarinatum. The methodology included (i) peptidomics, in which the venom peptides are sequenced through a de novo mass spectrometry approach or Edman degradation; (ii) transcriptomics, based on RT-PCR-cloning and DNA sequencing; and (iii) the data mining of the RNA-seq in the available transcriptome.

Evaluation of psychiatric hospital wastewater toxicity: what is its impact on aquatic organisms?

The primary source of pharmaceuticals to the aquatic environment is the discharge of wastewater effluents. Pharmaceuticals are a large and diverse group of compounds. Among them, psychotropic substances are particularly interesting to study due to their specific known mode of action.

Pharmacokinetic and antimicrobial activity of a new carvacrol-based product against a human pathogen, Campylobacter jejuni.

Aim: In vitro and in vivo studies were conducted to test a new carvacrol-based product designed to delay the carvacrol release so that it could reach the caeca of broiler chickens in order to control Campylobacter jejuni.

Methods And Results: Antimicrobial activity of carvacrol, a constituent of oregano and thyme essential oil, has been demonstrated against C. jejuni in vitro, and this compound was found beneficial for broiler growth.

Correction to: Assessment of Lemna minor (duckweed) and Corbicula fluminea (freshwater clam) as potential indicators of contaminated aquatic ecosystems: responses to presence of psychoactive drug mixtures.

The correct presentation of the Author names are shown in this paper.

P17, an Original Host Defense Peptide from Ant Venom, Promotes Antifungal Activities of Macrophages through the Induction of C-Type Lectin Receptors Dependent on LTB4-Mediated PPARγ Activation.

Despite the growing knowledge with regard to the immunomodulatory properties of host defense peptides, their impact on macrophage differentiation and on its associated microbicidal functions is still poorly understood. Here, we demonstrated that the P17, a new cationic antimicrobial peptide from ant venom, induces an alternative phenotype of human monocyte-derived macrophages (h-MDMs). This phenotype is characterized by a C-type lectin receptors (CLRs) signature composed of mannose receptor (MR) and Dectin-1 expression.

Assessment of Lemna minor (duckweed) and Corbicula fluminea (freshwater clam) as potential indicators of contaminated aquatic ecosystems: responses to presence of psychoactive drug mixtures.

The pharmaceutical products are emerging pollutants continuously released into the environment, because they cannot be effectively removed by the wastewater treatment plants. In recent years, questions have been raised concerning the environmental risks related to these pollutants. The goal of this research was to evaluate the responses in Lemna minor after 7 days and in Corbicula fluminea after differing durations (1, 3, 7, and 19 days) of exposure to the psychoactive drug mixture (valproic acid, citalopram, carbamazepine, cyamemazine, hydroxyzine, oxazepam, norfluoxetine, lorazepam, fluoxetine, and sertraline) in different concentrations (0, 0 + ethanol, drug concentration (DC) 1 = river water concentration, DC2 = effluent concentration, and DC3 = 10× effluent concentration).

De novo transcriptome sequencing and analysis of freshwater snail (Radix balthica) to discover genes and pathways affected by exposure to oxazepam.

Pharmaceuticals are increasingly found in aquatic ecosystems due to the non-efficiency of waste water treatment plants. Therefore, aquatic organisms are frequently exposed to a broad diversity of pharmaceuticals. Freshwater snail Radix balthica has been chosen as model to study the effects of oxazepam (psychotropic drug) on developmental stages ranging from trochophore to hatching.

Monoterpenoid-based preparations in beehives affect learning, memory, and gene expression in the bee brain.

Bees are exposed in their environment to contaminants that can weaken the colony and contribute to bee declines. Monoterpenoid-based preparations can be introduced into hives to control the parasitic mite Varroa destructor. The long-term effects of monoterpenoids are poorly investigated.

Biochemical and biophysical combined study of bicarinalin, an ant venom antimicrobial peptide.

We have recently characterized bicarinalin as the most abundant peptide from the venom of the ant Tetramorium bicarinatum. This antimicrobial peptide is active against Staphylococcus and Enterobacteriaceae. To further investigate the antimicrobial properties of this cationic and cysteine-free peptide, we have studied its antibacterial, antifungal and antiparasitic activities on a large array of microorganisms.