Limited effects of a glyphosate-based herbicide on the behaviour and immunity of males from six populations of the European earwig.

The use of herbicides on crops often results in unintentional, low-dose exposure of non-target organisms, such as insects. While these exposures are increasingly known to alter the survival and physiology of insects, it remains unclear whether these effects can vary between populations and modify other fitness-related traits, such as behaviour and immunity. Here, we addressed these questions by testing the effects of sublethal exposure to a glyphosate-based herbicide (GBH) on the behaviour and immunity of European earwig males from six natural populations.

Unveiling Molecular Effects of the Secondary Metabolite 2-Dodecanone in the Model Hymenopteran .

Over the past decade, multiple studies have suggested that the secondary metabolites produced by plants against herbivorous insects could be used as biopesticides. However, as the molecular mechanism of action of these compounds remains unknown, it is difficult to predict how they would affect non-target insects; thus, their innocuity needs to be clarified. Here, we investigate, from the molecular level to the organism, the responses of a useful parasitic insect (Walker, 1836) being exposed at the pupae stage for 48 h (up to 6 days) to sublethal doses (5 µg/L and 500 µg/L) of 2-Dodecanone.

Sublethal doses of pyriproxyfen stimulate reproduction and aggressive behavior in a non-target parasitoid wasp.

Insecticides are commonly used to control populations of pests and disease vectors. However, they can have multiple unintended effects on non-target species. Assessing their impacts on the physiology and behavior of beneficial insects, such as biological control agents, is thus necessary to gain insight into the diversity and nature of such side effects.

Exposure to pyriproxyfen (juvenile hormone agonist) does not alter maternal care and reproduction in the European earwig.

Sublethal exposure to pesticides can alter the survival and reproduction of a wide range of non-target organisms. However, it remains unclear whether this exposure can alter behaviours that are often essential for long-term population dynamics and maintenance, such as parental care. In this study, we tested the effect of pyriproxyfen exposure (an insect growth regulator) on maternal care in the European earwig, an insect that is both used in pest control in pip-fruit orchards and considered a pest in stone fruit orchards.

A comparative genomic approach using mouse and fruit fly data to discover genes involved in testis function in hymenopterans with a focus on Nasonia vitripennis.

Background: Spermatogenesis appears to be a relatively well-conserved process even among distantly related animal taxa such as invertebrates and vertebrates. Although Hymenopterans share many characteristics with other organisms, their complex haplodiploid reproduction system is still relatively unknown. However, they serve as a complementary insect model to Drosophila for studying functional male fertility.

Sublethal exposure to deltamethrin stimulates reproduction and has limited effects on post-hatching maternal care in the European earwig.

Although pesticides are typically used to limit pest population, the diversity and nature of their unintentional effects on non-target organisms remain unclear. Better understanding these effects requires to carry out risk assessments on key physiological and behavioral processes specific to beneficial insects. In this study, we addressed this question by exposing mothers of the European earwig (a beneficial insect) to two sublethal doses of deltamethrin (a common pesticide in agriculture) during family life and measured the short- and long-term effects on a series of behavioral, physiological, and reproductive traits.

Ecdysteroids affect female reproductive status and outcome of contest over hosts in the parasitoid wasp Eupelmus vuilleti.

Ecdysteroids are a family of insect hormones that may play a role in modulating aggressive behavior in reproductive contexts. In Hymenoptera, the few studies investigating the link between ecdysteroid titers, reproduction and aggressiveness during contests concern solely eusocial species. Here, we explored whether ecdysteroid titers influenced female reproductive status as well as aggressiveness and resolution of conflict in a solitary ectoparasitoid, Eupelmus vuilleti (Hymenoptera: Eupelmidae).

Sublethal exposure to deltamethrin impairs maternal egg care in the European earwig Forficula auricularia.

The application of pesticides typically leads to lethal and sublethal exposure of non-target insects. Whereas our current understanding of these sublethal effects typically focuses on reproductive and physiological parameters, recent works emphasize that sublethal effects on behaviors such as maternal care could be of major importance in non-target species. However, it remained unknown whether these sublethal effects occur in insects.

Physiological and biochemical responses to thermal stress vary among genotypes in the parasitic wasp Nasonia vitripennis.

In ectotherm species such as insects, thermal fluctuations represent a major environmental factor driving development, survival and reproduction of individuals. Reproductive traits are particularly sensitive to heat stress that can induce a permanent sterility, or at least hypofertility, of adult males. This study aims to compare physiological and biochemical responses associated to male performances to an exposure of 24 h to moderately high temperature (36 °C) among three inbred lines of N.

An evolutionary approach to recover genes predominantly expressed in the testes of the zebrafish, chicken and mouse.

Background: Previously, we have demonstrated that genes involved in ovarian function are highly conserved throughout evolution. In this study, we aimed to document the conservation of genes involved in spermatogenesis from flies to vertebrates and their expression profiles in vertebrates.

Results: We retrieved 379 Drosophila melanogaster genes that are functionally involved in male reproduction according to their mutant phenotypes and listed their vertebrate orthologs.

Sperm limitation affects sex allocation in a parasitoid wasp Nasonia vitripennis.

Insect reproduction is influenced by various external factors including temperature, a well-studied constraint. We investigated to what extent different levels of sperm limitation of males exposed to different heat stresses (34 and 36 °C) affect females' offspring production and sex allocation in Nasonia vitripennis. In this haplodiploid parasitoid wasp attacking different species of pest flies, we investigated the effect of the quantity of sperm females received and stored in their spermatheca on their sperm use decisions, hence sex allocation, over successive ovipositions.

The spatio-temporal partitioning of sperm by males of the prospermatogenic parasitoid Nasonia vitripennis is in line with its gregarious lifestyle.

Male fitness depends on the number of lifetime progeny of their mates and could be constrained by the chance of finding a mate, lifespan and temporal patterns of sperm production and allocation. Here, we used the parasitic wasp Nasonia vitripennis with a two-week lifespan and a gregarious lifestyle, to analyze how the reproductive system is organized to allocate spermatozoa over consecutive matings. Results show that spermatogenesis is synchronized and completed one day before emergence so that males emerge with a full sperm complement.

A combined approach to heat stress effect on male fertility in Nasonia vitripennis: from the physiological consequences on spermatogenesis to the reproductive adjustment of females mated with stressed males.

In recent years, several studies have shown a decline in reproductive success in males in both humans and wildlife. Research on male fertility has largely focused on vertebrates, although invertebrates constitute the vast majority of terrestrial biodiversity. The reduction of their reproductive capacities due to environmental stresses can have strong negative ecological impacts, and also dramatic consequences on world food production if it affects the reproductive success of biological control agents, such as parasitic wasps used to control crop pests.

Signaling via class IA Phosphoinositide 3-kinases (PI3K) in human, breast-derived cell lines.

We have addressed the differential roles of class I Phosphoinositide 3-kinases (PI3K) in human breast-derived MCF10a (and iso-genetic derivatives) and MDA-MB 231 and 468 cells. Class I PI3Ks are heterodimers of p110 catalytic (α, β, δ and γ) and p50-101 regulatory subunits and make the signaling lipid, phosphatidylinositol (3,4,5)-trisphosphate (PtdIns(3,4,5)P3) that can activate effectors, eg protein kinase B (PKB), and responses, eg migration. The PtdIns(3,4,5)P3-3-phosphatase and tumour-suppressor, PTEN inhibits this pathway.

Differential effects of bisphenol A and diethylstilbestrol on human, rat and mouse fetal leydig cell function.

Endocrine disruptors (ED) have been incriminated in the current increase of male reproductive alterations. Bisphenol A (BPA) is a widely used weak estrogenic environmental ED and it is debated whether BPA concentrations within the average internal exposure are toxic. In the present study we investigated the effects of 10(-12) to 10(-5) M BPA concentrations on fetal Leydig cell function, as fetal life is a critical period of sensitivity to ED effects on male reproductive function.

Cellular and molecular effect of MEHP Involving LXRα in human fetal testis and ovary.

Background: Phthalates have been shown to have reprotoxic effects in rodents and human during fetal life. Previous studies indicate that some members of the nuclear receptor (NR) superfamilly potentially mediate phthalate effects. This study aimed to assess if expression of these nuclear receptors are modulated in the response to MEHP exposure on the human fetal gonads in vitro.

Metformin exposure affects human and mouse fetal testicular cells.

Background: Metformin is a drug used in the treatment of diabetes and of some disorders related to insulin resistance, such as polycystic ovary syndrome. Gestational diabetes can cause complications for both mother and child, and some studies have shown a beneficial effect of metformin during pregnancy without an increase in perinatal complications. However, the effects on the gonads have not been properly studied.

GPCR activation of Ras and PI3Kc in neutrophils depends on PLCb2/b3 and the RasGEF RasGRP4.

The molecular mechanisms by which receptors regulate the Ras Binding Domains of the PIP3-generating, class I PI3Ks remain poorly understood, despite their importance in a range of biological settings, including tumorigenesis, activation of neutrophils by pro-inflammatory mediators, chemotaxis of Dictyostelium and cell growth in Drosophila. We provide evidence that G protein-coupled receptors (GPCRs) can stimulate PLCb2/b3 and diacylglycerol- dependent activation of the RasGEF, RasGRP4 in neutrophils. The genetic loss of RasGRP4 phenocopies knock-in of a Ras-insensitive version of PI3Kc in its effects on PI3Kc-dependent PIP3 accumulation, PKB activation, chemokinesis and reactive oxygen species (ROS) formation.

Effect of mono-(2-ethylhexyl) phthalate on human and mouse fetal testis: In vitro and in vivo approaches.

The present study was conducted to determine whether exposure to the mono-(2-ethylhexyl) phthalate (MEHP) represents a genuine threat to male human reproductive function. To this aim, we investigated the effects on human male fetal germ cells of a 10⁻⁵ M exposure. This dose is slightly above the mean concentrations found in human fetal cord blood samples by biomonitoring studies.

[Parasitic wasps, a model for studying male subfertility].

Many studies have reported an increase in male reproductive disorders due to the environment. Despite their ecological importance invertebrates have been poorly studied; they are yet affected in the same way as vertebrates by changes in the environment. Different stresses made on parasitic wasps are able to induce a male subfertility.

Adverse effects of endocrine disruptors on the foetal testis development: focus on the phthalates.

There are great concerns about the increasing incidence of abnormalities in male reproductive function. Human sperm counts have markedly dropped and the rate of testicular cancer has clearly augmented over the past four decades. Moreover, the prevalence rates of cryptorchidism and hypospadias are also probably increasing.

Ontogenesis of testicular function in humans.

The two major functions of the testis, steroidogenesis and gametogenesis, take place during fetal life. These two functions have been extensively studied in rodents and adult humans. However, their onset during fetal life is poorly documented in humans.

FSH-stimulated PTEN activity accounts for the lack of FSH mitogenic effect in prepubertal rat Sertoli cells.

Follicle-stimulating hormone (FSH) controls the proliferation and differentiation of Sertoli cells of the testis. FSH binds a G protein-coupled receptor (GPCR) to stimulate downstream effectors of the phosphoinositide-3 kinase (PI3K)-dependent pathway, without enhancing PI3K activity. To clarify this paradox, we explored the activity of phosphatase and tensin homolog deleted in chromosome 10 (PTEN), the PI3K major regulator, in primary cultures of rat Sertoli cells.

Developmental regulation of p70 S6 kinase by a G protein-coupled receptor dynamically modelized in primary cells.

The mechanisms whereby G protein-coupled receptors (GPCR) activate signalling pathways involved in mRNA translation are ill-defined, in contrast to tyrosine kinase receptors (TKR). We compared a GPCR and a TKR, both endogenously expressed, for their ability to mediate phosphorylation of 70-kDa ribosomal S6 kinase p70S6K in primary rat Sertoli cells at two developmental stages. In proliferating cells stimulated with follicle-stimulating hormone (FSH), active p70S6K was phosphorylated on T389 and T421/S424, through cAMP-dependent kinase (PKA) and phosphatidyl-inositide-3 kinase (PI3K) antagonizing actions.

Development of a real-time PCR assay with an internal amplification control for the screening of Shiga toxin-producing Escherichia coli in foods.

Aims: To develop and evaluate a real-time PCR assay incorporating an internal amplification control (IAC) suitable for the screening of Shiga toxin (Stx)-producing Escherichia coli (STEC) in foods.

Methods And Results: A competitive IAC was constructed and included in an stx-specific real-time PCR assay. Coupled to 18-h enrichment and automated DNA extraction, the assay could reliably detect the presence of STEC in minced meats inoculated at 10 CFU per 25 g.