Defensive secretions of nymphs and adults of five species Pyrrhocoridae (Insecta : Heteroptera)

International audience

Is mate choice in Drosophila males guided by olfactory or gustatory pheromones ?

International audience; Drosophila melanogaster flies use both olfactory and taste systems to detect sex pheromones and select the most suitable mate for reproduction. In nature, flies often face multiple potential partners and should have an acute sensory ability to discriminate between different pheromonal bouquets. We investigated both the pheromones and the chemosensory neurons influencing Drosophila mate choice. We measured various courtship traits in single tester males simultaneously presented with two target male and/or female flies carrying different pheromonal bouquets (pairs of control flies of the same or different sex, same-sex target pairs of pheromonal variant strains). The c…

Fatty-acid preference changes during development in Drosophila melanogaster.

WOS:000296521400044; International audience; Fatty-acids (FAs) are required in the diet of many animals throughout their life. However, the mechanisms involved in the perception of and preferences for dietary saturated and unsaturated FAs (SFAs and UFAs, respectively) remain poorly explored, especially in insects. Using the model species Drosophila melanogaster, we measured the responses of wild-type larvae and adults to pure SFAs (14, 16, and 18 carbons) and UFAs (C18 with 1, 2, or 3 double-bonds). Individual and group behavioral tests revealed different preferences in larvae and adults. Larvae preferred UFAs whereas SFAs tended to induce both a strong aversion and a persistent aggregation…

Courtship behaviour of Drosophila melanogaster revisited

0003-3472 doi: DOI: 10.1016/j.anbehav.2006.01.027; Nearly all studies of Drosophila melanogaster courtship have focused exclusively on male behaviour. Female precopulatory behaviour is often relegated to ‘accept' or ‘reject' mating, and how female behaviour interacts with that of males remains largely unknown. Using a video-computing approach, we measured 10 behavioural states and 22 elementary behaviours that occur during the precopulatory phase of Canton-S (Cs) flies. Male and female behaviours were studied under a variety of social conditions. This allowed us to identify which one(s) is relevant to courtship or to general activity. Our analysis showed that the courtship repertoire was no…

Incipient speciation in Drosophila melanogaster involves chemical signals.

WOS: 000300572900001; International audience; The sensory and genetic bases of incipient speciation between strains of Drosophila melanogaster from Zimbabwe and those from elsewhere are unknown. We studied mating behaviour between eight strains - six from Zimbabwe, together with two cosmopolitan strains. The Zimbabwe strains showed significant sexual isolation when paired with cosmopolitan males, due to Zimbabwe females discriminating against these males. Our results show that flies' cuticular hydrocarbons (CHs) were involved in this sexual isolation, but that visual and acoustic signals were not. The mating frequency of Zimbabwe females was highly significantly negatively correlated with t…

Pheromonal imprinting in Drosophila melanogaster: preadult exposure affects free flight odor tracking in adult

International audience

The preference behavior of Drosophila to fatty acids changes during development

The influence of smoke volatiles on sexual maturation and juvenile hormone biosynthesis in the black army cutworm, Actebia fennica (Lepidoptera: Noctuidae)

0965-1748 (Print) Journal Article Research Support, Non-U.S. Gov't; Outbreaks of the black army cutworm, Actebia fennica, are associated with recently burned sites, where larvae feed on early successional plants. In the present paper we show that smoke volatiles stimulate juvenile hormone biosynthesis in virgin females, resulting in a more rapid rate of oocyte maturation and a significant advance in the age of first calling (the release of the sex pheromone) compared to control females. The ecological implications of this physiological effect are discussed.

The desaturase1 gene affects reproduction before, during and after copulation in Drosophila melanogaster

Desaturase1 (desat1) is one of the few genes known to be involved in the two complementary aspects of sensory communication — signal emission and signal reception — in Drosophila melanogaster. In p...

Gene Regulation and Species-Specific Evolution of Free Flight Odor Tracking in Drosophila

Running title: flight evolution in Drosophila This is an invited contribution to the special issue on Genetics of Adaptation based on a symposium of the same name at the National Centre for Biological Sciences (TIFR, Bangalore, India) in November 2016; International audience; The flying ability of insects has coevolved with the development of organs necessary to take-off from the ground, generate, and modulate lift during flight in complex environments. Flight orientation to the appropriate food source and mating partner depends on the perception and integration of multiple chemical signals. We used a wind tunnel-based assay to investigate the natural and molecular evolution of free flight …

Transient and Permanent Experience with Fatty Acids Changes Drosophila melanogaster Preference and Fitness

Food and host-preference relies on genetic adaptation and sensory experience. In vertebrates, experience with food-related cues during early development can change adult preference. This is also true in holometabolous insects, which undergo a drastic nervous system remodelling during their complete metamorphosis, but remains uncertain in Drosophila melanogaster. We have conditioned D. melanogaster with oleic (C18:1) and stearic (C18:0) acids, two common dietary fatty acids, respectively preferred by larvae and adult. Wild-type individuals exposed either during a transient period of development-from embryo to adult-or more permanently-during one to ten generation cycles-were affected by such…

Production, regeneration and biochemical precursors of the major components of the defensive secretion of Eurycotis floridana (Dictyoptera, polyzosteriinae)

0965-1748 (Print) Journal Article; The defensive secretion of the cockroach Eurycotis floridana contains three main components, (E)-2-hexenal, (E)-2-hexenol and (E)-2-hexenoic acid, which represented about 98% of the organic phase. The quantity of the aldehyde, alcohol, and acid present in the defensive secretion increased rapidly for 60 days from the imaginal moult. Following artificial discharge, the males were able to regenerate their initial volume of secretion over a 30 day period. To investigate the possible routes of biosynthesis of the three components, E. floridana was injected with 14C-labeled fatty acids and acetate, and the incorporation of 14C into the three components were qua…

Male sex pheromone of cockroach Eurycotis floridana (Walker) (Blattidae, Polyzosteriinae): role and composition of tergites 2 and 8 secretions

0098-0331; In Eurycotis floridana, the male calling behavior is associated with the exposition of epidermal glands located under tergites 2, 7, and 8. 4-Hydroxy-5-methyl-3(2H)-furanone and 4-hydroxy-2,5-dimethyl-3(2H)-furanone were recently identified as the specific components of tergite 7 secretion. Methylene chloride extracts of tergite 7 and its major compound 4-hydroxy-5-methyl-3(2H)-furanone attract the conspecific females at a distance. Methylene chloride extracts of tergite 8 are also attractive at a distance to the females, whereas extracts of tergite 2 had no effect on males and females. Our GC investigations showed the absence of specific compounds in tergite 2 secretions. The GC…

Changes of species specific cuticular hydrocarbon profiles in the cockroaches Nauphoeta cinerea and Leucophaea maderae reared in heterospecific groups

0013-8703 (Print) 1570-7458 (Online); The cuticular hydrocarbon profiles of the cockroaches Nauphoeta cinerea and Leucophaea maderae are species-specific when maintained in homospecific rearings. When individuals were reared in mixed species colonies, they initially remained in homospecific groups under different shelters. However, after 14 days they formed one heterospecific group with cuticular profiles showing characteristics of both species. When individuals were returned in monospecific rearings, their cuticular hydrocarbon profiles returned to species-specific ones within 3 weeks.

Cholinergic Control of Synchronized Seminal Emissions in Drosophila

0960-9822 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; In many animal species, copulation involves the coordinated release of both sperm and seminal fluid, including substances that change female fertility and postmating behavior. In Drosophila melanogaster, these substances increase female fertility and prevent mating with a second male. By using a PGal4 strain, we targeted together with other cells a dozen cholinergic neurons found only in the male abdominal ganglion (Abg-MAch). Genetic feminization apparently deleted these neurons in males and significantly increased their copulation duration, blocked their fertility in 60% of cases, and only weakly repress…

Postembryonic development of Zophobas atratus Fab. (Coleoptera: Tenebrionidae) under crowded or isolated conditions and effects of juvenile hormone analogue applications

Abstract Pupation in Zophobas atratus is dependent on isolation and this provides a model for study of the onset of metamorphosis in beetles. We have analyzed the effects of isolation vs grouping on certain developmental parameters; the number of larval instars; their duration and weight. Sex differences were detected, such as the occurrence of regressive moults in females. Moreover, the development of Z. atratus is discussed in relation to Tenebrio molitor , the physiological timing of which appeared in part extendable to Z. atratus . Experiments show that 4–6 days of isolation are required for commencement of metamorphosis, as indicated by an immobile crooked posture observed at the end o…

Experimental introgression to evaluate the impact of sex specific traits onDrosophila melanogasterincipient speciation

ABSTRACTSex specific traits are involved in speciation but it is difficult to determine whether their variation initiates or reinforces sexual isolation. In some insects, speciation depends of the rapid change of expression in desaturase genes coding for sex pheromones. Two closely related desaturase genes are involved inDrosophila melanogasterpheromonal communication:desat1affects both the production and the reception of sex pheromones whiledesat2is involved in their production in flies of Zimbabwe populations. There is a strong asymmetric sexual isolation between Zimbabwe populations and all other “Cosmopolitan” populations: Zimbabwe females rarely copulate with Cosmopolitan males whereas…

The defensive secretion of Eurycotis floridana (Dictyoptera, Blattidae, Polyzosteriinae): chemical identification and evidence of an alarm function

0965-1748 doi: DOI: 10.1016/S0965-1748(97)00033-7; The defensive secretion of the cockroach Eurycotis floridana was believed to contain only (E)-2-hexenal. However, we have shown it consists of 40 components, of which 30 were tentatively identified. (E)-2-Hexenal, (E)-2-hexenol and (E)-2-hexenoic acid represented approximately 98% of the organic phase. The other 2% included 10 aldehydes, 10 alcohols, four acids, two lactones and one ether. Four compounds are novel insect exudates: 3-ethoxyhexanal, 3-hydroxyhexanal, [(E)-1-pentenyl]-4-propyl-1,3-dioxane and 3-[(E)-2-hexenoxyl-hexanal. In addition to its well-known allomonal function, we have demonstrated that the defensive secretion also act…

Caste-dependent reactions to soldier defensive secretion and chiral alarm/recruitment pheromone inNasutitermes princeps

The soldier frontal gland secretion ofNasutitermes princeps induces strong short-range caste-specific alarm and attraction in both soldiers and workers. Soldiers are excited and patrol the surroundings of the source. The secretion per se does not induce ejection of additional secretion. Large workers of the second stage or older are massively attracted when tested in homogeneous groups. They focus their activities much more accurately than the soldiers around the source. The workers' reaction is less intense in the presence of soldiers. Large and small workers of stage 1 scarcely react at all to the secretion, whether tested in homogeneous or mixed groups. These results suggest the followin…

Mild mutations in the pan neural gene prospero affect male-specific behaviour in Drosophila melanogaster

0376-6357 (Print) Journal Article Research Support, Non-U.S. Gov't; The fruitfly Drosophila melanogaster is one of the most appropriate model organisms to study the genetics of behaviour. Here, we focus on prospero (pros), a key gene for the development of the nervous system which specifies multiple aspects from the early formation of the embryonic central nervous system to the formation of larval and adult sensory organs. We studied the effects on locomotion, courtship and mating behaviour of three mild pros mutations. These newly isolated pros mutations were induced after the incomplete excision of a transposable genomic element that, before excision, caused a lethal phenotype during larv…

Ultrastructure of posterior sternal glands of Macrotermes annandalei (Silvestri): new members of the sexual glandular set found in termites (Insecta).

In female alates of Macrotermes annandalei, two types of abdominal glands are involved in the secretion of sex pheromone. Tergal glands are found at the anterior margin of tergites 6-10 and posterior sternal glands (PSGs) are located at the anterior margin of sternites 6-7. The cytological features of both types of glands are quite similar. The fine structural organization of PSGs is studied more precisely and described for the first time. The glandular cuticle is pitted with narrow apertures corresponding to the openings of numerous subcuticular pouches. Several Class 3 glandular units open in each pouch. One canal cell and one secretory cell make an individual glandular unit. The canal ce…

Desiccation resistance: effect of cuticular hydrocarbons and water content in Drosophila melanogaster adults

Background.The insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydrocarbons that prevent rapid dehydration. The waterproofing properties of cuticular hydrocarbons (CHs) depend on their chain length and desaturation number. Drosophila CH biosynthesis involves an enzymatic pathway including several elongase and desaturase enzymes. Methods.The link between desiccation resistance and CH profile remains unclear, so we t…

Chemically mediated sexual isolation between Zimbabwean endemic and cosmopolitan populations of Drosophila melanogaster

Chemically mediated sexual isolation between Zimbabwean endemic and cosmopolitan populations of [i]Drosophila melanogaster[/i]. ISCE 26. annual meeting

An inhibitory sex pheromone tastes bitter for Drosophila males

1932-6203 (Electronic) Journal Article; Sexual behavior requires animals to distinguish between the sexes and to respond appropriately to each of them. In Drosophila melanogaster, as in many insects, cuticular hydrocarbons are thought to be involved in sex recognition and in mating behavior, but there is no direct neuronal evidence of their pheromonal effect. Using behavioral and electrophysiological measures of responses to natural and synthetic compounds, we show that Z-7-tricosene, a Drosophila male cuticular hydrocarbon, acts as a sex pheromone and inhibits male-male courtship. These data provide the first direct demonstration that an insect cuticular hydrocarbon is detected as a sex ph…

Molecular bases of anorexia nervosa, bulimia nervosa and binge eating disorder: shedding light on the darkness

International audience; Eating-disorders (EDs) consequences to human health are devastating, involving social, mental, emotional, physical and life-threatening aspects, concluding on impairment and death in cases of extreme anorexia nervosa. It also implies that people suffering an ED need to find psychiatric and psychological help as soon as possible to achieve a fully physical and emotional recovery. Unfortunately, to date, there is a crucial lack of efficient clinical treatment to these disorders. In this review, we present an overview concerning the actual pharmacological and psychological treatments, the knowledge of cells, circuits, neuropeptides, neuromodulators and hormones in the h…

Drosophila cuticular hydrocarbons revisited : Mating status alters cuticular profiles

Editor: Frederic Marion-Poll, INRA - Paris 6 - AgroParisTech, France.; International audience; Most living organisms use pheromones for inter-individual communication. In Drosophila melanogaster flies, several pheromones perceived either by contact/at a short distance (cuticular hydrocarbons, CHs), or at a longer distance (cis-vaccenyl acetate, cVA), affect courtship and mating behaviours. However, it has not previously been possible to precisely identify all potential pheromonal compounds and simultaneously monitor their variation on a time scale. To overcome this limitation, we combined Solid Phase Micro-Extraction with gas-chromatography coupled with mass-spectrometry. This allowed us (i…

Taste discrimination of pheromones in Drosophila

1095-6433 doi: DOI: 10.1016/j.cbpa.2007.01.155

Defensive secretions of nymphs and adults of five species of Pyrrhocoridae (Insecta: Heteroptera)

Abstract The chemical composition of the defensive secretions of the nymphs and the adults of Dysdercus fasciatus was investigated. Thirty compounds were identified from the nymphal posterior dorsoabdominal glands, and 34 from the adult metathoracic glands of both sexes. The data were compared with those reported for other species of Pyrrhocoridae. For the species Dysdercus cingulatus, D. fasciatus , and Pyrrhocoris apertus , 63 identified compounds can be divided into 11 chemical groups: aldehydes, saturated hydrocarbons, acetates, alcohols, terpenes, lactones, ketones, esters, alkenes, acids and miscellaneous compounds. These data and those from the literature on Dysdercus intermedius and…

A functional analysis of ACP-20, an adult-specific cuticular protein gene from the beetle Tenebrio. Role of an intronic sequence in transcriptional activation during the late metamorphic period

0962-1075 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; A gene encoding the adult cuticular protein ACP-20 was isolated in Tenebrio. It consists of three exons interspersed by two introns, intron 1 interrupting the signal peptide. To understand the regulatory mechanisms of ACP-20 expression, ACP-20 promoter-luciferase reporter gene constructs were transfected into cultured pharate adult wing epidermis. Transfection assays needed the presence of 20-hydroxyecdysone, confirming that ACP-20 is up-regulated by ecdysteroids. Analysis of 5' deletion constructs revealed that three regions are necessary for high levels of transcription. Interaction experiments between i…

Effects of juvenile hormone analogues upon soldier differentiation in the termite Reticulitermes santonensis (Rhinotermitidae, Heterotermitinae).

Under the influence of juvenile hormone analogues (JHAs), termite workers are induced to differentiate into soldiers. In Reticulitermes santonensis, such induced differentiation is often incomplete, resulting in intercaste production. The morphology of the structures most affected during differentiation was analyzed descriptively and biometrically in normal workers, presoldiers, and soldiers, and in experimental intercastes. We observed that intercastes form a morphological and biometrical continuum between workers and presoldiers (presoldier intercastes), and between presoldiers and soldiers (soldier intercastes). We also compared the biochemistry of the normal individuals and of the inter…

Experimental Introgression To Evaluate the Impact of Sex Specific Traits on Drosophila melanogaster Incipient Speciation

AbstractSex specific traits are involved in speciation but it is difficult to determine whether their variation initiates or reinforces sexual isolation. In some insects, speciation depends of the rapid change of expression in desaturase genes coding for sex pheromones. Two closely related desaturase genes are involved in Drosophila melanogaster pheromonal communication: desat1 affects both the production and the reception of sex pheromones while desat2 is involved in their production in flies of Zimbabwe populations. There is a strong asymmetric sexual isolation between Zimbabwe populations and all other “Cosmopolitan” populations: Zimbabwe females rarely copulate with Cosmopolitan males w…

The Cryptocercus punctulatus species complex (Dictyoptera: Cryptocercidae) in the eastern United States: comparison of cuticular hydrocarbons, chromosome number, and DNA sequences.

1055-7903; The goal of the current study was to determine if cuticular hydrocarbons could be used to empirically delimit taxa within the Cryptocercus punctulatus species complex in the eastern United States. Cockroaches were collected from rotting logs in 22 locations across four states. Hydrocarbon phenotypes and two mitochondrial (16S and COII) genes and one nuclear (ITS2) gene were independently analyzed to determine their relationship with chromosome number. Five distinct hydrocarbon phenotypes were found, but these were only partly congruent with chromosome number and thus with purported species descriptions. Molecular and cuticular hydrocarbon data each indicate that Cryptocercus with…

Discrimination of C18 fatty-acids by Drosophila larvae and adults

International audience

(+)-α-Pinene in the defensive secretion ofNasutitermes princeps (Isoptera, Termitidae)

The frontal secretion ofNasutitermes princeps consists of 89% diterpenes and 11% monoterpenes. In the samples studied, (+)-α-pinene, whose optical purity reaches 99.5%, accounts for more than 80% of the monoterpenic content.

Volatile Drosophila cuticular pheromones are affected by social but not sexual experience.

International audience; Recognition of conspecifics and mates is based on a variety of sensory cues that are specific to the species, sex and social status of each individual. The courtship and mating activity of Drosophila melanogaster flies is thought to depend on the olfactory perception of a male-specific volatile pheromone, cis-vaccenyl acetate (cVA), and the gustatory perception of cuticular hydrocarbons (CHs), some of which are sexually dimorphic. Using two complementary sampling methods (headspace Solid Phase Micro-Extraction [SPME] and solvent extraction) coupled with GC-MS analysis, we measured the dispersion of pheromonal CHs in the air and on the substrate around the fly. We als…

Choice alters Drosophila oviposition site preference on menthol

Summary Food choice and preference relies on multiple sensory systems that are under the control of genes and sensory experience. Exposure to specific nutrients and nutrient-related molecules can change food preference in vertebrates and invertebrates. For example, larval exposure of several holometabolous insects to menthol can change their adult response to this molecule. However, studies involving Drosophila melanogaster exposure to menthol produced controversial results due maybe to methodological differences. Here, we compared the oviposition-site preference of wild-type D. melanogaster lines freely or forcibly exposed to menthol-rich food. After 12 generations, oviposition-site prefer…

Pre-imaginal conditioning alters adult sex pheromone response in Drosophila

https://peerj.com/articles/5585/#supplemental-information; International audience; Pheromones are chemical signals that induce innate responses in individuals of the same species that may vary with physiological and developmental state. In Drosophila melanogaster, the most intensively studied pheromone is 11-cis-vaccenyl acetate (cVA), which is synthezised in the male ejaculatory bulb and is transferred to the female during copulation. Among other effects, cVA inhibits male courtship of mated females. We found that male courtship inhibition depends on the amount of cVA and this effect is reduced in male flies derived from eggs covered with low to zero levels of cVA. This effect is not obser…

The desaturase1 gene affects reproduction before, during and after copulation in Drosophila melanogaster

Desaturase1 (desat1) is one of the few genes known to be involved in the two complementary aspects of sensory communication — signal emission and signal reception — in Drosophila melanogaster. In particular, desat1 is necessary for the biosynthesis of major cuticular pheromones in both males and females. It is also involved in the male ability to discriminate sex pheromones. Each of these two sensory communication aspects depends on distinct desat1 putative regulatory regions. Here, we used (i) mutant alleles resulting from the insertion/excision of a transposable genomic element inserted in a desat1 regulatory region, and (ii) transgenics made with desat1 regulatory regions used to target …

Supplemental Material for Cortot et al., 2019

The file "Cortot-SupplFigs.1-9" is a pdf containing all the Supplementary Figures 1-9 with their legendsThe file "Suppl_Tables_final" is a xlsx with Tables S1-S14 corresponding to all data shown in the Cortot et al. paper.