Showing papers on "Sex pheromone published in 1999"

Pheromones of Non-Lepidopteran Insects Associated with Agricultural Plants

Abstract: Termites grasshoppers bugs aphids scale insects sawflies beetles (forest, crops and postharvest) midges fruit flies predators parasitoids bees.

Vomeronasal neuroepithelium and forebrain Fos responses to male pheromones in male and female mice.

Abstract: Male urinary pheromones modulate behavioral and neuroendocrine function in mice after being detected by sensory neurons in the vomeronasal organ (VNO) neuroepithelium. We used nuclear Fos protein immunoreactivity (Fos-IR) as a marker of changes in neuronal activity to examine the processing of male pheromones throughout the VNO projection pathway to the hypothalamus. Sexually naive male and female Balb/c mice were gonadectomized and treated daily with estradiol benzoate (EB) or oil vehicle for 3 weeks. Subjects were then exposed to soiled bedding from gonadally intact Balb/c males or to clean bedding for 90 min prior to sacrifice and processing of their VNOs and forebrains for Fos-IR. Male pheromones induced similar numbers of Fos-IR cells in the VNO neuroepithelium of oil-treated male and female subjects; however, EB-treated females had significantly more Fos-IR neurons in the VNO than any other group. There was an equivalent neuronal Fos response to male odors in the mitral and granule cells of the anterior and posterior accessory olfactory bulb of males and females, regardless of hormone treatment. In central portions of the VNO projection pathway (i.e., bed nucleus of the stria terminalis, medial preoptic area) neuronal Fos responses to male pheromones were present in female but absent in male subjects, regardless of hormone treatment. In a separate experiment, mating induced neuronal Fos-IR in these brain regions at levels in gonadally intact male subjects which were equal to or greater than those seen in ovariectomized females primed with estrogen and progesterone. This suggests that neurons in the central portions of the male's VNO pathway are capable of expressing Fos. Our results suggest that sexually dimorphic central responses to pheromones exist in mice that may begin in the VNO neuroepithelium.

Genetic elimination of known pheromones reveals the fundamental chemical bases of mating and isolation in Drosophila

Abstract: Overexpression of the UAS-tra transgene in Drosophila melanogaster females led to the complete elimination of their cuticular pheromones. According to current models of Drosophila behavior, these flies should induce no courtship. In fact, they are still attractive to conspecific males. Three classes of stimuli are shown to induce courtship, with different effects on male behavior: (i) known pheromones produced by control females, (ii) stimuli produced by living control and transgenic flies, and (iii) as-yet-undetermined pheromones present on both control and transgenic flies. Only the latter class of pheromones are required for mating. They appear to represent a layer of ancestral attractive substances present in D. melanogaster and its sibling species; known cuticular pheromones modulate this attractivity positively or negatively. The absence of inhibitory pheromones leads to high levels of interspecific mating, suggesting an important role for these cuticular hydrocarbons in isolation between species.

Identification and Characterization of a Determinant (eep) on the Enterococcus faecalis Chromosome That Is Involved in Production of the Peptide Sex Pheromone cAD1

Abstract: Plasmid-free strains of Enterococcus faecalis secrete a peptide sex pheromone, cAD1, which specifically induces a mating response by donors carrying the hemolysin plasmid pAD1 or related elements. A determinant on the E. faecalis OG1X chromosome has been found to encode a 46.5-kDa protein that plays an important role in the production of the extracellular cAD1. Wild-type E. faecalis OG1X cells harboring a plasmid chimera carrying the determinant exhibited an eightfold enhanced production of cAD1, and plasmid-free cells carrying a mutated chromosomal determinant secreted undetectable or very low amounts of the pheromone. The production of other pheromones such as cPD1, cOB1, and cCF10 was also influenced, although there was no effect on the pheromone cAM373. The determinant, designated eep (for enhanced expression of pheromone), did not include the sequence of the pheromone. Its deduced product (Eep) contains apparent membrane-spanning sequences; conceivably it is involved in processing a pheromone precursor structure or in some way regulates expression or secretion.

Aquatic sex pheromone from a male tree frog

Abstract: Many creatures use chemical signals (pheromones) as sources of information about the world around them1,2,3 For example, a sex pheromone produced by one sex (usually the female) of a particular species induces an immediate behavioural response in the opposite sex of the same species2,3 However, very little is known about amphibian pheromones4 We have now discovered and characterized an aquatic, female-attracting pheromone from the parotoid and rostral glands of a male frog, the magnificent tree frog, Litoria splendida To our knowledge, this pheromone, which we have named splendipherin, is the first pheromone from an anuran (frog or toad) to be identified

Ostrinia spp. in Japan: their host plants and sex pheromones

Abstract: To contribute to the understanding of the genus Ostrinia (Lepidoptera; Pyralidae) in Japan, we collected larvae of Ostrinia spp. from known host plants and plants not recorded as hosts, and we examined the morphology and sex pheromones of the adults obtained. Consequently, the host plant ranges of the 7 Ostrinia spp. in Japan were clarified, and the sex pheromones of the 5 species O. scapulalis, O. zealis, O. zaguliaevi, O. palustralis and O. latipennis were identified in addition to that of the Asian corn borer O. furnacalis. The phylogenetic relationships of Japanese Ostrinia spp., with reference to the European corn borer O. nubilalis, are discussed based on these findings and results of molecular phylogenetic analyses.

Evolution and Specialization of Fish Hormonal Pheromones

Abstract: Teleost fish commonly release steroid and prostaglandin hormones and their metabolites to the water, where some function as water-borne odorants that induce specific physiological and/or behavioral reproductive responses in conspecifics. In this paper, we evaluate processes responsible for the evolution and specialization of these hormonal pheromones and give examples. Several new definitions are coined. The topic is complex owing to the evolutionary age and great diversity of fish species. We hypothesize that the evolution of fish hormonal pheromones has been influenced by two types of factors, factors intrinsic to the pheromonal function (e.g. factors which directly determine the nature of pheromones while being themselves influenced by how well the pheromones function), and extrinsic factors which are not subject to conspecific feedback. Both types of factors may influence receivers and/or donors of pheromonal stimuli in independent manners. We further hypothesize that hormonal pheromones originated through’ spying,’ in which the receiver benefits by detecting a hormonal cue and in which neither the donor nor its cue is specialized. However, we also suggest that in many instances the receiver’s response will benefit the donor, thereby driving specialization of pheromone production-a phenomenon we term’ communication.’ Whereas evolutionary pressures to increase the efficiency of cue detection may lead to an increase in the number of stimuli detected, sexual selection acting on the donor may cause species to increase the efficiency of signal production. Donors might achieve this by’ amplifying’ signal output and/or increasing the biological relevance by optimizing its information content through’ signal elaboration.’ In some instances hormonal pheromones also will be modified by extrinsic factors, a subset of which may lead to the evolution of species-specificity.

Effect of juvenile hormone on the central nervous processing of sex pheromone in an insect.

Abstract: Behavioral sex pheromone responsiveness in the male moth Agrotis ipsilon was previously shown to be controlled by juvenile hormone (JH). However, this morphogenetic hormone did not change the sensitivity of antennae to sex pheromones. To analyze the possible involvement of JH in the central integration of the female-produced sex pheromone, we investigated the pheromone response of olfactory antennal lobe (AL) interneurons in male A. ipsilon as a function of age and JH status by using intracellular recordings. When the antennae were stimulated with the sex pheromone blend, the sensitivity of olfactory AL neurons increased with age, as does the JH-dependent behavioral and physiological development of A. ipsilon males. Furthermore, males surgically deprived of JH showed a significant decrease in the sensitivity of the AL neurons. JH injection in operated or in young males restored or induced, respectively, a high sensitivity of the AL neurons. JH seems likely to be involved in the plasticity of the adult insect brain by modulating the central nervous processing of olfactory information, thus allowing mate recognition and reproduction at the optimal time.

Multiple sex pheromones and receptors of a mushroom-producing fungus elicit mating in yeast.

Abstract: The mushroom-producing fungus Schizophyllum communehas thousands of mating types defined, in part, by numerous lipopeptide pheromones and their G protein-linked receptors. Compatible combinations o...

Airborne Chemical Communication in the Wolf Spider Pardosa milvina

Abstract: Most studies involving chemical communication in spiders focus on contact pheromones attached to spider silk. Here we tested if males of the wolf spider Pardosa milvina use airborne pheromones to identify, locate, and follow females. Using a two-choice olfactometer, we tested the response of adult male P. milvina to a number of potential chemical cues while controlling for concomitant visual and vibratory stimuli. An airborne chemical cue from adult virgin female P. milvina elicited a positive taxis response from the male. We also tested adult male responses to penultimate instar female P. milvina, one adult male P. milvina, and two adult males together. In each case, test males showed no attraction to the stimuli. Additional experiments were run with pitfall traps baited with adult virgin female P. milvina as attractants. Again, we controlled for visual and vibratory cues from females. Pitfall traps containing virgin females captured significantly more males than control traps. Collectively, these experiments demonstrate evidence of an airborne sex pheromone in P. milvina.

Functional dichotomy within the vomeronasal system: distinct zones of neuronal activity in the accessory olfactory bulb correlate with sex-specific behaviors.

Abstract: Chemosensory neurons in the vomeronasal organ (VNO) detect pheromones that elicit social and reproductive behaviors in most terrestrial vertebrates. Vomeronasal receptor neurons are chemoarchitecturally divided into two populations based on their position in the VNO, the type of G-protein subunit expressed, the family of putative pheromone receptor expressed, and termination site of their axons in the accessory olfactory bulb (AOB). To investigate the functional implications of these two segregated VNO-AOB pathways, we stimulated mice with pheromonal cues associated with different behavioral contexts and examined cellular activation patterns in the AOB. Exposure of ICR male mice to BALB/c males resulted in aggressive behavior, accompanied by a VNO-dependent increase in c-fos immunoreactivity in a cluster of cells located almost exclusively in the caudal AOB in both strains. This caudal cluster of activated cells did not appear to require the overt display of aggressive behavior because it was present in both the dominant and submissive males and could be evoked when the stimulus animal was anesthetized. In contrast, exposure of an ICR male to an ICR female in diestrus resulted in activation of cells located predominantly in the rostral AOB. Our findings indicate that male-to-male interactions involving interstrain recognition activate a separate population of vomeronasal receptor neurons than chemosensory cues detected in a sexual context. The results suggest that the dichotomy in the peripheral vomeronasal system serves to separate pheromones based on the behaviors they drive. As such, the results provide a bioassay for identifying pheromone molecules.

Responses of olfactory receptor neurones to behaviourally important odours in gregarious and solitarious desert locust,Schistocerca gregaria

Abstract: .Recordings from antennal olfactory receptor neurones in young adult Schistocerca gregaria Forskal (Orthoptera: Acrididae) showed that behaviourally important odours are detected by receptor neurones present in morphologically identifiable sensillum types. Both nymph- and adult-produced aggregation pheromones activate receptor neurones housed in sensilla basiconica. The receptor neurones in this sensillum type in solitary-reared locusts display a higher sensitivity to aggregation pheromones and to some other behaviourally relevant odours than the same type of neurones in gregarious locusts. Receptor neurones present in sensilla coeloconica respond to green leaf odours, organic acids, and nymphal odours but are inhibited by mature adult-produced aggregation pheromones. Receptor neurones housed in sensilla trichodea respond to a possible sex pheromone. No phase differences were found in the response of coeloconic- or trichoid-associated receptor neurones.

Characterization of Pheromone Blend for Grapevine Moth, Lobesia botrana by Using Flight Track Recording

Abstract: The behavioral responses of Lobesia botrana males to calling females, pheromone gland extracts, and synthetic sex pheromones were recorded in a wind tunnel. Gland extracts and synthetic pheromones were released from a pheromone evaporator. The numbers of males reaching the source and their flight tracks in response to calling females and pheromone gland extracts were compared to those of synthetic blends. Upwind flights to natural sex pheromone were straighter and faster than to a three-component blend of (E)-7,(Z)-9-dodecadienyl acetate (E7,Z9–12:Ac), (E)-7,(Z)-9-dodecadien-1-ol (E7,Z9–12:OH), and (Z)-9-docecenyl acetate (Z9–12:Ac) (100:20:5). The optimum ratio of E7,Z9–12:OH and Z9–12:Ac to E7,Z9–12:Ac was found to be 5% and 1%, respectively. An additional seven compounds identified in the sex pheromone gland were investigated for their biological activity. Two unsaturated acetates, i.e., (E)-9-dodecenyl acetate (E9–12:Ac) and Δ11-dodecenyl acetate (Δ11–12:Ac), increased the number of males reaching the source as well as straightness, linear velocity, and decreased the track angle of upwind flight. Optimum response was obtained by releasing 10 pg/min E7,Z9–12:Ac in a mixture with 0.5 pg/min E7,Z9–12:OH, 0.1 pg/min Z9–12:Ac, 0.1 pg/min E9– 12:Ac and 1 pg/min Δ11-12–Ac. The saturated acetates previously identified in the female glands were biologically inactive.

Laminar distribution of pheromone receptive neurons in rat vomeronasal epithelium

Abstract: The vomeronasal organ (Jacobson's organ) exists in many vertebrates for receiving pheromones which are sometimes related to sexual and social behaviour (Keverne et al. 1986; Wysocki & Meredith, 1987; Halpern, 1987). Modulation of gonadal functions by urine has been well established in the rodent vomeronasal organ. Urinary compounds of low volatility stimulate the vomeronasal system and provide information that is normally not provided by gustation or olfaction (Wysocki et al. 1980). The pheromone involved in the induction of oestrus in unisexually grouped female mice (the Whitten effect) is different from the one involved in implantation failure (the Bruce effect) (Gangrade & Dominic, 1984). In female rats, pheromones in urine excreted from males and females induce various changes in gonadal functions such as reflex ovulation in the absence of coitus and mounting (Johns et al. 1978), reduction in the oestrous cycle of female rats from 5 to 4 days (Chateau et al. 1976), and oestrous synchrony among females that are living together (McClintock, 1978). These results suggest that the vomeronasal organ receives multiple kinds of urinary pheromones. The sensory neurons of rats and mice that have cell bodies located in the apical layer and the basal layer of the sensory epithelium express the G-proteins Gi2α and Goα, respectively (Jia & Halpern, 1996). Apically and basally situated sensory neurons have been described as projecting to the anterior and posterior portions of the accessory olfactory bulb, respectively (Jia & Halpern, 1996). In the present study, we measured the responses of vomeronasal sensory neurons of female Wistar rats to urine from male Wistar rats, female Wistar rats, male Donryu rats, male Sprague-Dawley rats, male C57BL/6 mice and male Syrian hamsters by the on-cell patch clamp method and examined the depth of the cell soma in the sensory epithelium of the neurons that responded to these stimuli.

Reidentification of the female sex pheromone of the Indian meal moth, Plodia interpunctella: evidence for a four-component pheromone blend

Abstract: Pheromone gland extracts from calling female Plodia interpunctella contained at least seven compounds that consistently elicited electroantennographic responses from male antennae upon gas chromatographic analysis. Three of these compounds were found to be the previously identified gland constituents, i.e., (Z,E)-9,12-tetradecadienyl acetate (Z9,E12-14:OAc), (Z,E)-9,12-tetradecadienal (Z9,E12-14:Ald) and (Z,E)-9,12-tetradecadienol (Z9,E1214:OH). A fourth EAD-active compound was identified as (Z)-9-tetradecenyl acetate (Z9-14:OAc). The homologue (Z)-11-hexadecenyl acetate (Z11-16:OAc) was also identified in the extracts, but showed no EAD activity. The identity of all five compounds was confirmed by comparison of GC retention times and mass spectra with those of synthetic standards. In flight tunnel tests there were no significant differences in response of male P. interpunctella to the bait containing all four EAD-active compounds and the responses to female gland extacts. A behavioural assay of different two-compound blends in the flight tunnel showed that only addition of the corresponding aldehyde to the major pheromone component Z9,E12-14:OAc raised the male response. A subtractive assay, however, revealed that the exclusion of any of the compounds from the complete four-compound blend reduced its activity significantly. We thus conclude that the female-produced sex pheromone of P. interpunctella consists of at least four components, i.e., Z9,E12-14:OAc, Z9,E12-14:Ald, Z9,E12-14:OH and Z9-14: OAc. In a field trapping test performed in a storage facility, the four-component blend attracted significantly more males of P. interpunctella than traps baited with Z9,E12-14:OAc alone. In contrast, the highest number of Ephestia kuehniella males was found in the traps baited with this major component, suggesting that the secondary pheromone components contribute to the species specificity of the blend. (Less)

Nereidid polychaetes as model organisms for marine chemical ecology

Abstract: Nereidid polychaetes and indeed many marine invertebrates use chemical signaling via sex pheromones to coordinate their reproductive behaviour Sex pheromones attract the sexual partner and ensure the coordinated release of gametes by both sexual partners In the current paper nereidids are used as model organisms to describe the chemical and behavioural basis of chemical communication in marine invertebrates Structure-activity relationships can be used to chemically classify signals according to their biological function and suitable purification strategies are described Pheromones in nereidids include diverse molecules such as volatile lipophilic 5-methyl-3-heptanone and 3,5-octadiene-2-one, uric acid and small glutathione derived peptides A prominent question in chemical signaling is the species specificity of chemical cues and the scale of their distribution in the marine environment This evolves when one considers the wide overlap in multispecies and multiphyla spawning such as in coral reefs Behavioural and electrophysiological assays with several nereidid species, confirm the existence of heterospecific activity of body fluids from various phyla The ‘nuptial dance’ reproductive behaviour, as well as the release of gametes, are elicited when individuals are exposed to coelomic fluid of another nereidid species and also from lugworms, starfish, and sea urchins The function of sex pheromones in nereidid polychaetes and their role in the timing of reproduction in relation to other environmental cues is discussed Future research will focus on biosynthesis and reception of nereidid pheromones as well as their molecular basis and possible interactions with pollutants such as endocrine disrupters and fuel oil derivatives

Responses to aphid sex pheromones by the pea aphid parasitoids Aphidius ervi and Aphidius eadyi

Abstract: Aphidius ervi and Aphidius eadyi, two parasitoids of the pea aphid Acyrthosiphon pisum, were attracted to components of the aphid sex pheromone in laboratory bioassays. Pre-test experience with host aphids in the presence of aphid sex pheromone did not affect the response of A. ervi to pheromone in a 4-way olfactometer, compared with that of naive parasitoids. Aphidius ervi females exposed only to the pheromone prior to testing did not respond in the olfactometer, suggesting habituation to the foraging cue by the parasitoid. In a wind tunnel, aphid sex pheromone increased the attraction of A. ervi to the plant-host complex (Vicia faba/A. pisum), suggesting an additive effect when two different foraging cues are present simultaneously.

Nontarget Hymenoptera collected in pheromone- and synthetic floral volatile-baited traps

Abstract: Monitoring traps baited with lepidopteran sex pheromones and synthetic floral volatiles were used to collect adult Hymenoptera in fields of cotton and corn. Species from Apoidea, Pompiloidea, Scolioidea, Sphecoidea, and Vespoidea were collected, including the genera Ammophila, Apis, Bombus, Cerceris, Larra, Melissodes, Myzinum, and Tachytes. More Bombus spp. were collected from traps baited with Spodoptera frugiperda (J. E. Smith) sex pheromone than those baited with phenylacetaldehyde, whereas more Sphecoidea were collected in phenylacetaldehyde-baited traps. Trap design was also an important factor in capture of various species. More Sphecoidea and Tiphioidea were collected in fabric cone-shaped traps than plastic funnel traps. Efforts should be made to develop traps and lures that consistently capture the target pest but do not attract or easily capture aculeate Hymenoptera to preserve beneficial populations.