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Journal of Chemical Ecology Jun 2012Pheromones are likely involved in all social activities of social insects including foraging, sexual behavior, defense, nestmate recognition, and caste regulation.... (Review)
Review
Pheromones are likely involved in all social activities of social insects including foraging, sexual behavior, defense, nestmate recognition, and caste regulation. Regulation of the number of fertile queens requires communication between reproductive and non-reproductive individuals. Queen-produced pheromones have long been believed to be the main factor inhibiting the differentiation of new reproductive individuals. However, since the discovery more than 50 years ago of the queen honeybee substance that inhibits the queen-rearing behavior of workers, little progress has been made in the chemical identification of inhibitory queen pheromones in other social insects. The recent identification of a termite queen pheromone and subsequent studies have elucidated the multifaceted roles of volatile pheromones, including functions such as a fertility signal, worker attractant, queen-queen communication signal, and antimicrobial agent. The proximate origin and evolutionary parsimony of the termite queen pheromone also are discussed.
Topics: Animals; Isoptera; Pheromones; Reproduction; Sexual Behavior, Animal; Volatile Organic Compounds
PubMed: 22623152
DOI: 10.1007/s10886-012-0137-3 -
ELife Jul 2021Foraging animals have to locate food sources that are usually patchily distributed and subject to competition. Deciding when to leave a food patch is challenging and...
Foraging animals have to locate food sources that are usually patchily distributed and subject to competition. Deciding when to leave a food patch is challenging and requires the animal to integrate information about food availability with cues signaling the presence of other individuals (e.g., pheromones). To study how social information transmitted via pheromones can aid foraging decisions, we investigated the behavioral responses of the model animal to food depletion and pheromone accumulation in food patches. We experimentally show that animals consuming a food patch leave it at different times and that the leaving time affects the animal preference for its pheromones. In particular, worms leaving early are attracted to their pheromones, while worms leaving later are repelled by them. We further demonstrate that the inversion from attraction to repulsion depends on associative learning and, by implementing a simple model, we highlight that it is an adaptive solution to optimize food intake during foraging.
Topics: Animals; Caenorhabditis elegans; Feeding Behavior; Pheromones
PubMed: 34227470
DOI: 10.7554/eLife.58144 -
Cell Metabolism Mar 2005In C. elegans, dauer pheromone is an indicator of population density and influences pathways that regulate metabolism, development, and aging. In a recent publication in... (Review)
Review
In C. elegans, dauer pheromone is an indicator of population density and influences pathways that regulate metabolism, development, and aging. In a recent publication in Nature, Paik and coworkers (Jeong at al., 2005) show the purified substance to be a pyran ring conjugated to heptanoic acid, setting the stage for dissecting downstream signaling pathways.
Topics: Adaptation, Physiological; Animals; Caenorhabditis elegans; Pheromones; Signal Transduction
PubMed: 16054058
DOI: 10.1016/j.cmet.2005.02.004 -
EMBO Reports Mar 2019The characterization of receptors for sex pheromones provides important clues for understanding the mechanisms controlling animal mating and reproduction. In this issue,...
The characterization of receptors for sex pheromones provides important clues for understanding the mechanisms controlling animal mating and reproduction. In this issue, Wan 1 identify a putative sex pheromone receptor, the G protein‐coupled receptor SRD‐1, acting in a single olfactory neuron class, called AWA, to mediate male attraction to volatile sex pheromones. Like in other systems, sex pheromone elicits sex‐specific responses even though sex pheromone activates sensory neurons of both sexes.
Topics: Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Female; Male; Neurons; Pheromones; Sex Attractants
PubMed: 30792216
DOI: 10.15252/embr.201847599 -
Journal of Chemical Ecology Jun 2022The canola flower midge, Contarinia brassicola Sinclair (Diptera: Cecidomyiidae), is a newly-described species that induces galls on canola, Brassica napus Linnaeus and...
The canola flower midge, Contarinia brassicola Sinclair (Diptera: Cecidomyiidae), is a newly-described species that induces galls on canola, Brassica napus Linnaeus and Brassica rapa Linnaeus (Brassicaceae). Identification of the sex pheromone of C. brassicola is essential to developing monitoring tools to elucidate the geographic range and hosts of this new pest, and the extent to which it threatens the $30 billion Canadian canola industry. The aim of this study was to identify and synthesize the female-produced sex pheromone of C. brassicola and demonstrate its effectiveness in attracting males to traps in the field. Two peaks were identified through GC-EAG analysis of female-produced volatiles which elicited electrophysiological responses in male antennae. These peaks were initially characterized through GC-MS and synthesis as 2,7-diacetoxynonane (major component) and 2-acetoxynonane (minor component), and the racemic compounds elicited EAG responses in male antennae. All four stereoisomers of 2,7-diacetoxynonane were synthesized and the naturally-produced compound was shown to be primarily the (2R,7S)-isomer by analysis on an enantioselective GC column, with a small amount of (2R,7R)-2,7-diacetoxynonane also present. The configuration of the minor component could not be determined because of the small amount present, but this was assumed to be (2R)-2-acetoxynonane by comparison with the configuration of the other two components. In field trials, none of the four stereoisomers of 2,7-diacetoxynonane, presented individually or as a racemic mixture, was attractive to male C. brassicola. However, dispensers loaded with a 10 µg:1 µg blend of (2R,7S)- and (2R,7R)-2,7-diacetoxynonane caught large numbers of male C. brassicola and significantly more than other blends tested. The addition of 0.5 µg of (2R)-2-acetoxynonane to this blend further increased the number of males caught. In future work, we will seek to identify the optimum trapping protocol for the application of the pheromone in monitoring and surveillance.
Topics: Brassica napus; Canada; Flowers; Pheromones; Sex Attractants
PubMed: 35771405
DOI: 10.1007/s10886-022-01369-z -
PloS One 2023The use of pheromone traps can minimize the excess application of synthetic insecticides, while can also benefit the environment. The use of pheromone traps has been...
The use of pheromone traps can minimize the excess application of synthetic insecticides, while can also benefit the environment. The use of pheromone traps has been promoted and suggested to vegetable farmers of Bangladesh for widespread adoption. However, the majority of farmers have continued to spray insecticides instead of using pheromone traps. The present study investigated the factors influencing farmers' adoption, dis-adoption, and non-adoption behavior of pheromone traps for managing insect pests. Primary data were collected from 438 vegetable growers. Data were analyzed using descriptive statistics and multinomial logistic regression. About 27% of the farmers abandoned the technique shortly after it was adopted as it was time-consuming to manage insect pests. Marginal effect analysis revealed that the likelihood of continued adoption was 34.6% higher for farmers who perceived that pheromone traps were useful in controlling insect pests. In contrast, the likelihood of dis-adoption was 16.5% and 10.4% higher for farmers who maintained communication with private pesticide company agents and neighbor farmers, respectively. Extension services by government extension personnel might be encouraged and maintained as a key component in increasing farmer awareness regarding the use of pheromone trap. Strategies to promote pheromone traps in vegetable production should highlight the positive impacts to farmers and the environment, as this would most likely lead to their continued and widespread use after initial adoption.
Topics: Animals; Humans; Insecticides; Farmers; Vegetables; Pheromones; Insecta; Pest Control, Biological; Agriculture
PubMed: 37773932
DOI: 10.1371/journal.pone.0292254 -
Frontiers in Neuroendocrinology Oct 2013A brain circuit (the accessory olfactory system) that originates in the vomeronasal organ (VNO) and includes the accessory olfactory bulb (AOB) plus additional forebrain... (Review)
Review
A brain circuit (the accessory olfactory system) that originates in the vomeronasal organ (VNO) and includes the accessory olfactory bulb (AOB) plus additional forebrain regions mediates many of the effects of pheromones, typically comprised of a variety of non-volatile and volatile compounds, on aspects of social behavior. A second, parallel circuit (the main olfactory system) that originates in the main olfactory epithelium (MOE) and includes the main olfactory bulb (MOB) has also been shown to detect volatile pheromones from conspecifics. Studies are reviewed that point to specific roles of several different steroids and their water-soluble metabolites as putative pheromones. Other studies are reviewed that establish an adult, 'activational' role of circulating sex hormones along with sex differences in the detection and/or processing of non-steroidal pheromones by these two olfactory circuits. Persisting questions about the role of sex steroids in pheromonal processing are posed for future investigation.
Topics: Animals; Brain; Gonadal Steroid Hormones; Humans; Neurons; Olfactory Bulb; Pheromones; Sexual Behavior; Vomeronasal Organ
PubMed: 23872334
DOI: 10.1016/j.yfrne.2013.07.004 -
Current Biology : CB Jan 2004Olfaction is the dominant sensory modality for most animals and chemosensory communication is particularly well developed in many mammals. Our understanding of this form... (Review)
Review
Olfaction is the dominant sensory modality for most animals and chemosensory communication is particularly well developed in many mammals. Our understanding of this form of communication has grown rapidly over the last ten years since the identification of the first olfactory receptor genes. The subsequent cloning of genes for rodent vomeronasal receptors, which are important in pheromone detection, has revealed an unexpected diversity of around 250 receptors belonging to two structurally different classes. This review will focus on the chemical nature of mammalian pheromones and the complementary roles of the main olfactory system and vomeronasal system in mediating pheromonal responses. Recent studies using genetically modified mice and electrophysiological recordings have highlighted the complexities of chemosensory communication via the vomeronasal system and the role of this system in handling information about sex and genetic identity. Although the vomeronasal organ is often regarded as only a pheromone detector, evidence is emerging that suggests it might respond to a much broader variety of chemosignals.
Topics: Afferent Pathways; Animal Communication; Animals; Chemoreceptor Cells; Mammals; Olfactory Bulb; Pheromones; Sex Factors; Smell; Vomeronasal Organ
PubMed: 14738757
DOI: 10.1016/j.cub.2003.12.052 -
Nature Communications Apr 2023The human fungal pathogen Candida albicans can switch stochastically and heritably between a "white" phase and an "opaque" phase. Opaque cells are the mating-competent...
The human fungal pathogen Candida albicans can switch stochastically and heritably between a "white" phase and an "opaque" phase. Opaque cells are the mating-competent form of the species, whereas white cells are thought to be essentially "sterile". Here, we report that glucose depletion, a common nutrient stress, enables C. albicans white cells to undergo efficient sexual mating. The relative expression levels of pheromone-sensing and mating-associated genes (including STE2/3, MFA1, MFα1, FIG1, FUS1, and CEK1/2) are increased under glucose depletion conditions, while expression of mating repressors TEC1 and DIG1 is decreased. Cph1 and Tec1, factors that act downstream of the pheromone MAPK pathway, play opposite roles in regulating white cell mating as TEC1 deletion or CPH1 overexpression promotes white cell mating. Moreover, inactivation of the Cph1 repressor Dig1 increases white cell mating ~4000 fold in glucose-depleted medium relative to that in the presence of glucose. Our findings reveal that the white-to-opaque epigenetic switch may not be a prerequisite for sexual mating in C. albicans in nature.
Topics: Humans; Candida albicans; Fungal Proteins; Reproduction; Pheromones; Epigenesis, Genetic; Gene Expression Regulation, Fungal; Genes, Mating Type, Fungal
PubMed: 37045865
DOI: 10.1038/s41467-023-37755-8 -
Journal of Chemical Ecology Mar 2017Chemical communication is a dominant method of communication throughout the animal kingdom and can be especially important in group-living animals in which communicating...
Chemical communication is a dominant method of communication throughout the animal kingdom and can be especially important in group-living animals in which communicating threats, either from predation or other dangers, can have large impacts on group survival. Social insects, in particular, have evolved a number of pheromonal compounds specifically to signal alarm. There is predicted to be little selection for interspecific variation in alarm cues because individuals may benefit from recognizing interspecific as well as conspecific cues and, consequently, alarm cues are not normally thought to be used for species or nestmate recognition. Here, we examine the composition of the alarm pheromones of seven species of fungus-growing ants (Attini), including both basal and derived species and examine the behavioral responses to alarm pheromone of Acromyrmex leaf-cutting ants, the sister genus to the highly studied Atta leaf-cutting ants. We find surprisingly high interspecific variation in alarm pheromone composition across the attine phylogeny. Interestingly, the active component of the alarm pheromone was different between the two leaf-cutting ant genera. Furthermore, in contrast to previous studies on Atta, we found no differences among morphological castes in their responses to alarm pheromone in Acromyrmex but we did find differences in responses among putative age classes. The results suggest that the evolution of alarm communication and signaling within social insect clades can be unexpectedly complex and that further work is warranted to understand whether the evolution of different alarm pheromone compounds is adaptive.
Topics: Age Factors; Aggression; Animal Communication; Animals; Ants; Behavior, Animal; Cues; Pheromones; Plant Leaves; Volatilization
PubMed: 28247150
DOI: 10.1007/s10886-017-0821-4