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Current Opinion in Insect Science Oct 2023Pheromone plasticity is widely observed in insects and enhances their survival, adaptation, and reproductive success. Aggregation pheromones, which cause notable... (Review)
Review
Pheromone plasticity is widely observed in insects and enhances their survival, adaptation, and reproductive success. Aggregation pheromones, which cause notable individual aggregation and consequently impact agriculture and human life, are renowned for their special function. Here, we present a review of research progress regarding pheromone plasticity in three typical aggregative insects: locusts, bark beetles, and cockroaches. These insects are major pest species with considerable impacts on the social economy and public health. Numerous studies have demonstrated the plasticity of aggregation pheromones in different populations of these insect species. Although pheromone chemicals and compositions vary across the three groups, the plasticity of aggregation pheromones is significantly impacted by population density, location, food resources, and gut symbiotic microorganisms, indicating the complexity of pheromone plasticity regulated by multiple factors. Finally, we discuss the potential application of pheromone plasticity in basic research and pest management.
PubMed: 37541387
DOI: 10.1016/j.cois.2023.101098 -
Current Opinion in Insect Science May 2024The common bed bug, Cimex lectularius (Cimicidae, Hemiptera), is obligate haematophagous and can carry pathogens but is not known to transmit diseases to humans in... (Review)
Review
The common bed bug, Cimex lectularius (Cimicidae, Hemiptera), is obligate haematophagous and can carry pathogens but is not known to transmit diseases to humans in natural settings. Bed bugs are activated and guided by semiochemicals and heat by potential hosts, as well as by an aggregation pheromone when searching for food and home. No sexual pheromone has been detected in bed bugs, which mate through traumatic insemination. First, after mounting, males are able to distinguish between large nymphs, other males, and females. To avoid unwanted traumatic inseminations, nymphs and adults emit an alarm pheromone. The olfactory system of bed bugs has relatively few odorant and ionotropic receptors, which likely reflects the simple environment that bed bugs live in, and use to search for hosts and conspecifics.
PubMed: 38821142
DOI: 10.1016/j.cois.2024.101207 -
Behavioural Processes Apr 2024It is generally believed that termites can't learn and are not "intelligent". This study aimed to test whether termites could have any form of memory. A Y-shaped test...
It is generally believed that termites can't learn and are not "intelligent". This study aimed to test whether termites could have any form of memory. A Y-shaped test device with one release chamber and two identical test chambers was designed and constructed by 3D printing. A colony of damp wood termites was harvested from the wild. Worker termites were randomly selected for experiment. Repellent odors that could mimic the alarm pheromone for termites were first identified. Among all substances tested, a tea tree oil and lemon juice were found to contain repellent odors for the tested termites, as they significantly reduced the time that termites spent in the chamber treated with these substances. As control, a trail pheromone was found to be attractive. Subsequently, a second cohort of termites were operant conditioned by punishment using both tea tree oil and lemon juice, and then tested for their ability to remember the path that could lead to the repellant odors. The test device was thoroughly cleaned between trials. It was found that conditioned termites displayed a reduced tendency to choose the path that led to expectant punishment as compared with naïve termites. Thus, it is concluded that damp wood termites are capable of learning and forming "fear memory", indicative of "intelligence" in termites. This result challenges established presumption about termites' intelligence.
Topics: Isoptera; Animals; Odorants; Conditioning, Operant; Pheromones; Memory; Learning; Tea Tree Oil; Citrus; Insect Repellents; Behavior, Animal; Punishment
PubMed: 38493970
DOI: 10.1016/j.beproc.2024.105012 -
Frontiers in Neural Circuits 2024Pheromones are specialized chemical messengers used for inter-individual communication within the same species, playing crucial roles in modulating behaviors and... (Review)
Review
Pheromones are specialized chemical messengers used for inter-individual communication within the same species, playing crucial roles in modulating behaviors and physiological states. The detection mechanisms of these signals at the peripheral organ and their transduction to the brain have been unclear. However, recent identification of pheromone molecules, their corresponding receptors, and advancements in neuroscientific technology have started to elucidate these processes. In mammals, the detection and interpretation of pheromone signals are primarily attributed to the vomeronasal system, which is a specialized olfactory apparatus predominantly dedicated to decoding socio-chemical cues. In this mini-review, we aim to delineate the vomeronasal signal transduction pathway initiated by specific vomeronasal receptor-ligand interactions in mice. First, we catalog the previously identified pheromone ligands and their corresponding receptor pairs, providing a foundational understanding of the specificity inherent in pheromonal communication. Subsequently, we examine the neural circuits involved in processing each pheromone signal. We focus on the anatomical pathways, the sexually dimorphic and physiological state-dependent aspects of signal transduction, and the neural coding strategies underlying behavioral responses to pheromonal cues. These insights provide further critical questions regarding the development of innate circuit formation and plasticity within these circuits.
Topics: Animals; Pheromones; Mice; Signal Transduction; Vomeronasal Organ
PubMed: 38742089
DOI: 10.3389/fncir.2024.1409994 -
Science Advances Jun 2023Sexual attraction and perception are crucial for mating and reproductive success. In , the male-specific isoform of Fruitless (Fru), Fru, is a known master...
Sexual attraction and perception are crucial for mating and reproductive success. In , the male-specific isoform of Fruitless (Fru), Fru, is a known master neuro-regulator of innate courtship behavior to control the perception of sex pheromones in sensory neurons. Here, we show that the non-sex-specific Fru isoform (Fru) is necessary for pheromone biosynthesis in hepatocyte-like oenocytes for sexual attraction. Loss of Fru in oenocytes resulted in adults with reduced levels of cuticular hydrocarbons (CHCs), including sex pheromones, and show altered sexual attraction and reduced cuticular hydrophobicity. We further identify () as a key target of Fru in directing fatty acid conversion to hydrocarbons. or depletion in oenocytes disrupts lipid homeostasis, resulting in a sex-dimorphic CHC profile that differs from and dependent CHC dimorphism. Thus, Fru couples pheromone perception and production in separate organs to regulate chemosensory communications and ensure efficient mating behavior.
Topics: Animals; Male; Drosophila melanogaster; Hepatocyte Nuclear Factor 4; Lipid Metabolism; Perception; Pheromones; Sex Attractants
PubMed: 37390217
DOI: 10.1126/sciadv.adf6254 -
Proceedings of the National Academy of... Oct 2023Meiosis is essential for generating genetic diversity and sexual spores, but the regulation of meiosis and ascosporogenesis is not clear in filamentous fungi, in which...
Meiosis is essential for generating genetic diversity and sexual spores, but the regulation of meiosis and ascosporogenesis is not clear in filamentous fungi, in which dikaryotic and diploid cells formed inside fruiting bodies are not free living and independent of pheromones or pheromone receptors. In this study, Gia1, a non-pheromone GPCR (G protein-coupled receptor) with sexual-specific expression in , is found to be essential for ascosporogenesis. The mutant was normal in perithecium development, crozier formation, and karyogamy but failed to undergo meiosis, which could be partially rescued by a dominant active mutation in and activation of the Gpmk1 pathway. orthologs have conserved functions in regulating meiosis and ascosporogenesis in Sordariomycetes. has a paralog, , in and other Hypocreales species which is essential for perithecium formation. differed from in expression profiles and downstream signaling during sexual reproduction. Whereas the C-terminal tail and IR3 were important for intracellular signaling, the N-terminal region and EL3 of Gia1 were responsible for recognizing its ligand, which is likely a protein enriched in developing perithecia, particularly in the mutant. Taken together, these results showed that encodes a non-pheromone GPCR that regulates the entry into meiosis and ascosporogenesis via the downstream Gpmk1 MAP kinase pathway in and other filamentous ascomycetes.
Topics: Triticum; Pheromones; Fungal Proteins; Fusarium; Ascomycota; Meiosis; Spores, Fungal
PubMed: 37812726
DOI: 10.1073/pnas.2313034120 -
Cold Spring Harbor Protocols Jul 2023Upon copulation, females undergo a switch-like change in their behavior and physiology, known as "postmating responses." These strong behavioral and physiological...
Upon copulation, females undergo a switch-like change in their behavior and physiology, known as "postmating responses." These strong behavioral and physiological changes are triggered by the transfer of male seminal proteins during copulation. Postmating response is associated with strong reduction in receptivity, indicated by the females kicking their legs toward the suitor and curving their abdomen downward to hide their genitalia from them and extruding their ovipositor at the tip of the abdomen, which physically prevents copulation. The transfer of male-specific pheromones, such as 11--vaccenyl-acetate, during copulation further reduces female attractiveness. In addition, mated females exhibit increased ovulation, egg-laying behavior, enhanced feeding behavior, and changes in food preference. However, females increase their rate of remating when they are in social groups or in the presence of food. This protocol describes methods for measuring female postmating behaviors, such as oviposition, female sexual receptivity, and mating plug ejection.
Topics: Animals; Female; Male; Sexual Behavior, Animal; Copulation; Ovulation
PubMed: 36781215
DOI: 10.1101/pdb.prot108108 -
Proceedings of the National Academy of... Jun 2023From bacterial quorum sensing to human language, communication is essential for social interactions. Nematodes produce and sense pheromones to communicate among...
From bacterial quorum sensing to human language, communication is essential for social interactions. Nematodes produce and sense pheromones to communicate among individuals and respond to environmental changes. These signals are encoded by different types and mixtures of ascarosides, whose modular structures further enhance the diversity of this nematode pheromone language. Interspecific and intraspecific differences in this ascaroside pheromone language have been described previously, but the genetic basis and molecular mechanisms underlying the variation remain largely unknown. Here, we analyzed natural variation in the production of 44 ascarosides across 95 wild strains using high-performance liquid chromatography coupled to high-resolution mass spectrometry. We discovered wild strains defective in the production of specific subsets of ascarosides (, the aggregation pheromone icas#9) or short- and medium-chain ascarosides, as well as inversely correlated patterns between the production of two major classes of ascarosides. We investigated genetic variants that are significantly associated with the natural differences in the composition of the pheromone bouquet, including rare genetic variants in key enzymes participating in ascaroside biosynthesis, such as the peroxisomal 3-ketoacyl-CoA thiolase, , and the carboxylesterase . Genome-wide association mappings revealed genomic loci harboring common variants that affect ascaroside profiles. Our study yields a valuable dataset for investigating the genetic mechanisms underlying the evolution of chemical communication.
Topics: Animals; Humans; Caenorhabditis elegans; Pheromones; Genome-Wide Association Study; Nematoda; Genetic Variation
PubMed: 37339205
DOI: 10.1073/pnas.2221150120