Search Results (122)

Background/Objectives: Numerous studies have investigated the responses of the gastrointestinal tract to tastants, particularly in specialized enteroendocrine and other chemosensory cells. However, many of these investigations used various taste stimuli often at high concentrations or relied on immortalized cell lines or heterogeneous cell populations, which can limit their physiological relevance and reproducibility. To establish a stable, physiologically representative model system for consistently investigating gut epithelial responses to tastants, our study developed 3D murine intestinal organoids (MIOs). Methods: Murine intestinal organoids were generated from isolated intestinal crypts and cultured under defined conditions to maintain epithelial differentiation. Organoids were stimulated with selected nutrients and tastants, and downstream signaling responses were assessed using hormone secretion assays. Results: The 3D MIO culture system was successfully established, providing a robust in vitro platform for studying extraoral bitter sensing and release of the enteroendocrine hormone cholecystokinin. Moreover, 5 mM denatonium benzoate and 30 mM L-glutamic acid specifically induced cholecystokinin secretion in MIOs, whereas other bitter or non-bitter stimuli did not. Conclusions: Murine intestinal organoids provide a stable model for studying nutrient- and tastant-evoked signaling in the gut. This approach enables precise investigation of underlying mechanisms and may advance our understanding of gut chemosensation and metabolic regulation. Full article

Spotted wing drosophila (Drosophila suzukii; SWD) has become a globally invasive pest by ovipositing in ripening, intact fruit rather than decaying material, a niche distinct from most other drosophilids. An expanding body of work implicates microbes and microbially derived chemistry as key drivers of this ecology, shaping fly biology across life stages. However, much of this evidence is derived from microbiome surveys and observational comparisons, further constrained by uncontrolled diet history, laboratory rearing, and insufficient ecological context. We examine how the SWD microbiome differs in which taxa are present (composition), how flies pick up those taxa from fruit and maternal sources (acquisition), how long those taxa are retained across life stages (persistence), and how each of these varies with diet, geography, season, and host crops. We then address how microbial cues and fermentation state function as context-dependent drivers of adult attraction, avoidance, and oviposition, and how microbe-mediated interspecific interactions reshape substrate suitability and competition among drosophilids. Throughout, we critically evaluate experimental designs and identify gaps that impede causal inference. These include limited strain-level resolution, incomplete fungal characterization, and weak linkages between microbial community structure and host phenotypes. Key unresolved questions include how SWD maintains performance across diverse hosts, how microbes modulate sensory processing during seasonal shifts, and which microbial metabolites drive attraction, avoidance, and competition. Resolving these questions is a direct prerequisite for field-stable integrated pest management (IPM), including microbially informed behavioral lures, oviposition deterrents derived from pathogen- and competitor-associated volatiles, and competitor-mediated suppression strategies. The experimental priorities identified here translate directly into a roadmap for the next generation of mechanistically grounded, ecologically realistic SWD management tools. Full article

The olfactory and gustatory systems are essential for survival, enabling organisms to detect and respond to environmental chemical cues. Although canonical signaling pathways in smell and taste have been well defined, growing evidence highlights additional ion channel families as key modulators of sensory responses. Recent studies identify the anoctamin, transmembrane channel-like, and TMEM63 superfamily as a class of non-canonical sensory effectors that regulate signal amplification, excitability, and epithelial homeostasis across chemosensory systems. In the mammalian olfactory epithelium, specific anoctamin channels enhance odor-evoked responses and contribute to tissue homeostasis. In the gustatory system, salt detection is now understood to involve multiple parallel signaling pathways, with TMC4 emerging as a key contributor to high-salt and salt-associated taste sensing. These channel families are evolutionarily conserved across species, including C. elegans, Drosophila, and aquatic organisms, where they mediate chemosensation, mechanosensation, humidity detection, and osmoregulation. This functional versatility is supported by a shared structural architecture that enables selective ion conduction and, in some members, regulated phospholipid scrambling. This review proposes a unifying framework in which anoctamin and transmembrane channel-like proteins act as multimodal regulators of sensory signaling, linking environmental cues to cellular excitability and microenvironmental control and highlighting new principles of chemosensory organization and therapeutic potential. Full article

Oviposition site selection is critical for mosquito population dynamics. Gravid mosquitoes rely on chemical cues to identify suitable breeding habitats. However, the sensory mechanisms governing this behavior in Anopheles stephensi remain poorly understood. Here, we examined the role of indole, a microbial volatile associated with aquatic environments, in oviposition site choice and assessed the involvement of sensory organs in its detection. In two-choice oviposition assays, water conditioned with first-instar larvae attracted gravid females (OAI = 0.56). In contrast, water from fourth-instar larvae was repellent (OAI = −0.20), consistent with avoidance of suboptimal, resource-depleted habitats. Single indole cue elicited strong oviposition attraction across a broad concentration range (0.5–50 µM), with no clear dose–response relationship. Surgical ablation of antennae and maxillary palps did not abolish indole-mediated preference but significantly reduced behavioral variability, suggesting that these structures modulate, rather than solely mediate, indole detection. Reanalysis of transcriptomes of antennae, maxillary palps, and legs in An. gambiae and An. coluzzii, along with quantitative RT-PCR in An. stephensi revealed the expression of chemosensory genes (including Obp1, Obp13, Obp25, Obp71, Or2, and Or10) in the legs, suggesting a potential role for leg chemosensation in oviposition decisions. These findings underscore the complexity of chemoperception in mosquito habitat assessment. Full article

The single mental barbel is a distinctive feature of the benthic Antarctic fishes of the «cryonotothenioid» subfamily Artedidraconinae. These barbels are unusual because their primary sensory modality is tactility, not chemosensation as in most other teleosts. They also exhibit considerable interspecific and intraspecific variation in length and in the appearance of the terminal expansion and its epidermis. Barbels range from short to long and the terminal expansion can be nonexistent, small and round, or large and oblong. In most species, the epidermal surface of the terminal expansion exhibits projections of various shapes and sizes. These range from smooth and furrowed, to ridged and furrowed, to pointed, to palmate (having lobes originating from a common point), and to fringed and leaf-like. Barbels are also subject to intraspecific variation among the species in the genera Dolloidraco, Histiodraco, Artedidraco and Pogonophryne. The various epidermal surface patterns all increase the sensory surface area exposed to the substrate and may enhance detection of their prey, primarily polychaetes. They also enhance surface roughness of the epidermis, thereby dissipating mechanical forces and providing some protection from abrasion by the substrate. The various patterns are likely an epigenetic response to different local conditions of the substrate. This variation warrants caution in their use as a defining taxonomic character. Full article

Chemosensory systems are crucial for insect survival, enabling host-seeking, food acquisition, and oviposition site selection. While insect-associated microbes are known to influence host development and immunity, their role in modulating chemosensory behavior remains poorly understood. Here, we show that mono-association with Escherichia coli alters sensory-driven behaviors in both larval and adult axenic Drosophila melanogaster. In larvae, E. coli mono-association altered phototaxis and mechanosensory responses across genotypes, while changes in tunneling and thermosensory behaviors were reduced or absent in ionotropic receptor (IR) co-receptor mutants. In adults, E. coli mono-association increased attraction to fermentation cues (apple cider vinegar, ethanol) and enhanced sucrose consumption in wild-type and Orco-deficient flies, whereas these effects were reduced or absent in IR co-receptor mutants (IR25a⁻ and IR76b⁻). Together, these findings indicate that under defined gnotobiotic conditions, E. coli exposure alters sensory-driven behavioral outputs relative to axenic controls. Effects are reduced or absent in IR co-receptor mutants, consistent with a role for IR pathways in mediating these behavioral shifts. These findings support a role for microbial cues in shaping insect sensory-driven behaviors and highlight the importance of microbial status in interpreting behavioral phenotypes. This work provides a framework for future studies investigating how microbial signals interact with conserved sensory pathways. Full article

Reports of carbon monoxide (CO) pharmacology have spurred intense interest in developing its fluorescent probes with much success. However, one unfortunate event in this area is the wide-spread use of chemically reactive metal/BH₃-CO complexes as “CO-releasing molecules” or CORMs that do not produce CO or produce CO in an idiosyncratic fashion. Consequently, a large number of reported fluorescent “CO probes” only respond to the CORM used, but not to CO. Though most of these issues have been clarified in the literature, there is a surprising recent publication on a Cu(II)-based fluorescent “CO probe,” Nap-BC-Cu(II), relying on undefined chemical principles. We reassessed the ability for Nap-BC-Cu(II) to detect CO and found no evidence for Nap-BC-Cu(II) to selectively detect CO at even non-physiologically relevant high concentrations (high micromolar) of CO. Marginal effects were observed only when CO was continuously bubbled through the “probe” solution for 15 min. Further, Nap-BC-Cu(II) was found to be sensitive to ascorbic acid and cysteine. Overall, this probe did not respond to CO in a pathophysiologically relevant context. Our findings do not support the notion of Nap-BC-Cu(II) being a CO probe for studying CO biology. We hope this will be the last of this saga of “CO probes” that do not afford selective detection of CO, largely due to the confusions caused by using chemically reactive CORMs. Full article

Boron-dipyrromethene (BODIPY) dyes belong to a class of organoboron compounds that have become ubiquitous for researchers in areas of fluorescence imaging, photodynamic therapy, and optoelectronics. The intrinsic qualities of BODIPY dyes and their meso-modified structural analogs, Aza-BODIPY dyes, have propelled their recent increase in use in biomedical applications. The two scaffolds have high quantum yields, narrow absorption, and emission bandwidths with large Stokes’ shifts, and high photostability and thermal stability. Because their properties are independent of solvent polarity and dye functionality, they can be tuned to promote novel analytical methods, resulting in the adaptation of the physicochemical and spectral properties of the dyes. In this review of BODIPY and Aza-BODIPY scaffolds, we will summarize their spectral properties, synthetic methods of preparation, and applications reported between 2014 and 2025. This review aims to summarize the advances in chemosensing, especially pH sensor development, and the advances in NIR-II window bioimaging probes. We hope that this succinct overview of Aza-BODIPY scaffolds will highlight their untapped potential, elucidating insights that may catalyze novel ideas in the physical organic realm of BODIPY. Full article

Sensory systems allow the detection of external and internal cues essential for adaptive responses. Chemosensation exemplifies this integration, guiding feeding, mating, and toxin avoidance while also influencing physiological regulation. Across taxa, chemical detection relies on diverse receptor families, and emerging evidence reveals that transient receptor potential (TRP) channels—traditionally associated with phototransduction, thermosensation, and mechanotransduction—also mediate chemosensory functions. Studies in Drosophila melanogaster and vertebrates demonstrate that TRPs detect tastants, odorants, and internal chemical states, highlighting their evolutionary conservation and functional versatility. This review synthesizes current insights into the roles of TRP channels across four major domains: taste, smell, internal state, and central circuit modulation. Using D. melanogaster and mammalian systems as comparative frameworks, we highlight how TRP channels function as polymodal sensors, signal amplifiers, and modulators embedded within canonical receptor pathways rather than as standalone chemoreceptors. Recognizing these integrative functions not only expands our understanding of how organisms coordinate behavior with internal states but also points to TRP channels as potential targets for addressing chemosensory disorders and metabolic diseases. This framework highlights key directions for future research into TRP-mediated sensory and homeostatic regulation. Full article

Olfactory perception depends on soluble proteins in the perireceptor environment that support odorant transport, mucosal protection, and tissue homeostasis. In insects, odorant-binding proteins (OBPs) in the sensillum lymph are indispensable for odor detection, whereas in humans the indispensability of OBPs (OBP2A/2B) remains unclear because they are inconsistently detected in nasal mucus. Consequently, it remains unclear whether other soluble proteins compensate for this function or how they contribute to odorant processing and signal transmission within the olfactory mucus. Accumulating evidence indicates that OBP-like lipocalins (LCN1, LCN2, LCN15) and apolipoprotein D, together with bactericidal/permeability-increasing (BPI)-fold proteins, act as major mediators of odorant solubilization, antimicrobial defense, oxidative stress regulation, and extracellular matrix (ECM) remodeling. Alterations in those proteins and ECM organization are linked to idiopathic and age-related smell loss, chronic rhinosinusitis, and neurodegenerative disorders, underscoring their broad relevance at the interface of chemosensation, mucosal defense, and brain health. Major unresolved issues include the functional indispensability of human OBPs, the receptor-specific contributions of OBP-like proteins, and the mechanistic relationships linking olfactory proteome remodeling, sensory signaling, and disease progression. This review provides an integrative overview of structural and mechanistic insights, highlights current controversies, and proposes future research directions, including receptor–protein mapping, integrated structural–functional studies, structural–functional analysis of OBP–ECM networks, and clinical validation of OBP-related biomarkers. Full article

Hierarchical super-hydrophilic surfaces were realized by forming porous anodic aluminum oxide (AAO) and boehmite [AlO(OH)] on micro-textured Si wafers. One-step anodization of e-beam-deposited Al followed by controlled pore-widening, thermal annealing, or hot-water treatment produced oxide architectures exhibiting near-zero water contact angles (aqueous regime) and pronounced H₂O adsorption–desorption responses (vapor regime). Thermogravimetric analysis, moisture isotherms, and FT-IR indicate that increased porosity and anion incorporation (O⁻/O²⁻/oxalate) enrich surface hydroxyl functionality, enhancing affinity to H₂O. The results delineate two complementary regimes—rapid capillary wetting and multilayer vapor adsorption—supporting the use of these oxide/Si hierarchies as interactive water-affine interfaces with potential relevance to moisture gettering and chemosensing. Full article

Gas chromatography–mass spectrometry (GC-MS) plays a crucial role in analyzing complex water samples due to its high sensitivity, selectivity, and robustness. Recent developments have transformed GC-MS into a powerful chemosensor platform, capable of generating detailed chemical fingerprints for targeted or untargeted environmental analysis. This review highlights the integration of GC-MS with atomistic modeling approaches, including quantum chemical calculations and molecular simulations, to enhance the interpretation of mass spectra and support the identification of emerging contaminants and transformation products. These computational tools offer mechanistic insight into fragmentation pathways, molecular reactivity, and pollutant behavior in aqueous environments. Emphasis is placed on recent trends that couple GC-MS with machine learning, advanced sample preparation, and simulation-based spectrum prediction, forming a synergistic analytical framework for advanced water contaminant profiling. The review concludes by addressing current challenges and outlining future perspectives in combining experimental and theoretical tools for intelligent environmental monitoring. Full article

Chemosensory systems are fundamental for insects to regulate behaviors such as prey detection, oviposition, and pollination. Despite their importance, the molecular mechanisms underlying chemosensation remain poorly understood in many insect groups. Hoverflies (Syrphidae), whose larvae are efficient aphid predators and adults act as pollinators, represent a functionally important but understudied lineage. Building on the genome of Eupeodes corollae that we recently published, we selected this dominant and widespread species as a representative model and performed a genome-wide identification and analysis of odorant-binding proteins (OBPs) to provide a molecular foundation for understanding chemosensory recognition mechanisms. Accordingly, a total of 47 OBPs were identified and classified into Classic, Minus-C, and Plus-C subfamilies, with conserved motifs and structural features observed within each group. Next, phylogenetic analysis revealed that several EcorOBPs are homologous to functionally characterized OBPs in other Diptera, suggesting conserved evolutionary roles. Moreover, chromosomal mapping showed that Minus-C EcorOBPs cluster on chromosome 2, and Ka/Ks analysis indicated strong purifying selection, reflecting evolutionary stability. In addition, synteny analysis demonstrated that E. corollae shares more collinear OBP gene pairs with predatory hoverflies (Episyrphus balteatus and Scaeva pyrastri) than with the saprophagous species Eristalis tenax, consistent with ecological divergence. Finally, transcriptomic profiling revealed tissue-specific expression patterns, including antennal-biased EcorOBP1 linked to olfaction and reproductive tissue-biased EcorOBP11 linked to reproduction, highlighting candidate genes for functional studies. Together, these findings provide a comprehensive characterization of OBPs in E. corollae and offer molecular insights into chemosensory mechanisms that support both pest control and pollination services. Full article

The brown planthopper (BPH), Nilaparvata lugens, is the most destructive insect pest of rice. BPH infestations severely threaten rice yield worldwide. The gustatory receptor NlGr23 plays a critical role in mediating the repulsive reaction to oxalic acid of the BPH. We integrated transcriptomic and proteomic analyses to determine the metabolic and behavioral consequences of NlGr23 silencing. The RNAi-mediated knockdown of NlGr23 increased body weight and honeydew production, indicating enhanced feeding activity. The results of multiomics profiling revealed disrupted lipid homeostasis, identifying 187 differentially expressed genes and 150 differentially expressed proteins. These genes were enriched in pathways including glycerophospholipid metabolism, fatty acid biosynthesis, and AMPK signaling. The results of biochemical assays showed that NlGr23 silencing elevated triacylglycerol levels by 68.83%, and reduced glycerol and free fatty acid levels, suggesting impaired lipolysis. The NlGr23 loss-of-function mutation mechanistically activates the AMPK pathway, suppresses lipid breakdown, and promotes energy storage. This study established NlGr23 as a key regulator linking chemosensation to metabolic reprogramming, providing new insights into gustatory receptor-mediated energy homeostasis in the BPH. Full article

Background: Chemosensation in ticks opens a novel and unique field for scientific research. This study highlights ticks’ chemosensory system to comprehend its host-searching behavior and other integrated chemistry and biology involving Haller’s structure. Methodology: This study combines microanatomical, electrophysiological, and behavioral experiments to investigate the role of Haller’s organ in adult ticks in response to different classes of organic compounds. Results: We showed the microscopic anatomy of Haller’s organ in Haemaphysalis darjeeling, present at the terminal segment of the first pair of appendages. Haller’s structure serves a vital function in perceiving odor. The electrophysiological activity of adult ticks to different classes of organic compounds via electroscutumography was explored at five different concentrations: w/v 0.001, 0.01, 0.1, 1.0, and 2.0%. Among 55 organic compounds, moderate to high stimulation was recorded with pyruvate (13.28 mv at 2%), ammonia (12.26 mv at 2%), benzoic acid (1.99 mv at 0.001%), isobutyric acid (1.39 mv at 0.001%), 2,6-dichlorophenol (1.34 mv at 0.001%), p-Tolualdehyde (1.26 mv at 2%), tetradecane (1.23 mv at 2%), docosane (1.17 mv at 2%), citronellal (1.13 mv at 0.1%), isopropyl acetate (1.05 mv at 0.01%), cyclohexanol (1.03 mv at 2%), 1-octane-3-ol (1.02 mv at 2%), and 1-octanol (1.01 mv at 0.001%). Olfactometric bioassays at w/v 2.0% concentration further confirmed that ammonia, pyruvate, 1-octane-3-ol, hematin porcine, p-Tolualdehyde, methyl salicylate, uric acid, tetradecane, carbon dioxide, propanoic acid, 3-hexanol, hexanoic acid, adenine, 2,6-dichlorophenol, hexadecane, heptanoic acid, pentanoic acid, octadecane, guanine, and nonanoic acid acted as strong attractants, while citronellal, eugenol, butyric acid, geraniol, benzaldehyde, and tiglic aldehyde showed an active repellent effect against the tick species. Conclusions: This investigation provides knowledge of the olfactory sensilla of Haller’s structure as biosensors behind tick olfaction and the possibility for chemical detection of diverse attractants and repellents for future development of anti-tick compounds. Full article