{"title":"Living on borrowed oxygen in the goldenrod gall fly (Eurosta solidaginis).","authors":"Qian Long, Glenn J Tattersall","doi":"10.1242/jeb.253204","DOIUrl":"https://doi.org/10.1242/jeb.253204","url":null,"abstract":"<p><p>Hypoxia in plant tissue should affect animals living within them. Gall makers stimulate their plant hosts to produce the gall they inhabit and feed on, and also influence the gall phenotype for other adaptations, such as defence against predators. In the context of adapting to potential gall hypoxia through the extended phenotype of the gall, we studied the prevalence and conditions leading to hypoxia in goldenrod galls induced by Eurosta solidaginis. Larval respirometry data showed only mild tolerance to hypoxia, based on elevated critical oxygen partial pressures (∼10 kPa). Mathematical modelling of gas diffusion into the gall suggested that the extent of prevalent hypoxia is tolerable to the larva, while more severe temporary hypoxia may occur early in the host plant's growth season. As galls mature, the cortex layer that makes up most of the gall volume becomes less metabolically active and more permeable to gas diffusion, which is important in preventing severe hypoxia. While the mature cortex layer is unlikely to have been specifically an adaptation to hypoxia, it could mitigate the need for other trade-offs in gas exchange. Since gall makers can influence gall size and tissue composition, this raises the possibility that, on top of the already established predation trade-offs, the gall maker must balance the hypoxia risk of remaining in less differentiated, cytoplasm-rich tissue with the costs associated with inducing a larger, more mature gall with greater gas diffusion capacity.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149220321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maitri Rangarajan-Paul, Scott A Nichols, Martin Tresguerres
{"title":"Co-option of Lysosomal machinery for sponge biosilicification.","authors":"Maitri Rangarajan-Paul, Scott A Nichols, Martin Tresguerres","doi":"10.1242/jeb.252876","DOIUrl":"https://doi.org/10.1242/jeb.252876","url":null,"abstract":"<p><p>Biomineralization evolved repeatedly across animals, resulting in novel strategies for buoyancy, locomotion, and defense. Sponges are the only metazoans that build silica-based skeletons, and the mechanisms underlying their biosilicification are relatively understudied compared to other major silicifiers. Here, we show that in freshwater sponges, cells specialized for biosilicification, termed sclerocytes, highly express lysosomal-associated genes, including the V-H+-ATPase (VHA) proton pump, oculocutaneous albinism type 2 (OCA2) anion channels, cathepsins, silicateins, TMEM55A/B, TMEM192, TMEM199, and other proteins involved in lysosomal function. We demonstrate that VHA protein localizes to the sclerocyte and propose that VHA-dependent silica deposition vesicle (SDV) acidification is likely essential for silica spicule formation. This function mirrors the role of VHA in diatom biosilicification and in biocalcification across a broad sweep of taxa. We also found that genes homologous to the plant silicon efflux transporter Lsi2 are highly upregulated in sclerocytes and confirmed their localization using Hybridization Chain Reaction Fluorescence In Situ Hybridization (HCR-FISH). These results corroborate phylogenetic and transcriptomic evidence that Lsi2 homologs are involved in sponge silicic acid transport. Data mining of previous studies revealed that many of the sponge sclerocyte lysosomal-associated genes have been correlated with biomineralization across eukaryotes, including coccolithophores, bryozoans, crustaceans, mollusks, and mammals. As detoxification was a likely driver for the evolution of biomineralization, we propose that lysosomal machinery aided in detoxification by allowing sponges to sequester Si in acidified compartments to prevent its catastrophic intracellular precipitation. This lysosomal toolkit was likely independently co-opted for the formation of biomineralized structures in multiple species.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149194677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Testing the gearbox hypothesis for insect flight control.","authors":"Abin Ghosh, Girish Kumar G S, Sanjay P Sane","doi":"10.1242/jeb.250768","DOIUrl":"10.1242/jeb.250768","url":null,"abstract":"<p><p>Across Diptera, sustained flight relies on stretch-activated asynchronous flight muscles that generate multiple contraction cycles per motor neuron impulse, enabling wingbeat frequencies of ∼100-1000 Hz. These muscles attach to the thorax as indirect flight muscles, driving wing flapping through thoracic deformation, while smaller steering muscles modulate wing kinematics stroke by stroke. The wings articulate with the thorax through a wing hinge, where the radial stop (RS) and grooved pleural wing process (PWP) are proposed to act as a mechanical 'gearbox' that modulates wingbeat amplitude during maneuvering. Supporting this hypothesis, previous studies observed that close RS-PWP interactions correlated with discrete wingbeat amplitude changes during fictive turns in tethered flies, although the functional significance of this in freely flying insects remained untested. Here, we first examined the morphological diversity of the wing hinge across Diptera using scanning electron microscopy and found substantial variation in PWP morphology, suggesting that this putative gearbox is not highly conserved. We next tested gearbox function by bilaterally ablating the PWP in freely flying houseflies (Musca domestica), released into an L-shaped arena requiring 90 deg yaw turns. Kinematic analyses revealed no significant differences between control and PWP-ablated flies in wing or body kinematics during yaw turns. Both groups differentially modulated wingbeat amplitude to generate yaw torques, indicating that PWP is inessential for wingbeat amplitude modulation and that active neuromuscular control, rather than passive RS-PWP engagement, predominates in regulating wingbeat amplitude during maneuvers. Our findings challenge a central prediction of the gearbox hypothesis and highlight the robustness of the dipteran flight control system.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148900557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tamzin A Blewett, Chris N Glover, Erin M Leonard, Connor B Stewart, Nic R Bury, Jenelle D McCuaig, James C McGeer, Chris M Wood
{"title":"An aquatic toxicology primer for the experimental biologist and guidance for conducting robust stressor exposures.","authors":"Tamzin A Blewett, Chris N Glover, Erin M Leonard, Connor B Stewart, Nic R Bury, Jenelle D McCuaig, James C McGeer, Chris M Wood","doi":"10.1242/jeb.252679","DOIUrl":"10.1242/jeb.252679","url":null,"abstract":"<p><p>The field of aquatic toxicology has undergone a paradigm shift in recent decades. The movement away from observational data detailing the concentrations that produce deleterious effects and towards a mechanistic understanding of how toxicants affect organismal physiology has significant advantages for the field. This mechanistic approach allows for the prediction of toxicant effects across species and among toxicants with similar modes of action. Critically, knowledge of the pathways by which toxicants exert their impacts can provide insight into how environmental factors such as temperature, salinity, dissolved oxygen, pH, alkalinity, dissolved organic carbon, major ions and co-occurring toxicants interact to modify toxicity, providing a more nuanced understanding of toxicity in natural settings. This mechanism-based approach has driven changes in the regulatory environment, through the incorporation of predictive modelling tools that can determine, on a site-specific basis, safe thresholds for concentrations of toxicants in aquatic settings. This represents an exemplar of how fundamental experimental biology translates into real-world application. However, we argue that while mechanistic aquatic toxicology is an important subfield of experimental biology, there are a number of factors that make it unique. In this Commentary, we outline best practices for the experimental biologist conducting research into toxicant effects on aquatic biota, provide examples of the utility of mechanistic approaches to the field of aquatic toxicology and outline how future advances in aquatic toxicology could benefit from experimental biology approaches.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"229 20","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149193731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Trystan B Sanders, M Basseer Codabaccus, Andrea Williamson, Adam Yeap, Christian Dietz, Robert P Ellis, Rod W Wilson, Chris G Carter
{"title":"Protein turnover in juvenile tropical rock lobster (Panulirus ornatus) and its implications for growth bioenergetics.","authors":"Trystan B Sanders, M Basseer Codabaccus, Andrea Williamson, Adam Yeap, Christian Dietz, Robert P Ellis, Rod W Wilson, Chris G Carter","doi":"10.1242/jeb.253102","DOIUrl":"10.1242/jeb.253102","url":null,"abstract":"<p><p>Protein turnover (the continuous synthesis and degradation of the proteome) is energetically expensive and strongly correlates with growth rate in ectotherms. However, in crustaceans, our understanding of whole-body protein turnover is limited. This restricts our ability to accurately determine dietary protein and energy utilisation efficiency, which are critical for optimising aquaculture nutrition. This study investigated how two isoenergetic feeds containing 42% (CP42) or 64% (CP64) crude protein affect post-prandial metabolism, nitrogen flux and protein turnover in tropical rock lobster (Panulirus ornatus). We found that dietary protein had no effect on rates of respiratory gas exchange (O2 and CO2) or total excretory nitrogen (NH3-N+urea-N) over the 48-h post-prandial period. However, lobsters retained >2-fold more dietary protein in CP64 (50% versus 19% in CP42). Using dietary 15N metabolic tracers, we observed one-third higher whole-body protein synthesis rates in CP64 (10.2±0.9% of body protein per day) but no differences in protein degradation. Protein turnover (the proportional degradation of daily synthesised protein) was higher in CP42 at 77±3% (versus 67±1% in CP64), which was associated with ∼2-fold higher protein growth costs (21.5±1.5 versus 10.2±0.4 kJ g-1 in CP64). Our results suggest that high protein intake in P. ornatus does not increase catabolism of dietary protein, but stimulates protein synthesis, leading to reduced protein turnover and more energy-efficient growth. These findings clearly demonstrate the importance of whole-body protein turnover to nutritional physiology and bioenergetics for optimising aquaculture productivity.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C A Radford, Kelsie A Murchy, Jessica Andrade, Shaye Ogurek, Brooke Vetter, Ben Laurel, Francis Juanes
{"title":"Seasonal differences in the sound detection ability of Arctic cod, Boreogadus saida.","authors":"C A Radford, Kelsie A Murchy, Jessica Andrade, Shaye Ogurek, Brooke Vetter, Ben Laurel, Francis Juanes","doi":"10.1242/jeb.253098","DOIUrl":"https://doi.org/10.1242/jeb.253098","url":null,"abstract":"<p><p>Human activities are rapidly altering marine ecosystems, with increasing vessel traffic elevating underwater sound levels worldwide. Polar regions are particularly vulnerable, as declining sea ice has expanded access to the Arctic Ocean. Arctic cod (Boreogadus saida) is a key species that spawns under sea ice, yet its hearing abilities remain entirely uncharacterised. Understanding how this species detects sound is essential for assessing the potential impacts of rising anthropogenic sound. Here, the detection sensitivity of spawning and non-spawning Arctic cod were evaluated using auditory evoked potentials (AEPs). Both groups were most sensitive to frequencies below 200 Hz when assessed using sound pressure. However, particle motion sensitivity differed markedly: spawning fish showed peak sensitivity at 400 Hz, whereas non-spawning fish were most sensitive near 90 Hz. Overall, Arctic cod exhibited significantly enhanced hearing sensitivity and an expanded detectable frequency range during spawning compared with non-spawning individuals. These results provide the first evidence of seasonal differences in auditory plasticity in a broadcast-spawning fish and highlight the potential vulnerability of Arctic cod spawning behaviour to increasing anthropogenic sound in a rapidly changing Arctic environment.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149194635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Why sustained, high-intensity fat-powered endurance rarely evolves in animals.","authors":"Martina S Müller, Scott R McWilliams","doi":"10.1242/jeb.252211","DOIUrl":"https://doi.org/10.1242/jeb.252211","url":null,"abstract":"<p><p>Most animals rely on flexible fuel-use strategies in which carbohydrates support short, high-power bursts of activity and fats fuel prolonged, low-intensity locomotion. A notable exception occurs in a small subset of taxa - primarily migratory birds, bats and some insects - that sustain vigorous, high-intensity aerobic locomotion while relying largely on lipid oxidation. In this Review, we examine why this extreme, fat-powered endurance phenotype has evolved so rarely. Synthesizing evidence across locomotor modes (swimming, running, flying), body sizes and patterns of endurance specialization, we argue that selection for endurance alone is insufficient to drive the evolution of this phenotype. Sustained fat-powered endurance emerges only where scaling constraints on power, heat dissipation and oxygen delivery are not prohibitive, the ecological demand for prolonged activity aligns with mechanical conditions that permit continuous high aerobic output, and the benefits of specialization outweigh the evolutionary costs of reduced metabolic flexibility. In most animals, endurance demands are intermittent or context dependent, favoring partial specialization that enhances aerobic capacity and lipid use while preserving the ability to shift fuels and performance modes. Crossing into this extreme phenotype requires coordinated, reversible co-expression of structural and regulatory changes that together commit organisms to a narrow performance phenotype and impose trade-offs in force production, metabolic versatility and resource allocation. Consequently, evolution often favors trajectories that approach, but do not fully cross into, this exceptional performance state. Together, these patterns show that sustained, high-intensity fat-powered endurance is a rare and conditional evolutionary outcome, arising only where ecological necessity, biomechanical permissibility and physiological feasibility align.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"229 20","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149193965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Avishikta Chakraborty, Enrique Rodríguez, Stefano Bettinazzi, Stefania Stroila, Nick Lane, M Florencia Camus
{"title":"Mitochondrial genetic effects mediate the response to stress through development, but not adult metabolic rate in Drosophila melanogaster.","authors":"Avishikta Chakraborty, Enrique Rodríguez, Stefano Bettinazzi, Stefania Stroila, Nick Lane, M Florencia Camus","doi":"10.1242/jeb.253155","DOIUrl":"10.1242/jeb.253155","url":null,"abstract":"<p><p>Energy expenditure is fundamental to physiology, behaviour, ecology and life history, yet the mechanisms that regulate metabolic rate remain poorly understood. At the cellular level, incompatibilities between the maternally inherited mitochondrial genome and the nuclear genome can impair energy production, signalling and gene expression, with potential to disrupt a wide range of physiological processes. However, how these often-subtle genomic mismatches influence whole-organism traits such as metabolic rate, activity and fitness remains unclear. Here, we generated mitonuclear-mismatched fly lines to test how early-life dietary and metabolic stress affect larval and adult physiology. Our results revealed sex- and line-specific physiological effects, with larval development, survival and female fertility strongly contingent on the haplotypes and treatment, while adult resting metabolic rate and activity were not influenced by mitochondrial haplotype, or by developmental stress.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148962894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eden A Chaplik, Ananya C Pokkula, Hannah M Smith, George A Brusch
{"title":"Temporal dynamics of dehydration differentially regulate components of innate immunity.","authors":"Eden A Chaplik, Ananya C Pokkula, Hannah M Smith, George A Brusch","doi":"10.1242/jeb.253214","DOIUrl":"https://doi.org/10.1242/jeb.253214","url":null,"abstract":"<p><p>Hydration state is an important regulator of vertebrate physiology, yet the temporal dynamics of hydration-associated immune responses remain poorly understood. We investigated how progressive dehydration and repeated dehydration-rehydration cycles influence innate immunity in Antaresia childreni (Children's pythons). Snakes were assigned to either a hydrated control group or a dehydration-treatment group, and plasma osmolality, agglutination, lytic ability, and bacterial killing ability were measured throughout two complementary experiments. Progressive dehydration produced stepwise increases in plasma osmolality, whereas immune responses changed later and differed among immune components. Agglutination and lytic ability increased during later stages of dehydration, whereas bacterial killing ability increased only at peak dehydration; following rehydration, no immune measure differed significantly between treatment and control animals. During repeated dehydration-rehydration cycles, plasma osmolality increased during both dehydration events and returned following rehydration, whereas immune responses differed in their persistence and repeatability. Agglutination remained higher than controls throughout both dehydration-rehydration cycles, lytic ability increased during both dehydration events but declined following rehydration, and bacterial killing ability increased during the first but not the second dehydration event. These findings demonstrate that innate immune function is influenced not only by dehydration, but also by the temporal dynamics and recent history of water limitation. More broadly, our results emphasize that physiological responses to environmental change cannot always be inferred from endpoint comparisons alone.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149168904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Food ration affects mRNA processing, translation, proteostasis, and cytoskeletal responses during heat shock in Mytilus californianus.","authors":"L Tomanek, R F Fabela, M A May","doi":"10.1242/jeb.252969","DOIUrl":"https://doi.org/10.1242/jeb.252969","url":null,"abstract":"<p><p>Despite a likely role in setting stress tolerance limits, food ration has received limited attention as an ecological factor affecting the cellular stress response (CSR). To study the interactive effects of food and temperature on the proteomic heat shock response, we acclimated intertidal mussels (Mytilus californianus) to four combinations of nearshore (low) and aquaculture (high) phytoplankton levels, combined with low (20 °C) and high (30 °C) aerial temperatures during daytime low tides. Mussels were then exposed to an acute (6 h), aerial heat stress (33 °C) and allowed to recover for 1 h and 25 h in pre-exposure conditions. Proteomic changes in the gill before and after heat shock were measured using label-free liquid-chromatography-mass spectrometry. Compared to other acclimation treatments, low-food-low-temperature (LTLF) mussels modified more splicing factors, heterogeneous nuclear ribonucleoproteins, ribosomal proteins, and translation initiation and elongation factors, suggesting systemic changes to RNA processing, selection, and translation. LTLF mussels also increased chaperones of the actin- and microtubule-associated cytoskeleton and proteins that mature along the endoplasmic reticulum to Golgi secretory pathway. Simultaneously, actin stress fiber formation at focal adhesions and the extracellular matrix, along with anchoring of microtubule-associated cilia, indicate a possible system-wide mechanical breakdown of the cytoskeleton. Signaling proteins causing cytoskeletal changes varied mainly in LTLF mussels and suggest a food-dependent role for prostaglandin synthesis. Overall, the acclimation-dependent proteomic changes show how thermal conditioning and food ration together will shape the CSR of mussels during heat waves.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149166654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}