Journal of Experimental Biology最新文献

{"title":"Sex and mating success impact resource allocation and life history traits in Gryllus vocalis field crickets.","authors":"Madison F Von Deylen, Susan N Gershman, Agustí Muñoz-Garcia","doi":"10.1242/jeb.249976","DOIUrl":"10.1242/jeb.249976","url":null,"abstract":"<p><p>Resource allocation plays a pivotal role in shaping life-history strategies, often reflecting trade-offs between growth, energy storage and reproduction. These trade-offs are influenced by sex-specific selective pressures, with males and females adopting distinct strategies to maximize fitness. In this study, we investigated how sex and mating status affect resource allocation to morphological traits (body mass, fat mass, gonadal mass and gut mass) and metabolic rate in Gryllus vocalis field crickets. Our findings reveal marked differences between sexes: females allocated more resources to direct reproductive investment, particularly when mated, while males prioritized structural size and energy storage. Notably, mating status significantly influenced female reproductive investment but had a minimal effect on males, suggesting that male reproductive success is more influenced by competition than direct reproductive effort. These results contribute to our understanding of the physiological limits to the evolution of traits driving fitness in crickets.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608563","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":"The effects of meal size and feeding frequency on digestion in common wall lizards (Podarcis muralis).","authors":"Brittney C Parks, Ashley Mollett, Eric J Gangloff, Allison R Litmer","doi":"10.1242/jeb.250509","DOIUrl":"10.1242/jeb.250509","url":null,"abstract":"<p><p>Understanding the interplay between feeding, energetics and temperature in ectotherms is essential, particularly regarding introduced species and responses to climate change. Despite its importance, how feeding regimes - including meal timing and size - affect digestion has been underexplored. Previous research suggests that digestion is thermally dependent, with warm temperatures promoting quick digestion, and that consuming smaller meals results in slower digestion. However, empirical evidence is limited. Our study quantified digestive passage time, energy budgets, and fecal and urate production in the introduced common wall lizard (Podarcis muralis) relative to meal size and timing under a naturalistic temperature cycle (warm days at 34°C and cool nights at 25°C). We implemented four treatment groups based on meal size (large or small) and timing (morning only or morning and afternoon). While lizards consuming less food took significantly longer to completely pass food items, energy budgets and fecal and urate production did not differ among treatments. Our findings suggest that feeding regime may have some influence on digestive processes, but not to the extent of regulating energetics in the common wall lizard. Consistent energy budgets, despite variable meal sizes and timing of food consumption in relation to temperature, may contribute to wall lizard invasion success. Digestive processes play a critical role in regulating population persistence and expansion. The results of this study highlight the importance of quantifying feeding regimes and natural temperature cycles, with implications for invasion biology and predicting responses to climate change.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144707643","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":"Beetling the heat - the diurnal Namib Desert beetle Onymacris plana cools by running.","authors":"Carole S Roberts, Elizabeth L McClain, Mary K Seely, Duncan Mitchell, Victoria L Goodall, Joh R Henschel","doi":"10.1242/jeb.250379","DOIUrl":"10.1242/jeb.250379","url":null,"abstract":"<p><p>Onymacris plana (Coleoptera: Tenebrionidae) is a black beetle that runs at high speed for a pedestrian insect in direct solar radiation in the Namib Desert, a behaviour expected to impose potentially lethal body temperature within minutes. We measured the body temperature of beetles active in their natural habitat using fine thermocouples inserted into the prothorax. The measurements revealed that when beetles sprinted in conditions of low wind, high radiation and moderate ambient temperature, their body temperature dropped rather than rose. The effect depended on convective cooling and efficient locomotion, i.e. sprinting with low energy expenditure. We confirmed the convection effect in the laboratory by exposing beetles to combinations of radiation, air temperature and wind speed comparable to those found in the Namib Desert and simulating the forced convection of running in a headwind. Under these simulated conditions, peak radiation caused the temperature of stationary male beetles to rise at about 6°C min-1 and females at almost 4°C min-1. However, in wind-calm conditions at peak radiation, the convection of simulated running dropped the equilibrium body temperature of live beetles by about 13°C. We believe that ours is the first report of exercise-induced cooling in a pedestrian animal and that O. plana's diurnal lifestyle depends on that exercise-induced cooling.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12401538/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144591394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"When size matters: energy allocation and thermogenic mechanisms in very small mammals, African pygmy mice.","authors":"Mélanie Boël, Léa Herpe, Claude Duchamp, Caroline Romestaing, François-Xavier Dechaume-Moncharmont, Loïc Teulier, Frédéric Veyrunes, Damien Roussel, Nicolas Pichaud, Yann Voituron","doi":"10.1242/jeb.250373","DOIUrl":"10.1242/jeb.250373","url":null,"abstract":"<p><p>Thermoregulation is a major challenge for extremely small mammals such as the African pygmy mice Mus mattheyi and Mus minutoides, weighing less than 12 g. A previous study showed that these tiny mice exhibit different mitochondrial energy efficiency for ATP synthesis, with a higher efficiency in M. mattheyi (∼6 g) than in M. minutoides (∼10 g). This result suggests a lower mitochondrial heat production at rest in M. mattheyi, despite its lower body surface and inevitably greater heat loss from its body surface, than in M. minutoides. Consequently, a compensatory thermoregulatory strategy should exist in M. mattheyi to maintain homeothermy. The present study aimed to assess whether M. mattheyi uses non-shivering thermogenesis in brown adipose tissue (BAT) and/or activity-thermoregulatory heat substitution. For this purpose, multidisciplinary approaches involving behavioral, physiological, biochemical and molecular analyses were used. Mus mattheyi showed higher daily mass-specific energy expenditure and food intake per unit mass and allocated more daily energy to vital function, spent less time moving in their cage during the daytime but exhibited higher non-locomotor activity and higher movement-related energy cost compared with M. minutoides. BAT of M. mattheyi was metabolically more active, exhibiting higher mitochondrial respiration rates and citrate synthase activity than in M. minutoides, but lower uncoupling protein 1 content. Altogether, these results suggest that the tiny M. mattheyi mainly uses non-exercise activity thermogenesis, increased cost of movement and, to a lesser extent, BAT non-shivering thermogenesis for remaining warm.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144690485","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":"Correction: Honeybee navigation en route to the goal: visual flight control and odometry.","authors":"M V Srinivasan, S W Zhang, M Lehrer, T S Collett","doi":"10.1242/jeb.251105","DOIUrl":"https://doi.org/10.1242/jeb.251105","url":null,"abstract":"","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 15","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144690487","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":"The thermal dependence of metabolism in three sea turtle species and the effects of activity.","authors":"Manfred R Enstipp, Virginie Plot, Stéphane Ciccione, Katia Ballorain, Jean-Yves Georges","doi":"10.1242/jeb.250844","DOIUrl":"10.1242/jeb.250844","url":null,"abstract":"<p><p>Temperature is of central importance to life and structures biological processes across levels of organization. For ectothermic marine turtles, temperature profoundly affects their metabolism, overall physiology, behaviour and distribution. Marine turtles are globally threatened and a detailed understanding of their energy requirements is essential to comprehend their role in marine ecosystems and to guide conservation efforts. We used flow-through respirometry to study the effects of seasonal changes in water temperature (Tw) on the resting oxygen consumption rates (V̇O2) of three sea turtle species (green, loggerhead and hawksbill turtles). Tw changes between winter and summer (maximum range: 20.3-31.9°C) had a clear effect on mass-specific V̇O2 (sV̇O2) that increased on average by ∼50% across species in summer. Hence, the thermal sensitivity of metabolism was similar in all species with Q10 values ranging between 2.1 and 2.7, typical for reptiles. Changes in sV̇O2 were paralleled by changes in respiratory frequency (fR) in all species. In separate trials with loggerhead turtles resting and swimming in a tank, we recorded body acceleration (PDBA) together with V̇O2 to investigate the effects of activity on metabolism and to establish a predictive equation that can be used to estimate turtle energy expenditure at sea from the recording of body acceleration. Moderate swimming activity increased sV̇O2 up to 3.2 times over resting. We found a significant positive relationship between sV̇O2 and PDBA (r2=0.63, P<0.0001) with small associated error estimates, indicating that body acceleration is a good predictor of V̇O2 in loggerhead turtles, similar to what has previously been reported for green turtles.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 15","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144682693","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":"Giovanni A. Cavagna (1934-2025).","authors":"Mario A Legramandi, Alberto E Minetti, Gaspare Pavei, Matteo M Pecchiari","doi":"10.1242/jeb.250986","DOIUrl":"https://doi.org/10.1242/jeb.250986","url":null,"abstract":"","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 15","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144873415","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":"Prenatal conditions do not affect brain physiology and learning in a lizard.","authors":"Pablo Recio, Dalton C Leibold, Ondi L Crino, Christopher R Friesen, Daniel W A Noble","doi":"10.1242/jeb.250716","DOIUrl":"10.1242/jeb.250716","url":null,"abstract":"<p><p>Early environmental factors such as heat or stress hormones can impair learning through brain metabolic function, which is crucial for neural development and synaptic plasticity. However, whether early environments always result in cognitive impairment through changes in neural physiology is not well established outside of a few model systems. Here, we investigated the effects of prenatal temperature and corticosterone (CORT) on brain mitochondrial activity and spatial learning in the delicate skink (Lampropholis delicata). We treated eggs with either CORT or a control vehicle and incubated at cold (23±3°C) or hot (28±3°C) temperatures. Juveniles were tested in a spatial learning task over 40 days after which mitochondrial function in the medial cortex was assessed. Despite among-individual variation in learning ability, mitochondrial physiology and spatial learning in L. delicata remained robust to prenatal temperature and CORT exposure. No significant relationship was found between mitochondrial function and cognitive performance, contrary to predictions. Increased metabolic capacity correlated with higher production of reactive oxygen species but did not affect oxidative damage, possibly as a result of protective mechanisms. These findings highlight the physiological and cognitive resilience of L. delicata to early-life challenges. Future research should explore whether this robustness extends to other brain regions, cognitive domains and life stages.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12401535/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144674946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prolonged fasting and glucocorticoid exposure drive dynamic DNA methylation in northern elephant seals.","authors":"Emily F Gibson, Julia María Torres-Velarde, David C Ensminger, Diana D Moreno-Santillán, Daniel E Crocker, José Pablo Vázquez-Medina","doi":"10.1242/jeb.250046","DOIUrl":"10.1242/jeb.250046","url":null,"abstract":"<p><p>Northern elephant seals experience prolonged fasting while breeding, molting and undergoing postnatal development. Fasting elephant seals adjust neuroendocrine function and gene expression to cope with potentially detrimental effects associated with extended fasting. DNA methylation alters gene expression by modulating accessibility to regions necessary to initiate transcription. The effect of fasting and glucocorticoids on DNA methylation in elephant seals is understudied. We evaluated whether fasting alters global blood DNA methylation, the potential correlation between increased glucocorticoids and methylation, and the effects of glucocorticoids on DNA methylation in cultured northern elephant seal muscle cells. We found that fasting transiently increases blood DNA methylation and that blood DNA methylation levels correlate with plasma cortisol. We then conducted bioinformatic analyses to identify regions in the northern elephant seal glucocorticoid receptor (GR) promoter that influence gene transcription through methylation (CpG islands). We identified one CpG island within the putative GR promoter. Methylation in this region, however, was unaffected by prolonged fasting. We then investigated whether exogenous glucocorticoids alter DNA methylation and gene expression profiles in seal muscle cells in primary culture (myotubes). Exposure to glucocorticoids for 12 or 48 h decreased DNA methylation while upregulating pro-survival gene expression in northern elephant seal muscle cells. Our results show that whereas prolonged fasting transiently increases DNA methylation in northern elephant seal blood, sustained exposure to exogenous glucocorticoids decreases DNA methylation and activates a pro-survival transcriptional program in seal muscle cells. Therefore, our results suggest that DNA methylation is a plastic, potentially cell type-specific response that regulates gene expression in fasting northern elephant seals.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12319411/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Behavioral recovery profiling of cockroaches stung by the venomous wasp Ampulex compressa.","authors":"Sena Borbor, Stefania Nordio, Frederic Libersat","doi":"10.1242/jeb.249768","DOIUrl":"10.1242/jeb.249768","url":null,"abstract":"<p><p>The parasitoid wasp Ampulex compressa injects venom into the brain of the American cockroach, targeting the central complex, a sensory-motor region. The venom induces grooming, followed by long-lasting hypokinesia. While grooming is attributed to dopamine in the venom, the mechanisms underlying hypokinesia remain unclear. Given the role of dopamine in modulating arousal and locomotion in insects, and our finding of long-term impairment in venom-induced grooming behavior, we hypothesized that the mechanisms behind long-term grooming impairments may provide insight into the mechanisms driving hypokinesia. We analyzed the recovery profile of venom-induced grooming in stung cockroaches and investigated dopamine receptor involvement through D1-like receptor agonist injections into the central complex. Our results reveal a deficient grooming response to a second sting 1 month after the first, and that this change is not caused by a lasting impairment of D1 receptor signaling but rather a complex interaction between venom components and the recovered brain.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12377806/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144560293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}