Journal of Experimental Biology最新文献_第7页

A review of the empirical evidence for costs of plasticity in ectothermic animals. 对变温动物可塑性成本的经验证据的回顾。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-09 DOI: 10.1242/jeb.249226

Alexander G Little, Frank Seebacher

{"title":"A review of the empirical evidence for costs of plasticity in ectothermic animals.","authors":"Alexander G Little, Frank Seebacher","doi":"10.1242/jeb.249226","DOIUrl":"10.1242/jeb.249226","url":null,"abstract":"Phenotypic plasticity can represent a vital adaptive response to environmental stressors, including those associated with climate change. Despite its evolutionary advantages, the expression of plasticity varies significantly within and among species, and is likely to be influenced by local environmental conditions. This variability in plasticity has important implications for evolutionary biology and conservation physiology. Theoretical models suggest that plasticity might incur intrinsic fitness costs, although the empirical evidence is inconsistent and there is ambiguity in the term 'cost of plasticity'. Here, we systematically review the literature to investigate the prevalence of costs associated with phenotypic plasticity in ectothermic animals. We categorized studies into those assessing 'costs of phenotype' (trade-offs between different plastic trait values) and 'costs of plasticity' (intrinsic costs of the capacity for plasticity). Importantly, the experimental designs required to detect costs of plasticity are inherently more complex and onerous than those required to detect costs of phenotype. Accordingly, our findings reveal a significant focus on costs of phenotype over costs of plasticity, with the former more frequently detecting costs. Contrary to theoretical expectations, our analysis suggests that costs of plasticity are neither universal nor widespread. This raises questions about the evolutionary dynamics of plasticity, particularly in stable environments. Our analysis underscores the need for precise terminology and methodology in researching costs of plasticity, to avoid conflating costs associated with plastic traits with costs more intrinsic to plasticity. Understanding these nuances is crucial for predicting how species might adapt to rapidly changing environments.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950005","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}

引用次数: 0

Behavior and biomechanics: flapping frequency during tandem and solo flights of cliff swallows. 行为和生物力学：崖燕串联和单独飞行时的拍击频率。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-02 DOI: 10.1242/jeb.249393

Sophia Chizhikova, Laura X Mendez, Tyson L Hedrick

引用次数: 0

Torque-angle relationships of human toe flexor muscles highlight their capacity for propulsion in gait. 人类脚趾屈肌的转矩-角度关系突显了它们在步态中的推进能力。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-10 DOI: 10.1242/jeb.249816

Samuel J Wisdish, Hannah M Rice, Dominic J Farris

{"title":"Torque-angle relationships of human toe flexor muscles highlight their capacity for propulsion in gait.","authors":"Samuel J Wisdish, Hannah M Rice, Dominic J Farris","doi":"10.1242/jeb.249816","DOIUrl":"10.1242/jeb.249816","url":null,"abstract":"Human proficiency for bipedal locomotion relies on the structure and function of our feet, including the interplay between active muscles and passive structures acting on the toes during the propulsive phase of gait. However, our understanding of the relative contributions of these different structures remains incomplete. We aimed to determine the distinct toe-flexion torque-angle relationships of the plantar intrinsic muscles (PIMs), extrinsic muscles and passive structures, therefore offering insight into their force-generating capabilities and importance for walking and running. Torque-angle data were twice collected from nine healthy individuals (6 males, 3 females; 28±5 years) using supramaximal transcutaneous electrical stimuli applied at two tibial nerve sites to distinguish between muscle-driven and passive toe-flexion torque about the metatarsophalangeal (MTP) joint. Innervating extrinsic muscles and PIMs concurrently produced peak torques (hallux=3.05±0.70 N m, MTP angle=48.0±13.6 deg; lesser digits=3.19±0.98 N m, MTP angle=42.6±13.4 deg) exceeding by 208% (hallux) and 150% (lesser digits), respectively, those from PIM stimulation alone. Notably, MTP joint angles pertinent to gait corresponded to the ascending limb of the active torque-angle relationship, with active muscle joint torques being the dominant contributor over passive torques. The latter finding suggests that human toe flexors are well adapted to generate the MTP joint torques that are necessary for walking and running. This further supports the notion that muscles acting within the foot play an important role in the foot's mechanical function and our ability to walk and run in an upright posture.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11744321/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142739495","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}

引用次数: 0

Frictional adhesion of geckos predicts maximum running performance in nature. 壁虎的摩擦粘附预示着在自然界中最大的运行性能。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-09 DOI: 10.1242/jeb.247906

Timothy E Higham

{"title":"Frictional adhesion of geckos predicts maximum running performance in nature.","authors":"Timothy E Higham","doi":"10.1242/jeb.247906","DOIUrl":"10.1242/jeb.247906","url":null,"abstract":"Despite the myriad studies examining the diversity and mechanisms of gecko adhesion in the lab, we have a poor understanding of how this translates to locomotion in nature. It has long been assumed that greater adhesive strength should translate to superior performance in nature. Using 13 individuals of Bradfield's Namib day gecko (Rhoptropus bradfieldi) in Namibia, I tested the hypothesis that maximum running performance in nature (speed and acceleration) is driven by maximum frictional adhesive strength. Specifically, those individuals with greater frictional adhesion should escape with faster speed and acceleration because of increased contact with the surface from which to apply propulsive forces. I tested this prediction by quantifying laboratory adhesive performance and then releasing the geckos into the field while simultaneously recording the escape using high-speed videography. Additional measurements included how this species modulates maximum running speed (stride length and/or stride frequency) and how temperature influences field performance. I found that maximum acceleration was significantly correlated with maximum frictional adhesive strength, whereas maximum sprinting speed was only correlated with increases in stride frequency (not stride length) and temperature. Thus, different measures of performance (acceleration and speed) are limited by very different variables. Acceleration is key for rapidly escaping predation and, given their correlation, maximum frictional adhesion likely plays a key role in fitness.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11744320/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950007","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}

引用次数: 0

Calcification in sea urchin larvae is associated with low metabolic costs. 海胆幼体的钙化与低代谢成本有关。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-13 DOI: 10.1242/jeb.248145

Marian Y Hu, Tina M Bassarab, William W J Chang, Smilla L Tetzlaff, Feli Strohbach, Sam Dupont, Meike Stumpp

{"title":"Calcification in sea urchin larvae is associated with low metabolic costs.","authors":"Marian Y Hu, Tina M Bassarab, William W J Chang, Smilla L Tetzlaff, Feli Strohbach, Sam Dupont, Meike Stumpp","doi":"10.1242/jeb.248145","DOIUrl":"10.1242/jeb.248145","url":null,"abstract":"The energetic costs of generating calcium carbonate skeletons and shells in marine organisms remain largely speculative because of the scarcity of empirical data. However, this information is critical for estimating energetic limitations of marine calcifiers that can explain their sensitivity to changes in sea water carbonate chemistry in past, present and future marine systems. Here, the cost of calcification was evaluated using larval stages of the purple sea urchin, Strongylocentrotus purpuratus. We developed a skeleton re-mineralization assay, in which the skeleton was dissolved in live larvae followed by a re-mineralization over a few days. During skeleton re-mineralization, energetic costs were estimated through the measurement of key metabolic parameters including whole-animal metabolic rate, citrate synthase (CS) enzyme activity and mRNA expression as well as mitochondrial density in the calcifying primary mesenchyme cells (PMCs). Minor increases in CS activity and a 10-15% increase in mitochondrial density in PMCs were observed in re-mineralizing larvae as compared with control larvae. Re-mineralization under three different pH conditions (pH 8.1, pH 7.6 and pH 7.1) decreased with decreasing pH, accompanied by pronounced increases in CS expression levels and increased mitochondrial density in PMCs at pH 7.6. Despite a prominent increase in mitochondrial density of primary mesenchyme cells, particularly in the calcifying cohort of this cell type, this work demonstrated a low overall metabolic response to increased mineralization rates at the whole-animal level under both high and low pH conditions. We conclude that calcification in sea urchin larvae is compromised under low pH conditions, associated with low energetic efforts to fuel compensatory processes.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142501704","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}

引用次数: 0

A microcontroller-based system for flexible oxygen control in laboratory experiments. 基于微控制器的实验室氧气柔性控制系统。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-07 DOI: 10.1242/jeb.249207

Stefan Mucha

引用次数: 0

Scaling of quantitative cardiomyocyte properties in the left ventricle of different mammalian species. 不同哺乳动物左心室心肌细胞特性的定量测量。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-10 DOI: 10.1242/jeb.249489

Tanja Kloock, David J Jörg, Christian Mühlfeld

{"title":"Scaling of quantitative cardiomyocyte properties in the left ventricle of different mammalian species.","authors":"Tanja Kloock, David J Jörg, Christian Mühlfeld","doi":"10.1242/jeb.249489","DOIUrl":"10.1242/jeb.249489","url":null,"abstract":"Small mammals have a higher heart rate and, relative to body mass (Mb), a higher metabolic rate than large mammals. In contrast, heart weight and stroke volume scale linearly with Mb. With mitochondria filling approximately 50% of a shrew cardiomyocyte - space unavailable for myofibrils - it is unclear how small mammals generate enough contractile force to pump blood into circulation. Here, we investigated whether the total number or volume of cardiomyocytes in the left ventricle compensates for allometry-related volume shifts of cardiac mitochondria and myofibrils. Through statistical analysis of data from 25 studies with 19 different mammalian species with Mb spanning seven orders of magnitude (2.2 g to 920 kg), we determined how number, volume density and total volume of cardiomyocytes, mitochondria and myofibrils in the left ventricle depend on Mb. We found that these biological variables follow scaling relationships and are proportional to a power b of Mb. The number [b=1.02 (95% CI: 0.89, 1.14); t-test for b=1: P=0.72] and volume [b=0.95 (95% CI: 0.89, 1.03); t-test for b=1: P=0.18] of cardiomyocytes in the left ventricle increases linearly with increasing Mb. In cardiomyocytes, volume density of mitochondria decreases [b=-0.056 (95% CI: -0.08, -0.04); t-test for b=0: P<0.0001] and that of myofibrils increases [b=0.024 (95%CI: 0.01, 0.04); t-test for b=0: P<0.01] with increasing Mb. Thus, the number or volume of left ventricular cardiomyocytes does not compensate for the higher heart rate and specific metabolic rate of small mammals although a higher mitochondrial and lower myofibrillar volume per cardiomyocyte are present.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11744323/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950010","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}

引用次数: 0

Residual force enhancement is not altered while force depression is amplified at the cellular level in old age. 老年时，残余力的增强没有改变，而力的抑制在细胞水平上被放大。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-13 DOI: 10.1242/jeb.248155

Binta S Njai, Avery Hinks, Makenna A Patterson, Geoffrey A Power

{"title":"Residual force enhancement is not altered while force depression is amplified at the cellular level in old age.","authors":"Binta S Njai, Avery Hinks, Makenna A Patterson, Geoffrey A Power","doi":"10.1242/jeb.248155","DOIUrl":"10.1242/jeb.248155","url":null,"abstract":"Residual force enhancement (rFE) and residual force depression (rFD) are history-dependent properties of muscle which refer to increased and decreased isometric force following a lengthening or shortening contraction, respectively. The history dependence of force is greater in older than in younger human adults when assessed at the joint level. However, it is unclear whether this amplification of the history dependence of force in old age is owing to cellular mechanisms or is a consequence of age-related remodelling of muscle architecture. Single muscle fibres from the psoas major of old and young F344BN rats were dissected and chemically permeabilized. Single muscle fibres were mounted between a force transducer and length controller, then maximally activated (pCa 4.5). To assess rFD, fibres were actively shortened from 3.1 to 2.5 µm at both a slow (0.15 Lo s-1) and fast (0.6 Lo s-1) speed, with a fixed-end isometric reference contraction at 2.5 µm. To assess rFE, fibres were activated and stretched at 0.3 Lo s-1 from a sarcomere length of 2.2 to 2.5 µm, and 2.7 to 3.0 µm, and compared with fixed-end isometric reference contractions at 2.5 and 3.0 µm, respectively. Isometric force (2.5 µm) was ∼19% lower in muscle fibres from old as compared with young rats (P<0.001). Upon normalizing to fibre cross-sectional area, there was no age-related difference in specific force (P>0.05). rFD was ∼33% greater in muscle fibres from old as compared with young rats (P<0.05), while rFE did not differ between groups (P>0.05). rFD is amplified in old age at the cellular level, while rFE appears to be unchanged; thus, previously reported age-related modification of rFE occurs upstream from the cellular level.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142837080","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}

引用次数: 0

Solar radiation alters heat balance and thermoregulation in a flying desert bee. 太阳辐射改变了沙漠蜜蜂的热平衡和体温调节。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-07 DOI: 10.1242/jeb.247335

Meredith G Johnson, Meghan Barrett, Jon F Harrison

{"title":"Solar radiation alters heat balance and thermoregulation in a flying desert bee.","authors":"Meredith G Johnson, Meghan Barrett, Jon F Harrison","doi":"10.1242/jeb.247335","DOIUrl":"10.1242/jeb.247335","url":null,"abstract":"Solar radiation is an important environmental variable for terrestrial animals, but its impact on the heat balance of large flying insects has been poorly studied. Desert bees are critical to ecosystem function through their pollination services, and are exposed to high radiant loads. We assessed the role of solar radiation in the heat balance of flying desert Centris pallida bees by calculating heat budgets for individuals in a respirometer in shaded versus sunny conditions from 16 to 37°C air temperatures, comparing the large and small male morphs and females. Solar radiation was responsible for 43 to 54% of mean total heat gain. Bees flying in the sun had thorax temperatures 1.7°C warmer than bees flying in the shade, storing a very small fraction of incident radiation in body tissues. In most cases, flight metabolic rate was not suppressed for bees flying in the sun, but evaporative water loss rates more than doubled. The most dramatic response to solar radiation was an increase in convection, mediated by a more than doubling of convective conductance, allowing thermoregulation while conserving body water. In large morph males and females, the increased convective conductance in the sun was mediated by increased heat transfer from the thorax to abdomen. Because convection is limited as body temperatures approach air temperatures, solar radiation combined with warming air temperatures may cause endothermic flying bees to reach a tipping point at which increases in non-sustainable evaporation are necessary for survival.","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818274","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}

引用次数: 0

The Company of Biologists: celebrating 100 years. 生物学家公司：庆祝100周年。

IF 2.8 2区生物学

Journal of Experimental Biology Pub Date : 2025-01-01 Epub Date: 2025-01-06 DOI: 10.1242/jeb.249955

Sarah J Bray, Stephen J Royle, Holly A Shiels, Daniel St Johnston

引用次数: 0