Journal of Experimental Biology最新文献

{"title":"Beyond ecology: the importance of gut motility in predicting the responses of species to climate change.","authors":"Catharina Olsson, Albin Gräns, Jeroen Brijs","doi":"10.1242/jeb.249822","DOIUrl":"https://doi.org/10.1242/jeb.249822","url":null,"abstract":"<p><p>This Review explores the impact of environmental factors, with temperature as a starting point, on gut motility and digestive function in non-mammalian vertebrates, with a focus on species that are likely to be affected by climate change. Understanding gut physiology, particularly motility, is crucial in allowing us to predict how animals will respond to changing environmental conditions, as it plays a key role in nutrient absorption, immune defence and overall health. Rising temperatures and heatwaves pose significant challenges, especially for ectothermic species, the gut functions of which may be compromised under conditions outside their thermal tolerance. Here, we provide examples of how temperature-induced changes in gut motility affect gut transit time and digestive efficiency, and discuss their effects on the balance of energetic cost and gain. Although higher temperatures generally accelerate motility, further research is needed to assess how these changes impact digestion across species and under fluctuating environmental conditions. This Review emphasizes the need for integrated studies on motility patterns, digestive efficiency and energetic costs - along with the neural and cellular mechanisms controlling motility - to better predict the resilience of species in a warming world.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 14","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144560294","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":"An early-life perspective is needed to explain the impact of gut microbiota on wild vertebrate phenotypes.","authors":"Samantha S Fontaine, Brian K Trevelline","doi":"10.1242/jeb.250130","DOIUrl":"10.1242/jeb.250130","url":null,"abstract":"<p><p>Vertebrates house dense and diverse communities of microorganisms in their gastrointestinal tracts. These communities shape host physiological and ecological phenotypes in diverse ways, with implications for animal fitness in nature. Exposure to microbes during the earliest stages of life is particularly important because, during critical developmental windows, the microbiome is exceptionally plastic and interactions with microbes can have long-lasting physiological impacts on the host. Despite our understanding that early-life microbial interactions are important to host function broadly, the majority of research in this area has been performed in human or model organisms that are not representative of animals in the wild. Specifically, most gut microbiome studies in wildlife are cross-sectional and compare microbial communities across life stages using different individuals, as opposed to tracking the microbial communities and phenotypes of the same individuals from early to later life. This knowledge gap may hinder wildlife microbiome research, as the current model lacks an early-life perspective that can contextualize host phenotypic and fitness differences observed between animals at later life stages. Further, considering early-life microbial dynamics may offer insights to applied research, such as determining the optimal age to manipulate microbiomes for desired conservation outcomes. In this Commentary, we consider current understanding of the importance of early-life host-microbe interactions to vertebrate physiology across the lifespan, discuss why this perspective is necessary in wildlife studies, and provide practical recommendations for experimental designs that can address these questions, including field and laboratory approaches.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 14","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144540462","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":"A second look at the stomach - a fishy perspective.","authors":"Patrícia G Ferreira, L Filipe C Castro, Jonathan M Wilson","doi":"10.1242/jeb.250054","DOIUrl":"10.1242/jeb.250054","url":null,"abstract":"<p><p>Despite the established evolutionary importance of stomach acidification in vertebrates, the exact contribution of this process to overall protein digestion, nutrient absorption, growth, energy metabolism and development has not been fully elucidated and is oftentimes subject to extensive scientific debate. This Commentary sets out to frame the current state of our understanding, highlighting unresolved issues and proposing where experimental approaches can be applied to address these questions. Furthermore, we explore in depth the tantalizing evolutionary and physiological puzzle of repeated loss of gastric function in fishes. In this way, we hope to help clarify the role of the gastric proton pump and stomach acidification in digestion, metabolism and growth in vertebrates.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 14","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528165","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":"Extracellular and intracellular digestion in bivalves, studied by magnetic resonance imaging with a contrast reagent.","authors":"Eriko Seo, Yoshiteru Seo","doi":"10.1242/jeb.249932","DOIUrl":"10.1242/jeb.249932","url":null,"abstract":"<p><p>We investigated extracellular and intracellular digestion in bivalves, employing magnetic resonance imaging (MRI). Ruditapes philippinarum clams and Mytilus galloprovincialis mussels were incubated in seawater containing a contrast reagent [gadolinium-diethylenetriamine pentaacetic acid (GdDTPA)] at 20°C. The digestive systems, from the esophagus to the rectum, were visualized at a high signal intensity by the T1-weighted MRI. The crystalline style of the clam was also identified, which turned counterclockwise when viewed from a ventral-posterior position at a rate of 16 revolutions min-1. Determined using the T1 relaxation rate, the uptake and excretion rates of the GdDTPA in the mussel's digestive glands were 2.9 and 0.25 day-1, respectively, indicating that intracellular digestion in the gland acinar cells is slower than extracellular digestion. These results demonstrate that MRI with contrast reagents is useful to study the activity of the digestive system in bivalves, and that this technique could be applied to study other invertebrates.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143047019","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":"Accounting for the role of the gastro-intestinal tract in the ammonia and urea nitrogen dynamics of freshwater rainbow trout on long-term satiation feeding.","authors":"Chris M Wood, Junho Eom","doi":"10.1242/jeb.249654","DOIUrl":"10.1242/jeb.249654","url":null,"abstract":"<p><p>The contribution of the gut to the ingestion, production, absorption and excretion of the extra ammonia and urea nitrogen (urea-N) associated with feeding ('exogenous' fraction) has received limited attention. Analysis of commercial pellet food revealed appreciable concentrations of ammonia and urea-N. Long-term satiation feeding increased whole-trout ammonia and urea-N excretion rates by 2.5-fold above fasting levels. Blood was sampled from the dorsal aorta, posterior, mid- and anterior sub-intestinal veins, as well as the hepatic portal vein in situ. Ammonia, urea-N and fluid flux rates were measured in vitro using novel gut sac preparations filled with native chyme. The sacs maintained the extreme physico-chemical conditions of the lumen seen in vivo. Overall, these results confirmed our hypothesis that the stomach, and anterior intestine and pyloric caecae regions play important roles in ammonia and urea-N production and/or absorption. There was a very high rate of urea-N production in the anterior intestine and pyloric caecae, whereas the posterior intestine dominated for ammonia synthesis. The stomach was the major site of ammonia absorption, and the anterior intestine and pyloric caecae region dominated for urea-N absorption. Model calculations indicated that over 50% of the exogenous ammonia and urea-N excretion associated with satiation feeding was produced in the anaerobic gut. This challenges standard metabolic theory used in fuel-use calculations. The novel gut sac preparations gained fluid during incubation, especially in the anterior intestine and pyloric caecae, owing to marked hyperosmolality in the chyme. Thus, satiation feeding with commercial pellets is beneficial to the water balance of freshwater trout.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143006503","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":"Dynamic reciprocal morphological changes in insect hosts and bacterial symbionts.","authors":"Anthony D Junker, Jason Z Chen, James G DuBose, Nicole M Gerardo","doi":"10.1242/jeb.249474","DOIUrl":"10.1242/jeb.249474","url":null,"abstract":"<p><p>Symbiotic interactions, central to most life on Earth, are interwoven associations that vary in intimacy and duration. Some of the most well-known examples of symbioses occur between animals and gut bacteria. These associations lead to physiological integration of host and symbionts. The diversity of microbes within animal hosts can make studying them technically challenging. Thus, most science heavily focuses on the animal side of symbioses, limiting study of the microbial symbionts to characterization of their genetic and functional diversity. These limitations are minimized in Heteropteran insects that have specialized midguts that separately house single symbiont species away from ingested food. These insect-bacteria associations allow us to address fundamental questions regarding how both hosts and symbionts change to establish a cooperative relationship. In this study, through ex vivo and in vivo observations of cellular behaviors, we explore concurrent structural and cellular dynamics in both the squash bug host (Anasa tristis) and its Caballeronia zhejiangensis symbionts during the initiation of symbiosis. We elucidate how C. zhejiangensis is sequestered within a specialized symbiotic organ within the A. tristis midgut, how the symbiont uses active motility to reach the symbiotic organ, how symbionts colonize host crypts within the organ and how host crypt morphogenesis progresses during the initiation of symbiotic interactions. Our findings provide insight into how dynamic cellular activity and morphological development reciprocally change in both host and symbiont as they establish symbiotic interactions.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11993259/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065655","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":"Gut microbial contributions to thermogenesis.","authors":"Alexis Kazen, Justin L Grobe, John R Kirby","doi":"10.1242/jeb.249791","DOIUrl":"https://doi.org/10.1242/jeb.249791","url":null,"abstract":"<p><p>The role of the gut microbiota in influencing physiological processes has become increasingly evident over the past several decades. One such process, thermogenesis, has become a topic of interest in recent years owing to the threat of climate change as well as the ongoing obesity epidemic. Here, we offer an overview of current knowledge regarding the contributions of the gut microbiota to thermogenesis in ecological and biomedical contexts. We first describe how the metabolic and behavioral changes associated with the gut microbiota can lead to changes in energy balance, allowing animals to adapt to environmental stressors. We then discuss how changes in the gut microbial community composition, such as through antibiotic use, can lead to dysfunctional thermoregulation and, ultimately, disease states. Finally, we consider how microbes can be exploited to improve energy balance and propose some future directions worthy of additional study.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 14","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608566","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":"Multigenerational exposure to glyphosate has only modest effects on life-history traits, stress tolerance and microbiome in a field cricket.","authors":"J W Whitlock, P M Orwin, Z R Stahlschmidt","doi":"10.1242/jeb.250210","DOIUrl":"10.1242/jeb.250210","url":null,"abstract":"<p><p>Glyphosate is the most used herbicide worldwide, and it can be toxic to off-target species, such as insects. Although GLY-based herbicides (GBHs) can influence insect microbiomes, little is known about its cascading effects on fitness-related traits, such as life history or stress tolerance, especially in the context of long-term, multigenerational exposure. Thus, we exposed the variable field cricket, Gryllus lineaticeps, to GBH within and across generations to examine the potential role of GBH in developmental plasticity and evolution. Specifically, we measured its effects on life-history traits (e.g. developmental duration, adult body size and mass, and a life-history trade-off between investment into reproduction and flight), stress (heat and desiccation) tolerance and the gut microbiome. One generation of exposure to GBH reduced desiccation tolerance, which was also lower in flight-capable individuals. However, after 11 generations of exposure to GBH, this cost of GBH disappeared, and GBH exposure instead increased adult body size and mass in flight-incapable individuals. Flight capacity had a stronger effect on the gut bacterial community than GBH exposure, where flight-capable individuals contained more than twice as many Family Oscillospiraceae and fewer than half as many Family Erysipelotrichaceae. The effects of both flight capacity and GBH on the microbiome were only evident in generation 1. Together, our results indicate that GBH exposure may have quite modest long-term effects on stress tolerance and the gut microbiome. However, GBH may facilitate the evolution of flightlessness given its potential benefits to flight-incapable individuals, which exhibit greater reproductive potential and tolerance to climate stressors compared with flight-capable individuals.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143670042","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":"Diet-dependent production of calcium- and phosphorus-rich 'spheroids' along the intestine of Burmese pythons: identification of a new cell type?","authors":"Jehan-Hervé Lignot, Robert K Pope, Stephen M Secor","doi":"10.1242/jeb.249620","DOIUrl":"10.1242/jeb.249620","url":null,"abstract":"<p><p>Burmese pythons, Python molurus bivittatus, digest the skeleton of their prey; this must result in a high amount of calcium and phosphorus passing through the intestinal lining. To determine how Burmese pythons can process this ion influx, the effects of different nutritional diets were examined in juveniles reared in captivity using three different diets: a normal diet with calcium and phosphorus provided from entire rodents; a low-calcium and phosphorus diet using rodents with no bones ('boneless prey'); and a calcium-rich diet composed of boneless rodents supplemented with calcium carbonate (CaCO3) through intraperitoneal injections inside the prey. The effect of these diets was analysed along the intestinal mucosa using light and electron microscopy techniques (Alizarin Red S and peroxidase staining, EDX analysis). Blood calcium and hormone levels [parathyroid hormone (PTH) and calcitonin] were also analysed from fasting pythons and snakes repeatedly fed with either a normal prey diet or a low-calcium and -phosphorus diet (boneless rats). The results revealed the presence of specialised cells in the intestinal epithelium that are involved in the production of calcium and phosphorus particles in fed snakes. These cells have an apical crypt possessing a multi-layered particle made of calcium, phosphorus and iron-rich nucleation elements in the centre. In fasting snakes, this cell type has empty crypts. When snakes are fed with boneless prey, particles are not produced by this cell type, although iron elements are located within the crypts. When calcium supplements are added to a boneless meal, large particles fill the crypts. When snakes are fed repeatedly with a low-calcium diet, blood calcium level drops while levels of calcitonin, and particularly of those of PTH, increase. Therefore, Burmese pythons possess a specialised intestinal cell type involved in excreting excess dissolved calcium and phosphorus that originate from the prey and are precipitated as particles that must accumulate in the faeces. This cell type is also found in other snake species that eat vertebrates (some Boidae and a colubrid) along with a lizard, the Gila monster, Heloderma suspectum. A broader analysis among vertebrates that ingest their prey whole and dissolve the prey skeleton would allow a thorough evolutionary analysis.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143995652","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":"Bridging digestive physiology and ecology for a more integrative understanding of invertebrate predators.","authors":"Shawn M Wilder, Colton Herzog, Jamie Reeves, Olivia Knowles, Jordan P Cuff","doi":"10.1242/jeb.249697","DOIUrl":"https://doi.org/10.1242/jeb.249697","url":null,"abstract":"<p><p>Nutritional ecology aims to explore the connections between the behaviour, physiology and ecology of organisms using nutrients as the unifying currency. Although significant progress has been made in studying the nutritional ecology of vertebrates and herbivorous invertebrates, research on predatory invertebrates has lagged, despite their importance in driving ecosystem processes and services, such as nutrient cycling and pest management. However, recent methodological and conceptual advances have provided significant opportunities to explore the interface of digestive physiology and ecology in predatory invertebrates. The goal of this Commentary is to explore evidence for interactions between the ecology and physiology of invertebrate predators, and to propose hypotheses and directions for future studies to expand our understanding in this area. Connections between invertebrate predator ecology and digestive physiology are discussed in relation to four pertinent topics that allow for integrative studies of invertebrate predators: micronutrients, foraging behaviour, microbial symbiosis and the Anthropocene. We hope that these areas of research will serve as examples of how physiology and ecology can be integrated for a more holistic understanding of the nutritional ecology of predatory invertebrates.</p>","PeriodicalId":15786,"journal":{"name":"Journal of Experimental Biology","volume":"228 14","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144608565","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}