Frontiers in Zoology最新文献

{"title":"Response mechanism to heat and hypoxia stress in hard clam: insights from antioxidation and lipid metabolism.","authors":"Zhi Hu,Mei-Jie Yang,Xing-Hao Ma,Pu Shi,Tao Zhang,Hao Song","doi":"10.1186/s12983-026-00622-5","DOIUrl":"https://doi.org/10.1186/s12983-026-00622-5","url":null,"abstract":"BACKGROUNDThe hard clam (Mercenaria mercenaria) is native to the coast of the United States and Canada. Following its introduction to China, it has become an economically important bivalve species cultured in ponds. Extreme heat and hypoxia events severely impact the physiological status of marine organisms. Excess reactive oxygen species produced by environmental stress can lead to antioxidant stress response and lipid remodeling. Antioxidant stress response and lipid metabolism can reveal the response mechanism and adaptation ability of organisms to environmental changes.RESULTSIn the present study, coupled lipidomic and biochemical approaches were employed to reveal the response mechanism to heat and hypoxia stress at the antioxidant stress and lipid metabolism level in the hard clam. The antioxidant system was enhanced showing stress-specific to increase total antioxidant capacity (T-AOC) capacity and maintain relatively stable malondialdehyde (MDA) level. 913 lipid metabolites were identified by widely targeted lipidomic analysis. Glycerophospholipids (GP), glycerolipids (GL), and sphingolipids (SP) were the main differential expression lipid metabolites. Lipid remodeling of the gill tissue was mainly caused by GP, GL and SP metabolism in the hard clam.CONCLUSIONActivation of the antioxidant system which evidenced by elevated T-AOC, can alleviate oxidative damage, thereby preventing excessive accumulation of MDA under environmental stress. Concurrently, increased abundances of GP and SP metabolites drive remodeling of membrane lipids, which is critical for maintaining membrane fluidity and structural integrity during stress. Furthermore, the accumulation of GL metabolites functions as thermos-protectant. This study expands our understanding of hard clam responses to heat and hypoxia stress at the antioxidant and lipid metabolism level.","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"8 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148349113","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":"Elevational constraints and climatic buffering: comparison of Pierinae and Coliadinae across Taiwan Island and mainland China.","authors":"Riaz Hussain,Lianxi Xing,Yuan Hua","doi":"10.1186/s12983-026-00621-6","DOIUrl":"https://doi.org/10.1186/s12983-026-00621-6","url":null,"abstract":"Different elevational gradients and anthropogenic pressures between island and mainland systems mediate discrete climatic sensitivities and distribution trends in butterfly lineages. We assess the comparative distributional changes of Pieridae (Pierinae and Coliadinae) on Taiwan Island and mainland China. Across Taiwan Island, the geographic range of Pieridae is mainly limited to lowlands due to the sharp decline in temperature with rising elevation. In mainland China, both reduced temperature and low precipitation at upper elevations shape Pieridae's spatial pattern. Across Taiwan, both subfamilies showed positive associations with human disturbances at greater elevations, while Pierinae showed a positive relationship with thick vegetation cover at lower elevations. Throughout mainland China, Pieridae exhibited negative associations with human disturbances and vegetation density at higher elevations. According to the MaxEnt results, across Taiwan Island, elevation is mainly responsible (80.6%) for the distribution of Pierinae, while maximum temperature of warmest month (Bio5) is mainly influencing (53.7%) the distribution of Coliadinae. Initially Pierinae exhibited an increase in highly suitable regions across the three historical periods, followed by a decrease. Conversely, Coliadinae showed an initial contraction, followed by an expansion. Future global warming may result in a reduction of highly appropriate habitats for both subfamilies without significant evidence of upslope migration. Most Pieridae species are projected to undergo habitat contraction, resulting in decreased species diversity. These outcomes indicate stronger ecological constraints and higher vulnerability to Pieridae diversity in island systems, highlighting the necessity of implementing regional conservation strategies.","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"32 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148299208","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":"Endoreduplication underlies body size variation in monomorphic ants.","authors":"Mateusz Okrutniak, Olga Jabłońska, Alicja Frost, Grzegorz Nowak, Adam Świerczyński, Irena M Grześ","doi":"10.1186/s12983-026-00619-0","DOIUrl":"10.1186/s12983-026-00619-0","url":null,"abstract":"<p><strong>Background: </strong>In ants, morphological variation is particularly important, as it constitutes a key mechanism underlying the division of labor. Despite this, relatively few studies have addressed the proximate cellular mechanisms responsible for worker size variation. Endoreduplication represents a promising contributor to morphological diversity, as it is a process with a well-established cellular basis.</p><p><strong>Methods: </strong>In this study, we investigated whether endoreduplication can account for variation in body size in monomorphic ants, analogous to patterns previously reported in polymorphic species. We tested whether body size correlates with the level of endoreduplication in workers of three monomorphic ant species that differ in ecology, colony structure, and life-history traits. The analysis showed that individual worker size was positively correlated with nuclear DNA content (C-value), both in the overall linear mixed-effects model (LMM) and in species-specific analyses. As an additional finding, the C-value level exhibited body-part specificity, reaching the highest values in the abdomen.</p><p><strong>Conclusion: </strong>Our results demonstrate that endoreduplication contributes to body size variation not only in ants with distinct worker subcastes, but also in species with subtle size variability. This suggests that endoreduplication represents an evolutionarily ancient and potentially widespread mechanism, which may have served as a developmental foundation for the evolution of advanced polymorphism in ants.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13501564/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148260714","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":"Correlated evolution of core skin structures in freshwater fishes and challenges to epidermal club cells as the material basis of alarm responses.","authors":"Lu Li, Songtao Li, Haoyu Wang, Huan Xiong, Hongyan Wang, Haowen Wang, Zhijian Wang, Haoran Gu","doi":"10.1186/s12983-026-00618-1","DOIUrl":"10.1186/s12983-026-00618-1","url":null,"abstract":"<p><strong>Background: </strong>Correlated evolution refers to the coordinated changes of multiple traits during species evolution. Fish skin exhibits diverse structures comprising the epidermis, dermis, scales, epidermal mucous cells (EMCs), and epidermal club cells (ECCs), yet the correlated evolution among these components remains unexplored. ECCs are classically hypothesized to be the source of chemical alarm cues in ostariophysan fishes, which are passively released during predator-inflicted skin damage to alert nearby conspecifics of active predation threats, this process known as the alarm response. However, we identified two critical exceptions from 53 freshwater fishes: naked carp (Gymnocypris, ostariophysans) have lost ECCs, while mandarin fish (Siniperca, non-ostariophysans) have acquired them. The established link between ECCs and alarm responses in ostariophysans may be confounded by phylogeny. Their consistent co-occurrence does not establish a causal relationship. The two evolutionary exceptions serve as ideal models to test this relationship.</p><p><strong>Results: </strong>We investigated correlated evolution across seven core skin structures, including epidermal thickness, dermal thickness, scale thickness, EMCs size/number, ECCs size/number in 53 freshwater fishes. Analysis revealed significant correlated evolution among skin structures. Epidermal thickness showed positive correlations with all other metrics, except for the relationship between scale thickness and EMCs number. Scale thickness exhibited antagonistic correlations with both epidermal and dermal thickness. Notably, scale thickness positively correlated with EMCs number, reflecting functional adaptation to reduce inter-scale friction. Critically, behavioral experiments demonstrated that naked carp, despite lacking ECCs, exhibited robust alarm responses. Furthermore, we tested six close relatives of the naked carp, all of which possessed ECCs and exhibited robust alarm responses. Conversely, mandarin fish, despite possessing ECCs, showed no alarm responses. This evidence does not support ECCs as the necessary source of chemical alarm cues.</p><p><strong>Conclusions: </strong>In conclusion, our study demonstrates significant correlated evolution among core skin structures in freshwater fishes. Crucially, we challenge the prevailing paradigm by showing that chemical alarm cues can originate from integumentary components other than ECCs, evidenced by the robust alarm response in ECCs-lacking naked carp. Secondly, ECCs may play a multifunctional role evidenced by the absence of alarm response in ECCs-possessing mandarin fish. These insights advance our understanding of fish skin functional morphology and ecology.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13440240/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148254703","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":"In silico screening for safe and potent essential oils against mosquito neural targets.","authors":"Mohamed Nagy, Esraa Mansour, Hanaa Elbrense","doi":"10.1186/s12983-026-00620-7","DOIUrl":"10.1186/s12983-026-00620-7","url":null,"abstract":"<p><strong>Background: </strong>Mosquito-borne diseases remain a major global health challenge, highlighting the need for eco-friendly alternatives to conventional chemical insecticides. This study aimed to evaluate a tiered in silico screening framework to prioritize plant-derived essential oils as potential sustainable mosquito control agents.</p><p><strong>Results: </strong>A large-scale virtual screening of 5,183 essential oils was conducted, followed by toxicity-based filtering, yielding 1,345 low-toxicity candidates. Subsequent molecular docking against neural targets of Culex pipiens identified 51 top-priority oils. Among these, German chamomile (Matricaria chamomilla) consistently appeared across multiple chemotypes. The Egyptian German chamomile essential oil was selected for experimental validation. Chemical analysis revealed sesquiterpenes, particularly bisabolol oxide derivatives and β-farnesene, as major constituents. Docking results demonstrated strong binding affinities toward multiple neural targets. Larvicidal bioassays showed 100% mortality at 400 ppm after 24 h, accompanied by significant behavioral, morphological,and histopathological abnormalities. Neurochemical assays indicated increased acetylcholinesterase activity, alongside decreased γ-aminobutyric acid levels, suggesting disruption of neural signaling.</p><p><strong>Conclusions: </strong>This study demonstrates the effectiveness of in silico screening in identifying safe and potent plant-based mosquito control agents. German chamomile essential oil emerges as a promising eco-friendly candidate for sustainable vector management, warranting further field-based validation.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13285536/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148254710","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":"Reactive oxygen species drive wound epithelium and blastema formation in regenerating tail of Scincella tsinlingensis.","authors":"Yiwen Zhang, Jinyu Sun, Xinyue Wang, Yuwei Gao, Qing Li, Chun Yang","doi":"10.1186/s12983-026-00617-2","DOIUrl":"10.1186/s12983-026-00617-2","url":null,"abstract":"<p><p>Hydrogen peroxide (H₂O₂) is a crucial signaling molecule in vertebrate regeneration, yet its functional role across diverse lizard species remains incompletely defined. This study elucidates the master regulatory function of H₂O₂ during tail regeneration in the lizard Scincella tsinlingensis using integrated pharmacological, morphological, histological, and transcriptomic approaches. Pharmacological modulation revealed that H₂O₂ markedly enhances regeneration, achieving 5.89 ± 0.69 mm tail length at 21 days post-amputation (dpa), whereas ROS inhibition severely impairs regenerative outgrowth (0.88 ± 0.07 mm). Transcriptomic analysis at 7 dpa demonstrated that H₂O₂ establishes fundamentally distinct molecular trajectories, with only 5 common differentially expressed genes (DEGs) shared between the DMSO-vs-APO (713 DEGs) and DMSO-vs-H₂O₂ (593 DEGs) comparisons. Functionally, H₂O₂ synchronizes three core pathways-phagocytosis, immune regulation, and cellular motility-into an integrated repair program while temporally coordinating MAPK, mTOR, Wnt, and Hippo-YAP signaling cascades. This establishes a sequential regulatory framework where the immediate post-amputation period constitutes an H₂O₂-dependent critical window with limited plasticity, explaining the only partial rescue achieved with delayed intervention. Transcriptomic data further suggest inferred associations of NADPH oxidase 2/DUOXA2-derived H₂O₂ with cellular proliferation, YAP1 expression, potential EMT (via HIF-1α), as well as G2/M arrest and chromatin remodeling. These findings support the paradigm that ROS act as evolutionarily conserved, spatiotemporal integrators of tissue repair, coordinating injury response, immune modulation, metabolic reprogramming, and developmental pathway activation. This work provides a mechanistic foundation for developing redox-based therapies aimed at enhancing regeneration in clinical contexts of impaired healing.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13455431/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148151919","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":"Drivers and functional consequences of covering in a pervasive marine grazer (green sea urchin, Strongylocentrotus droebachiensis).","authors":"Chantelle R Clermont, Patrick Gagnon","doi":"10.1186/s12983-026-00616-3","DOIUrl":"10.1186/s12983-026-00616-3","url":null,"abstract":"<p><strong>Background: </strong>The circumpolar green sea urchin, Strongylocentrotus droebachiensis, exhibits a fascinating behaviour, termed \"covering\", which consists of coating the body with materials collected in the environment. The lack of a consensus about the drivers of covering in green sea urchin and their relative importance prevents accurate predictions about the frequency and intensity of the behaviour and its functional consequences in a globally changing ocean climate. We paired an experiment in an oscillatory wave tank with green sea urchins collected from an extensive sea urchin barren in southeastern Newfoundland (Canada), and a 3-mo survey of this barrens, to examine individual and interactive effects of wave action, light, sea urchin body size, and types of covering materials on sea urchin's displacement and covering.</p><p><strong>Results: </strong>Our findings establish that covering in S. droebachiensis is: (a) predominantly controlled by hydrodynamic forces, with the existence of water current-induced covering tipping points; (b) ontogenetically determined, with a continuous inclination to cover in small individuals and a seasonal component to covering in larger individuals; (c) opportunistic, with multiple types of covering materials employed based on availability; and (d) functionally costly, as it significantly reduces mobility. We largely rule out the paradigm that light induces covering or at least clearly marginalize it as a trigger or effector. Our results and those of other studies of the behavioural repertoire of S. droebachiensis, are consistent with the notion that covering serves a complementary function to mitigation of hydrodynamic forces.</p><p><strong>Conclusions: </strong>We propose that covering in S. droebachiensis primarily serves a mechanical protection function, whereby the species shields its body surface to protect its external sensory, defensive, and locomotory organs against physical contact with moving debris.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386655/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148058271","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":"Preparing for parenthood: molecular reprogramming precedes parenting in the burying beetle Nicrophorus vespilloides.","authors":"Julius Rombach, Heiko Vogel, Sandra Steiger, Volker Nehring","doi":"10.1186/s12983-026-00615-4","DOIUrl":"10.1186/s12983-026-00615-4","url":null,"abstract":"<p><strong>Background: </strong>Subsocial insects transition from solitary to social behavior during reproduction. They engage in cooperative and parental care activities that increase their offspring's survival. Elucidating the molecular mechanisms underlying such social transitions is crucial for understanding the genetic basis of social behavior. Burying beetles reproduce on a nutritious yet ephemeral resource. They provide intensive pre-hatching care by burying and preparing a vertebrate carcass, and post-hatching care by feeding the larvae.</p><p><strong>Results: </strong>We analyzed female gene expression during the transition from solitary life to brood care in the subsocial burying beetle Nicrophorus vespilloides. We collected RNA-seq data from the heads and fat bodies of beetles at four different time points: solitary life, early pre-hatching care, late pre-hatching care, and post-hatching care. The most pronounced shift in gene expression occurred during the initial onset of social behavior. Carcass discovery caused massive changes in the transcription of genes involved in metabolism, translation, and immunity. Changes in gene expression between the different brood care phases were comparatively modest: Females upregulated the expression of genes associated with social immunity as parental care intensified. During brood care, they gradually downregulated fecundity-related genes.</p><p><strong>Conclusions: </strong>The regulatory pattern indicates that carcass discovery triggers an increased metabolism to cope with the demands of brood care, alongside a reduced investment in body maintenance. The overall regulatory pattern indicates a strong investment into the current reproduction bout at the expense of future reproduction.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13188450/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147977321","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":"Geographic differentiation of ectoparasitic flatworms in the pelagic zone of Lake Tanganyika, Africa.","authors":"Nikol Kmentová, Kelly J M Thys, Christoph Hahn, Jiří Vorel, Lutz Bachmann, Stephan Koblmüller, Maarten Van Steenberge, Auguste Chocha Manda, Lawrence Makasa, Théophile Mulimbwa N'Sibula, Pascal Masilya Mulungula, Maarten P M Vanhove","doi":"10.1186/s12983-026-00602-9","DOIUrl":"10.1186/s12983-026-00602-9","url":null,"abstract":"<p><p>Monopisthocotylan parasites have been proposed as tags for studying host population structure due to their direct life cycles and short generation times. However, their effectiveness in reflecting host population connectivity remains under scrutiny. The poorly-understood connectivity of fisheries stocks in Lake Tanganyika, the second deepest lake in the world with a permanently stratified, relatively species-poor and well-delimited pelagic zone, serves as a case-study to test utility of parasites for fish stock identification. This study investigates the population structure of two Kapentagyrus species parasitizing dorosomatid fish in Lake Tanganyika, by analyzing variation in mitochondrial protein-coding genes across a geographic gradient. The study comprised 12 population genomic datasets from the central and southern subbasins of the lake sampled within the same week to account for host migration. We observed differences in geographic population structure of the two parasite species, with restricted gene flow in Kapentagyrus limnotrissae infecting a single dorosomatid species and smaller hosts preferring the littoral zone. Conversely, K. tanganicanus exhibited no geographical structure, reflecting its broader host range and preference for larger hosts preferring the pelagic zone. The results also highlight that other mitochondrial genes such as those from the dehydrogenase family or atp6 provide higher resolution for population genetic studies in these parasites than the frequently used cox1. The study also compared two sequencing strategies-individual versus pooled sequencing (PoolSeq)-for assessing population structure of monopisthocotylan parasites, and found that PoolSeq yielded similar results with lower demands on individual DNA quantity and sequencing costs. This work supports the use of host-specific, directly transmitted parasites as ecosystem tags and provides valuable insights into the role of host ecology and parasite life-history traits in shaping population dynamics.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"23 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13159304/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147876687","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":"Glycans in adhesion and fertilization: histochemical and ultrastructural insights from the chaetognath Spadella cephaloptera.","authors":"Cristian Camilo Barrera Grijalba, Sabine Thetter-Dürr, Julian Bibermair, Tim Wollesen","doi":"10.1186/s12983-026-00614-5","DOIUrl":"10.1186/s12983-026-00614-5","url":null,"abstract":"<p><strong>Background: </strong>To cope with the dynamic intertidal environment, some marine invertebrates have evolved carbohydrate-based adhesive mechanisms. Glycans are also involved in reproductive processes in protostomes, yet data about their distribution and function in chaetognaths are scarce. Among them, the benthic arrow worm Spadella cephaloptera can rapidly and temporarily attach to substrates, making it an interesting target for investigating the underlying glycobiology of its adhesion and reproductive systems. In this study, we characterized the distribution of different glycans in S. cephaloptera using histochemistry, immunofluorescence, lectin binding assays, and transmission electron microscopy, with a focus on the adhesive system during ontogeny.</p><p><strong>Results: </strong>Adhesive cells showed stage-specific distribution: in hatchlings, these cells form protrusions in the epidermis (papillae) and concentrate anteriorly, while in juveniles and adults, they group into multicellular adhesive cells forming clusters (compound papillae) in the posterior region. Ultrastructurally, the adhesive cells contain secretion granules enriched in fibrillar structures, and feature synaptic vesicles. Lectin binding revealed strong Peanut Agglutinin (PNA) affinity to the apical region of the cells, indicating the presence of Galβ1-3GalNAc moieties similar to other temporary adhesive systems. In addition, we detected acidic and sulfated mucosubstances in the sperm ducts, while a carboxylated jelly coat surrounds mature oocytes.</p><p><strong>Conclusions: </strong>Our findings suggest that the ontogenetic shift of adhesive cells from the anterior to the posterior body region is correlated with the alimentary and foraging behavior during the life cycle of S. cephaloptera. Evidence from lectin-assays, histological stainings, and ultrastructural analyses reveals the involvement of glycans in both reproductive and adhesive systems, with patterns suggesting functional conservation of mechanisms present in other marine invertebrates. The observed glycan moieties in the adhesive cells of S. cephaloptera indicate convergently evolved traits, such as the presence of neutral mucosubstances and PNA-binding glycans, as reported for other temporary adhesive systems in marine invertebrates. This work provides a framework for a molecular characterization of the reproductive and adhesive systems of the enigmatic chaetognaths.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13330366/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147864854","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}