Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology最新文献

{"title":"Effect of acute intraperitoneal injection of methylglyoxal on organ injury and oxidative stress in chicks (Gallus gallus domestics)","authors":"Meiko Okino ,&nbsp;Ryosuke Makino ,&nbsp;Mana Aoki ,&nbsp;Tetsuya Tachibana","doi":"10.1016/j.cbpa.2026.111975","DOIUrl":"10.1016/j.cbpa.2026.111975","url":null,"abstract":"<div><div>Methylglyoxal (MGO) is an α-dicarbonyl compound and produced from several metabolic pathways, including glucose metabolism. This compound induces oxidative stress and organ damage in mammals and is associated with various diseases, including diabetes. Birds typically have higher blood-glucose levels than mammals, yet they rarely develop diabetic complications. This observation suggests that birds possess resistance to MGO, preventing the onset of diabetes-related issues. Nevertheless, the effects of MGO in birds remain poorly understood. In this study, the impact of high-dose MGO affect on organ injury and oxidative stress was investigated in chicks (<em>Gallus gallus</em>). Intraperitoneal injection of 400 mg/kg MGO resulted in decreased food intake at 6 and 24 h post-injection. However, plasma activities of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase—biomarkers for organ injury—were not elevated at both times. MGO did not increase plasma lipid peroxidation; instead, it enhanced total antioxidant capacity and uric acid concentration in the plasma at 6 h. In contrast, MGO increased lipid peroxidation in the liver and pectoralis major muscle at 6 h. Additionally, glutathione levels were reduced in these organs following exposure to MGO at 6 h. In summary, high doses of MGO induce oxidative stress in chicks, as seen in rodents, but may not lead to organ injury in avian models, at least acute injection.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"313 ","pages":"Article 111975"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vagal control of pulmonary peripheral circulation in the rattlesnake modulates relevant hemodynamic adjustments to temperature change","authors":"Samanta A. Castro ,&nbsp;Edwin W. Taylor ,&nbsp;Renato Filogonio ,&nbsp;Cléo A.C. Leite","doi":"10.1016/j.cbpa.2026.111972","DOIUrl":"10.1016/j.cbpa.2026.111972","url":null,"abstract":"<div><div>The vagal influence over large pulmonary arteries has been clearly demonstrated in Squamates. Additionally, diverse <em>in situ</em> experiments suggest that pulmonary circulation was either not responsive or much less responsive than the systemic circuit to known local, humoral, and nervous modulators. We suggest that the systemic alterations should be counterbalanced by pulmonary circuit modulation in awaken animals with a cardiac shunt, and the lack of pulmonary circuit responses is a collateral effect of the anesthesia used in <em>in situ</em> experiments. The use of a decerebrate experimental model allowed for diverse concomitant cardiovascular and respiratory measurements in two rattlesnake groups: left-vagotomized – LV (<em>i.e.</em> without vagal innervation of pulmonary arteries) and non-vagotomized (NV) at a range of body temperatures (T_b - 10, 20, and 30 °C). Aerobic metabolism increased proportionally to T_b. Unexpectedly, systemic conductance remained stable while the right-to-left shunt reduced. Therefore, inactive rattlesnakes change blood oxygenation rather than tissue perfusion to support alterations in aerobic demands. Peripheral pulmonary circulation was the main target of vascular modulatory adjustments following T_b change. Although LV snakes were unable to modulate pulmonary compliance, cardiac shunt was compensated as they reached the same O₂ uptake, which was attained by the modulation of the pulmonary conductance. This was the first time such modulation was recorded. Our findings also suggest the presence of bilateral vagal innervation of the unique rattlesnake lung, in which the left vagus innervates the proximal arteries, while the right vagus modulates functioning of the distal vasculature.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"313 ","pages":"Article 111972"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hematopoietic and immune homeostasis programs of the Polian vesicle after evisceration in Apostichopus japonicus","authors":"Qianwen Wu ,&nbsp;Wei Cui ,&nbsp;Chunxi Jiang ,&nbsp;Lina Sun ,&nbsp;Qiming Feng ,&nbsp;Fang Su","doi":"10.1016/j.cbpa.2025.111964","DOIUrl":"10.1016/j.cbpa.2025.111964","url":null,"abstract":"<div><div>Polian vesicles (PVs) are key components of the water vascular system in sea cucumbers, functioning in hematopoiesis and immune defense, and notably remaining as the sole organs within the coelomic cavity after evisceration. To elucidate how accessory water-vascular organs participate in visceral regeneration, we performed time-resolved transcriptome profiling of PVs collected at early post-evisceration stages (at 6 h, 1 day, 3 days, and 7 days post-evisceration) in <em>Apostichopus japonicus</em>. Our study reveals a highly dynamic and sequential regulatory process, characterized by an acute transcriptional response transitioning to stabilized remodeling. The number of differentially expressed genes (DEGs) peaked at the early stage (6 hpe) and subsequently declined. At 6 hpe, pathways for metabolic activation and DNA replication predominated. During 1–3 dpe, signals shifted to structural reconstruction and immune activation. By 7 dpe, modules linked to immune homeostasis and functional recovery. Notably, ECM remodeling and signal transduction were sustained. Network analysis highlighted key gene modules and hub genes driving each distinct regenerative stages. Collectively, our results position the PV as a dynamic regulatory hub that supports early visceral regeneration by coupling hematopoietic output with tissue-repair signaling.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"312 ","pages":"Article 111964"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145783727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of light wavelength on HPA axis function in non-human animals: A meta-analysis","authors":"Isabella Robertson-Dixon,&nbsp;Melanie J. Murphy,&nbsp;Nina Riddell","doi":"10.1016/j.cbpa.2025.111961","DOIUrl":"10.1016/j.cbpa.2025.111961","url":null,"abstract":"<div><div>The suprachiasmatic nucleus regulates circadian rhythms in physiological and behavioural processes partly through modulation of the hypothalamic–pituitary–adrenal (HPA) axis. The suprachiasmatic nucleus is entrained by light via input from intrinsically photosensitive retinal ganglion cells that are particularly sensitive to short wavelengths, theoretically linking light spectra to HPA axis function. This systematic review and meta-analysis evaluated the effects of wavelength of light on biochemical markers of the HPA axis in terrestrial non-human animals. A search of seven databases on 13 January 2025 identified 23 studies meeting inclusion criteria. Study subjects spanned a variety of animal species. Subjects were typically exposed to coloured light for the entire daytime light period for multiple weeks prior to HPA axis assessment. Corticosterone was the most frequently reported HPA axis measure. Melatonin, an additional hormonal index of circadian rhythms, was reported alongside corticosterone when data were available. Meta-analyses showed that in poultry, blue, blue-enriched, and red light rearing induced medium to large statistically non-significant increases in daytime corticosterone levels relative to white light, while green and UV-enriched light elicited weaker or inconsistent effects. In melatonin-proficient laboratory rodents, blue-enriched light induced a large significant decrease in daytime corticosterone and a large significant increase in nighttime melatonin. These findings highlight the importance of considering light wavelength for animal welfare and the optimisation of lighting conditions in research, agricultural, and ecological settings.</div><div><strong>Registration:</strong> osf.io/rvu4w.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"312 ","pages":"Article 111961"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145752406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the transcriptional mechanisms of yellowfin tuna (Thunnus albacares) juveniles in response to acute cold stress in brain and muscle tissues","authors":"Junhua Huang ,&nbsp;Zhengyi Fu ,&nbsp;Zhenhua Ma","doi":"10.1016/j.cbpa.2025.111962","DOIUrl":"10.1016/j.cbpa.2025.111962","url":null,"abstract":"<div><div>La Nina events caused by global climate change have amplified ocean temperature fluctuations, challenging aquaculture operations for species such as yellowfin tuna (<em>Thunnus albacares</em>), particularly under winter cooling conditions. To investigate the physiological responses of juvenile tuna, two experimental treatments low-temperature group (LT, 24 °C) and ultra-low-temperature group (ULT, 18 °C) were established and sampled at 0, 12, 24, and 36 h, alongside a 30 °C control group (CG). Transcriptomic analysis of the brain, red muscle, and white muscle revealed that, upon sensing low temperatures, the brain activated multiple immune, stress, and endocrine pathways, including TNF and Toll-like receptor signaling. In response to this activation, genes such as <em>hspa5</em>, <em>hsp90aa1.2</em>, <em>STAT1</em>, and <em>CXCR2</em> showed altered expression, indicating their involvement in downstream stress and immune regulatory processes. Cold-stress signals were then transmitted to the muscles, which adapted via key genes linked to energy metabolism (glycolysis, gluconeogenesis, fatty acid oxidation), protein folding (<em>HSPA1s</em>), and myofiber remodeling (<em>col6a2</em>, <em>PXN</em>). Notably, responses were more pronounced at 18 °C. Muscle contraction-related genes (<em>myl2b</em>, <em>myl13</em>) collaborated with signaling molecules (<em>SRC</em>, <em>PIK3CA_B_D</em>) to form a stress-response network ensuring efficient energy supply, fiber stability, and contractile function. Furthermore, muscle-derived metabolites and stress proteins are fed back to the brain, establishing a cross-tissue, bidirectional regulatory loop that preserves energy provision, immune defense, and muscle integrity under cold stress. These findings advance our understanding of the molecular responses in yellowfin tuna to low-temperature conditions, offering valuable guidance for improving cold tolerance and optimizing aquaculture and ecological adaptation strategies.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"312 ","pages":"Article 111962"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145783634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glycogen synthase 2 knock-out zebrafish exhibit enhanced glucose metabolism in the liver","authors":"Keita Sameshima ,&nbsp;Aya Yokose ,&nbsp;Rei Yanagida ,&nbsp;Yoshiki Sato ,&nbsp;Yuta Suzuki ,&nbsp;Makoto Kashima ,&nbsp;Mayu Inokuchi ,&nbsp;Otto Baba ,&nbsp;Tatsuki Yoshinaga ,&nbsp;Fumiya Furukawa","doi":"10.1016/j.cbpa.2025.111960","DOIUrl":"10.1016/j.cbpa.2025.111960","url":null,"abstract":"<div><div>The liver is one of the major organs for glycogen storage and is essential for maintaining glucose homeostasis in the whole body. Glycogen synthesis in liver is regulated by the rate-limiting enzyme, glycogen synthase 2 (Gys2). In fish, however, the detailed roles of glycogen and Gys2 are poorly understood. In this study, we generated, for the first time, <em>gys2</em> knock-out (<em>gys2</em> −/−) zebrafish and evaluated the effects of impaired glycogen synthesis on physiological parameters of this fish. No effects on development or maturation were observed in <em>gys2</em> −/− strain lacking Gys2. Periodic acid Schiff (PAS) staining, immunofluorescence staining with anti-glycogen antibody, and transmission electron microscopy (TEM) observations confirmed that glycogen synthesis does not occur in the <em>gys2</em> −/− liver. Liquid chromatography-mass spectrometry (LC-MS/MS) metabolite analysis and isotope tracing revealed a marked increase in the activity of glucose metabolism and levels of related metabolites in the livers of adult <em>gys2</em> −/−. Surprisingly, glucoamylase treatment released higher amount of glucose from <em>gys2</em> −/− liver extract than that of the wild-type (WT) counterpart, suggesting the existence of putative compensatory or abberant glucose polymer, which might be caused by the elevated glucose metabolism in the <em>gys2</em> −/− liver. Meanwhile, RNA-Seq analysis did not show increased expression levels of glucose metabolism–related genes consistent with the metabolic activity in <em>gys2</em> −/− liver. These results suggest that liver Gys2 is dispensable in zebrafish, and enhanced glucose metabolism and putative backup mechanism to accumulate extra glucose may support the fish lacking Gys2.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"312 ","pages":"Article 111960"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145758341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Offspring innate immunity varies with parental age in a long-lived seabird","authors":"Beatrice Berardi ,&nbsp;Gianluca Damiani ,&nbsp;Gábor Á. Czirják ,&nbsp;Silvia Filippi ,&nbsp;Giacomo Dell'Omo ,&nbsp;David Costantini","doi":"10.1016/j.cbpa.2025.111963","DOIUrl":"10.1016/j.cbpa.2025.111963","url":null,"abstract":"<div><div>Parental age at reproduction is increasingly recognized as a factor influencing offspring lifespan and other fitness-related traits, yet the underlying proximate physiological mechanisms remain poorly understood. Immune function and oxidative status are two potential mediators of age-related parental effects, as both are key hallmarks of ageing. However, very few studies have examined the relationship between parental age and offspring physiological condition in wild populations. We examined immunological and cellular mechanisms potentially responsible for parental age effects in the long-lived seabird Scopoli's shearwater (<em>Calonectris diomedea</em>). We measured 10 markers of immune function and oxidative status in 35 chicks from either younger or older parents at two different developmental phases: one month of age and at fledging. Chicks of younger parents exhibited higher haptoglobin levels at fledging compared to chicks of older parents. No effects of parental age were found on leukocyte profiles, humoral components of acquired immunity, antioxidant enzyme activity, or DNA damage in the offspring. Our results suggest, whilst chicks of younger parents might experience more stressful conditions, overall mechanisms supporting somatic maintenance might shield offsprings from the transgenerational transfer of molecular damage that parents accumulate with age. Our findings provide novel insights into the physiological bases of parental age effects in a long-lived species.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"312 ","pages":"Article 111963"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145783715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Captive Gut: the impacts of long-term captivity on the intestinal digestive enzyme activities of a marine herbivorous fish","authors":"Jordan E. Buckner ,&nbsp;Leyna Vo ,&nbsp;Michelle J. Herrera ,&nbsp;Karina Brocco French,&nbsp;Daniel R. Rankins,&nbsp;Jacqueline Vasquez,&nbsp;Asmita Pande,&nbsp;Kwasi M. Connor,&nbsp;Valentina I. Peña Gonzalez,&nbsp;Donovan P. German","doi":"10.1016/j.cbpa.2025.111965","DOIUrl":"10.1016/j.cbpa.2025.111965","url":null,"abstract":"<div><div>Given that digestion is largely a chemical process in fishes that do not masticate or triturate their food, digestive enzyme activities are frequently measured as indicators of what nutrients a fish can readily digest. Here, we explored what happens to digestive tract length and digestive enzyme activities in a marine herbivorous fish (<em>Xiphister mucosus</em>) fed in captivity for more than two years. Captivity is known to impact nearly all aspects of an animal's biology, but the gut microbiome has received more attention than digestive biochemistry in this regard. After consuming a prepared diet primarily composed of algae collected from the same site from which the fish were collected for over two years, the lab-fed fish showed a marked reduction in amylase, trypsin, and aminopeptidase activities in comparison to wild-caught fish. Moreover, the gradient of activity moving along the intestine (activities decreasing distally for amylase and trypsin, increasing for aminopeptidase) completely disappeared in the lab-fed fish. The relative gut length decreased by about 18 % in the lab-fed fish, suggesting that they ate less than their wild counterparts, which likely led to slower gut transit and more time for enzymes to interact with substrates. Hence, digestive enzyme activities were lower in the lab-fed fish. A formulated diet in the laboratory presents a different gut environment for the herbivorous <em>X. mucosus</em>, and perhaps feeding them a live algal diet would better replicate the wild-gut phenotype if this fish is to be held for lengthy periods of time for display or aquaculture purposes.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"312 ","pages":"Article 111965"},"PeriodicalIF":2.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145806480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal changes in Gpdh1 expression in Bombyx mori: its correlation with embryonic diapause initiation and maternal modulation via insulin and sugar metabolism","authors":"Shi-Hong Gu,&nbsp;Pei-Ling Lin","doi":"10.1016/j.cbpa.2025.111943","DOIUrl":"10.1016/j.cbpa.2025.111943","url":null,"abstract":"<div><div>Cytosolic NAD-dependent glycerol-3-phosphate dehydrogenases (GPDHs) catalyze the reduction of dihydroxyacetone phosphate (DHAP) to glycerol-3-phosphate using NADH, representing the first step in the glycerol biosynthesis pathway. While it is well established that the onset of egg diapause in <em>Bombyx mori</em> is accompanied by the rapid conversion of glycogen into sorbitol and glycerol, the regulation of <em>Gpdh1</em> gene expression during embryonic diapause remains less well understood. In the present study, we investigated changes in the expression levels of the <em>Gpdh1</em> gene. In diapause eggs, <em>Gpdh1</em> expression remained relatively high during the first three days after oviposition, then gradually declined. In contrast, HCl-treated developing eggs exhibited an abrupt decrease in <em>Gpdh1</em> expression upon treatment, followed by persistently low levels. Non-diapause eggs exhibited a similarly abrupt decrease as observed in HCl-treated eggs, indicating a correlation between the sharp decrease in <em>Gpdh1</em> expression and embryonic development. To further explore the potential mechanisms regulating <em>Gpdh1</em> expression, we analyzed the expression of several genes—including <em>Gpdh1</em>, insulin signaling (<em>bombyxin-A6</em> and <em>-Z1</em>), sugar transporters (<em>Tret1</em>, <em>St1</em>, <em>St3</em>, <em>St4</em>, and <em>St5</em>), and trehalases (<em>Treh1</em> and <em>Treh2</em>)—in the mother ovaries during the pupal stage of diapause- and non-diapause-destined silkworms. Our results showed that the expression of <em>Gpdh1</em>, <em>bombyxin-Z1</em>, <em>Tret1</em>, and <em>Treh2</em> genes in diapause-destined ovaries increased in a stage-dependent manner compared to non-diapause-destined ovaries. In contrast, diapause-destined mother ovaries exhibited significantly lower expression levels of <em>bombyxin-A6</em>, indicating reduced insulin signaling during the pupal stage. Our findings suggest that reduced insulin signaling, along with elevated expression of <em>Gpdh1</em>, <em>bombyxin-Z1</em>, <em>Tret1</em>, and <em>Treh2</em> genes may promote glycogen accumulation in the ovaries of diapause-destined mothers during the pupal stage. This accumulation could, in turn, lead to increased <em>Gpdh1</em> gene expression in diapause eggs laid by these mothers, thereby contributing to the initiation of diapause.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111943"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145330932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 tidally changing salinities on branchial tight junction protein gene expression in tilapia","authors":"G.H.T. Malintha ,&nbsp;Ke Cao ,&nbsp;Fritzie T. Celino-Brady ,&nbsp;Jason P. Breves ,&nbsp;Andre P. Seale","doi":"10.1016/j.cbpa.2025.111956","DOIUrl":"10.1016/j.cbpa.2025.111956","url":null,"abstract":"<div><div>To maintain hydromineral balance during transitions between different environmental salinities, euryhaline teleosts adjust the permeability characteristics of their surface epithelia to align with ambient conditions. Tight junctions (TJs), which form the apical-lateral barriers between epithelial cells, control the paracellular movement of solutes and water. Consequently, euryhaline species must efficiently reorganize branchial TJs when acclimating to freshwater (FW) and seawater (SW) environments. However, little is known about how TJs are regulated under tidally changing salinities. In the current study, we employed RNA-Seq to identify several branchial TJ transcripts that are differentially expressed in Mozambique tilapia (<em>Oreochromis mossambicus</em>) acclimated to FW, SW, or a tidal regime (TR). The most abundant and differentially expressed TJ transcripts, which included claudins (<em>cldn-4 like</em>, <em>cldn7b</em>, <em>cldn23a</em>, and <em>cldn-like ZF-A89</em>), occludins (<em>oclna</em> and <em>oclnb</em>), and TJ proteins (<em>tjp1a</em> and <em>tjp3</em>), were further investigated by qPCR. Generally, the expression of TJ transcripts varied to a greater extent between the FW and SW phases of the TR (denoted TF and TS, respectively) than between steady-state FW and SW conditions. Furthermore, TJ transcripts were usually upregulated in TF compared to TS or SW controls. In contrast, the gene expression of branchial ion transporters did not change as markedly under a TR. Together, these results suggest that TJs play a crucial role in regulating the permeability of branchial epithelia by preventing ion loss in hyposmotic conditions, particularly during short-term tidally changing salinities.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"311 ","pages":"Article 111956"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145607606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}