The more than 35 described biogenic polyamines have important roles in physiological processes ranging from acid-base buffering to the scavenging of oxygen free radicals. As such they have key cellular- and organismal-level functions in environmental adaptation, cell growth, cell differentiation, fertilization, and biomineralization. To determine cellular polyamine distribution profiles in animals at the base of the phylogenetic tree, the acid-extracted polyamines from cultured cells of a unicellular choanoflagellate and whole bodies of five multicellular invertebrate groups (total 20 species) were quantitatively analyzed using high-performance liquid chromatography and high-performance gas chromatography. Both the choanoflagellate and hydra contained putrescine and spermidine. Diaminopropane, putrescine, cadaverine, norspermidine, spermidine, homospermidine, norspermine, spermine, thermospermine and agmatine were commonly identified among the other invertebrates. In unusual/rare polyamines, aminopropylhomospermidine, homospermine, caldopentamine and homopentamine were found in sponges; aminopropylhomospermidine and canavalmine in the comb jelly; canavalmine, aminopropylcanavalmine and homopyropentamine in jellyfishes; and canavalmine and homopyropentamine in sea anemones. However, long-chain polyamines were not found in soft corals.
{"title":"Polyamine distributions in invertebrates VI: Comparative cellular polyamine analysis of unicellular choanoflagellates and multicellular sponges, comb jellies, hydras, jellyfishes, sea anemones and soft corals","authors":"Koei Hamana , Hidenori Hayashi , Takemitsu Furuchi , Masaru Niitsu","doi":"10.1016/j.cbpb.2025.111141","DOIUrl":"10.1016/j.cbpb.2025.111141","url":null,"abstract":"<div><div>The more than 35 described biogenic polyamines have important roles in physiological processes ranging from acid-base buffering to the scavenging of oxygen free radicals. As such they have key cellular- and organismal-level functions in environmental adaptation, cell growth, cell differentiation, fertilization, and biomineralization. To determine cellular polyamine distribution profiles in animals at the base of the phylogenetic tree, the acid-extracted polyamines from cultured cells of a unicellular choanoflagellate and whole bodies of five multicellular invertebrate groups (total 20 species) were quantitatively analyzed using high-performance liquid chromatography and high-performance gas chromatography. Both the choanoflagellate and hydra contained putrescine and spermidine. Diaminopropane, putrescine, cadaverine, norspermidine, spermidine, homospermidine, norspermine, spermine, thermospermine and agmatine were commonly identified among the other invertebrates. In unusual/rare polyamines, aminopropylhomospermidine, homospermine, caldopentamine and homopentamine were found in sponges; aminopropylhomospermidine and canavalmine in the comb jelly; canavalmine, aminopropylcanavalmine and homopyropentamine in jellyfishes; and canavalmine and homopyropentamine in sea anemones. However, long-chain polyamines were not found in soft corals.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"280 ","pages":"Article 111141"},"PeriodicalIF":1.8,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144796201","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}
Pub Date : 2025-07-23DOI: 10.1016/j.cbpb.2025.111138
Andrea C. Murillo-Cisneros , Ramón Gaxiola-Robles , Claudia J. Camacho-Hernández , Martha Reyes-Becerril , Orlando Lugo-Lugo , Tania Zenteno-Savín
Developing immortalized cell lines could significantly accelerate studies on marine mammal adaptations to breath-hold diving, ischemia/reperfusion cycles and oxidative stress. In this study, skeletal muscle-derived cells from California sea lions (Zalophus californianus) were transfected with simian virus 40 large T antigen (SV40 LT), a viral oncoprotein known to inactivate cell cycle regulators such as p53 and retinoblastoma (pRB). Although transfection and puromycin selection were successful, transfected cells exhibited morphological abnormalities and reduced viability, suggesting altered cellular proliferation pathways. Significantly higher superoxide dismutase (SOD) and glutathione S-transferase (GST) activities (2- and 6.1-fold, respectively), higher protein oxidative damage (3.9-fold), and lower catalase (CAT) activity (6.9-fold) were observed in transfected cells relative to control (untransfected) cells. These findings suggest that peroxide (H₂O₂) accumulation, likely triggered by genotoxic stress, disrupted cellular proliferation and/or cell death pathways in SV40 LT-transfected skeletal muscle-derived cells from California sea lions. Future studies should consider co-transfection with human telomerase reverse transcriptase (hTERT) and the use of lentiviral delivery systems to enhance transfection efficiency, reduce genotoxic effects, and improve culture stability. This study highlights current challenges and offers potential solutions for generating immortalized marine mammal cell lines.
{"title":"Transfection with SV40 LT promotes oxidative damage in primary cultures of California sea lion muscle cells","authors":"Andrea C. Murillo-Cisneros , Ramón Gaxiola-Robles , Claudia J. Camacho-Hernández , Martha Reyes-Becerril , Orlando Lugo-Lugo , Tania Zenteno-Savín","doi":"10.1016/j.cbpb.2025.111138","DOIUrl":"10.1016/j.cbpb.2025.111138","url":null,"abstract":"<div><div>Developing immortalized cell lines could significantly accelerate studies on marine mammal adaptations to breath-hold diving, ischemia/reperfusion cycles and oxidative stress. In this study, skeletal muscle-derived cells from California sea lions (<em>Zalophus californianus</em>) were transfected with simian virus 40 large T antigen (SV40 LT), a viral oncoprotein known to inactivate cell cycle regulators such as p53 and retinoblastoma (pRB). Although transfection and puromycin selection were successful, transfected cells exhibited morphological abnormalities and reduced viability, suggesting altered cellular proliferation pathways. Significantly higher superoxide dismutase (SOD) and glutathione S-transferase (GST) activities (2- and 6.1-fold, respectively), higher protein oxidative damage (3.9-fold), and lower catalase (CAT) activity (6.9-fold) were observed in transfected cells relative to control (untransfected) cells. These findings suggest that peroxide (H₂O₂) accumulation, likely triggered by genotoxic stress, disrupted cellular proliferation and/or cell death pathways in SV40 LT-transfected skeletal muscle-derived cells from California sea lions. Future studies should consider co-transfection with human telomerase reverse transcriptase (hTERT) and the use of lentiviral delivery systems to enhance transfection efficiency, reduce genotoxic effects, and improve culture stability. This study highlights current challenges and offers potential solutions for generating immortalized marine mammal cell lines.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"280 ","pages":"Article 111138"},"PeriodicalIF":1.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702695","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}
This study investigated the behavioral and physiological responses of the freshwater prawn Macrobrachium rosenbergii in relation to fighting activity, aiming to elucidate how energy metabolism varies across locomotory organs under different combat durations. Based on observed fighting times, individuals were divided into control (no fighting), short-duration (16.67 ± 8.22 min), and long-duration (38.33 ± 9.65 min) groups. The movement frequency of the second pereiopods, pleopods, and uropods, along with energy substrates and metabolic enzyme activities in these appendages and abdominal muscles, was analyzed. Results showed that the second pereiopods exhibited the most pronounced increase in beating frequency during prolonged fighting, followed by pleopods and uropods, reflecting their hierarchical involvement in locomotion and aggression. Glycogen content decreased significantly with fighting duration, with the greatest depletion observed in the second pereiopods (up to 36.78 %), compared to moderate decreases in pleopods and abdominal muscles. This indicates a dominant metabolic burden on primary combat appendages. Long-duration fighting induced significant increases in lactate levels, as well as hexokinase (HK) and lactate dehydrogenase (LDH) activities in the second pereiopods and abdominal muscles, suggesting a shift toward anaerobic metabolism. In contrast, short-duration fighting was characterized by elevated malate dehydrogenase (MDH) and cytochrome c oxidase (COX) activities in the second pereiopods and pleopods, reflecting reliance on aerobic pathways. These results demonstrate that M. rosenbergii adopts organ-specific metabolic strategies during aggression. This mechanistic insight lays the groundwork for future aquaculture applications involving behavioral conditioning, dietary interventions, and selective breeding to reduce energy loss and improve animal welfare in intensive farming systems.
{"title":"Metabolic biochemistry of the fighting limbs and muscles of the freshwater prawn, Macrobrachium rosenbergii, reflects agonistic behavior","authors":"Jiangtao Li, Zheng Xiao, Kexuan Zhang, Zhongjie You, Licheng Zeng, Li Lin, Xiaojing Lv","doi":"10.1016/j.cbpb.2025.111137","DOIUrl":"10.1016/j.cbpb.2025.111137","url":null,"abstract":"<div><div>This study investigated the behavioral and physiological responses of the freshwater prawn <em>Macrobrachium rosenbergii</em> in relation to fighting activity, aiming to elucidate how energy metabolism varies across locomotory organs under different combat durations. Based on observed fighting times, individuals were divided into control (no fighting), short-duration (16.67 ± 8.22 min), and long-duration (38.33 ± 9.65 min) groups. The movement frequency of the second pereiopods, pleopods, and uropods, along with energy substrates and metabolic enzyme activities in these appendages and abdominal muscles, was analyzed. Results showed that the second pereiopods exhibited the most pronounced increase in beating frequency during prolonged fighting, followed by pleopods and uropods, reflecting their hierarchical involvement in locomotion and aggression. Glycogen content decreased significantly with fighting duration, with the greatest depletion observed in the second pereiopods (up to 36.78 %), compared to moderate decreases in pleopods and abdominal muscles. This indicates a dominant metabolic burden on primary combat appendages. Long-duration fighting induced significant increases in lactate levels, as well as hexokinase (HK) and lactate dehydrogenase (LDH) activities in the second pereiopods and abdominal muscles, suggesting a shift toward anaerobic metabolism. In contrast, short-duration fighting was characterized by elevated malate dehydrogenase (MDH) and cytochrome <em>c</em> oxidase (COX) activities in the second pereiopods and pleopods, reflecting reliance on aerobic pathways. These results demonstrate that <em>M. rosenbergii</em> adopts organ-specific metabolic strategies during aggression. This mechanistic insight lays the groundwork for future aquaculture applications involving behavioral conditioning, dietary interventions, and selective breeding to reduce energy loss and improve animal welfare in intensive farming systems.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"280 ","pages":"Article 111137"},"PeriodicalIF":1.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711308","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}
The identification of myostatin (mstn) gene functions in salmonids has been complicated by two whole-gene duplications (WGDs), leading to the presence of up to four mstn genes in their genomes, as opposed to the one or two copies found in other vertebrates. In this research, we molecularly cloned and characterized four mstn genes—Sl-mstna1, Sl-mstna2, Sl-mstnb1, and Sl-mstnb2—in the Black Sea trout (Salmo labrax). We propose that Sl-mstnb2 is a pseudogene due to a nonfunctionalization event, while Sl-mstna1, Sl-mstna2, and Sl-mstnb1 are retained in the Salmo labrax genome due to subfunctionalization. Notably, the expression level of the Sl-mstna1 and Sl-mstna2 genes varied across different tissues, implying divergent regulatory mechanisms. Starvation and high temperature increased mRNA expression of Sl-mstna1 and Sl-mstna2, while Sl-mstnb1 transcription was decreased by both stress factors. The tissue-specific transcription and modulation of Sl-mstnb1 were distinctly different from those of the Sl-mstna duplicates, suggesting functional divergence between the Sl-mstna and Sl-mstnb1 genes.
{"title":"Characterization of myostatin genes in Black Sea trout, Salmo labrax, and their differential responses to high temperature and starvation stressors","authors":"Burcu Naz Uzun , Mehtap Bayır , Eyüp Çakmak , Gökhan Arslan , Wenjing Tao , Serpil Turhan , Selma Saoula , Hakan Özkan , Abdulkadir Bayır","doi":"10.1016/j.cbpb.2025.111136","DOIUrl":"10.1016/j.cbpb.2025.111136","url":null,"abstract":"<div><div>The identification of myostatin (<em>mstn</em>) gene functions in salmonids has been complicated by two whole-gene duplications (WGDs), leading to the presence of up to four <em>mstn</em> genes in their genomes, as opposed to the one or two copies found in other vertebrates. In this research, we molecularly cloned and characterized four <em>mstn</em> genes—<em>Sl-mstna1</em>, <em>Sl-mstna2</em>, <em>Sl-mstnb1</em>, and <em>Sl-mstnb2</em>—in the Black Sea trout (<em>Salmo labrax</em>). We propose that <em>Sl-mstnb2</em> is a pseudogene due to a nonfunctionalization event, while <em>Sl-mstna1</em>, <em>Sl-mstna2</em>, and <em>Sl-mstnb1</em> are retained in the <em>Salmo labrax</em> genome due to subfunctionalization. Notably, the expression level of the <em>Sl-mstna1</em> and <em>Sl-mstna2</em> genes varied across different tissues, implying divergent regulatory mechanisms. Starvation and high temperature increased mRNA expression of <em>Sl-mstna1</em> and <em>Sl-mstna2</em>, while <em>Sl-mstnb1</em> transcription was decreased by both stress factors. The tissue-specific transcription and modulation of <em>Sl-mstnb1</em> were distinctly different from those of the <em>Sl-mstna</em> duplicates, suggesting functional divergence between the <em>Sl-mstna</em> and <em>Sl-mstnb1</em> genes.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"280 ","pages":"Article 111136"},"PeriodicalIF":1.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686088","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}
Pub Date : 2025-07-19DOI: 10.1016/j.cbpb.2025.111129
Francisco A. Leone , Leonardo M. Fabri , Samuel C. Faria , Cintya M. Moraes , Luana G.L. Antonio , Daniel L. Farias , Daniela P. Garçon
Mangrove ecosystems are tidal wetlands with anaerobic, salt-saturated soils that support diverse fauna. Despite intensive studies on the osmoregulatory mechanisms of decapods inhabiting distinct osmotic niches, there is little information on the kinetic characteristics of the gill (Na+, K+)-ATPase of decapod crustaceans inhabiting mangroves. Here, we provide a comprehensive kinetic characterization of the K-phosphatase activity of the gill (Na+, K+)-ATPase in two semi-terrestrial brachyuran crabs, Goniopsis cruentata and Cardisoma guanhumi, which respectively inhabit intermittently flooded lower zones and drier upper zones along the vertical gradient of mangrove environments. This study revealed distinct kinetic profiles between the two species. Goniopsis cruentata shows twice as much K-phosphatase activity and a 3-fold greater affinity for p-nitrophenyl phosphate than Cardisoma guanhumi. Substrate hydrolysis by the Goniopsis cruentata enzyme follows cooperative kinetics, whereas Cardisoma guanhumi displays typical Michaelis-Menten behavior. In both species, stimulation by K+ ions shows cooperative kinetics. Notably, Cardisoma guanhumi also exhibits 25% higher K-phosphatase activity when both K+ and NH₄+ are present. However, whether these differences arise from phylogenetic divergence or reflect physiological adaptation to different mangrove microhabitats remains unresolved. Given the paucity of kinetic studies on (Na+, K+)-ATPase in semi-/terrestrial crabs, our data contribute novel insights into the enzymatic basis of ion transport in decapods inhabiting variable salinity environments.
{"title":"Functional modulation of gill (Na+, K+)-ATPase K-phosphatase activity in mangrove crabs with different degrees of terrestriality","authors":"Francisco A. Leone , Leonardo M. Fabri , Samuel C. Faria , Cintya M. Moraes , Luana G.L. Antonio , Daniel L. Farias , Daniela P. Garçon","doi":"10.1016/j.cbpb.2025.111129","DOIUrl":"10.1016/j.cbpb.2025.111129","url":null,"abstract":"<div><div>Mangrove ecosystems are tidal wetlands with anaerobic, salt-saturated soils that support diverse fauna. Despite intensive studies on the osmoregulatory mechanisms of decapods inhabiting distinct osmotic niches, there is little information on the kinetic characteristics of the gill (Na<sup>+</sup>, K<sup>+</sup>)-ATPase of decapod crustaceans inhabiting mangroves. Here, we provide a comprehensive kinetic characterization of the K-phosphatase activity of the gill (Na<sup>+</sup>, K<sup>+</sup>)-ATPase in two semi-terrestrial brachyuran crabs, <em>Goniopsis cruentata</em> and <em>Cardisoma guanhumi,</em> which respectively inhabit intermittently flooded lower zones and drier upper zones along the vertical gradient of mangrove environments. This study revealed distinct kinetic profiles between the two species. <em>Goniopsis cruentata</em> shows twice as much K-phosphatase activity and a 3-fold greater affinity for <em>p</em>-nitrophenyl phosphate than <em>Cardisoma guanhumi.</em> Substrate hydrolysis by the <em>Goniopsis cruentata</em> enzyme follows cooperative kinetics, whereas <em>Cardisoma guanhumi</em> displays typical Michaelis-Menten behavior. In both species, stimulation by K<sup>+</sup> ions shows cooperative kinetics. Notably, <em>Cardisoma guanhumi</em> also exhibits 25% higher K-phosphatase activity when both K<sup>+</sup> and NH₄<sup>+</sup> are present<em>.</em> However, whether these differences arise from phylogenetic divergence or reflect physiological adaptation to different mangrove microhabitats remains unresolved. Given the paucity of kinetic studies on (Na<sup>+</sup>, K<sup>+</sup>)-ATPase in semi-/terrestrial crabs, our data contribute novel insights into the enzymatic basis of ion transport in decapods inhabiting variable salinity environments.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"280 ","pages":"Article 111129"},"PeriodicalIF":1.9,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144683628","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}
Pub Date : 2025-07-10DOI: 10.1016/j.cbpb.2025.111128
Xiang Li , Ning Kong , Wentong Hao , Lixin Feng , Lingling Wang , Linsheng Song
Metallothioneins (MTs) are a family of small, metal-binding proteins that play a pivotal role in metal storage and detoxification. The Pacific oyster Crassostrea gigas is known for its exceptionally high zinc content, and investigating the role of MTs in oyster zinc metabolism will help elucidate the mechanisms underlying its zinc accumulation. In this study, a MT homolog CgMTIII was cloned from C. gigas to investigate its function in zinc binding and accumulation. The transcripts of CgMTIII were distributed in all examined oyster tissues including gill, mantle, adductor muscle, hepatopancreas, gonad, labial palp and haemocytes, with the highest expression in the gill and the lowest in the haemocytes. Immobilized metal ion affinity chromatography (IMAC) demonstrated that the recombinant CgMTIII protein exhibited high retention on the zinc-charged column, confirming its zinc-binding activity. Overexpression of CgMTIII in HEK293T cells led to a 2.34-fold increase in intracellular zinc content after 24 h of exposure to 100 μM zinc, compared to the control group. Moreover, knockdown of CgMTIII through RNA interference resulted in a 24% reduction in zinc content in the gill tissue of oysters. Collectively, CgMTIII exhibited zinc-binding activity and contributed significantly to zinc accumulation in C. gigas. These findings deepen our understanding of the zinc-enrichment mechanism in oysters and provide a theoretical foundation for breeding high‑zinc oyster varieties.
{"title":"Metallothionein CgMTIII is involved in zinc binding and accumulation in the Pacific oyster Crassostrea gigas","authors":"Xiang Li , Ning Kong , Wentong Hao , Lixin Feng , Lingling Wang , Linsheng Song","doi":"10.1016/j.cbpb.2025.111128","DOIUrl":"10.1016/j.cbpb.2025.111128","url":null,"abstract":"<div><div>Metallothioneins (MTs) are a family of small, metal-binding proteins that play a pivotal role in metal storage and detoxification. The Pacific oyster <em>Crassostrea gigas</em> is known for its exceptionally high zinc content, and investigating the role of MTs in oyster zinc metabolism will help elucidate the mechanisms underlying its zinc accumulation. In this study, a MT homolog <em>Cg</em>MTIII was cloned from <em>C. gigas</em> to investigate its function in zinc binding and accumulation. The transcripts of <em>Cg</em>MTIII were distributed in all examined oyster tissues including gill, mantle, adductor muscle, hepatopancreas, gonad, labial palp and haemocytes, with the highest expression in the gill and the lowest in the haemocytes. Immobilized metal ion affinity chromatography (IMAC) demonstrated that the recombinant <em>Cg</em>MTIII protein exhibited high retention on the zinc-charged column, confirming its zinc-binding activity. Overexpression of <em>Cg</em>MTIII in HEK293T cells led to a 2.34-fold increase in intracellular zinc content after 24 h of exposure to 100 μM zinc, compared to the control group. Moreover, knockdown of <em>Cg</em>MTIII through RNA interference resulted in a 24% reduction in zinc content in the gill tissue of oysters. Collectively, <em>Cg</em>MTIII exhibited zinc-binding activity and contributed significantly to zinc accumulation in <em>C. gigas</em>. These findings deepen our understanding of the zinc-enrichment mechanism in oysters and provide a theoretical foundation for breeding high‑zinc oyster varieties.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"279 ","pages":"Article 111128"},"PeriodicalIF":1.9,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144621214","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}
Pub Date : 2025-07-09DOI: 10.1016/j.cbpb.2025.111122
Sana Gavarikar, Paul M. Craig
In their natural environments, fish are exposed to diel thermal fluctuations, the range of which is expected to increase dramatically with climate change. Recently, it has been posited that epigenetic modulators like microRNAs (miRNAs) could buffer fish against such changes. To investigate this, we conducted two sequential experiments using zebrafish (Danio rerio). In Experiment 1, we exposed zebrafish to constant control (CTRL; 28°C), fluctuating (FLUX; 28±5°C), or elevated (HEAT; 33°C) temperatures throughout early development (embryo to juvenile, up to 30 days post-fertilization [dpf]). Throughout early development, we assessed survival, metabolism, and the expression of seven thermosensitive miRNAs and three heat shock proteins (HSPs). While HEAT conditions significantly reduced survival, FLUX exposure did not. Both FLUX and HEAT juveniles exhibited metabolic compensation, though this was more pronounced in FLUX fish. Notably, miR-181a-5p, which regulates mitochondrial biogenesis and respiration, was significantly upregulated in FLUX juveniles, suggesting its involvement in improving metabolic performance. Experiment 2 evaluated the long-term effects of ontogenetic thermal variability. Starting at 30 dpf, remaining fish in both CTRL and FLUX treatments were maintained under CTRL conditions until adulthood. We then assessed miRNA expression in the brain and thermal tolerance (CTmax). miR-181a-5p remained elevated in the brains of adult fish with FLUX developmental histories, though CTmax was unaffected. Together, these findings suggest that early-life exposure to diel thermal fluctuations induces lasting epigenetic changes, potentially optimizing metabolic performance in the short-term at the cost of reduced capacity for further thermal tolerance and stress recovery later in life.
{"title":"Developmental exposure to constant elevated temperatures and diel thermal variation alters microRNA expression and performance in zebrafish (Danio rerio).","authors":"Sana Gavarikar, Paul M. Craig","doi":"10.1016/j.cbpb.2025.111122","DOIUrl":"10.1016/j.cbpb.2025.111122","url":null,"abstract":"<div><div>In their natural environments, fish are exposed to diel thermal fluctuations, the range of which is expected to increase dramatically with climate change. Recently, it has been posited that epigenetic modulators like microRNAs (miRNAs) could buffer fish against such changes. To investigate this, we conducted two sequential experiments using zebrafish (<em>Danio rerio</em>). In Experiment 1, we exposed zebrafish to constant control (CTRL; 28°C), fluctuating (FLUX; 28±5°C), or elevated (HEAT; 33°C) temperatures throughout early development (embryo to juvenile, up to 30 days post-fertilization [dpf]). Throughout early development, we assessed survival, metabolism, and the expression of seven thermosensitive miRNAs and three heat shock proteins (HSPs). While HEAT conditions significantly reduced survival, FLUX exposure did not. Both FLUX and HEAT juveniles exhibited metabolic compensation, though this was more pronounced in FLUX fish. Notably, miR-181a-5p, which regulates mitochondrial biogenesis and respiration, was significantly upregulated in FLUX juveniles, suggesting its involvement in improving metabolic performance. Experiment 2 evaluated the long-term effects of ontogenetic thermal variability. Starting at 30 dpf, remaining fish in both CTRL and FLUX treatments were maintained under CTRL conditions until adulthood. We then assessed miRNA expression in the brain and thermal tolerance (CT<sub>max</sub>). miR-181a-5p remained elevated in the brains of adult fish with FLUX developmental histories, though CT<sub>max</sub> was unaffected. Together, these findings suggest that early-life exposure to diel thermal fluctuations induces lasting epigenetic changes, potentially optimizing metabolic performance in the short-term at the cost of reduced capacity for further thermal tolerance and stress recovery later in life.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"279 ","pages":"Article 111122"},"PeriodicalIF":1.9,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144621213","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}
Pub Date : 2025-07-09DOI: 10.1016/j.cbpb.2025.111125
Weifeng Zhang , Tiancheng Chen , Yazhuo Hu , Xuejia Li , Xizhi Shi , Yongbo Bao
The Escherichia coli expression system, combined with site-directed mutagenesis, is a powerful tool for investigating the structure-function relationship of hemoglobin (Hb). However, producing biologically active recombinant hemoglobin (rHb) from invertebrates, especially in multimeric forms, remains difficult. Here, we describe the recombinant expression, purification, and characterization of homodimeric rHbI and heterotetrameric rHbII from the blood clam Tegillarca granosa. Optimization of expression conditions demonstrated that high yields (65.4–135.6 g/L) of soluble T. granosa rHbs could be achieved using the JM109(DE3) strain with 15 °C induction, 0.25 mM isopropyl β-D-thiogalactoside (IPTG) levels, and codon optimization. Circular dichroism and ultraviolet-visible spectroscopy verified that purified rHbs exhibited a secondary structure similar to that of native Hbs (nHbs) and preserved their diverse ligand-binding capacities. Oxygen-binding assays further showed that the oxygen affinity of rHbs was comparable to that of nHbs. Nitrite reduction assays revealed that T. granosa nHbs exhibited weak nitrite reductase activity (0.049–0.116 M−1 s−1 at 25 °C), generally lower than that of vertebrate globins. However, rHbs, particularly rHbI, displayed substantially higher reduction rate constants (0.147–4.589 M−1 s−1 at 25 °C) than nHbs, possibly due to differences in structural conformation or the N-terminal tag carried by rHbs. Overall, the recombinant expression and purification method established in this study provides a valuable framework for future research on the structure-function relationships of T. granosa Hb and invertebrate Hbs more broadly.
{"title":"Soluble expression and functional characterization of multi-subunit hemoglobins from the blood clam, Tegillarca granosa","authors":"Weifeng Zhang , Tiancheng Chen , Yazhuo Hu , Xuejia Li , Xizhi Shi , Yongbo Bao","doi":"10.1016/j.cbpb.2025.111125","DOIUrl":"10.1016/j.cbpb.2025.111125","url":null,"abstract":"<div><div>The <em>Escherichia coli</em> expression system, combined with site-directed mutagenesis, is a powerful tool for investigating the structure-function relationship of hemoglobin (Hb). However, producing biologically active recombinant hemoglobin (rHb) from invertebrates, especially in multimeric forms, remains difficult. Here, we describe the recombinant expression, purification, and characterization of homodimeric rHbI and heterotetrameric rHbII from the blood clam <em>Tegillarca granosa</em>. Optimization of expression conditions demonstrated that high yields (65.4–135.6 g/L) of soluble <em>T. granosa</em> rHbs could be achieved using the JM109(DE3) strain with 15 °C induction, 0.25 mM isopropyl β-D-thiogalactoside (IPTG) levels, and codon optimization. Circular dichroism and ultraviolet-visible spectroscopy verified that purified rHbs exhibited a secondary structure similar to that of native Hbs (nHbs) and preserved their diverse ligand-binding capacities. Oxygen-binding assays further showed that the oxygen affinity of rHbs was comparable to that of nHbs. Nitrite reduction assays revealed that <em>T. granosa</em> nHbs exhibited weak nitrite reductase activity (0.049–0.116 M<sup>−1</sup> s<sup>−1</sup> at 25 °C), generally lower than that of vertebrate globins. However, rHbs, particularly rHbI, displayed substantially higher reduction rate constants (0.147–4.589 M<sup>−1</sup> s<sup>−1</sup> at 25 °C) than nHbs, possibly due to differences in structural conformation or the N-terminal tag carried by rHbs. Overall, the recombinant expression and purification method established in this study provides a valuable framework for future research on the structure-function relationships of <em>T. granosa</em> Hb and invertebrate Hbs more broadly.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"279 ","pages":"Article 111125"},"PeriodicalIF":1.9,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144605745","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}
Pub Date : 2025-07-09DOI: 10.1016/j.cbpb.2025.111126
Rosilane Gomes de Souza Oliveira , Iraní Silva de Morais , Rômulo Veiga Paixão , Izabel Correa Bandeira , Wallice Luiz Paxiúba Duncan , Fernanda Loureiro de Almeida O'Sullivan
In tambaqui (Colossoma macropomum), a rheophilic Amazonian fish of significant aquaculture importance that typically fails to spawn under captive conditions, gonadorelin has demonstrated potential in inducing ovulation and enabling strip spawning. However, the molecular mechanisms underlying gonadorelin action, particularly on the transcriptional regulation of follicle-stimulating hormone (fshβ) and luteinizing hormone (lhβ), remain poorly understood and warrant further investigation. The present study aimed to investigate the efficacy of this synthetic drug in modulating the expression of gonadotropins and in enhancing circulating concentrations of 17β-estradiol (E2), 17α-hydroxyprogesterone (17α-OHP), and testosterone (T) in tambaqui; as well as its effects on the developmental dynamics and maturation stages of ovarian follicles. Gonadorelin at 60 μg kg−1 body weight had no statistical effect on lhβ expression, but decreased fshβ expression in females (p = 0.021). E2, 17α-OHP and T increased in all treated fish. In the treated group, the appearance of post-ovulatory complexes and the presence of eggs in the coelomic cavity indicated that 6 of 9 (67 %) of the females ovulated, while none of the control group did. The findings indicate that gonadorelin suppresses fshβ transcription in mature female tambaqui, and this downregulation may promote final oocyte maturation and ovulation by favoring a hormonal environment with increased progesterone influence. Hence, our data provides the first detailed analysis of the effects of a drug on tambaqui gonadotropins and sex steroids and sets a foundation for refining dose strategies to improve large-scale controlled breeding practices in tambaqui aquaculture.
{"title":"Effects of gonadorelin on gonadotropin expression, plasma sex steroid concentrations and ovarian follicle dynamics in mature tambaqui (Colossoma macropomum)","authors":"Rosilane Gomes de Souza Oliveira , Iraní Silva de Morais , Rômulo Veiga Paixão , Izabel Correa Bandeira , Wallice Luiz Paxiúba Duncan , Fernanda Loureiro de Almeida O'Sullivan","doi":"10.1016/j.cbpb.2025.111126","DOIUrl":"10.1016/j.cbpb.2025.111126","url":null,"abstract":"<div><div>In tambaqui (<em>Colossoma macropomum</em>), a rheophilic Amazonian fish of significant aquaculture importance that typically fails to spawn under captive conditions, gonadorelin has demonstrated potential in inducing ovulation and enabling strip spawning. However, the molecular mechanisms underlying gonadorelin action, particularly on the transcriptional regulation of follicle-stimulating hormone (<em>fshβ</em>) and luteinizing hormone (<em>lhβ</em>), remain poorly understood and warrant further investigation. The present study aimed to investigate the efficacy of this synthetic drug in modulating the expression of gonadotropins and in enhancing circulating concentrations of 17β-estradiol (E2), 17α-hydroxyprogesterone (17α-OHP), and testosterone (T) in tambaqui; as well as its effects on the developmental dynamics and maturation stages of ovarian follicles. Gonadorelin at 60 μg kg<sup>−1</sup> body weight had no statistical effect on <em>lhβ</em> expression, but decreased <em>fshβ</em> expression in females (<em>p</em> = 0.021). E<sub>2</sub>, 17α-OHP and T increased in all treated fish. In the treated group, the appearance of post-ovulatory complexes and the presence of eggs in the coelomic cavity indicated that 6 of 9 (67 %) of the females ovulated, while none of the control group did. The findings indicate that gonadorelin suppresses <em>fshβ</em> transcription in mature female tambaqui, and this downregulation may promote final oocyte maturation and ovulation by favoring a hormonal environment with increased progesterone influence. Hence, our data provides the first detailed analysis of the effects of a drug on tambaqui gonadotropins and sex steroids and sets a foundation for refining dose strategies to improve large-scale controlled breeding practices in tambaqui aquaculture.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"279 ","pages":"Article 111126"},"PeriodicalIF":1.9,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596748","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}
Pub Date : 2025-07-07DOI: 10.1016/j.cbpb.2025.111127
Nguyen Vu Linh , Luu Tang Phuc Khang , Nguyen Dinh-Hung , Suwanna Wisetkaeo , Phatthanaphong Therdtatha , Papungkorn Sangsawad , Supreya Wannavijit , Jakree Jitjumnong , Patima Permpoonpattana , Hien Van Doan
Corn silk is a promising aquafeed additive due to its antioxidant, antibacterial, and anti-inflammatory properties. This study evaluated the impact of graded dietary levels of powdered corn silk (PCS) on growth, immunity, antioxidant enzyme activities, histology, gut microbiota composition, gene expression profiles, and sensitivity to acute ammonia exposure in koi carp (Cyprinus carpio var. koi). A total of 300 fish were assigned to five dietary treatments (0, 5, 10, 20, and 30 g/kg PCS) for eight weeks. Fish fed the PCS-30 diet showed significant improvements in growth parameters, including weight gain (WG) and specific growth rate (SGR) (p < 0.05). Antioxidant capacity (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid); ABTS) and superoxide dismutase (SOD) activity, increased dose-dependently, while malondialdehyde (MDA) levels remained unchanged (p > 0.05). Expression of the immune and antioxidant genes interleukin 8 (il-8), lysozyme (lyz), catalase (cat), nuclear factor-κB (Nf-κB), and toll-like receptor 4 (tlr4) was significantly upregulated in the PCS-20 and PCS-30 groups (p < 0.05). Histological analysis revealed progressive improvements in anterior intestinal morphology, with the PCS-30 group exhibiting the greatest villus height and width. Gut microbiota analysis showed increased relative abundance of beneficial taxa (Gammaproteobacteria, Lactobacillales, Prevotella), which positively correlated with growth and antioxidant markers, and negatively with MDA levels. Survival under acute ammonia exposure was highest in the PCS-20 and PCS-30 groups. These findings demonstrate the efficacy of PCS, particularly at 30 g/kg, in enhancing growth, immunity, and stress resilience.
{"title":"Effects of dietary corn silk (Zea mays L.) on growth, immune and antioxidant pathways, histological morphology, gut microbiome, and sensitivity to acute ammonia exposure in the koi carp (Cyprinus carpio var. koi)","authors":"Nguyen Vu Linh , Luu Tang Phuc Khang , Nguyen Dinh-Hung , Suwanna Wisetkaeo , Phatthanaphong Therdtatha , Papungkorn Sangsawad , Supreya Wannavijit , Jakree Jitjumnong , Patima Permpoonpattana , Hien Van Doan","doi":"10.1016/j.cbpb.2025.111127","DOIUrl":"10.1016/j.cbpb.2025.111127","url":null,"abstract":"<div><div>Corn silk is a promising aquafeed additive due to its antioxidant, antibacterial, and anti-inflammatory properties. This study evaluated the impact of graded dietary levels of powdered corn silk (PCS) on growth, immunity, antioxidant enzyme activities, histology, gut microbiota composition, gene expression profiles, and sensitivity to acute ammonia exposure in koi carp (<em>Cyprinus carpio</em> var. <em>koi</em>). A total of 300 fish were assigned to five dietary treatments (0, 5, 10, 20, and 30 g/kg PCS) for eight weeks. Fish fed the PCS-30 diet showed significant improvements in growth parameters, including weight gain (WG) and specific growth rate (SGR) (<em>p < 0.05</em>). Antioxidant capacity (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid); ABTS) and superoxide dismutase (SOD) activity, increased dose-dependently, while malondialdehyde (MDA) levels remained unchanged (<em>p</em> > 0.05). Expression of the immune and antioxidant genes interleukin 8 (<em>il-8</em>)<em>,</em> lysozyme (<em>lyz</em>)<em>,</em> catalase (<em>cat</em>)<em>,</em> nuclear factor-κB (<em>Nf-κB</em>)<em>,</em> and toll-like receptor 4 (<em>tlr4</em>) was significantly upregulated in the PCS-20 and PCS-30 groups (<em>p</em> < 0.05). Histological analysis revealed progressive improvements in anterior intestinal morphology, with the PCS-30 group exhibiting the greatest villus height and width. Gut microbiota analysis showed increased relative abundance of beneficial taxa (<em>Gammaproteobacteria, Lactobacillales, Prevotella</em>), which positively correlated with growth and antioxidant markers, and negatively with MDA levels. Survival under acute ammonia exposure was highest in the PCS-20 and PCS-30 groups. These findings demonstrate the efficacy of PCS, particularly at 30 g/kg, in enhancing growth, immunity, and stress resilience.</div></div>","PeriodicalId":55236,"journal":{"name":"Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology","volume":"279 ","pages":"Article 111127"},"PeriodicalIF":1.9,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144602304","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}
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