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

Role of the cell cycle-related gene cdk2 and its associated ceRNA network in sexual size dimorphism of Cynoglossus semilaevis

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-04-16 DOI: 10.1016/j.cbpa.2025.111867

Xihong Li , Jiacheng Wang , Jiaqi Mai , Yuqi Sun , Wenjie Li , Zhenyu Cai , Wenteng Xu , Zhangfan Chen , Songlin Chen , Na Wang

Sexual size dimorphism (SSD) in Cynoglossus semilaevis affects its annual production and restricts aquaculture development. Our previous multi-omics data analysis showed that cell cycle genes and the relevant non-coding RNAs (ncRNAs) were closely involved in SSD regulation. In this study, we analyzed cyclin-dependent kinase 2 (cdk2) gene together with its associated microRNA (miRNA) and long ncRNA (lncRNA) in C. semilaevis, predicting a competing endogenous RNA (ceRNA) regulatory network (MSTRG.24810.1-miR-460-cdk2) and verifying the targeting relationship using dual luciferase reporter assays. Expression profile analysis showed that cdk2 and the lncRNA MSTRG.24810.1 were highly expressed in female gonad and muscle, and their expression levels increased from 3-month-old (3M) to 8M. On the other hand, their negative regulator miR-460-x displayed lower expression in female than in male. After miR-460-x mimic transfection in C. semilaevis ovarian cells, the expressions of cdk2, cyclin E, and MSTRG.24810.1 were significantly decreased and cell cycle transition through G1 to S phase was obviously blocked. In vitro and in vivo experiments also indicated that RNAi-mediated knock-down of cdk2 caused down-regulation of MSTRG.24810.1 and other cell cycle related genes like cyclin E, cyclin A, e2f1, and h2b. Taken together, these results suggested that cdk2 gene and its associated ceRNA network may affect sex growth difference and differentiation of C. semilaevis individuals via regulating cell division and proliferation. The study will not only expand our knowledge on SSD regulatory mechanism, but also help to make an application on promoting growth and development of the fish.

{"title":"Role of the cell cycle-related gene cdk2 and its associated ceRNA network in sexual size dimorphism of Cynoglossus semilaevis","authors":"Xihong Li , Jiacheng Wang , Jiaqi Mai , Yuqi Sun , Wenjie Li , Zhenyu Cai , Wenteng Xu , Zhangfan Chen , Songlin Chen , Na Wang","doi":"10.1016/j.cbpa.2025.111867","DOIUrl":"10.1016/j.cbpa.2025.111867","url":null,"abstract":"<div><div>Sexual size dimorphism (SSD) in <em>Cynoglossus semilaevis</em> affects its annual production and restricts aquaculture development. Our previous multi-omics data analysis showed that cell cycle genes and the relevant non-coding RNAs (ncRNAs) were closely involved in SSD regulation. In this study, we analyzed <em>cyclin-dependent kinase 2</em> (<em>cdk2</em>) gene together with its associated microRNA (miRNA) and long ncRNA (lncRNA) in <em>C. semilaevis</em>, predicting a competing endogenous RNA (ceRNA) regulatory network (MSTRG.24810.1-miR-460-cdk2) and verifying the targeting relationship using dual luciferase reporter assays. Expression profile analysis showed that <em>cdk2</em> and the lncRNA MSTRG.24810.1 were highly expressed in female gonad and muscle, and their expression levels increased from 3-month-old (3M) to 8M. On the other hand, their negative regulator miR-460-x displayed lower expression in female than in male. After miR-460-x mimic transfection in <em>C. semilaevis</em> ovarian cells, the expressions of <em>cdk2</em>, <em>cyclin E</em>, and MSTRG.24810.1 were significantly decreased and cell cycle transition through G1 to S phase was obviously blocked. <em>In vitro</em> and <em>in vivo</em> experiments also indicated that RNAi-mediated knock-down of <em>cdk2</em> caused down-regulation of MSTRG.24810.1 and other cell cycle related genes like <em>cyclin E</em>, <em>cyclin A</em>, <em>e2f1</em>, and <em>h2b</em>. Taken together, these results suggested that <em>cdk2</em> gene and its associated ceRNA network may affect sex growth difference and differentiation of <em>C. semilaevis</em> individuals <em>via</em> regulating cell division and proliferation. The study will not only expand our knowledge on SSD regulatory mechanism, but also help to make an application on promoting growth and development of the fish.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111867"},"PeriodicalIF":2.1,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844663","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}

引用次数: 0

Transcriptional analysis reveals antioxidant, ion transport, and glycolysis mechanisms in Litopenaeus vannamei gills involved in the response to high alkali stress

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-04-15 DOI: 10.1016/j.cbpa.2025.111868

Yiming Li , Yucong Ye , Xiaoyi Zhu , Yuxing Wei , Yan Li , Zhen Sun , Kai Zhou , Pengcheng Gao , Zongli Yao , Qifang Lai

Saline-alkali aquacultural systems have an important role in improving the economic output of the aquacultural industry. However, the survival rate of shrimp in intensive aquacultural systems is affected by alkalinity fluctuations. This study explored the ion transport and molecular responses of the whiteleg shrimp Litopenaeus vannamei to short-term high alkaline stress (96 h). The results showed that survival rate decreased significantly with time, hemolymph osmotic pressure and oxygen consumption dropped sharply after peaking at 48 h, and ammonia excretion followed a non-monotonic pattern, with an initial decline followed by a subsequent increase. Analysis of key physiological indicators revealed that urea nitrogen continued to accumulate, antioxidant (SOD and CAT) and glycolytic (PFK and LDH) enzymes were significantly activated, but ion regulatory enzymes (Na⁺/K⁺-ATPase) were severely suppressed. Gill histopathology showed typical injuries (such as gill filament shrinkage, vacuolation, and hemocytopenia). Furthermore, transcriptome analysis confirmed that high alkali stress activated insulin signaling pathway and glycolysis-related genes (e.g., upregulating PFK and GLUT expression). These results indicate that the high alkalinity causes an ion imbalance, changes the ammonia transport process, and activates the glycolysis pathway. These conclusions provide a theoretical basis for the subsequent development for the saline-alkaline aquacultural of Litopenaeus vannamei.

{"title":"Transcriptional analysis reveals antioxidant, ion transport, and glycolysis mechanisms in Litopenaeus vannamei gills involved in the response to high alkali stress","authors":"Yiming Li , Yucong Ye , Xiaoyi Zhu , Yuxing Wei , Yan Li , Zhen Sun , Kai Zhou , Pengcheng Gao , Zongli Yao , Qifang Lai","doi":"10.1016/j.cbpa.2025.111868","DOIUrl":"10.1016/j.cbpa.2025.111868","url":null,"abstract":"<div><div>Saline-alkali aquacultural systems have an important role in improving the economic output of the aquacultural industry. However, the survival rate of shrimp in intensive aquacultural systems is affected by alkalinity fluctuations. This study explored the ion transport and molecular responses of the whiteleg shrimp <em>Litopenaeus vannamei</em> to short-term high alkaline stress (96 h). The results showed that survival rate decreased significantly with time, hemolymph osmotic pressure and oxygen consumption dropped sharply after peaking at 48 h, and ammonia excretion followed a non-monotonic pattern, with an initial decline followed by a subsequent increase. Analysis of key physiological indicators revealed that urea nitrogen continued to accumulate, antioxidant (SOD and CAT) and glycolytic (PFK and LDH) enzymes were significantly activated, but ion regulatory enzymes (Na<sup>+</sup>/K<sup>+</sup>-ATPase) were severely suppressed. Gill histopathology showed typical injuries (such as gill filament shrinkage, vacuolation, and hemocytopenia). Furthermore, transcriptome analysis confirmed that high alkali stress activated insulin signaling pathway and glycolysis-related genes (e.g., upregulating <em>PFK</em> and <em>GLUT</em> expression). These results indicate that the high alkalinity causes an ion imbalance, changes the ammonia transport process, and activates the glycolysis pathway. These conclusions provide a theoretical basis for the subsequent development for the saline-alkaline aquacultural of <em>Litopenaeus vannamei</em>.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"306 ","pages":"Article 111868"},"PeriodicalIF":2.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860209","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}

引用次数: 0

Compensatory sensory mechanisms in naïve blind cavefish navigating novel environments after lateral line ablation

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-04-11 DOI: 10.1016/j.cbpa.2025.111863

Sofia Z. Marketaki , Fidji Berio , Valentina Di Santo

Fishes navigating complex aquatic environments rely on various sensory systems, primarily the lateral line system and vision, to guide their movements. One interesting example is the Mexican blind cavefish (Astyanax mexicanus). This fish relies on the lateral line system as it navigates through the environment without the aid of sight. It is unclear, however, how they might navigate through a novel environment when the lateral line is not functional. In this study, we used high-speed videography to quantify whether naïve blind cavefish alter locomotor behavior, navigation patterns, and the use of body and fins to explore a novel environment with obstacles when the lateral line is ablated. Blind cavefish with an intact lateral line demonstrated deliberate slower exploratory movements and navigated around obstacles with fewer touching events. Conversely, fish with ablated lateral line exhibited increased speed to potentially improve flow sensing. Fish with an ablated lateral line also touched obstacles more often, suggesting a reliance on fin and snout mechanoreception for navigation. These results show the blind cavefish have compensatory sensory mechanisms to navigate novel environments when their major sensory system is not functioning.

{"title":"Compensatory sensory mechanisms in naïve blind cavefish navigating novel environments after lateral line ablation","authors":"Sofia Z. Marketaki , Fidji Berio , Valentina Di Santo","doi":"10.1016/j.cbpa.2025.111863","DOIUrl":"10.1016/j.cbpa.2025.111863","url":null,"abstract":"<div><div>Fishes navigating complex aquatic environments rely on various sensory systems, primarily the lateral line system and vision, to guide their movements. One interesting example is the Mexican blind cavefish (<em>Astyanax mexicanus</em>). This fish relies on the lateral line system as it navigates through the environment without the aid of sight. It is unclear, however, how they might navigate through a novel environment when the lateral line is not functional. In this study, we used high-speed videography to quantify whether naïve blind cavefish alter locomotor behavior, navigation patterns, and the use of body and fins to explore a novel environment with obstacles when the lateral line is ablated. Blind cavefish with an intact lateral line demonstrated deliberate slower exploratory movements and navigated around obstacles with fewer touching events. Conversely, fish with ablated lateral line exhibited increased speed to potentially improve flow sensing. Fish with an ablated lateral line also touched obstacles more often, suggesting a reliance on fin and snout mechanoreception for navigation. These results show the blind cavefish have compensatory sensory mechanisms to navigate novel environments when their major sensory system is not functioning.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111863"},"PeriodicalIF":2.1,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143837898","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}

引用次数: 0

Cardiovascular responses of embryonic alligator (Alligator mississippiensis) exposed to 10% O2 and sodium cyanide (NaCN), a chemoreflex-inducing compound

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-04-10 DOI: 10.1016/j.cbpa.2025.111865

John Eme , Gil Martinez Bautista , Audrey Keneda , Kevin Tate , George Melancon , Dane A. Crossley II

The possibly interactive effects of changes in atmospheric respiratory gases (hypoxia or hypercapnia) and pharmacological chemoreceptor stimulation have not been assessed previously. We present a series of experimental protocols investigating embryonic alligators' capacity to modulate a cardiovascular neural chemoreflex response to a known chemoreceptor stimulant, sodium cyanide (NaCN). We incubated alligator embryos in 21 % (normoxia) and 10 % O₂ (hypoxia) beginning at 20 % of embryonic incubation, and at 70 % and 90 % of incubation we measured heart rate and blood pressure responses to NaCN. These NaCN responses also included examining the effects of NaCN after 1-h exposure to 10 % O₂., ganglionic blockade with hexamethonium chloride and α-adrenergic blockade with phentolamine. Injections of NaCN into the chorioallantoic artery caused a rapid bradycardia followed by a secondary hypertension, which can be attributed to an autonomic nervous system mediated reflex loop. We compared the heart rate response to injections of 1 mg kg⁻¹ NaCN before and after a 1-h 10 % O₂ exposure, and it was clear that embryonic alligators lacked capacity to change the intensity of cardiovascular responses to this compound. Hexamethonium greatly lessened the rapid bradycardia, and at 90 % of incubation, the secondary hypertensive response to NaCN appeared due to α-adrenergic stimulation, as phentolamine lessened the response. Collectively, data indicate that while a cardiovascular chemoreflex can be induced by NaCN, the heart rate response lacks plasticity and is not modulated by hypoxic incubation in embryonic alligators.

{"title":"Cardiovascular responses of embryonic alligator (Alligator mississippiensis) exposed to 10% O2 and sodium cyanide (NaCN), a chemoreflex-inducing compound","authors":"John Eme , Gil Martinez Bautista , Audrey Keneda , Kevin Tate , George Melancon , Dane A. Crossley II","doi":"10.1016/j.cbpa.2025.111865","DOIUrl":"10.1016/j.cbpa.2025.111865","url":null,"abstract":"<div><div>The possibly interactive effects of changes in atmospheric respiratory gases (hypoxia or hypercapnia) <em>and</em> pharmacological chemoreceptor stimulation have not been assessed previously. We present a series of experimental protocols investigating embryonic alligators' capacity to modulate a cardiovascular neural chemoreflex response to a known chemoreceptor stimulant, sodium cyanide (NaCN). We incubated alligator embryos in 21 % (normoxia) and 10 % O<sub>2</sub> (hypoxia) beginning at 20 % of embryonic incubation, and at 70 % and 90 % of incubation we measured heart rate and blood pressure responses to NaCN. These NaCN responses also included examining the effects of NaCN after 1-h exposure to 10 % O<sub>2</sub>., ganglionic blockade with hexamethonium chloride and α-adrenergic blockade with phentolamine. Injections of NaCN into the chorioallantoic artery caused a rapid bradycardia followed by a secondary hypertension, which can be attributed to an autonomic nervous system mediated reflex loop. We compared the heart rate response to injections of 1 mg kg<sup>−1</sup> NaCN before and after a 1-h 10 % O<sub>2</sub> exposure, and it was clear that embryonic alligators lacked capacity to change the intensity of cardiovascular responses to this compound. Hexamethonium greatly lessened the rapid bradycardia, and at 90 % of incubation, the secondary hypertensive response to NaCN appeared due to α-adrenergic stimulation, as phentolamine lessened the response. Collectively, data indicate that while a cardiovascular chemoreflex can be induced by NaCN, the heart rate response lacks plasticity and is not modulated by hypoxic incubation in embryonic alligators.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111865"},"PeriodicalIF":2.1,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833810","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}

引用次数: 0

Adjustments to energy provisioning and oxidative balance in response to temperature in a wild passerine

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-04-06 DOI: 10.1016/j.cbpa.2025.111864

Pierre Deviche , Karen Sweazea , Nadia Upah

Climate change and urbanization are associated with elevated ambient temperature (T_a). This increase may negatively impact organisms by creating conditions that are outside their resilience limits, but the physiological mechanisms that limit phenotypic plasticity in response to T_a variation remain poorly understood. We investigated these mechanisms in captive House Finches, Haemorhous mexicanus, a common native resident of rural and urban environments. We exposed finches to temperatures either slightly below the species' lower critical temperature (constant 20 °C; COOL group) or close to its upper critical temperature (daily min. 27 °C, daily max. 35 °C; WARM group) for two weeks. Birds in the COOL group ate more than birds in the WARM group, which is consistent with the prediction that cool T_a exposure increased the metabolic rate. However, finches of the two groups did not differ with regard to their body masses, fat reserves, or blood concentrations of ketone bodies, uric acid, and erythrocytic peroxidized lipids. Thus, exposure to the two experimental treatments did not result in major metabolic differences between groups. Acute stress caused by handling and restraint for 30 min decreased plasma uric acid, which may have been associated with its utilization as a free radical scavenger and so may have decreased stress-associated oxidative damage. Acute stress also increased plasma ketone bodies, suggesting increased lipid oxidation. These stress-related metabolic changes did not differ in the COOL and WARM groups, indicating within the range of T_a to which birds were exposed that temperature did not affect the birds' physiological sensitivity to acute stress.

{"title":"Adjustments to energy provisioning and oxidative balance in response to temperature in a wild passerine","authors":"Pierre Deviche , Karen Sweazea , Nadia Upah","doi":"10.1016/j.cbpa.2025.111864","DOIUrl":"10.1016/j.cbpa.2025.111864","url":null,"abstract":"<div><div>Climate change and urbanization are associated with elevated ambient temperature (T<sub>a</sub>). This increase may negatively impact organisms by creating conditions that are outside their resilience limits, but the physiological mechanisms that limit phenotypic plasticity in response to T<sub>a</sub> variation remain poorly understood. We investigated these mechanisms in captive House Finches, <em>Haemorhous mexicanus</em>, a common native resident of rural and urban environments. We exposed finches to temperatures either slightly below the species' lower critical temperature (constant 20 °C; COOL group) or close to its upper critical temperature (daily min. 27 °C, daily max. 35 °C; WARM group) for two weeks. Birds in the COOL group ate more than birds in the WARM group, which is consistent with the prediction that cool T<sub>a</sub> exposure increased the metabolic rate. However, finches of the two groups did not differ with regard to their body masses, fat reserves, or blood concentrations of ketone bodies, uric acid, and erythrocytic peroxidized lipids. Thus, exposure to the two experimental treatments did not result in major metabolic differences between groups. Acute stress caused by handling and restraint for 30 min decreased plasma uric acid, which may have been associated with its utilization as a free radical scavenger and so may have decreased stress-associated oxidative damage. Acute stress also increased plasma ketone bodies, suggesting increased lipid oxidation. These stress-related metabolic changes did not differ in the COOL and WARM groups, indicating within the range of T<sub>a</sub> to which birds were exposed that temperature did not affect the birds' physiological sensitivity to acute stress.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111864"},"PeriodicalIF":2.1,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791680","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}

引用次数: 0

Respiratory flow and tidal volume scale with body mass in sea turtles but not breath duration

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-04-04 DOI: 10.1016/j.cbpa.2025.111855

Kino Sakai , Tomoko Narazaki , Masanori Mori , Tomomi Matsumoto , Kagari Aoki , Andreas Fahlman , Kentaro Q. Sakamoto

The ventilatory capacity of sea turtles is an important factor in their diving ability because they spend most of their time submerged. However, there is limited information on the relationship between the ventilatory capacity and body mass of sea turtles. To investigate the allometric scaling of the functional ventilatory capacity, we measured respiratory flow, tidal volume, and breath duration of spontaneous breaths in 40 sea turtles from 3 species (loggerhead, Caretta caretta; green, Chelonia mydas; hawksbill, Eretmochelys imbricata) of various body sizes (range: 0.7–120.6 kg) on land and in water. The results showed that the ventilatory capacity did not differ on land or in water. The respiratory flow and tidal volume increased with body mass with an allometric exponent of 0.76–0.80 and 0.87–0.89, respectively. In contrast, the breath duration and the ratio of tidal volume to the maximum lung volume were constant. These results suggest that sea turtles increase respiratory flow by increasing tidal volume with increasing body mass rather than prolonging breath duration, which may allow them to reduce the surface interval to breathe. This study improves the understanding of the ventilatory capacity of sea turtles.

{"title":"Respiratory flow and tidal volume scale with body mass in sea turtles but not breath duration","authors":"Kino Sakai , Tomoko Narazaki , Masanori Mori , Tomomi Matsumoto , Kagari Aoki , Andreas Fahlman , Kentaro Q. Sakamoto","doi":"10.1016/j.cbpa.2025.111855","DOIUrl":"10.1016/j.cbpa.2025.111855","url":null,"abstract":"<div><div>The ventilatory capacity of sea turtles is an important factor in their diving ability because they spend most of their time submerged. However, there is limited information on the relationship between the ventilatory capacity and body mass of sea turtles. To investigate the allometric scaling of the functional ventilatory capacity, we measured respiratory flow, tidal volume, and breath duration of spontaneous breaths in 40 sea turtles from 3 species (loggerhead, <em>Caretta caretta</em>; green, <em>Chelonia mydas</em>; hawksbill, <em>Eretmochelys imbricata</em>) of various body sizes (range: 0.7–120.6 kg) on land and in water. The results showed that the ventilatory capacity did not differ on land or in water. The respiratory flow and tidal volume increased with body mass with an allometric exponent of 0.76–0.80 and 0.87–0.89, respectively. In contrast, the breath duration and the ratio of tidal volume to the maximum lung volume were constant. These results suggest that sea turtles increase respiratory flow by increasing tidal volume with increasing body mass rather than prolonging breath duration, which may allow them to reduce the surface interval to breathe. This study improves the understanding of the ventilatory capacity of sea turtles.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111855"},"PeriodicalIF":2.1,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143797223","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}

引用次数: 0

The histological and molecular response of acute hypoxia and reoxygenation in rainbow trout and steelhead

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-04-02 DOI: 10.1016/j.cbpa.2025.111854

Xiao-Qun Chen , Yan-Gen Zhou , Kun-Tong Jia , Yu-Hang Wang , Zhen Zhao , Yue-Huan Zhang , Zhi-Tao Huang , Qin-Feng Gao , Yun-Wei Dong , Shuang-Lin Dong

Hypoxia is a critical environmental stressor affecting fish survival and physiological function. Landlocked rainbow trout (Oncorhynchus mykiss) and anadromous steelhead (Oncorhynchus mykiss), two ecotypes of the same species, exhibit distinct physiological adaptations to fluctuating oxygen levels. To investigate their responses to acute hypoxia in these fish, brain histology and transcriptome analyses were conducted before stress, after hypoxia (12 and 24 h), and after reoxygenation (24 h). The results showed that the number of vacuolated nerve cells in the brain increased with the duration of hypoxia and decreased after 24 h of reoxygenation in both fish. RNA-Seq analysis identified 8409 differentially expressed genes (3952 in rainbow trout and 4457 in steelhead), one hypoxia-related module (MEred), and two significantly expressed gene clusters (cluster 3 in rainbow trout and cluster 8 in steelhead) through differential expression analysis, weighted gene co-expression network analysis (WGCNA), and Mfuzz clustering. KEGG pathway enrichment analysis revealed that signal transduction, immune response, angiogenesis, and apoptosis were significantly influenced by hypoxia in both fish. Distinct hypoxic responses were observed: in rainbow trout, ferroptosis, necroptosis, phosphatidylinositol signaling, calcium, and apelin signaling pathways were enriched, whereas in steelhead, the enriched pathways included platelet activation, Rap1, PI3K-Akt, Hippo, relaxin, and oxytocin signaling. Steelhead display marginally greater hypoxia tolerance than rainbow trout, although the difference is minimal, likely owing to their classification as the same species. These findings provide insight into the physiological and molecular mechanisms underlying hypoxia and reoxygenation stress in salmonids, contributing to a broader understanding of oxygen homeostasis in fish.

{"title":"The histological and molecular response of acute hypoxia and reoxygenation in rainbow trout and steelhead","authors":"Xiao-Qun Chen , Yan-Gen Zhou , Kun-Tong Jia , Yu-Hang Wang , Zhen Zhao , Yue-Huan Zhang , Zhi-Tao Huang , Qin-Feng Gao , Yun-Wei Dong , Shuang-Lin Dong","doi":"10.1016/j.cbpa.2025.111854","DOIUrl":"10.1016/j.cbpa.2025.111854","url":null,"abstract":"<div><div>Hypoxia is a critical environmental stressor affecting fish survival and physiological function. Landlocked rainbow trout (<em>Oncorhynchus mykiss</em>) and anadromous steelhead (<em>Oncorhynchus mykiss</em>), two ecotypes of the same species, exhibit distinct physiological adaptations to fluctuating oxygen levels. To investigate their responses to acute hypoxia in these fish, brain histology and transcriptome analyses were conducted before stress, after hypoxia (12 and 24 h), and after reoxygenation (24 h). The results showed that the number of vacuolated nerve cells in the brain increased with the duration of hypoxia and decreased after 24 h of reoxygenation in both fish. RNA-Seq analysis identified 8409 differentially expressed genes (3952 in rainbow trout and 4457 in steelhead), one hypoxia-related module (MEred), and two significantly expressed gene clusters (cluster 3 in rainbow trout and cluster 8 in steelhead) through differential expression analysis, weighted gene co-expression network analysis (WGCNA), and Mfuzz clustering. KEGG pathway enrichment analysis revealed that signal transduction, immune response, angiogenesis, and apoptosis were significantly influenced by hypoxia in both fish. Distinct hypoxic responses were observed: in rainbow trout, ferroptosis, necroptosis, phosphatidylinositol signaling, calcium, and apelin signaling pathways were enriched, whereas in steelhead, the enriched pathways included platelet activation, Rap1, PI3K-Akt, Hippo, relaxin, and oxytocin signaling. Steelhead display marginally greater hypoxia tolerance than rainbow trout, although the difference is minimal, likely owing to their classification as the same species. These findings provide insight into the physiological and molecular mechanisms underlying hypoxia and reoxygenation stress in salmonids, contributing to a broader understanding of oxygen homeostasis in fish.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111854"},"PeriodicalIF":2.1,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Novel mechanisms of epithelial ion transport and its regulation

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-03-30 DOI: 10.1016/j.cbpa.2025.111852

Dennis Kolosov , Sima Jonusaite

引用次数: 0

Feeding time modulates the daily rhythms of expression of digestive and metabolic enzymes in the liver, and food intake regulation and reward systems in the hypothalamus of the European sea bass (Dicentrarchus labrax)

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-03-29 DOI: 10.1016/j.cbpa.2025.111853

Elisa Samorì , Inmaculada Rodríguez , José Antonio Paullada-Salmerón , José Antonio Muñoz-Cueto , Verónica González-Nunez , Francisco Javier Sánchez-Vázquez , José Fernando López-Olmeda

Fish exhibit daily rhythms at the molecular level across different tissues, synchronized by zeitgebers, such as food availability. To optimize feeding, organisms align internal timekeeping systems to environmental cues. Previous studies on intermediary metabolism and the hypothalamic control of food intake in fish have underscored the significance of feeding time and daily rhythms. This study examined how feeding times—mid-light (ML) versus mid-dark (MD)—influence the rhythmic transcription of digestive and metabolic enzymes in the liver, and regulatory factors of food intake in the hypothalamus of European sea bass (Dicentrarchus labrax). It also explored the connection between food intake control and the reward system. When fish were fed at ML, genes involved in protein digestion (tryp2, tryp3, ctrl, and cpa5) exhibited daily rhythms with peaks early in the dark phase (ZT 11:17–13:36). These peaks were delayed in MD-fed fish (ZT 16:57–18:27). Pla2, a gene related to lipid metabolism, and transamination genes (c-alt, m-alt) showed rhythms only in ML-fed fish, with acrophases in the light phase (ZT 5:01–13:58), such as pyruvate kinase (pk) that peaked at ZT 6:16. Orexigenic genes (npy, orexin) had rhythms only in the MD group, with nocturnal peaks (ZT 13:09, 16:06). Conversely, reward system genes (th, bdnf) were rhythmic in ML-fed fish (ZT 17:35, 11:46), with only th retaining its rhythm in MD-fed fish (ZT 15:30). These findings suggest feeding time significantly affects rhythms in digestive and metabolic processes. They also highlight the intricate nature of food intake regulation systems, which present diverse synchronization patterns in relation to feeding time.

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引用次数: 0

Comparative analysis of differential gene expression in hepatopancreas of Chinese mitten crabs (Eriocheir sinensis) with different carapace colors

IF 2.1 3区生物学 Q4 BIOCHEMISTRY & MOLECULAR BIOLOGY

Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology

Pub Date : 2025-03-29 DOI: 10.1016/j.cbpa.2025.111851

Qi Zhu , Maolei Wei , Xinxin Chen , Xugan Wu , Xiaowu Chen

The carapace color of the Chinese mitten crab (Eriocheir sinensis) significantly influences consumer preference and market value, yet the underlying molecular mechanisms remain poorly understood. In this study, transcriptome sequencing coupled with weighted gene co-expression network analysis (WGCNA) was employed to elucidate genetic and metabolic pathways involved in three genetically distinct carapace color phenotypes (red, white, and green). Hepatopancreatic transcriptome analyses across these color variants identified 910, 1555, and 1598 differentially expressed genes (DEGs) in pairwise comparisons. Functional enrichment analyses revealed significant activation of oxidoreductase activity, retinol metabolism, and mitochondrial energy metabolism pathways in crabs with red carapaces. Notably, key pigmentation-associated genes, including ninaB (carotenoid isomerase) and sno1 (flavin monooxygenase), were markedly upregulated. Additionally, WGCNA identified a highly correlated (r = 0.97) red-specific gene module enriched predominantly with oxidative phosphorylation-related genes, such as atpsycf6 and ndufb4, emphasizing the energetic investment associated with pigment biosynthesis. Furthermore, retinol metabolism emerged as a pivotal pathway connecting carotenoid processes with immune and antioxidant functions, implying potential physiological trade-offs between pigmentation and stress resilience. Overall, this study advances our understanding of crustacean carapace coloration mechanisms and provides valuable genetic targets for selective breeding aimed at enhancing desirable color traits in E. sinensis.

{"title":"Comparative analysis of differential gene expression in hepatopancreas of Chinese mitten crabs (Eriocheir sinensis) with different carapace colors","authors":"Qi Zhu , Maolei Wei , Xinxin Chen , Xugan Wu , Xiaowu Chen","doi":"10.1016/j.cbpa.2025.111851","DOIUrl":"10.1016/j.cbpa.2025.111851","url":null,"abstract":"<div><div>The carapace color of the Chinese mitten crab (<em>Eriocheir sinensis</em>) significantly influences consumer preference and market value, yet the underlying molecular mechanisms remain poorly understood. In this study, transcriptome sequencing coupled with weighted gene co-expression network analysis (WGCNA) was employed to elucidate genetic and metabolic pathways involved in three genetically distinct carapace color phenotypes (red, white, and green). Hepatopancreatic transcriptome analyses across these color variants identified 910, 1555, and 1598 differentially expressed genes (DEGs) in pairwise comparisons. Functional enrichment analyses revealed significant activation of oxidoreductase activity, retinol metabolism, and mitochondrial energy metabolism pathways in crabs with red carapaces. Notably, key pigmentation-associated genes, including <em>ninaB</em> (carotenoid isomerase) and <em>sno1</em> (flavin monooxygenase), were markedly upregulated. Additionally, WGCNA identified a highly correlated (<em>r</em> = 0.97) red-specific gene module enriched predominantly with oxidative phosphorylation-related genes, such as <em>atpsycf6</em> and <em>ndufb4</em>, emphasizing the energetic investment associated with pigment biosynthesis. Furthermore, retinol metabolism emerged as a pivotal pathway connecting carotenoid processes with immune and antioxidant functions, implying potential physiological trade-offs between pigmentation and stress resilience. Overall, this study advances our understanding of crustacean carapace coloration mechanisms and provides valuable genetic targets for selective breeding aimed at enhancing desirable color traits in <em>E. sinensis</em>.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"305 ","pages":"Article 111851"},"PeriodicalIF":2.1,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747069","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}

引用次数: 0