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

{"title":"Melatonin modulates autophagy, mitochondria and antioxidant in the liver and brain of Perccottus glenni during recovery from freezing","authors":"Cunrun Ye,&nbsp;Zhaoyang Ning,&nbsp;Tingting Hu,&nbsp;Xiaoyu Zhao,&nbsp;Weijie Mu","doi":"10.1016/j.cbpa.2025.111824","DOIUrl":"10.1016/j.cbpa.2025.111824","url":null,"abstract":"<div><div>The Amur sleeper (<em>Percottus glenii</em>), a freeze tolerant fish species, can survive being frozen in ice, survival after recovery from freezing. This study investigated the role of melatonin in the recovery of <em>Perccottus glenni</em> following freezing. The fish were categorized into the following groups: non-treated control (Con), pinealectomy (Px), melatonin injection (Mlt), sham control (Sham), and saline injection control (Sal). The results revealed that the melatonin levels were affected by pinealectomy and melatonin injection. The liver and brain of the Px and Mlt groups exhibited autophagy after 4 h, along with the differential expression of endoplasmic reticulum stress-related genes. Furthermore, the activities of the mitochondrial complex initially increased at 4 h and then decreased by 12 h in the Px and Mlt groups, while antioxidant enzyme activities varied across groups and time points. These findings indicated that melatonin plays a key role in the recovery of <em>P. glenni</em> in a time-dependent manner, affecting autophagy, mitochondrial function, and antioxidant capacity. This study is the first to demonstrate melatonin's time-dependent role in facilitating the recovery of <em>P. glenni</em> after freezing, highlighting its critical involvement in modulating autophagy, mitochondrial function, and antioxidant processes. These findings shed light on the physiological mechanisms underlying freeze tolerance and recovery in fish, offering valuable insights for understanding and potentially enhancing the recovery processes in other species.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"303 ","pages":"Article 111824"},"PeriodicalIF":2.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403510","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":"Contrasting the effects of immobilisation and anaesthesia on the stress physiology and behaviour of juvenile lake sturgeon (Acipenser fulvescens)","authors":"Connor H. Reid ,&nbsp;Raegan Davis ,&nbsp;Kathleen M. Gilmour ,&nbsp;Cheryl N. Klassen ,&nbsp;James A. Crossman ,&nbsp;Steven J. Cooke","doi":"10.1016/j.cbpa.2025.111823","DOIUrl":"10.1016/j.cbpa.2025.111823","url":null,"abstract":"<div><div>Anaesthesia and/or immobilisation are typically required to facilitate experimental procedures on fishes such as the surgical implantation of electronic tags. Yet, optimal anaesthetic or immobilisation methods have primarily been developed and tested in teleosts, with relevant information on efficacy and suitability of these methods lacking for basal ray-finned fishes such as imperilled sturgeons (Acipenseridae). Here, we investigated the behavioural and physiological responses of hatchery-origin juvenile lake sturgeon (<em>Acipenser fulvescens</em>) to four immobilisation or anaesthetic methods. We conducted an experiment wherein fish were held in a fashion designed to induce tonic immobility, exposed to electroanaesthesia with a TENS unit, anaesthetised with MS-222, or anaesthetised with clove oil, and then subjected to a simulated intracoelomic tagging surgery. Following reflex indicator scoring, fish were “released” into a circular tank arena for behaviour trials and blood sampling at 0.5, 2, and 4 h post-release. Both tonic immobility and electroanaesthesia were ineffective at immobilising fish, and surgery under these methods led to relatively little behavioural impairment but the highest plasma cortisol peaks. Fish anaesthetised with MS-222 or clove oil had greater post-release behavioural impairment but lower cortisol levels. We discuss the implications of our findings for the practical application of these methods, and the challenges with identifying the most suitable method for immobilising or anaesthetising sturgeons in laboratory and field settings.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"303 ","pages":"Article 111823"},"PeriodicalIF":2.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403509","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":"Molecular characterization and function of sodium-dependent glucose transporter 1 in postprandial glucose homeostasis in Macrobrachium rosenbergii","authors":"Qun Jiang,&nbsp;Wenjing Xu,&nbsp;Qianqian Ding,&nbsp;Xiaoyu Cai,&nbsp;Qi Dong,&nbsp;Xiaojian Gao,&nbsp;Yao Zhang,&nbsp;Xiaojun Zhang","doi":"10.1016/j.cbpa.2025.111822","DOIUrl":"10.1016/j.cbpa.2025.111822","url":null,"abstract":"<div><div>Aquatic animals often exhibit glucose intolerance following a glucose load, and understanding the mechanisms of glucose uptake is crucial for elucidating the underlying processes. Sodium-dependent glucose transporter 1 (<em>SGLT</em>1) plays a crucial role in the process of intestinal glucose absorption and transport in vertebrates, but there is limited information about its function in crustaceans. This study identified the <em>SGLT</em>1 gene (named <em>MrSGLT</em>1) from <em>Macrobrachium rosenbergii</em>. The full cDNA sequence is 3764 bp, encoding 903 amino acids. Unlike SGLT1 in most teleost fish, which have 14 transmembrane domains, MrSGLT1 protein has only 12. <em>MrSGLT</em>1 was predominantly expressed in the intestine, with its expression increasing after feeding. This was accompanied by elevated levels of glucose and trehalose in the hemolymph, and increased glycogen levels in the hepatopancreas. Silencing <em>MrSGLT</em>1 in vivo resulted in decreased glucose and trehalose levels in the hemolymph and reduced glycogen levels in the hepatopancreas, although muscle glycogen levels were unaffected. Moreover, knockdown of <em>MrSGLT</em>1 led to increased expression of genes involved in glycogenolysis and decreased expression of genes associated with glycogenesis, inhibiting postprandial glycogen accumulation in the hepatopancreas. Feeding-induced glycolysis was also inhibited following <em>MrSGLT</em>1 silencing, while no significant changes were observed in gluconeogenesis-related genes. These findings highlight the critical role of <em>MrSGLT</em>1 in regulating postprandial glucose homeostasis in crustaceans.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"302 ","pages":"Article 111822"},"PeriodicalIF":2.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348519","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":"A circadian clock controls the daily function of the intestine in rainbow trout. Influence of light and food as synchronizers","authors":"María Alborja-Valado ,&nbsp;Mauro Chivite ,&nbsp;Jessica Calo ,&nbsp;Antía Verde ,&nbsp;Carlos A. Ramírez-Rodríguez ,&nbsp;Jesús M. Míguez ,&nbsp;Marcos A. López Patiño","doi":"10.1016/j.cbpa.2025.111821","DOIUrl":"10.1016/j.cbpa.2025.111821","url":null,"abstract":"<div><div>Environmental factors (daily light/dark cycles, food availability, etc.) entrain endogenous oscillators in living organisms, thereby allowing them to control the rhythms of behavioral and physiological functions, such as energy homeostasis. The gastrointestinal tract (GIT) is the first site of nutrient contact upon food intake. Thus, the GIT is key in energy homeostasis. Circadian oscillators exist within the GIT of mammals, modulating the daily function of the tissue. However, little information in this respect is available for other vertebrates, such as fish. Thus, we aimed to confirm the presence of a circadian oscillator within the GIT of rainbow trout (<em>Oncorhynchus mykiss</em>) and its interaction with locally released hormones that participate in feeding regulation in this species. We subsequently evaluated the role of food and light in synchronizing the rhythmic functioning of the GIT. According to our results, a circadian oscillator exists throughout the GIT of rainbow trout, based on the daily rhythms of clock gene (<em>clock1a, bmal1b, per1, cry2</em> and <em>reb-ervβ-like</em>) mRNA abundance. Light influences the function of the circadian oscillator within the GIT, but food is a key factor as a synchronizer. The feeding time and the presence and/or absence of food synchronize the rhythmic function of the GIT, as observed for GIT hormones (Ghrelin, Glp1 and Cck). Understanding the functioning of the circadian machinery in peripheral organs such as the GIT will ultimately help to improve different aspects of aquaculture, from farming strategies to welfare, among others.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"303 ","pages":"Article 111821"},"PeriodicalIF":2.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143375043","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":"Olfactory specialization in the Senegalese sole (Solea senegalensis): CO2 acidified water triggers nostril-specific immune processes","authors":"Rita A. Costa ,&nbsp;Peter C. Hubbard ,&nbsp;Manuel Manchado ,&nbsp;Deborah M. Power ,&nbsp;Zélia Velez","doi":"10.1016/j.cbpa.2025.111820","DOIUrl":"10.1016/j.cbpa.2025.111820","url":null,"abstract":"<div><div>Increased carbon dioxide (CO₂) in the ocean is changing seawater chemistry. Behavioural alterations in CO₂ exposed fish have been linked to changes in the central nervous system (CNS). However, we hypothesise that receptor cells in direct contact with the environment are more susceptible to changes in water chemistry than the CNS. Electrophysiology, histology, and transcriptomics were used to explore the effect of exposure to CO₂ acidified water on the olfactory epithelium (OE) of the Senegalese sole (<em>Solea senegalensis</em>). The upper and lower OE of this flatfish detect different odorants and are in contact with different environments. Acute exposure to acidified water decreased olfactory sensitivity more in the upper than in the lower OE. After chronic exposure to high CO₂ there were no histological changes in the upper OE; however, in the lower OE, there was a massive infiltration of melanomacrophage (MMC) and tissue disorganization. In addition, in the upper OE, differential expressed gene transcripts (DETs) were related to inflammation and innate immune processes whereas in the lower OE, DETs were related to the adaptative immune response. Differential regulation of genes related to neurogenesis and plasticity occurred in both epithelia.</div><div>The effects of ocean acidification in sole OE depends on the nostril; however, the occurrence of an exacerbated immune response, OE remodelling and reduced sensitivity indicate that ocean acidification is likely to have significant and unpredictable consequences for behaviour.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"302 ","pages":"Article 111820"},"PeriodicalIF":2.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143366760","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}

{"title":"High temperature induces the upward shift of the thermal neutral zone and decreases metabolic capacity in zebra finches","authors":"Jing Wang ,&nbsp;Ming-Hui Shao ,&nbsp;Juan Li ,&nbsp;Jia-Qi Liu ,&nbsp;Xin-Yi Xu ,&nbsp;Ming-Ru Xu ,&nbsp;Ming Li ,&nbsp;Jin-Song Liu","doi":"10.1016/j.cbpa.2024.111788","DOIUrl":"10.1016/j.cbpa.2024.111788","url":null,"abstract":"<div><div>The thermal neutral zone (TNZ) represents a fundamental concept in the thermal physiology of homeothermic organisms. TNZ is characterized as a specific range of environmental temperatures within which the metabolic rate remains at its basal level. The ambient temperature is regarded as a critical environmental factor that affects an animal's thermoregulation and propels the development of various morphological, physiological, and behavioral adaptations. In the present investigation, we assessed the influence of environmental temperature on various physiological parameters, including body mass, metabolic rate, thermoneutral zone (TNZ), state 4 respiration (S4R), cytochrome <em>c</em> oxidase (CCO) activity, body fat content, triglyceride content, free fatty acid content, β-hydroxyacyl Co-A dehydrogenase (HOAD) and citrate synthase (CS) activities, <em>AMPK</em> and <em>PGC-1α</em> mRNA levels, and triiodothyronine (T₃) and tetraiodothyronine (T₄) concentrations in zebra finches acclimated to 25 °C or 38 °<em>C. zebra</em> finches were found to have a TNZ of 32–42 °C when acclimated to 25 °C and a TNZ of 34–42 °C when acclimated to 38 °C. Acclimation to a high temperature led to an increase in the lower critical temperature (LCT), consequently resulting in a narrower TNZ. Zebra finches acclimated to 38 °C for a duration of four weeks exhibited a notable reduction in both body mass and basal metabolic rate as opposed to individuals maintained at 25 °C. Additionally, finches that were acclimatized to 38 °C exhibited a reduction in liver mass and a lower S4R level in both the liver and kidneys. Furthermore, these finches showed decreased CCO activity in the pectoral muscle and liver and lower avian uncoupling protein expression in the pectoral muscle compared with the birds acclimated to 25 °C. The T₃ level in the serum was lower in the 38 °C-acclimated finches than the 25 °C-acclimated finches. These findings suggested that the shift in the LCT of TNZ in zebra finches may possibly be associated with their metabolic capacity as well as their T₃ levels at a different ambient temperature. The changes in LCT of TNZ could be an important strategy in adapting to variations in ambient temperature in zebra finches.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"300 ","pages":"Article 111788"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142792939","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":"Does intestine length explain digesta retention times in birds and mammals?","authors":"María J. Duque-Correa ,&nbsp;Marcus Clauss ,&nbsp;Carlo Meloro ,&nbsp;Andrew J. Abraham","doi":"10.1016/j.cbpa.2024.111789","DOIUrl":"10.1016/j.cbpa.2024.111789","url":null,"abstract":"<div><div>Previous studies have indicated that across birds and mammals, body mass is a comparatively poor predictor of the time digesta is retained in the digestive tract (mean retention time, MRT). Rather, MRT might be determined by gastrointestinal anatomy, which can differ considerably within and between trophic guilds. Here, we used two recent literature compilations on the intestine length and the MRT in birds (<em>n</em> = 33 species) and mammals (<em>n</em> = 149) and applied comparative statistical approaches to assess whether intestine length is more closely correlated with MRT than body mass. Regardless of the statistical model used, whether small species (&lt; 120 g and any larger bats) were included or not, or whether birds and mammals were assessed together or separately, intestinal length generally yielded a better model fit to MRT than body mass, supporting the general concept. Nevertheless, data scatter was substantial, indicating that intestine length, though better than body mass, is still a limited explanatory factor for MRT. The intestine length-MRT relationship is an example of the direct statistical assessment of a generally presumed form-function relationship that is typically represented as a narrative. In the comparative literature, such assessments are rare.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"300 ","pages":"Article 111789"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142803561","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}

{"title":"Modulation of mitochondrial dynamics genes and mtDNA during embryonic development and under UVB exposure","authors":"Thaline de Quadros,&nbsp;Michael Lorenz Jaramillo,&nbsp;Cairé Barreto,&nbsp;Rafael Diego da Rosa,&nbsp;Madson Silveira de Melo ,&nbsp;Evelise Maria Nazari","doi":"10.1016/j.cbpa.2024.111790","DOIUrl":"10.1016/j.cbpa.2024.111790","url":null,"abstract":"<div><div>Studies using the embryos of the freshwater prawn <em>Macrobrachium olfersii</em> have reported changes in embryonic cells after exposure to ultraviolet B (UVB) radiation, such as DNA damage and apoptosis activation. Considering the importance of mitochondria in embryonic cells, this study aimed to characterize the aspects of mitochondrial morphofunctionality in <em>M. olfersii</em> embryos and mitochondrial responses to UVB radiation exposure. The coding sequences of genes <em>Tfam, Nrf1, Mfn1</em>, and <em>Drp1</em> were identified from the transcriptome of <em>M. olfersii</em> embryos. The phylogenetic relationship showed strong amino acid identity and a highly conserved nature of the sequences. Additionally, the number of mitochondrial DNA (mtDNA) copies were higher in the early embryonic days. The results showed that the expression of the analyzed genes was highly regulated during embryonic development, increasing their levels near hatching. Furthermore, when embryos were exposed to UVB radiation, mitochondrial biogenesis was activated, recognized by higher levels of transcripts of genes <em>Tfam</em> and <em>Nrf1</em>, accompanied by mitochondrial fission. Additionally, these mitochondrial events were supported by an increase of mtDNA copies. Our results showed that UVB radiation was able to change the mitochondrial morphofunctionality, and under the current knowledge, certainly compromise embryonic cellular integrity. Additionally, mitochondria is an important cellular target of this radiation and its responses can be used to assess environmental stress caused by UVB radiation in embryos of aquatic species.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"300 ","pages":"Article 111790"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815037","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":"Hypoxia increases intracellular calcium in glutamate-activated horizontal cells of goldfish retina via mitochondrial KATP channels and intracellular stores","authors":"Nicole V. Nagy-Watson ,&nbsp;Michael G. Jonz","doi":"10.1016/j.cbpa.2024.111786","DOIUrl":"10.1016/j.cbpa.2024.111786","url":null,"abstract":"<div><div>Central neurons of the common goldfish (<em>Carassius auratus</em>) are exceptional in their capacity to survive Ca²⁺-induced excitotoxicity and cell death during hypoxia. Horizontal cells (HCs) are inhibitory interneurons of the retina that are tonically depolarized by the neurotransmitter, glutamate, yet preserve intracellular Ca²⁺ homeostasis. In HCs isolated from goldfish, and in the absence of glutamatergic input, intracellular Ca²⁺ concentration ([Ca²⁺]_i) is protected from prolonged exposure to hypoxia by mitochondrial ATP-dependent K⁺ (mK_ATP) channel activity. In the present study, we investigated the effects of hypoxia upon [Ca²⁺]_i in isolated HCs during tonic activation by glutamate to better predict the effects of hypoxia in the active retina. Dynamic changes in [Ca²⁺]_i were measured using the ratiometric Ca²⁺ indicator, Fura-2. Application of 100 μM glutamate during hypoxia (P_O2 = 25 mmHg) produced a 1.3-fold greater rise in [Ca²⁺]_i compared to the same glutamate stimulus during normoxia. The hypoxia-dependent increase in [Ca²⁺]_i was abolished by application of 5-hydroxydecanoic acid, which renders mK_ATP channels inactive. Extracellular Ca²⁺ did not contribute to the elevated [Ca²⁺]_i observed during hypoxia, as the effect persisted in Ca²⁺-free solution and during application of verapamil, an L-type Ca²⁺ channel blocker. By contrast, inhibition of the mitochondrial Ca²⁺ uniporter or ryanodine receptors (with ruthenium red or ryanodine, respectively) abolished the hypoxia-dependent rise in [Ca²⁺]_i. This study reports an mK_ATP-dependent rise in [Ca²⁺]_i during hypoxia in HCs activated by glutamate, and suggests roles for the mitochondria and intracellular Ca²⁺ stores in regulating this mechanism.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"300 ","pages":"Article 111786"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142752239","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}

{"title":"HSP70 is upregulated after heat but not freezing stress in the freeze-tolerant cricket Gryllus veletis","authors":"Victoria E. Adams,&nbsp;Maranda L. van Oirschot,&nbsp;Jantina Toxopeus","doi":"10.1016/j.cbpa.2024.111791","DOIUrl":"10.1016/j.cbpa.2024.111791","url":null,"abstract":"<div><div>Heat shock proteins (HSPs) are well known to prevent and repair protein damage caused by various abiotic stressors, but their role in low temperature and freezing stress is not well-characterized in insects compared to other thermal challenges such as heat stress. Ice formation in and around cells is hypothesized to cause protein damage, yet many species of insects can survive freezing, suggesting HSPs may be an important mechanism in freeze tolerance. Here, we studied <em>HSP70</em> in a freeze-tolerant cricket <em>Gryllus veletis</em> to better understand the role of HSPs in this phenomenon. We measured expression of one heat-inducible <em>HSP70</em> isoform at the mRNA level (using RT-qPCR), as well as the relative abundance of total HSP70 protein (using semi-quantitative Western blotting), in five tissues from crickets exposed to a survivable heat treatment (2 h at 40 °C), a 6-week fall-like acclimation that induces freeze tolerance, and a survivable freezing treatment (1.5 h at −8 °C). While <em>HSP70</em> expression was upregulated by heat at the mRNA or protein level in all tissues studied (fat body, Malphigian tubules, midgut, femur muscle, nervous system ganglia), no tissue exhibited <em>HSP70</em> upregulation within 2–24 h following a survivable freezing stress. During fall-like acclimation to mild low temperatures, we only saw moderate upregulation of <em>HSP70</em> at the protein level in muscle, and at the RNA level in fat body and nervous tissue. Although HSP70 is important for responding to a wide range of stressors, our work suggests that this chaperone may be less critical in the preparation for, and response to, moderate freezing stress.</div></div>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":"300 ","pages":"Article 111791"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142808734","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}