Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology最新文献_第7页

Seasonal variation in sleep time: jackdaws sleep when it is dark, but do they really need it? 睡眠时间的季节变化：寒鸦在天黑时睡觉，但它们真的需要吗？

IF 1.7 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-06-01 Epub Date: 2023-10-03 DOI: 10.1007/s00360-023-01517-1

Sjoerd J van Hasselt, Massimiliano Coscia, Giancarlo Allocca, Alexei L Vyssotski, Peter Meerlo

{"title":"Seasonal variation in sleep time: jackdaws sleep when it is dark, but do they really need it?","authors":"Sjoerd J van Hasselt, Massimiliano Coscia, Giancarlo Allocca, Alexei L Vyssotski, Peter Meerlo","doi":"10.1007/s00360-023-01517-1","DOIUrl":"10.1007/s00360-023-01517-1","url":null,"abstract":"Sleep is an important behavioural and physiological state that is ubiquitous throughout the animal kingdom. Birds are an interesting group to study sleep since they share similar sleep features with mammals. Interestingly, sleep time in birds has been shown to vary greatly amongst seasons. To understand the mechanisms behind these variations in sleep time, we did an electro-encephalogram (EEG) study in eight European jackdaws (Coloeus monedula) in winter and summer under outdoor seminatural conditions. To assess whether the amount and pattern of sleep is determined by the outdoor seasonal state of the animals or directly determined by the indoor light-dark cycle, we individually housed them indoors where we manipulated the light-dark (LD) cycles to mimic long winter nights (8:16 LD) and short summer nights (16:8 LD) within both seasons. Jackdaws showed under seminatural outdoor conditions 5 h less sleep in summer compared to winter. During the indoor conditions, the birds rapidly adjusted their sleep time to the new LD cycle. Although they swiftly increased or decreased their sleep time, sleep intensity did not vary. The results indicate that the strong seasonal differences in sleep time are largely and directly driven by the available dark time, rather than an endogenous annual clock. Importantly, these findings confirm that sleep in birds is not a rigid phenomenon but highly sensitive to environmental factors.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"335-345"},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11233326/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41174602","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

Sleep deprivation soon after recovery from synthetic torpor enhances tau protein dephosphorylation in the rat brain. 从合成迟钝中恢复后不久的睡眠剥夺增强了大鼠大脑中tau蛋白的去磷酸化。

IF 1.7 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-06-01 Epub Date: 2023-10-09 DOI: 10.1007/s00360-023-01516-2

Timna Hitrec, Fabio Squarcio, Emiliana Piscitiello, Matteo Cerri, Davide Martelli, Alessandra Occhinegro, Ludovico Taddei, Domenico Tupone, Roberto Amici, Marco Luppi

{"title":"Sleep deprivation soon after recovery from synthetic torpor enhances tau protein dephosphorylation in the rat brain.","authors":"Timna Hitrec, Fabio Squarcio, Emiliana Piscitiello, Matteo Cerri, Davide Martelli, Alessandra Occhinegro, Ludovico Taddei, Domenico Tupone, Roberto Amici, Marco Luppi","doi":"10.1007/s00360-023-01516-2","DOIUrl":"10.1007/s00360-023-01516-2","url":null,"abstract":"Neuronal Tau protein hyperphosphorylation (PPtau) is a hallmark of tauopathic neurodegeneration. However, a reversible brain PPtau occurs in mammals during either natural or \"synthetic\" torpor (ST), a transient deep hypothermic state that can be pharmacologically induced in rats. Since in both conditions a high sleep pressure builds up during the regaining of euthermia, the aim of this work was to assess the possible role of post-ST sleep in PPtau dephosphorylation. Male rats were studied at the hypothermic nadir of ST, and 3-6 h after the recovery of euthermia, after either normal sleep (NS) or total sleep deprivation (SD). The effects of SD were studied by assessing: (i) deep brain temperature (Tb); (ii) immunofluorescent staining for AT8 (phosphorylated Tau) and Tau-1 (non-phosphorylated Tau), assessed in 19 brain structures; (iii) different phosphorylated forms of Tau and the main cellular factors involved in Tau phospho-regulation, including pro- and anti-apoptotic markers, assessed through western blot in the parietal cortex and hippocampus; (iv) systemic factors which are involved in natural torpor; (v) microglia activation state, by considering morphometric variations. Unexpectedly, the reversibility of PPtau was more efficient in SD than in NS animals, and was concomitant with a higher Tb, higher melatonin plasma levels, and a higher frequency of the microglia resting phenotype. Since the reversibility of ST-induced PPtau was previously shown to be driven by a latent physiological molecular mechanism triggered by deep hypothermia, short-term SD soon after the regaining of euthermia seems to boost the possible neuroprotective effects of this mechanism.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"347-368"},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41162347","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

Embryonic methionine triggers post-natal developmental programming in Japanese quail. 胚胎蛋氨酸触发了日本鹌鹑出生后的发育程序。

IF 2 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-04-01 Epub Date: 2024-03-23 DOI: 10.1007/s00360-024-01542-8

Sawadi F Ndunguru, Gebrehaweria K Reda, Brigitta Csernus, Renáta Knop, Gabriella Gulyás, Csaba Szabó, Levente Czeglédi, Ádám Z Lendvai

{"title":"Embryonic methionine triggers post-natal developmental programming in Japanese quail.","authors":"Sawadi F Ndunguru, Gebrehaweria K Reda, Brigitta Csernus, Renáta Knop, Gabriella Gulyás, Csaba Szabó, Levente Czeglédi, Ádám Z Lendvai","doi":"10.1007/s00360-024-01542-8","DOIUrl":"10.1007/s00360-024-01542-8","url":null,"abstract":"Embryonic development is one of the most sensitive and critical stages when maternal effects may influence the offspring's phenotype. In birds and other oviparous species, embryonic development is confined to the eggs, therefore females must deposit resources into the eggs to prepare the offspring for the prevailing post-natal conditions. However, the mechanisms of such phenotypic adjustments remain poorly understood. We simulated a maternal nutritional transfer by injecting 1 mg of L-methionine solution into Japanese quail eggs before the onset of incubation. The increase in early methionine concentration in eggs activated the insulin/insulin-like signalling and mechanistic target of rapamycin (IIS/mTOR) signalling pathways and affected post-natal developmental trajectories. Chicks from methionine-supplemented eggs had higher expression of liver IGF1 and mTOR genes at hatching but were similar in size, and the phenotypic effects of increased growth became apparent only a week later and remained up to three weeks. Circulating levels of insulin-like growth factor-1 (IGF-1) and expression of ribosomal protein serine 6 kinase 1 (RPS6K1), the mTOR downstream effector, were elevated only three weeks after hatching. These results show that specific nutritional cues may have phenotypic programming effects by sequentially activating specific nutrient-sensing pathways and achieving transgenerational phenotypic plasticity.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"179-189"},"PeriodicalIF":2.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11070397/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140195197","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

The costs of overwintering in paper wasps (Polistes dominula and Polistes gallicus): the use of energy stores. 纸黄蜂（Polistes dominula 和 Polistes gallicus）的越冬成本：能量储存的使用。

IF 1.7 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-04-01 Epub Date: 2024-03-05 DOI: 10.1007/s00360-024-01540-w

Anton Stabentheiner, Teresa Mauerhofer, Regina Willfurth, Helmut Kovac, Edith Stabentheiner, Helmut Käfer, Iacopo Petrocelli

{"title":"The costs of overwintering in paper wasps (Polistes dominula and Polistes gallicus): the use of energy stores.","authors":"Anton Stabentheiner, Teresa Mauerhofer, Regina Willfurth, Helmut Kovac, Edith Stabentheiner, Helmut Käfer, Iacopo Petrocelli","doi":"10.1007/s00360-024-01540-w","DOIUrl":"10.1007/s00360-024-01540-w","url":null,"abstract":"Overwintering insects are facing energetic challenges because of food shortage, low temperature, and desiccation stress. Paper wasps of the genus Polistes overwinter as mated adults (gynes) in hibernacula protecting them from predation, snow, and rain but barely from low environmental temperature. In different climates, they face differing overwintering temperature regimes, and therefore they may differ in their energy use. We investigated how much of energy resources built up until autumn is used during diapause dormancy in natural hibernacula by measuring lipid, glycogen, and free carbohydrate content in autumn and early spring in Polistes dominula from temperate European (Austrian) and warm Mediterranean (Italian) climate and Polistes gallicus from Mediterranean climate. Winter energy consumption amounted to ~ 339 and ~ 310 J per wasp in the Austrian and Italian Polistes dominula populations. The smaller Italian Polistes gallicus consumed ~ 247 J. This amounts to 2.62, 2.35, and 1.79 J per day. Of this, the energy demand was mainly fuelled by lipids (84%, 93%, and 90%, respectively), but glycogen stores contributed also considerably (16%, 6%, and 9%). Free carbohydrates decreased only by 0.7%, 1%, and 0.8%. While fat stores seem still sufficient in spring, the wasps depleted most of their carbohydrates. The energy reserves of 396, 400, and 147 J per wasp remaining in spring in the three populations seem sufficient to fuel rest or simple brood care activities for a whole summer but restrict foraging flights to a few hours (~ 3.5-6 h). Results suggest that energy supply might become challenging in expected future climate scenarios.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"131-144"},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11070328/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140029651","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

An investigation of gill and blood carbonic anhydrase characteristics in three basal actinopterygian species: alligator gar (Atractosteus spatula), white sturgeon (Acipenser transmontanus) and Senegal bichir (Polypterus senegalus). 对三种基础翼手目动物：鳄鱼（Atractosteus spatula）、白鲟（Acipenser transmontanus）和塞内加尔比奇鱼（Polypterus senegalus）的鳃和血液碳酸酐酶特性的研究。

IF 2 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-04-01 Epub Date: 2024-03-09 DOI: 10.1007/s00360-024-01539-3

Charlotte Nelson, Emily M Standen, Peter J Allen, Colin J Brauner

{"title":"An investigation of gill and blood carbonic anhydrase characteristics in three basal actinopterygian species: alligator gar (Atractosteus spatula), white sturgeon (Acipenser transmontanus) and Senegal bichir (Polypterus senegalus).","authors":"Charlotte Nelson, Emily M Standen, Peter J Allen, Colin J Brauner","doi":"10.1007/s00360-024-01539-3","DOIUrl":"10.1007/s00360-024-01539-3","url":null,"abstract":"Many teleosts possess a unique set of respiratory characteristics allowing enhanced oxygen unloading to the tissues during stress. This system comprises three major components: highly pH sensitive haemoglobins (large Bohr and Root effects), rapid red blood cell (RBC) intracellular pH (pHi) protection, and a heterogeneous distribution of membrane-bound plasma-accessible carbonic anhydrase (paCA; absence in the gills). The first two components have received considerable research effort; however, the evolutionary loss of branchial paCA has received little attention. In the current study, we investigated the availability of branchial membrane-bound CA, along with several other CA-related characteristics in species belonging to three basal actinopterygian groups: the Lepisosteiformes, Acipenseriformes and Polypteriformes to assess the earlier hypothesis that Root effect haemoglobins constrain branchial paCA availability. We present the first evidence suggesting branchial membrane-bound CA presence in a basal actinopterygian species: the Senegal bichir (Polypterus senegalus) and show that like the teleosts, white sturgeon (Acipenser transmontanus) and alligator gar (Atractosteus spatula) do not possess branchial membrane-bound CA. We discuss the varying respiratory strategies for these species and propose that branchial paCA may have been lost much earlier than previously thought, likely in relation to the changes in haemoglobin buffer capacity associated with the increasing magnitude of the Bohr effect. The findings described here represent an important advancement in our understanding of the evolution of the unique system of enhanced oxygen unloading thought to be present in most teleosts, a group that encompasses half of all vertebrates.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"155-166"},"PeriodicalIF":2.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140068935","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

Evidence for transporter-mediated uptake of environmental L-glutamate in a freshwater sponge, Ephydatia muelleri. 淡水海绵 Ephydatia muelleri 通过转运体吸收环境中 L-谷氨酸的证据。

IF 2 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-04-01 Epub Date: 2024-03-29 DOI: 10.1007/s00360-024-01544-6

Alyssa M Weinrauch, Zachary J Dumar, Sienna L Overduin, Greg G Goss, Sally P Leys, Tamzin A Blewett

{"title":"Evidence for transporter-mediated uptake of environmental L-glutamate in a freshwater sponge, Ephydatia muelleri.","authors":"Alyssa M Weinrauch, Zachary J Dumar, Sienna L Overduin, Greg G Goss, Sally P Leys, Tamzin A Blewett","doi":"10.1007/s00360-024-01544-6","DOIUrl":"10.1007/s00360-024-01544-6","url":null,"abstract":"The freshwater sponge, Ephydatia muelleri, lacks a nervous or endocrine system and yet it exhibits a coordinated whole-body action known as a \"sneeze\" that can be triggered by exposure to L-glutamate. It is not known how L-glutamate is obtained by E. muelleri in sufficient quantities (i.e., 70 µM) to mediate this response endogenously. The present study tested the hypothesis that L-glutamate can be directly acquired from the environment across the body surface of E. muelleri. We demonstrate carrier mediated uptake of two distinct saturable systems with maximal transport rates (Jmax) of 64.27 ± 4.98 and 25.12 ± 1.87 pmols mg-1 min-1, respectively. The latter system has a higher calculated substrate affinity (Km) of 2.87 ± 0.38 µM compared to the former (8.75 ± 1.00 µM), indicative of distinct systems that can acquire L-glutamate at variable environmental concentrations. Further characterization revealed potential shared pathways of L-glutamate uptake with other negatively charged amino acids, namely D-glutamate and L-aspartate, as well as the neutral amino acid L-alanine. We demonstrate that L-glutamate uptake does not appear to rely on exogenous sodium or proton concentrations as removal of these ions from the bathing media did not significantly alter uptake. Likewise, L-glutamate uptake does not seem to rely on internal proton motive forces driven by VHA as application of 100 nM of the VHA inhibitor bafilomycin did not alter uptake rates within E. muelleri tissues. Whether the acquired amino acid is used to supplement feeding or is stored and accumulated to mediate the sneeze response remains to be determined.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"121-130"},"PeriodicalIF":2.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140327471","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

Plasticity changes in iron homeostasis in hibernating Daurian ground squirrels (Spermophilus dauricus) may counteract chronically inactive skeletal muscle atrophy. 冬眠的达乌尔地松鼠（Spermophilus dauricus）体内铁平衡的可塑性变化可能会抵消长期不活动的骨骼肌萎缩。

IF 2 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-04-01 Epub Date: 2024-03-24 DOI: 10.1007/s00360-024-01543-7

Yong Kong, Rongrong Yin, Yue He, Fangyang Pan, Huajian Yang, Huiping Wang, Jie Zhang, Yunfang Gao

{"title":"Plasticity changes in iron homeostasis in hibernating Daurian ground squirrels (Spermophilus dauricus) may counteract chronically inactive skeletal muscle atrophy.","authors":"Yong Kong, Rongrong Yin, Yue He, Fangyang Pan, Huajian Yang, Huiping Wang, Jie Zhang, Yunfang Gao","doi":"10.1007/s00360-024-01543-7","DOIUrl":"10.1007/s00360-024-01543-7","url":null,"abstract":"Disuse-induced muscular atrophy is frequently accompanied by iron overload. Hibernating animals are a natural animal model for resistance to disuse muscle atrophy. In this paper, we explored changes in skeletal muscle iron content of Daurian ground squirrels (Spermophilus dauricus) during different periods of hibernation as well as the regulatory mechanisms involved. The results revealed that compared with the summer active group (SA), iron content in the soleus muscle (SOL) decreased (- 65%) in the torpor group (TOR), but returned to normal levels in the inter-bout arousal (IBA); splenic iron content increased in the TOR group (vs. SA, + 67%), decreased in the IBA group (vs. TOR, - 37%). Expression of serum hepcidin decreased in the TOR group (vs. SA, - 22%) and returned to normal levels in the IBA groups; serum ferritin increased in the TOR group (vs. SA, + 31%), then recovered in the IBA groups. Soleus muscle transferrin receptor 1 (TfR1) expression increased in the TOR group (vs. SA, + 83%), decreased in the IBA group (vs. TOR, - 30%); ferroportin 1 increased in the IBA group (vs. SA, + 55%); ferritin increased in the IBA group (vs. SA, + 42%). No significant differences in extensor digitorum longus in iron content or iron metabolism-related protein expression were observed among the groups. Significantly, all increased or decreased indicators in this study returned to normal levels after the post-hibernation group, showing remarkable plasticity. In summary, avoiding iron overload may be a potential mechanism for hibernating Daurian ground squirrels to avoid disuse induced muscular atrophy. In addition, the different skeletal muscle types exhibited unique strategies for regulating iron homeostasis.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"191-202"},"PeriodicalIF":2.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140195198","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

Hypoxic and hypercapnic burrow conditions lead to downregulation of free triiodothyronine and hematocrit in Ansell's mole-rats (Fukomys anselli). 缺氧和高碳酸洞穴条件导致安塞尔鼹鼠游离三碘甲状腺原氨酸和红细胞压积的下调(Fukomys anselli)。

IF 2 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-02-01 Epub Date: 2023-12-07 DOI: 10.1007/s00360-023-01526-0

Yoshiyuki Henning, Kamilla Adam, Patricia Gerhardt, Sabine Begall

{"title":"Hypoxic and hypercapnic burrow conditions lead to downregulation of free triiodothyronine and hematocrit in Ansell's mole-rats (Fukomys anselli).","authors":"Yoshiyuki Henning, Kamilla Adam, Patricia Gerhardt, Sabine Begall","doi":"10.1007/s00360-023-01526-0","DOIUrl":"10.1007/s00360-023-01526-0","url":null,"abstract":"African mole-rats live in self-dug burrow systems under hypoxic and hypercapnic conditions. Adaptations to hypoxia include suppression of resting metabolic rate (RMR) and core body temperature (Tb). Because the thyroid hormones (THs) thyroxine (T4) and triiodothyronine (T3) are positive regulators of RMR and Tb, we hypothesized that serum TH concentrations would also be downregulated under hypoxic conditions. To test this hypothesis, we kept Ansell's mole-rats (Fukomys anselli) in terraria filled with soil in which they were allowed to construct underground burrows to achieve chronic intermittent hypoxia and hypercapnia. The animals stayed in these hypoxic and hypercapnic burrows voluntarily, although given the choice to stay aboveground. We collected blood samples before and after treatment to measure serum T4 and T3 concentrations as well as hematological parameters. The free fraction of the transcriptionally-active T3 was significantly decreased after treatment, indicating that cellular TH signaling was downregulated via peripheral mechanisms, consistent with the assumption that aerobic metabolism is downregulated under hypoxic conditions. Furthermore, we found that hematocrit and hemoglobin concentrations were also downregulated after treatment, suggesting that oxygen demand decreases under hypoxia, presumably due to the metabolic shift towards anaerobic metabolism. Taken together, we have identified a potential upstream regulator of physiological adaptations to hypoxia in these highly hypoxia-tolerant animals.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"33-40"},"PeriodicalIF":2.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10940439/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138500343","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

Functional interactions between coat structure and colour in the determination of solar heat load on arid living kangaroos in summer: balancing crypsis and thermoregulation. 被毛结构和颜色在决定夏季干旱生活袋鼠的太阳热负荷中的功能相互作用：平衡隐性和体温调节。

IF 2 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-02-01 Epub Date: 2024-02-09 DOI: 10.1007/s00360-024-01534-8

Terence J Dawson, Shane K Maloney

{"title":"Functional interactions between coat structure and colour in the determination of solar heat load on arid living kangaroos in summer: balancing crypsis and thermoregulation.","authors":"Terence J Dawson, Shane K Maloney","doi":"10.1007/s00360-024-01534-8","DOIUrl":"10.1007/s00360-024-01534-8","url":null,"abstract":"Interactions of solar radiation with mammal fur are complex. Reflection of radiation in the visible spectrum provides colour that has various roles, including sexual display and crypsis, i.e., camouflage. Radiation that is absorbed by a fur coat is converted to heat, a proportion of which impacts on the skin. Not all absorption occurs at the coat surface, and some radiation penetrates the coat before being absorbed, particularly in lighter coats. In studies on this phenomenon in kangaroos, we found that two arid zone species with the thinnest coats had similar effective heat load, despite markedly different solar reflectances. These kangaroos were Red Kangaroos (Osphranter rufus) and Western Grey Kangaroos (Macropus fuliginosus).Here we examine the connections between heat flow patterns associated with solar radiation, and the physical structure of these coats. Also noted are the impacts of changing wind speed. The modulation of solar radiation and resultant heat flows in these coats were measured at wind speeds from 1 to 10 m s-1 by mounting them on a heat flux transducer/temperature-controlled plate apparatus in a wind tunnel. A lamp with a spectrum like solar radiation was used as a proxy for the sun. The integrated reflectance across the solar spectrum was higher in the red kangaroos (40 ± 2%) than in the grey kangaroos (28 ± 1%). Fur depth and insulation were not different between the two species, but differences occurred in fibre structure, notably in fibre length, fibre density and fibre shape. Patterns of heat flux within the species' coats occurred despite no overall difference in effective solar heat load. We consider that an overarching need for crypsis, particularly for the more open desert-adapted red kangaroo, has led to the complex adaptations that retard the penetrance of solar radiation into its more reflective fur.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"53-64"},"PeriodicalIF":2.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10940446/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139713421","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

Expression patterns of heat-shock genes during stopover and the trade-off between refueling and stress response in a passerine migrant. 停留期间热休克基因的表达模式以及雀形目迁徙鸟在补充能量和应激反应之间的权衡。

IF 2 3区生物学

Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology Pub Date : 2024-02-01 Epub Date: 2024-01-31 DOI: 10.1007/s00360-023-01529-x

Anastasios Bounas, Chrysoula Komini, Elisavet-Aspasia Toli, Artemis Talioura, Konstantinos Sotiropoulos, Christos Barboutis

{"title":"Expression patterns of heat-shock genes during stopover and the trade-off between refueling and stress response in a passerine migrant.","authors":"Anastasios Bounas, Chrysoula Komini, Elisavet-Aspasia Toli, Artemis Talioura, Konstantinos Sotiropoulos, Christos Barboutis","doi":"10.1007/s00360-023-01529-x","DOIUrl":"10.1007/s00360-023-01529-x","url":null,"abstract":"Migrating birds are often exposed to variable environments and face a multitude of stress exposures along their long-distance flights. During stopover refueling, migratory birds must balance the need to accumulate energy reserves to continue their migration with the need to respond to environmental and physiological stressors. We examined the gene expression patterns of different Heat Shock Proteins (HSPs) in migrating birds during stopover at different body condition states (lean vs. fat), to provide some first insights on the role of HSPs in bird migration and explore the concept of a trade-off between refueling and stress response. Our results showed upregulation of HSP expression at release that could be associated with muscle growth and increased cholesterol and lipid synthesis needed for birds to fuel their upcoming migration. On the other hand, during capture, upregulation of HSP5 could be attributed to physiological recovery from the non-stop endurance flight when crossing the Sahara Desert-Mediterranean Sea ecological barrier. All birds significantly increased their fuel loads up to 48% of lean body mass and we provide evidence for muscle rebuilding during stopover as flight muscle mass increased by 10%, highlighting the fact that stopover sites can play a major role in the physiological recovery of migrants.","PeriodicalId":56033,"journal":{"name":"Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology","volume":" ","pages":"1-6"},"PeriodicalIF":2.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10940366/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139652284","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}

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