THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY最新文献_第5页

Thermogenesis is supported by high rates of circulatory fatty acid and triglyceride delivery in highland deer mice. 高原鹿小鼠的高循环脂肪酸和甘油三酯输送率支持产热。

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-13 DOI: 10.1242/jeb.244080

S. A. Lyons, G. McClelland

{"title":"Thermogenesis is supported by high rates of circulatory fatty acid and triglyceride delivery in highland deer mice.","authors":"S. A. Lyons, G. McClelland","doi":"10.1242/jeb.244080","DOIUrl":"https://doi.org/10.1242/jeb.244080","url":null,"abstract":"Highland native deer mice (Peromyscus maniculatus) have greater rates of lipid oxidation during maximal cold challenge in hypoxia (hypoxic cold-induced V˙O2max) compared to their lowland conspecifics. Lipid oxidation is also increased in deer mice acclimated to simulated high altitude (cold hypoxia), regardless of altitude ancestry. The underlying lipid metabolic pathway traits responsible for sustaining maximal thermogenic demand in deer mice is currently unknown. The objective of this study was to characterize key steps in the lipid oxidation pathway in highland and lowland deer mice acclimated to control (23oC, 21kPa O2) or cold hypoxic (5oC, 12kPa O2) conditions. We hypothesized that capacities for lipid delivery and tissue uptake will be greater in highlanders and further increase with cold hypoxia acclimation. With the transition from rest to hypoxic cold-induced V˙O2max, both highland and lowland deer mice showed increased plasma glycerol concentrations and fatty acid availability. Interestingly, cold hypoxia acclimation led to increased plasma triglyceride concentrations at cold-induced V˙O2max, but only in highlanders. Highlanders also had significantly greater delivery rates of circulatory free fatty acids and triglycerides due to higher plasma flow rates at cold-induced V˙O2max. We found no population or acclimation differences in fatty acid translocase (FAT/CD36) abundance in the gastrocnemius or brown adipose tissue, suggesting fatty acid uptake across membranes is not limiting during thermogenesis. Our data indicate that circulatory lipid delivery plays a major role in supporting the high thermogenic rates observed in highland versus lowland deer mice.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83032219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

A therian mammal with sprawling kinematics? Gait and 3D forelimb X-ray motion analysis in tamanduas. 一种伸展运动的兽类哺乳动物?tamanduas的步态和3D前肢x线运动分析。

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-13 DOI: 10.1242/jeb.243625

Adrian Scheidt, Paulo C Ditzel, S. Geiger, Franziska C. Wagner, C. Mülling, J. Nyakatura

{"title":"A therian mammal with sprawling kinematics? Gait and 3D forelimb X-ray motion analysis in tamanduas.","authors":"Adrian Scheidt, Paulo C Ditzel, S. Geiger, Franziska C. Wagner, C. Mülling, J. Nyakatura","doi":"10.1242/jeb.243625","DOIUrl":"https://doi.org/10.1242/jeb.243625","url":null,"abstract":"Therian mammals are known to move their forelimbs in a parasagittal plane, retracting the mobilised scapula during stance phase. Non-cursorial therian mammals often abduct the elbow out of the shoulder-hip parasagittal plane. This is especially prominent in Tamandua (Xenarthra), which suggests they employ aspects of sprawling (e.g., lizard-like-) locomotion. Here, we test if tamanduas use sprawling forelimb kinematics, i.e., a largely immobile scapula with pronounced lateral spine bending and long-axis rotation of the humerus. We analyse high speed videos and use X-ray motion analysis of tamanduas walking and balancing on branches of varying inclinations and provide a quantitative characterization of gaits and forelimb kinematics. Tamanduas displayed lateral sequence lateral-couplets gaits on flat ground and horizontal branches, but increased diagonality on steeper in- and declines, resulting in lateral sequence diagonal-couplets gaits. This result provides further evidence for high diagonality in arboreal species, likely maximising stability in arboreal environments. Further, the results reveal a mosaic of sprawling and parasagittal kinematic characteristics. The abducted elbow results from a constantly internally rotated scapula about its long axis and a retracted humerus. Scapula retraction contributes considerably to stride length. However, lateral rotation in the pectoral region of the spine (range: 21°) is higher than reported for other therian mammals. Instead, it is similar to skinks and alligators, indicating an aspect generally associated with sprawling locomotion is characteristic for forelimb kinematics of tamanduas. Our study contributes to a growing body of evidence of highly variable non-cursorial therian mammal locomotor kinematics.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82004048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Honey bees respond to multimodal stimuli following the principle of inverse effectiveness 蜜蜂对多模态刺激的反应遵循反作用原理

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-09 DOI: 10.1242/jeb.243832

Oswaldo Gil-Guevara, Hernán A. Bernal, A. J. Riveros

{"title":"Honey bees respond to multimodal stimuli following the principle of inverse effectiveness","authors":"Oswaldo Gil-Guevara, Hernán A. Bernal, A. J. Riveros","doi":"10.1242/jeb.243832","DOIUrl":"https://doi.org/10.1242/jeb.243832","url":null,"abstract":"ABSTRACT Multisensory integration is assumed to entail benefits for receivers across multiple ecological contexts. However, signal integration effectiveness is constrained by features of the spatiotemporal and intensity domains. How sensory modalities are integrated during tasks facilitated by learning and memory, such as pollination, remains unsolved. Honey bees use olfactory and visual cues during foraging, making them a good model to study the use of multimodal signals. Here, we examined the effect of stimulus intensity on both learning and memory performance of bees trained using unimodal or bimodal stimuli. We measured the performance and the latency response across planned discrete levels of stimulus intensity. We employed the conditioning of the proboscis extension response protocol in honey bees using an electromechanical setup allowing us to control simultaneously and precisely olfactory and visual stimuli at different intensities. Our results show that the bimodal enhancement during learning and memory was higher as the intensity decreased when the separate individual components were least effective. Still, this effect was not detectable for the latency of response. Remarkably, these results support the principle of inverse effectiveness, traditionally studied in vertebrates, predicting that multisensory stimuli are more effectively integrated when the best unisensory response is relatively weak. Thus, we argue that the performance of the bees while using a bimodal stimulus depends on the interaction and intensity of its individual components. We further hold that the inclusion of findings across all levels of analysis enriches the traditional understanding of the mechanics and reliance of complex signals in honey bees.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87342126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Additive and epistatic effects influence spectral tuning in molluscan retinochrome opsin. 加性和上位性效应影响软体动物视色素视蛋白的光谱调谐。

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-09 DOI: 10.1242/jeb.242929

G. D. Smedley, Kyle E. McElroy, K. Feller, J. Serb

{"title":"Additive and epistatic effects influence spectral tuning in molluscan retinochrome opsin.","authors":"G. D. Smedley, Kyle E. McElroy, K. Feller, J. Serb","doi":"10.1242/jeb.242929","DOIUrl":"https://doi.org/10.1242/jeb.242929","url":null,"abstract":"The relationship between genotype and phenotype is nontrivial due to often complex molecular pathways that make it difficult to unambiguously relate phenotypes to specific genotypes. Photopigments, an opsin apoprotein bound to a light-absorbing chromophore, present an opportunity to directly relate the amino acid sequence to an absorbance peak phenotype (λmax). We examined this relationship by conducting a series of site-directed mutagenesis experiments of retinochrome, a non-visual opsin, from two closely related species: the common bay scallop, Argopecten irradians, and the king scallop, Pecten maximus. Using protein folding models, we identified three amino acid sites of likely functional importance and expressed mutated retinochrome proteins in vitro. Our results show that the mutation of amino acids lining the opsin binding pocket are responsible for fine spectral tuning, or small changes in the λmax of these light sensitive proteins Mutations resulted in a blue or red shift as predicted, but with dissimilar magnitudes. Shifts ranged from a 16 nm blue shift to a 12 nm red shift from the wild-type λmax. These mutations do not show an additive effect, but rather suggests the presence of epistatic interactions. This work highlights the importance of binding pocket shape in the evolution of spectral tuning and builds on our ability to relate genotypic changes to phenotypes in an emerging model for opsin functional analysis.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74922873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

The functional basis for variable antipredatory behavioral strategies in the chameleon Chamaeleo calyptratus 变色龙可变反掠食行为策略的功能基础

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-06 DOI: 10.1242/jeb.242955

Rachel M Drown, A. Liebl, Christopher V. Anderson

{"title":"The functional basis for variable antipredatory behavioral strategies in the chameleon Chamaeleo calyptratus","authors":"Rachel M Drown, A. Liebl, Christopher V. Anderson","doi":"10.1242/jeb.242955","DOIUrl":"https://doi.org/10.1242/jeb.242955","url":null,"abstract":"ABSTRACT To counterbalance demands of different selective pressures, many species possess morphological, physiological and behavioral specializations that increase survival in their environments. Predation is one such pressure that can elicit multiple adaptive responses, and the effectiveness of antipredator behaviors likely vary both by environment and individual across time. Chameleons use multiple antipredator strategies, many of which vary with body size and habitat type. Although their unique morphological and physiological traits produce relatively slow locomotion, which is poorly suited for fleeing, chameleons can also use crypsis or aggression to avoid predation. To examine the functional basis for variable antipredator behavioral responses, we subjected chameleons to a series of mock predation trials and determined how often individuals adopted each antipredator strategy, and then quantified the performance capacities underlying each strategy. In particular, we measured bite force as a determinant for aggression, sprint velocity for fleeing, and degree of color change for crypsis. We found that aggression was predicted by traits associated with higher absolute and relative bite force, as well as habitat type; fleeing was predicted by higher normalized sprint velocity and habitat type; and crypsis was predicted by habitat type, color change capacity in bird color space and the interaction between the two. These results illustrate the importance of considering both functional capacity and environmental context in antipredator behavior decision-making.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88691942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Serotonin mediates stress-like effects on responses to non-nociceptive stimuli in the medicinal leech Hirudo verbana 5 -羟色胺介导应激样效应对非伤害性刺激的反应在药用水蛭蛭草

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-05 DOI: 10.1242/jeb.243404

D. Mack, Andrew Yevugah, K. Renner, B. Burrell

{"title":"Serotonin mediates stress-like effects on responses to non-nociceptive stimuli in the medicinal leech Hirudo verbana","authors":"D. Mack, Andrew Yevugah, K. Renner, B. Burrell","doi":"10.1242/jeb.243404","DOIUrl":"https://doi.org/10.1242/jeb.243404","url":null,"abstract":"ABSTRACT Noxious stimuli can elicit stress in animals that produce a variety of adaptations including changes in responses to nociceptive and non-nociceptive sensory input. One example is stress-induced analgesia that may be mediated, in part, by the endocannabinoid system. However, endocannabinoids can also have pro-nociceptive effects. In this study, the effects of electroshock, one experimental approach for producing acute stress, were examined on responses to non-nociceptive mechanical stimuli and nociceptive thermal stimuli in the medicinal leech (Hirudo verbana). The electroshock stimuli did not alter the leeches’ responses to nociceptive stimuli, but did cause sensitization to non-nociceptive stimuli, characterized by a reduction in response threshold. These experiments were repeated with drugs that either blocked synthesis of the endocannabinoid transmitter 2-arachidonoylglycerol (2-AG) or transient receptor potential vanilloid (TRPV) channel, which is known to act as an endocannabinoid receptor. Surprisingly, neither treatment had any effect on responses following electroshock. However, the electroshock stimuli reliably increased serotonin (5-hydroxytryptamine or 5HT) levels in the H. verbana CNS. Injection of 5HT mimicked the effects of the electroshocks, sensitizing responses to non-nociceptive stimuli and having no effect on responses to nociceptive stimuli. Injections of the 5HT receptor antagonist methysergide reduced the sensitization effect to non-nociceptive stimuli after electroshock treatment. These results indicate that electroshocks enhance response to non-nociceptive stimuli but do not alter responses to nociceptive stimuli. Furthermore, while 5HT appears to play a critical role in this shock-induced sensitizing effect, the endocannabinoid system seems to have no effect.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87665132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Context dependent effects on attack and defense behaviors in the praying mantis Tenodera sinensis. 环境对中华螳螂攻击和防御行为的影响。

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-03 DOI: 10.1242/jeb.243710

Jacob W. Bosse, Gavin J. Svenson, Troy A Bowers, Brendan M. BOURGES-SEVENIER, R. Ritzmann

{"title":"Context dependent effects on attack and defense behaviors in the praying mantis Tenodera sinensis.","authors":"Jacob W. Bosse, Gavin J. Svenson, Troy A Bowers, Brendan M. BOURGES-SEVENIER, R. Ritzmann","doi":"10.1242/jeb.243710","DOIUrl":"https://doi.org/10.1242/jeb.243710","url":null,"abstract":"Most behavior needs to strike a balance between the competing needs to find food and protect an animal from predators. The factors that influence this balance and the resulting behavior are not well understood in many animals. Here we examined these influences in the praying mantis Tenodera sinensis (Saussure) by presenting perching individuals with alternating sinusoidally moving prey-like stimuli and rapidly expanding looming stimuli then scoring their behavior on a defensive - aggressive scale. In this way, we tested the hypothesis that such behaviors are highly context dependent. Specifically, we found that defensive responses, which are normally very consistent, are decreased in magnitude if the animal has just performed an aggressive response to the previous sinusoid. A thrash behavior not normally seen with looming alone was often seen following aggression. In thrashing the animal tries to push the looming stimulus away. It almost exclusively followed aggressive responses to the sinusoid stimulus. Moreover, aggression levels were found to shift from low to high and back to low as adult animals aged and, in general, female mantises were more aggressive than males. Finally, the specific nature of the mid-life spike in aggressive behaviors differed according to whether the animals were lab-raised or caught in the wild. Lab raised animals showed roughly equal amounts of increased attention to the stimulus and very aggressive strike behaviors whereas wild caught animals tended to either ignore the stimulus or react very aggressively with strikes. Therefore, our hypothesis regarding context dependent effects was supported with all 4 factors influencing the behaviors that were studied.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91252260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Circulating Isotocin, not Angiotensin II, is the Major Dipsogenic Hormone in Eels. 循环异催产素，而不是血管紧张素II，是鳗鱼的主要致病激素。

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-03 DOI: 10.1242/jeb.244094

Shigenori Nobata, Y. Takei

{"title":"Circulating Isotocin, not Angiotensin II, is the Major Dipsogenic Hormone in Eels.","authors":"Shigenori Nobata, Y. Takei","doi":"10.1242/jeb.244094","DOIUrl":"https://doi.org/10.1242/jeb.244094","url":null,"abstract":"Angiotensin II (AngII) is generally known as the most important dipsogenic hormone throughout vertebrates, while two other neurohypophysial hormones, vasopressin and oxytocin, are not dipsogenic in mammals. In this study, we found that systemic isotocin, but not vasotocin, is the potent dipsogenic hormone in eels. When injected intra-arterially into conscious eels, isotocin, vasotocin and AngII equally increased ventral aortic pressure dose-dependently at 0.03-1.0 nmol/kg, but only isotocin induced copious drinking. The dipsogenic effect was dose-dependent and occurred significantly at as low as 0.1 nmol/kg. By contrast, a sustained inhibition of drinking occurred after AngII, probably due to baroreflexogenic inhibition. No such inhibition was observed after isotocin despite similar concurrent hypertension. The baroreceptor may exist distal to the gill circulation because the vasopressor effect occurred at both ventral and dorsal aorta after AngII but only at ventral aorta after isotocin. By contrast, intra-cerebroventricular (i.c.v.) injection of isotocin had no effect on drinking or blood pressure, but AngII increased drinking and aortic pressure dose-dependently at 0.03-0.3 nmol/eel. Lesioning of the area postrema (AP), a sensory circumventricular organ, abolished drinking induced by peripheral isotocin, but not i.c.v. AngII. Collectively, isotocin seems to be a major circulating hormone that induces swallowing through its action on the AP, while AngII may be an intrinsic brain peptide that induces drinking through its action on a different circumventricular site, possibly a recently identified blood-brain barrier-deficient structure in the antero-ventral third ventricle of eels, as shown in birds and mammals.","PeriodicalId":22458,"journal":{"name":"THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90060377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterizing the hypoxic performance of a fish using a new metric: PAAS-50. 用新指标PAAS-50表征鱼类的缺氧性能。

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-03 DOI: 10.1242/jeb.244239

Yangfan Zhang, D. W. Montgomery, C. White, J. Richards, C. Brauner, A. Farrell

引用次数: 3

An accelerometer-derived ballistocardiogram method for detecting heart rate in free-ranging marine mammals 一种用于检测自由放养的海洋哺乳动物心率的加速度计衍生的弹道心动图方法

THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY Pub Date : 2022-05-03 DOI: 10.1242/jeb.243872

M. Czapanskiy, P. Ponganis, J. Fahlbusch, T. Schmitt, J. Goldbogen

引用次数: 3