scholarly journals Fast weight recovery, metabolic rate adjustment and gene-expression regulation define responses of cold-stressed honey bee brood

2020 ◽  
Author(s):  
Leonor Ramirez ◽  
Facundo Luna ◽  
Claudio Andoni Mucci ◽  
Lorenzo Lamattina
Keyword(s):  
Metabolic Rate ◽  
Cold Stress ◽  
Honey Bee ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Gene Expression Regulation ◽  
Uncoupling Protein ◽  
Late Winter ◽  
Adipokinetic Hormone ◽  
Regulatory Pathways

ABSTRACTIn temperate climates, low ambient temperatures in late winter and in spring can result in cold stress conditions in brood areas of weakened honey bee colonies, leading to increased levels of developmental interruptions and death of the brood. Very little is known about the physiological and molecular mechanisms that regulate honey bee brood responses to acute cold-stress. Here, we hypothesized that central regulatory pathways mediated by insulin/insulin-like peptide signalling (IIS) and adipokinetic hormone (AKH) are linked to metabolic changes in cold-stressed honey bee brood. A. mellifera brood reared at suboptimal temperatures showed diminished growth rate and arrested development progress. Notably, cold-stressed brood rapidly recovers the growth in the first 24 h after returning at control rearing temperature, sustained by the induction of compensatory mechanisms. We determined fast changes in the expression of components of IIS and AKH pathways in cold-stressed brood supporting their participation in metabolic events, growth and stress responses. We also showed that metabolic rate keeps high in brood exposed to stress suggesting a role in energy supply for growth and cell repair. Additionally, transcript levels of the uncoupling protein MUP2 were elevated in cold-stressed brood, suggesting a role for heat generation through mitochondrial decoupling mechanisms and/or ROS attenuation. Physiological, metabolic and molecular mechanisms that shape the responses to cold-stress in honey bee brood are addressed and discussed.

scholarly journals Overexpression of SgGH3.1 from Fine-Stem Stylo (Stylosanthes guianensis var. intermedia) Enhances Chilling and Cold Tolerance in Arabidopsis thaliana

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1367
Author(s):  
Ming Jiang ◽  
Long-Long Ma ◽  
Huai-An Huang ◽  
Shan-Wen Ke ◽  
Chun-Sheng Gui ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cold Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Transcriptome Profiling ◽  
Pasture Legumes ◽  
Cold Tolerant ◽  
Whole Transcriptome ◽  
Altered Sensitivity ◽  
Exogenous Iaa

Stylosanthes (stylo) species are commercially significant tropical and subtropical forage and pasture legumes that are vulnerable to chilling and frost. However, little is known about the molecular mechanisms behind stylos’ responses to low temperature stress. Gretchen-Hagen 3 (GH3) proteins have been extensively investigated in many plant species for their roles in auxin homeostasis and abiotic stress responses, but none have been reported in stylos. SgGH3.1, a cold-responsive gene identified in a whole transcriptome profiling study of fine-stem stylo (S. guianensis var. intermedia) was further investigated for its involvement in cold stress tolerance. SgGH3.1 shared a high percentage of identity with 14 leguminous GH3 proteins, ranging from 79% to 93%. Phylogenetic analysis classified SgGH3.1 into Group Ⅱ of GH3 family, which have been proven to involve with auxins conjugation. Expression profiling revealed that SgGH3.1 responded rapidly to cold stress in stylo leaves. Overexpression of SgGH3.1 in Arabidopsis thaliana altered sensitivity to exogenous IAA, up-regulated transcription of AtCBF1-3 genes, activated physiological responses against cold stress, and enhanced chilling and cold tolerances. This is the first report of a GH3 gene in stylos, which not only validated its function in IAA homeostasis and cold responses, but also gave insight into breeding of cold-tolerant stylos.

scholarly journals PACAP is essential for the adaptive thermogenic response of brown adipose tissue to cold exposure

2014 ◽  
Vol 222 (3) ◽  
pp. 327-339 ◽  
Author(s):  
Abdoulaye Diané ◽  
Nikolina Nikolic ◽  
Alexander P Rudecki ◽  
Shannon M King ◽  
Drew J Bowie ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Metabolic Rate ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Molecular Mechanisms ◽  
Uncoupling Protein ◽  
Morphological Properties ◽  
Brown Adipose ◽  
Thermogenic Response

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a widely distributed neuropeptide that acts as a neurotransmitter, neuromodulator, neurotropic factor, neuroprotectant, secretagogue,and neurohormone. Owing to its pleiotropic biological actions, knockout ofPacap(Adcyap1) has been shown to induce several abnormalities in mice such as impaired thermoregulation. However, the underlying physiological and molecular mechanisms remain unclear. A previous report has shown that cold-exposedPacapnull mice cannot supply appropriate levels of norepinephrine (NE) to brown adipocytes. Therefore, we hypothesized that exogenous NE would rescue the impaired thermogenic response ofPacapnull mice during cold exposure. We compared the adaptive thermogenic capacity ofPacap−/−toPacap+/+mice in response to NE when housed at room temperature (24 °C) and after a 3.5-week cold exposure (4 °C). Biochemical parameters, expression of thermogenic genes, and morphological properties of brown adipose tissue (BAT) and white adipose tissue (WAT) were also characterized. Results showed that there was a significant effect of temperature, but no effect of genotype, on the resting metabolic rate in conscious, unrestrained mice. However, the normal cold-induced increase in the basal metabolic rate and NE-induced increase in thermogenesis were severely blunted in cold-exposedPacap−/−mice. These changes were associated with altered substrate utilization, reduced β3-adrenergic receptor (β3-Ar(Adrb3)) and hormone-sensitive lipase (Hsl(Lipe)) gene expression, and increased fibroblast growth factor 2 (Fgf2) gene expression in BAT. Interestingly,Pacap−/−mice had depleted WAT depots, associated with upregulated uncoupling protein 1 expression in inguinal WATs. These results suggest that the impairment of adaptive thermogenesis inPacapnull mice cannot be rescued by exogenous NE perhaps in part due to decreased β3-Ar-mediated BAT activation.

scholarly journals Comparative Analysis of Transcriptome Responses to Cold Stress in Galeruca daurica (Coleoptera: Chrysomelidae)

2019 ◽  
Vol 19 (6) ◽  
Author(s):  
Xiao-Rong Zhou ◽  
Yan-Min Shan ◽  
Yao Tan ◽  
Zhuo-Ran Zhang ◽  
Bao-Ping Pang
Keyword(s):  
Cold Stress ◽  
Stress Responses ◽  
Low Temperatures ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Transcriptome Assembly ◽  
Glucose Dehydrogenase ◽  
Insect Pest ◽  
Cuticle Protein

Abstract Galeruca daurica (Joannis) has become a new insect pest in the Inner Mongolia grasslands since 2009, and its larvae and eggs have strong cold tolerance. To get a deeper insight into its molecular mechanisms of cold stress responses, we performed de novo transcriptome assembly for G. daurica by RNA-Seq and compared the transcriptomes of its larvae exposed to five different temperature treatments (−10, −5, 0, 5, and 25°C for 1 h and then recovered at 25°C for 1 h), respectively. Compared with the control (25°C), the numbers of differentially expressed genes (DEGs) decreased from 1,821 to 882, with the temperature declining from 5 to −10°C. Moreover, we obtained 323 coregulated DEGs under different low temperatures. Under four low temperatures (−10, −5, 0, and 5°C), a large number of genes were commonly upregulated during recovery from cold stresses, including those related to cuticle protein, followed by cytochrome P450, clock protein, fatty acid synthase, and fatty acyl-CoA reductase; meanwhile, lots of genes encoding cuticle protein, RNA replication protein, RNA-directed DNA polymerase, and glucose dehydrogenase were commonly downregulated. Our findings provide important clues for further investigations of key genes and molecular mechanisms involved in the adaptation of G. daurica to harsh environments.

scholarly journals Physiological Responses and Proteomic Analysis on the Cold Stress Responses of Annual Pitaya (Hylocereus spp.) Branches

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Junliang Zhou ◽  
Lijuan Wang ◽  
Tujian Xiao ◽  
Zhuang Wang ◽  
Yongya Mao ◽  
...  
Keyword(s):  
Cold Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Cold Resistance ◽  
Physiological Responses ◽  
Soluble Sugar ◽  
Multivariate Statistical ◽  
Chlorophyll Contents ◽  
Proteomic Approach ◽  
Related Proteins

In this study, the physiological response of the annual branches of three varieties of pitaya (Xianmi, Fulong, and Zihonglong) in cold stress was investigated using a multivariate statistical method. Physiological change results showed that cold stress could decrease the moisture and chlorophyll contents, on the contrary, increase the relative electric conductivity, the contents of malonadehyde, soluble protein, soluble sugar, and free proline, and enhance the enzyme activities of peroxidase, superoxide dismutase, and catalase. Meanwhile, a comparative proteomic approach was also conducted to clarify the cold resistance-related proteins and pathways in annual pitaya branches. Proteomics results concluded that the cold tolerance of annual pitaya branches could be improved by modulating autophagy. Therefore, we hypothesized that an increased autophagy ability may be an important characteristic of the annual pitaya branches in response to cold stress conditions. Our results provide a good understanding of the physiological responses and molecular mechanisms of the annual pitaya branches in response to cold stress.

scholarly journals Characterization of Biological Pathways Regulating Acute Cold Resistance of Zebrafish

2021 ◽  
Vol 22 (6) ◽  
pp. 3028
Author(s):  
Jing Ren ◽  
Yong Long ◽  
Ran Liu ◽  
Guili Song ◽  
Qing Li ◽  
...  
Keyword(s):  
Cold Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Cold Resistance ◽  
Biological Pathways ◽  
Mitogen Activated Protein Kinase ◽  
Rna Seq ◽  
Zebrafish Larvae ◽  
P53 Signaling ◽  
Mitogen Activated Protein

Low temperature stress represents a major threat to the lives of both farmed and wild fish species. However, biological pathways determining the development of cold resistance in fish remain largely unknown. Zebrafish larvae at 96 hpf were exposed to lethal cold stress (10 °C) for different time periods to evaluate the adverse effects at organism, tissue and cell levels. Time series RNA sequencing (RNA-seq) experiments were performed to delineate the transcriptomic landscape of zebrafish larvae under cold stress and during the subsequent rewarming phase. The genes regulated by cold stress were characterized by progressively enhanced or decreased expression, whereas the genes associated with rewarming were characterized by rapid upregulation upon return to normal temperature (28 °C). Genes such as trib3, dusp5 and otud1 were identified as the representative molecular markers of cold-induced damages through network analysis. Biological pathways involved in cold stress responses were mined from the transcriptomic data and their functions in regulating cold resistance were validated using specific inhibitors. The autophagy, FoxO and MAPK (mitogen-activated protein kinase) signaling pathways were revealed to be survival pathways for enhancing cold resistance, while apoptosis and necroptosis were the death pathways responsible for cold-induced mortality. Functional mechanisms of the survival-enhancing factors Foxo1, ERK (extracellular signal-regulated kinase) and p38 MAPK were further characterized by inhibiting their activities upon cold stress and analyzing gene expression though RNA-seq. These factors were demonstrated to determine the cold resistance of zebrafish through regulating apoptosis and p53 signaling pathway. These findings have provided novel insights into the stress responses elicited by lethal cold and shed new light on the molecular mechanisms underlying cold resistance of fish.

scholarly journals Effects of cold stress and starvation on the liver of yellow drum Nibea albiflora: histological alterations and transcriptomic analysis

2020 ◽  
Vol 12 ◽  
pp. 359-369
Author(s):  
Q Zhu ◽  
H Song ◽  
Y Zhang ◽  
R Chen ◽  
L Tian ◽  
...  
Keyword(s):  
Cold Stress ◽  
Mass Loss ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Body Weight Loss ◽  
Transcriptomic Analysis ◽  
Feeding Strategies ◽  
Cold Temperatures ◽  
Histological Alterations ◽  
Nibea Albiflora

The yellow drum Nibea albiflora is a marine fish of great economic value in China. Despite efforts to improve yields, aquaculture of this species has been hindered by increases in winter-related mortalities associated with cold temperatures and associated natural fasting periods. To better understand the molecular mechanisms that regulate stress responses in yellow drum during periods of cold and starvation, the effect of these stresses on the liver was investigated by performing comparative analyses among fish subjected to different temperatures and feeding strategies. The experiment lasted for 22 d and involved 4 groups: one fed group (control) and one fasted group at 16°C, and one fed group and one fasted group at 8°C. Our results showed that all stress-treated groups exhibited body weight loss during the experiment, demonstrating that both cold stress and fasting caused growth inhibition, but only the fish in the fasted group at 16°C showed a loss in the liver/body ratio, suggesting that starvation can cause mass loss in the liver while cold stress can result in mass loss in both liver and other tissues. Histological alterations were observed in the liver cells from stress-treated groups, also indicating mass loss in the liver during cold stress and starvation. Transcriptomic analysis showed that genes related to the metabolism of carbohydrates, lipids and amino acids were the most enriched differentially expressed genes during the challenge conditions. These findings can help reveal molecular mechanisms regulating the stress responses of yellow drum exposed to cold and starvation.

scholarly journals Novel insights into the cold resistance of Hevea brasiliensis through coexpression networks

2021 ◽  
Author(s):  
Carla Cristina Silva ◽  
Stephanie Karenina Bajay ◽  
Alexandre Hild Aono ◽  
Felipe Roberto Francisco ◽  
Ramir Bavaresco Junior ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cold Stress ◽  
Cold Exposure ◽  
Stress Responses ◽  
Hevea Brasiliensis ◽  
Large Scale ◽  
Gene Expression Regulation ◽  
Rubber Tree ◽  
Early Years ◽  
Cold Response

Hevea brasiliensis, a tropical tree species from the Amazon rainforest, is the main source of natural rubber worldwide. Due to the high pressure of fungal diseases in hot, humid regions, rubber plantations have been moved to escape areas, which are dryer and have lower temperatures during the winter. Here, we combined gene expression data of a primary (GT1) and a secondary (RRIM600) young rubber tree clones, which present different cold tolerance strategies, to analyze rubber tree gene expression regulation during 24 h of cold exposure (10 degrees Celsius). Together with traditional differential expression approaches, a RNA sequencing (RNA-seq) gene coexpression network (GCN) comprising 27,220 genes was established in which the genes were grouped into 832 clusters. In the GCN, most of the rubber tree molecular responses to cold stress were grouped in 26 clusters, which were divided into three GCN modules: a downregulated group comprising 12 clusters and two upregulated groups comprising eleven and three clusters. Considering the three modules identified, the general Hevea response to short-term cold exposure involved downregulation of gibberellin (GA) signaling, complex regulation of jasmonic acid (JA) stress responses and programmed cell death (PCD) and upregulation of ethylene responsive genes. The hub genes of the cold-responsive modules were subsequently identified and analyzed. As a result of the GCN strategy applied in this study, we could not only access individual DEGs related to the Hevea cold response, but also provide insights into a deeper cascade of associated mechanisms involved in the response to cold stress in young rubber trees. Our results may represent the genetic stress responses of the species, developed during its evolution, since the varieties chosen for this work are genotypes that were selected during the early years of rubber tree domestication. The understanding of H. brasiliensis cold response mechanisms can greatly improve the breeding strategies for this crop, which has a narrow genetic base, is impacted by climate change and is the only source for large-scale rubber production.

scholarly journals Leaf senescence: progression, regulation, and application

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Yongfeng Guo ◽  
Guodong Ren ◽  
Kewei Zhang ◽  
Zhonghai Li ◽  
Ying Miao ◽  
...  
Keyword(s):  
Leaf Senescence ◽  
Stress Responses ◽  
Translational Regulation ◽  
Molecular Mechanisms ◽  
Leaf Age ◽  
Genetic Research ◽  
Crop Plants ◽  
Stay Green ◽  
Regulatory Pathways ◽  
Nutrient Remobilization

AbstractLeaf senescence, the last stage of leaf development, is a type of postmitotic senescence and is characterized by the functional transition from nutrient assimilation to nutrient remobilization which is essential for plants’ fitness. The initiation and progression of leaf senescence are regulated by a variety of internal and external factors such as age, phytohormones, and environmental stresses. Significant breakthroughs in dissecting the molecular mechanisms underpinning leaf senescence have benefited from the identification of senescence-altered mutants through forward genetic screening and functional assessment of hundreds of senescence-associated genes (SAGs) via reverse genetic research in model plant Arabidopsis thaliana as well as in crop plants. Leaf senescence involves highly complex genetic programs that are tightly tuned by multiple layers of regulation, including chromatin and transcription regulation, post-transcriptional, translational and post-translational regulation. Due to the significant impact of leaf senescence on photosynthesis, nutrient remobilization, stress responses, and productivity, much effort has been made in devising strategies based on known senescence regulatory mechanisms to manipulate the initiation and progression of leaf senescence, aiming for higher yield, better quality, or improved horticultural performance in crop plants. This review aims to provide an overview of leaf senescence and discuss recent advances in multi-dimensional regulation of leaf senescence from genetic and molecular network perspectives. We also put forward the key issues that need to be addressed, including the nature of leaf age, functional stay-green trait, coordination between different regulatory pathways, source-sink relationship and nutrient remobilization, as well as translational researches on leaf senescence.

Therapeutic Application of Diacylglycerol Oil for Obesity: Serotonin Hypothesis

2012 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
Hidekatsu Yanai ◽  
Hiroshi Yoshida ◽  
Yuji Hirowatari ◽  
Norio Tada
Keyword(s):  
Energy Expenditure ◽  
Molecular Mechanisms ◽  
Uncoupling Protein ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Serotonin Release ◽  
Intestinal Cell ◽  
Therapeutic Application ◽  
Postprandial Triglyceride

Characteristics for the serum lipid abnormalities in the obesity/metabolic syndrome are elevated fasting, postprandial triglyceride (TG), and decreased high-density lipoprotein-cholesterol (HDL-C). Diacylglycerol (DAG) oil ingestion has been reported to ameliorate postprandial hyperlipidemia and prevent obesity by increasing energy expenditure, due to the intestinal physiochemical dynamics that differ from triacylglycerol (TAG). Our study demonstrated that DAG suppresses postprandial increase in TG-rich lipoprotein, very low-density lipoprotein (VLDL), and insulin, as compared with TAG in young, healthy individuals. Interestingly, our study also presented that DAG significantly increases plasma serotonin, which is mostly present in the intestine, and mediates thermogenesis, proposing a possible mechanism for a postprandial increase in energy expenditure by DAG. Our other study demonstrated that DAG suppresses postprandial increase in TG, VLDL-C, and remnant-like particle-cholesterol, in comparison with TAG in an apolipoprotein C-II deficient subject, suggesting that DAG suppresses postprandial TG-rich lipoprotein independently of lipoprotein lipase. Further, to understand the molecular mechanisms for DAG-mediated increase in serotonin and energy expenditure, we studied the effects of 1-monoacylglycerol and 2-monoacylglycerol, distinct digestive products of DAG and TAG, respectively, on serotonin release from the Caco-2 cells, the human intestinal cell line. We also studied effects of 1- and 2-monoacylglycerol, and serotonin on the expression of mRNA associated with β-oxidation, fatty acids metabolism, and thermogenesis, in the Caco-2 cells. 1-monoacylglycerol significantly increased serotonin release from the Caco-2 cells, compared with 2-monoacylglycerol by approximately 40%. The expression of mRNA of acyl-CoA oxidase (ACO), fatty acid translocase (FAT), and uncoupling protein-2 (UCP-2), was significantly higher in 1-MOG-treated Caco-2 cells, than 2-MOG-treated cells. The expression of mRNA of ACO, medium-chain acyl-CoA dehydrogenase, FAT, and UCP-2, was significantly elevated in serotonin-treated Caco-2 cells, compared to cells incubated without serotonin. In conclusion, our clinical and in vitro studies suggested a possible therapeutic application of DAG for obesity, and obesity-related metabolic disorders.Key words: Diacylglycerol, intestine, obesity, serotonin, thermogenesis

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