Search Results (2,543)

Water temperature stands as a crucial environmental element, exerting an impact on the survival and growth of organisms in aquaculture. Heat stress poses a significant threat to the survival and aquaculture of the Hong Kong oyster Magallana hongkongensis (also known as Crassostrea hongkongensis), yet the underlying physiological and molecular mechanisms remain poorly understood. This study investigated the effects of elevated temperatures (35 °C and 37 °C) on survival, DNA damage, antioxidant enzyme activities, and gene expression related to apoptosis, inflammation, and heat shock proteins (HSPs) in M. hongkongensis. The median lethal temperature (LT50) of M. hongkongensis was determined to be 37.09 °C, with significant mortality observed at 35 °C compared with the control (29 °C). Antioxidant enzyme activities (SOD, CAT, and GPx) and T-AOC were up-regulated initially but exhibited divergent patterns under prolonged stress, indicating a temperature-dependent threshold for oxidative defense. Comet assay results also showed that heat stress induced severe DNA damage in hemocytes. Moreover, heat stress significantly up-regulated mRNA expression of apoptosis-related genes (Caspase-2, Caspase-8, Bax, and P53), inflammatory genes (TNF, p38-MAPK, and AP-1), and HSP family members (Hsp70, Hsp90, Hsp27, and Hsp68). The expression peaks of these genes were generally earlier and more pronounced at 37 °C, reflecting intensified cellular damage and protective responses. Collectively, this study demonstrates that M. hongkongensis employs integrated antioxidant, apoptotic, inflammatory, and HSP-mediated mechanisms to counteract heat stress, but temperatures exceeding 35 °C disrupt these defenses, leading to survival impairment. These findings provide critical insights into the heat adaptation strategies of M. hongkongensis and serve as a scientific foundation for developing sustainable aquaculture practices to mitigate summer heat stress. Full article

The livestock sector, a crucial source of revenue and global food security, is facing serious challenges due to climate change driven by global warming. This leads to serious effects on animal health and productivity, making it difficult for the livestock industry to meet the global demand and sustain the livelihoods of farmers. The main factor affecting livestock’s productivity is heat stress. However, animals develop various adaptive mechanisms to cope with the effects of heat stress. Cellular and molecular responses act as key defense mechanisms, enabling animals adapt to environmental changes. The recent advancements in molecular biology have opened up opportunities for extensive research on epigenetics, which has a key role in regulating gene expression in animals in response to environmental stimuli. Such studies have gained considerable attention regarding heat acclimation in animals due to the fact that epigenetic mechanisms have been recognized as key players in long-term adaptation to high temperatures in farm animals. This review summarizes the different mechanisms and methodologies used to assess heat stress-associated epigenetic changes, including DNA methylation, which is an extensively studied epigenetic regulatory mechanism in relation to gene expression. The review also highlights the mechanisms and regulation of adaptation to heat stress in animals and collates information related to various epigenetic markers to assess the heat stress response, thereby aiding in improving thermal resilience in animals. Full article

Managing transition cows and preventing diseases related to this period is challenging due to the latter’s multifactorial nature. The aim of this applied observational case study is to illustrate and discuss the different aspects involved and provide an approach to analysis and the resulting management solutions using a real-life case within a 500-cow herd. The initial assessment, involving the collection of data on the level of production, animal health and behaviour, and metabolic indicators, as well as management and housing key indicators, revealed key risk factors, including overcrowding, suboptimal feeding strategies, inadequate water supply, and insufficient disease monitoring. These factors contributed to increased cases of metabolic disorders such as hypocalcemia (annual incidence 7.8%), excessive lipomobilisation, and displaced abomasum (annual incidence 5.2%). A holistic approach combining feeding adjustments, disease monitoring, facility improvements, and long-term management strategies was implemented to address these challenges. Short-term interventions, such as optimizing the dietary cation–anion balance and enhancing disease detection protocols, led to noticeable improvements. However, structural constraints and external factors, such as extreme weather conditions (heat stress) and economic limitations, created significant hurdles in achieving immediate and sustained success. The farm ultimately opted for infrastructural improvements, including a new transition cow facility, to provide a long-term solution to these recurring issues. This case highlights the complexity of transition cow management, demonstrating that long-term success depends on continuous monitoring, interdisciplinary collaboration, and adaptability in response to evolving challenges in dairy production. Full article

The Western Reef Heron (Egretta gularis) has a wide geographic distribution, ranging from the coasts of West Africa to Southwest Asia, including the Arabian Peninsula. Despite this extensive range, detailed information on its incubation behavior remains scarce. To address this gap, we investigated the 24 h incubation behavior of Western Reef Herons on Al-Fanateer Island, Eastern Saudi Arabia, during early summer—a period characterized by pronounced diurnal fluctuations in ambient temperature. Using trail cameras and temperature loggers, we found that adults maintained nearly continuous attendance at the nest throughout the day, with incubation coverage exceeding 97% across all two-hour intervals. A slight reduction in nest attendance was observed during nighttime (lowest at 86.8% between 20:00–21:59). Incubating adults exhibited behavioral plasticity in response to ambient temperature: a sitting posture was predominant during cooler periods, while a shading posture was more frequent during peak heat. Incubating adults also adjusted their orientation with the solar angle, actively avoiding southern and western exposures during the hottest parts of the day. Despite substantial variation in ambient temperature, the temperature beneath the clutch ranged from 29.4 to 37.8 °C, which may indicate effective thermoregulation. These findings suggest that a combination of near-continuous nest attendance, posture adjustment, and solar orientation avoidance allows Western Reef Herons to mitigate thermal stress and maintain optimal conditions for embryo and chick development. We recommend long-term monitoring of incubation behavior in this species to further evaluate its adaptability to environmental changes, particularly those driven by climate variability. Full article

The northern South China Sea has abundant frontal systems near coastal and island regions, which play crucial roles in regional ocean dynamics and ecosystem. While previous studies have established preliminary understanding of their spatial distribution, seasonal variability, and dynamic characteristics, the atmospheric response to these frontal systems remains poorly understood. This study integrates observations from a moored buoy deployed on the continental shelf of the South China Sea with satellite remote sensing data to analyze oceanic and atmospheric variations during frontal passage. The results reveal that the ocean front can not only induce pronounced oceanic changes characterized by significant cooling, saltiness, and surface current acceleration, but also exert substantial influence on the overlying atmosphere, with consistent decreasing trends in air temperature, humidity, and atmospheric pressure, all of which rapidly recovered following frontal retreat. Notably, when the front directly traversed the buoy location, diurnal temperature cycles were markedly suppressed, while turbulent heat flux and downfront wind-stress curl reached peak magnitudes. These findings demonstrate that ocean fronts and associated sea surface temperature gradients can trigger intense air–sea exchange processes at the ocean–atmosphere interface. Full article

Background/Objectives: Ecballium elaterium is a widely distributed species and is one of the earliest recorded in traditional medicine. With global temperatures rising, this study aimed to investigate the changes in E. elaterium plantlets subjected to thermal stress. The goal was to understand how thermal stress affects morphology, physiology, and bioactive metabolite production, both for ecological adaptation and potential therapeutic applications. Methods: Seedlings were cultivated under controlled conditions and subjected to either the control temperature (22 °C) or the heat stress temperature (35 °C) for one week. Morphological and anatomical traits were assessed, along with physiological parameters such as chlorophyll content, malondialdehyde (MDA), hydrogen peroxide (H₂O₂), L-proline, soluble sugars, and total phenolic content. Methanolic leaf extracts from both groups were analyzed via LC-HRMS/MS and examined in vitro for cytotoxic activity against three human cancer cell lines: MCF-7 (breast), DU-145 (prostate), and SH-SY5Y (neuroblastoma). Results: Heat stress reduced dry mass and stomatal density but increased the diameter of the root transition zone, indicating anatomical adaptation. Leaves exhibited elevated oxidative stress markers and altered metabolite accumulation, while the roots showed a more integrated stress response. LC-HRMS/MS profiling revealed significant shifts in Cucurbitacin composition. Extracts from heat-stressed plants displayed stronger cytotoxicity, particularly toward DU-145 and SH-SY5Y cells, correlating with higher levels of glycosylated Cucurbitacins. Conclusions: E. elaterium demonstrates organ-specific thermotolerance mechanisms, with heat stress enhancing the production of bioactive metabolites. These stress-induced phytochemicals, especially Cucurbitacins, hold promise for future cancer research and therapeutic applications. Full article

For monitoring animal adaptation when facing environmental challenges, and more specifically when addressing the impacts of global warming—particularly responses to heat stress and short-term fluctuations in osmotic regulations in the different organs influencing animal physiology—there is an increasing demand for digital tools to understand and monitor a range of biomarkers. Microneedle arrays (MNAs) have recently emerged as promising devices minimally invasively penetrating human skin to access dermal interstitial fluid (ISF) to monitor deviations in physiology and consequences on health. The ISF is a blood filtrate where the concentrations of ions, low molecular weight metabolites (<70 kDa), hormones, and drugs, often closely correlate with those in blood. However, anatomical skin differences between human and farm animals, especially large animals, as well as divergent tolerances of such devices among species with behavior specificities, motivate new MNA designs. We addressed technological challenges to design higher microneedles for farm animal (pigs and cattle) measurements. We designed microneedle arrays composed of 37 microneedles, each 2.8 mm in height, using dextran-methacrylate, a photo-crosslinked biocompatible biopolymer-based hydrogel. The arrays were characterized geometrically and mechanically. Their abilities to perforate pig and cow skin were demonstrated through histological analysis. The MNAs successfully absorbed approximately 10 µL of fluid within 3 h of application. Full article

Background/Objectives: Rice production faces threats from rising temperatures, demanding thermotolerant varieties. This study characterizes transcriptomic dynamics and identifies Hsp101-1 (heat shock protein 101-1)-associated gene regulatory modules in rice under reproductive-stage heat stress. Methods: Transcriptomics and WGCNA (weighted gene co-expression network analysis) were conducted in flag leaves and spikelets for wild-type (WT) and Hsp101-1-overexpressing (OE) lines under 40 °C stress at six time points (0–24 h) to reveal the change in gene expressions. Results: The number of DEGs (differentially expressed genes) revealed substantial pre-existing differences in WT and OE lines. Pre treatment, OE flag leaves showed 545 upregulated and 676 downregulated DEGs versus WT leaves. Post heat shock, the number of DEGs in flag leaves and spikelets was significantly reduced by 70–80%. KEGG enrichment of common DEGs across time points showed both WT and OE flag leaves enriched for ribosome biogenesis, ribosomes, and chaperones/folding catalysts. WGCNA identified that the MEdarkslateblue module correlated negatively with WT and positively with OE flag leaves. The MEturquoise module was suppressed at 1 h but activated by 8 h. Spikelet analysis identified the MElightpink4 module (negative correlation with WT, positive with OE) and a similarly dynamic MEturquoise module. Venn analysis identified 76 shared module genes, 71 of which were upregulated in the OE line, indicating that Hsp101-1 activates common protective targets. Hsp101-1’s expression in the WT line was low basally, significantly upregulated at 1–8 h post shock, and returned to low levels by 24 h. Conclusions: Hsp101-1 enhances thermotolerance by (1) constitutively pre-stabilizing transcriptomic networks and reducing transcriptional fluctuations under heat stress and (2) modularly coordinating tissue-specific responses, providing a climate resilience framework. Full article

The purpose of this experiment was to study the effects of heat stress on the performance and protein metabolism of skeletal muscle in meat rabbits. A total of 160 New Zealand White rabbits aged 80 days with mean initial body weights of 2359 ± 200 g were randomly divided into a control group and a heat stress group. The experiment duration was 20 days. Heat stress treatment reduced the growth performance and slaughter performance of the rabbits (p < 0.05) and increased muscle yellowness (b*, p < 0.05). In addition, heat stress treatment increased the concentrations of leptin, cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol in serum (p < 0.05), and decreased the serum total protein and immunoglobulin (IgG, IgM, and IgA) contents of rabbits. Under the criteria fold-change ≥ 1.20 or ≤0.84 and p-value ≤ 0.05, 7 up-regulated proteins and 122 down-regulated proteins were screened. A gene ontology (GO) enrichment analysis of the differentially expressed proteins was performed. The most enriched specific GO terms among the differential proteins were response to stress, extracellular region, and protein binding in the biological process (BP), cellular component (CC), and molecular function (MF) categories, respectively, and the most enriched pathway was the PI3K/Akt signalling pathway. In conclusion, heat stress could reduce the carcass yield of meat rabbits, change the physical characteristics of the skeletal muscle, and influence protein metabolism by changing blood indices, potentially through the PI3K/Akt signalling pathway. Full article

The heat shock protein 70 (Hsp70) family mediates responses to environmental stress in insects. The wheat midge Sitodiplosis mosellana, a worldwide pest, avoids summer and winter temperature extremes by diapause of the third-instar larvae in the soil. To explore the functions of Hsp70s in this process, we characterized two cytoplasmic Hsp70 genes (SmHsp70A1-1 and SmHsp70A1-2) from this insect. Both SmHsp70s contained three signature motifs of the family and lacked introns. Developmental expression profiling revealed maximal SmHsp70A1-1 expression during early larval stages, while the expression of SmHsp70A1-2 was highest in the pupal stages. The expression of SmHsp70A1-1 was significantly upregulated during diapause, particularly during summer and winter, whereas SmHsp70A1-2 showed marked downregulation and dose-dependent induction by 20-hydroxyecdysone (20E). Furthermore, both genes exhibited similar expression patterns in over-summering and over-wintering larvae under thermal stress, with maximal expression at 40 °C and −10 °C, respectively, but were not significantly induced at prolonged extreme temperatures (50 °C or −15 °C). Knockdown of the two SmHsp70 genes by RNA interference (RNAi) significantly increased the susceptibility of the larvae to cold stress. These results suggest the important role of both SmHsp70 genes in diapause-associated stress tolerance and provide crucial insights into the mechanisms underlying thermal adaptation in S. mosellana. Full article

Dairy cattle are constantly exposed to a wide range of pathogens, which can produce substantial economic losses. The maintenance of homeostasis is not only dependent on the intrinsic characteristics of the animals but also on environmental factors such as the productive system, heat stress, and exposure to vectors and contaminated pastures. In this context, the bovine immune system plays a critical role in maintaining health and productivity. This review provides a comprehensive overview of both innate and adaptive responses in cattle, remarking on key components and summarizing the normal immune response against some of the most frequent pathogens in bovines, as well as how these pathogens have developed strategies to evade or modulate the host’s immune system. A deeper understanding of these mechanisms is essential for improving therapeutic strategies and disease prevention in livestock production. Full article

Marine litter provides novel habitats for substrate-dependent species, potentially facilitating their expansion under climate change. This study investigated the thermal adaptability and substrate selectivity of the cold-water sea anemone Metridium senile in the Yellow Sea, where rising temperatures and anthropogenic substrates may drive its proliferation. Behavioral experiments revealed diminished adhesion capacity under thermal stress (13 °C and 18 °C), with no substrate preference observed. Transcriptomic analysis identified 175 and 340 differentially expressed genes (DEGs) at 13 °C and 18 °C, respectively, compared with the control (8 °C). These DEGs were enriched in metabolic processes, oxidative stress, and cell homeostasis, with key pathways including dorso-ventral axis formation, ECM–receptor interaction, TGF-β, and Wnt signaling pathways. Notably, 7 regeneration-related, 20 adhesion-related, and 16 collagen-related DEGs were implicated in adaptive responses to heat stress. Our findings elucidate the molecular mechanisms underlying M. senile’s resilience and highlight its potential to exploit human-modified habitats under warming conditions, offering insights into ecological shifts in marine ecosystems. Full article

Ginger, an economically important crop, fulfills multifunctional roles as a spice, vegetable, and raw material for medicinal and chemical products. The family of Auxin Response Factors (ARFs) plays an essential role in facilitating auxin signal transduction and regulating plant growth and development. However, the role of ARF genes in ginger, a crop of considerable economic importance, remains elucidated. In this study, a total of 26 ZoARF genes were identified in the ginger genome, which were further categorized into four subfamilies (I–IV) and displayed a non-uniform distribution across 11 chromosomes. The proteins are predominantly localized to the nucleus. Promoter regions contained numerous cis-elements linked to light signaling, phytohormones, growth, development, and stress responses. Collinearity analysis revealed 9 pairs of fragment duplication events in ZoARFs, all uniformly distributed across their related chromosomes. In addition, the expression profiles of ZoARFs in ginger were analyzed during development and under several stress conditions like ABA, cold, drought, heat, and salt, employing RNA-seq data and qRT-PCR analysis. Notably, expression profiling revealed tissue-specific functions, with ZoARF#04/05/12/22 associated with flower development and ZoARF#06/13/14/23 implicated in root growth. This work provides an in-depth insight into the ARF family and establishes a foundation for future investigations of ZoARF gene functions in ginger growth, development, and abiotic stress tolerance. Full article

Microwave-assisted rock fragmentation has been considered as one of the most promising technologies in rock excavation, but due to the fact that excavation is usually carried out in water-rich environments, understanding the dynamic fracture properties of rocks with different water contents after microwave irradiation is thus desirable. This study employed an enhanced split Hopkinson pressure bar (SHPB) system to perform dynamic fracture tests on pre-cracked semi-circular bending (SCB) specimens. It systematically explores the changes in the mechanical properties of sandstone under both dry and saturated conditions after exposure to 700 W of microwave radiation for 10 min. Infrared thermal imaging was utilized to capture the temperature distribution across the specimens, while digital image correlation (DIC) and high-speed photography were used to simultaneously record the crack propagation process. Based on the principle of energy conservation, the analysis of energy dissipation during fracture was performed, and the micro-damage evolution mechanism of the material was revealed through scanning electron microscopy (SEM). The results demonstrated that saturated sandstone exhibited a more rapid heating response and significantly lower dynamic fracture toughness and fracture energy compared to dry samples after microwave irradiation. These findings indicate that water saturation amplifies the weakening effect induced by microwaves, making the rock more susceptible to low-stress fractures. The underlying damage mechanisms of microwave radiation on water-bearing sandstone were interpreted with the theory of pore water pressure and structural thermal stresses. Full article

Epigenetic regulation, particularly DNA methylation, plays a crucial role in plant adaptation to environmental stresses by modulating gene expression without altering the underlying DNA sequence. In response to major abiotic stresses such as salinity, drought, heat, cold, and heavy metal toxicity, plants undergo dynamic changes in DNA methylation patterns. These modifications are orchestrated by DNA methyltransferases and demethylases with variations depending on plant species, genetic background, and ontogenic phase. DNA methylation affects the expression of key genes involved in cellular, physiological, and metabolic processes essential for stress tolerance. Furthermore, it contributes to the establishment of stress memory, which can be transmitted across generations, thereby enhancing long-term plant resilience. The interaction of DNA methylation with other epigenetic mechanisms, including histone modifications, small RNAs, and chromatin remodeling, adds layers of regulatory complexity. Recent discoveries concerning N6-methyladenine have opened new avenues for understanding the epigenetic landscape in plant responses to abiotic stress. Overall, this review addresses the central role of DNA methylation in regulating plant stress responses and emphasizes its potential for application in crop improvement through epigenetic and advanced biotechnological approaches. Full article