Hsp27 Gene Research Articles

Heat Shock Proteins expression in malaria and dengue vector.

The survival of mosquitoes under changing climatic conditions particularly temperature, is known to be supported by Heat Shock Proteins (HSPs). In view of climate change, it is imperative to know whether the mosquito vectors will be able to withstand the increased temperatures or perish. Therefore, the present study was undertaken on the expression of HSPs' gene in An. stephensi and Ae. aegypti by exposing them to temperatures ranging from 5 to 45°C for 15-180-minutes for once and continuously or with rest in between. We compared the temperature-tolerance of both the vectors in terms of expression of HSP83, HSP70, and HSP26 genes at varying degrees of temperature and duration. HSP70 and HSP26 were found distinctively expressed in both the vectors as compared to HSP83. With continuous exposure up to 180-minutes at 35°C and 40°C, HSP70 was found upregulated up to 35 and 47 folds in Ae. aegypti while in An. stephensi, the expression was only 1 fold. Between the genes, HSP70 was highly expressed at different temperatures followed by HSP26 and HSP83. The manifold up-regulation of HSP genes in Ae. aegypti than An. stephensi may be attributed to the robustness of Aedes vector in terms of temperature tolerance. This study has shown that Ae. aegypti and An. stephensi can withstand considerable temperature stress by expressing HSPs when exposed to variable temperature and duration. In view of changing climate, the study provides a clue that the vector of dengue and zika virus will be difficult to control.

Diminish the chances of Mediterranean fruit fly Ceratitis capitata eggs surviving by suppressing the expression of the heat shock protein 27 gene (Hsp27).

The hypothesized role of stress-inducible heat shock proteins is to act as a buffer against environmental variations and affect fitness in suboptimal conditions. Our study examining the functions of heat shock protein 27 (Hsp27) in the eggs of the Mediterranean fruit fly (Ceratitis capitata). We utilized double-stranded RNA, specifically targeting the Hsp27 gene, to reduce its expression and assessed the consequent impact on egg viability. The investigation included the examination of early eggs (less than 6 hours post-laying) and late eggs (more than 42 hours post-laying), using varying concentrations (0.02, 0.1, and 0.2 µg/µL) of Hsp27 dsRNA. Control groups of eggs were dsRNA of ATPase, Cctra-2, or phosphate buffer solution (ph-B-S). Down-regulating Hsp27 dsRNA reduced the hatching rate of the eggs compared to the hatching rate in the control groups, especially in the ph-B-S group. The early eggs were more affected than the late eggs after soaking with Hsp27 dsRNA, where the Hsp27 dsRNA decreased the hatching rates to 12.91% early. The tested concentration of 0.2 µg/µL of Hsp27 dsRNA was achieved with the most significant reduction of 2.75 in egg viability. The sex ratio of insects hatched from treated eggs was investigated after hatching. After the down-regulation of Hsp27, there was no significant effect of the Hsp27 down-regulation on the sex ratio.

Antibacterial mechanism of thermoultrasound combined with potassium sorbate against Pichia membranifaciens

The effect of the antimicrobial mechanism of ultrasound (US) in combination with heat (T) and potassium sorbate (PS) treatment on Pichia membranifaciens (P. membranifaciens) is investigated in this study. It is found that ultrasound combined with heat (thermoultrasound [TS]) exhibits a synergistic inactivation efficiency, and the combinations of US, T, and TS with PS also improve inactivation efficacy through reductions of 0.32 ± 0.02 log, 0.73 ± 0.04 log, and 4.50 ± 0.04 log in P. membranifaciens achieved using US + PS, T + PS, and TS + PS, respectively. Further, use of the TS + PS treatment leads to cytoplasmic leakage and a decrease in dehydrogenase activity, as well as a significant increase in cell membrane permeability, causing membrane depolarization and the inward flow of extracellular calcium ions. In addition, the cell membrane composition is detected by infrared spectroscopy, demonstrating that TS + PS treatment results in a decrease in lipid and protein content and an increase in phospholipid content in the cell membrane. Scanning and transmission electron microscopy reveals a deformed cell structure and damage to cell membrane integrity after TS + PS treatment. In addition, the expression of heat shock protein (Hsp82 and Hsp70) genes is shown to decrease after TS and TS + PS treatment compared to the T and T + PS treatment groups, indicating cellular homeostasis has been broken and cells are responding to the damage by activating the protective gene expression program.

Growth performance, hematological profile, and related genes expression in goldfish (Carassius auratus) fed on rosmarinic acid-enriched diets and subjected to ambient ammonia

Recently, supplementing fish diets with polyphenols has attracted more attention because of their great nutritional role. The unionized ammonia is one of the critical water parameters that adversely affects the fish performance and welfare status. Hence, the present perspective outlines the potential value of dietary rosmarinic acid (RA) in boosting growth, hematological, and immune biomarkers, besides related-genes expressions post-exposure of goldfish (Carassius auratus) to ambient ammonia. Fish (n = 240) were separated into four groups; RA0 (the control), RA400, RA600, and RA800 received 0, 400, 600, and 800 mg RA/kg feed, respectively. After 56 days, counts of white and red blood cells and growth indices (weight gain, specific growth rate, feed intake, and feed conversion ratio) were evaluated. After that, the fish per each treatment were exposed to 0.5 mg/L of unionized ammonia for three hours. After the challenging time, many biomarkers were measured including immune response (ACH50, total immunoglobulin, and lysozymes activity), digestion (proteases activity), and genes expression involving MUC, HSP27, HSP30, HSP47, TNFa, Lp1, and Fas genes plus the anti-inflammatory cytokines (IL6, IL8, and IL10). The findings of the current research revealed that dietary RA intervention fostered growth performance, improved blood picture (p < 0.05), and enhanced (p < 0.05) the expression of genes, which are responsible for modulating immunity and anti-inflammatory status in a dose-dependent manner. The present study concluded that dietary RA is a successful natural feed supplement for goldfish with an optimal level of 600 mg RA/kg feed. However, it verifies antitoxic and anti-inflammatory properties against ambient ammonia toxicity. It also has a promising influence on the growth, hematological, and immunity and anti-inflammatory related genes expression of goldfish, C. auratus.

Molecular evolution of the heat shock protein family and the role of HSP30 in immune response and wound healing in lampreys (Lethenteron reissneri)

Heat shock proteins (HSPs) are molecular chaperones that ubiquitously exist in various organisms and play essential roles in protein folding, transport, and expression. While most HSPs are highly conserved across species, a few HSPs are evolutionarily distinct in some species and may have unique functions. To explore the evolutionary history of the vertebrate HSP family, we identify members of the HSP family at the genome-wide level in lampreys (Lethenteron reissneri), a living representative of jawless vertebrates diverged from jawed vertebrates over 500 million years ago. The phylogenetic analysis reveals that the lamprey HSP family contains HSP90a1, HSP90a2, HSC70, HSP60, HSP30, HSP27, HSP17, and HSP10, which have a primitive status in the molecular evolution of vertebrate HSPs. Transcriptome analysis reveals the expression distribution of members of the HSP family in various tissues of lampreys. It is shown that HSP30, normally found in birds, amphibians, and fish, is also present in lampreys, with remarkable expansion of HSP30 gene copies in the lamprey genome. The transcription of HSP30 is significantly induced in leukocytes and heart of lampreys during various pathogens or poly(I:C) stimulation, indicating that HSP30 may be involved in the immune defense of lampreys in response to bacterial or viral infection. Immunohistochemistry demonstrates significantly increased HSP30 expression in subcutaneous muscle tissue after skin injury in lamprey models of wound repair. Furthermore, transcriptome analysis shows that ectopic expression of HSP30 in 3T3-L1 fibroblasts affect the expression of genes related to the PI3K-AKT signaling pathway, suggesting that HSP30 could serves as a negative regulator of fibrosis. These results indicate that HSP30 may play a critical role in facilitating the process of lamprey skin repair following injury. This study provides new insights into the origin and evolution of the HSP gene family in vertebrates and offers valuable clues to reveal the important role of HSP30 in immune defense and wound healing of lampreys.

Transcriptional modulation of heat shock proteins and adipogenic regulators in bovine adipocytes following heat exposure

This research endeavored to elucidate the transcriptional modulation of heat shock proteins and adipogenic regulators in bovine subcutaneous adipocytes following thermal exposure. Post-differentiation, mature adipocytes were subjected to three treatments of control (CON), moderate (MHS), and extreme (EHS) heat stress. These treatments consist of thermal conditions at temperatures of 38 °C (CON), 39.5 °C (MHS), or 41 °C (EHS) along with of 3 or 12 h. There was no statistically significant variations observed in the gene expressions of HSP27 and HSP70 when comparing CON with MHS across both exposures. Contrastingly, when comparing CON with EHS, an upregulation (P < 0.01) in HSP27 gene expression was evident for both 3 and 12 h of incubation, while HSP70 gene expression exhibited elevation (P < 0.01) at the 3-h mark, with no change observed at 12 h. Protein quantification, however, revealed an elevation (P < 0.01) in HSP27 and HSP70 for both CON vs. MHS and CON vs. EHS at the 12-h exposure. This trend in protein level mirrored (P < 0.05) that of proliferator-activated receptor-gamma (PPARγ). Elevated (P < 0.05) protein levels of fatty acid synthase (FAS) were exclusively discernible in the CON vs. MHS. Increased (P < 0.01) transcriptional activity of PPARγ, CCAAT/enhancer-binding protein alpha (C/EBPα), stearoyl-CoA desaturase (SCD), and FAS was evident in the CON vs. EHS comparison. Complementary to these molecular findings, an augmented lipid droplet accumulation was observed (P < 0.01) in EHS-exposed adipocytes progressively from day 6 through day 9. Our current study highlights how different levels and lengths of heat stress can impact the activity of important heat-related proteins and factors that play a role in fat development in beef cattle. These findings can help guide strategies to manage how beef cattle are exposed to heat, which can affect fat storage and ultimately the quality of the meat's marbling.

Insights into the Neuroprotective Potential of Epicatechin: Effects against Aβ-Induced Toxicity in Caenorhabditis elegans.

Medical therapies to avoid the progression of Alzheimer's disease (AD) are limited to date. Certain diets have been associated with a lower incidence of neurodegenerative diseases. In particular, the regular intake of foods rich in polyphenols, such as epicatechin (EC), could help prevent or mitigate AD progression. This work aims to explore the neuroprotective effects of EC using different transgenic strains of Caenorhabditis elegans, which express human Aβ1-42 peptides and contribute to elucidating the mechanisms involved in the effects of EC in AD. The performed assays indicate that this flavan-3-ol was able to reduce the signs of β-amyloid accumulation in C. elegans, improving motility and chemotaxis and increasing survival in transgenic strain peptide producers compared to nematodes not treated with EC. The neuroprotective effects exhibited by EC in C. elegans could be explained by the modulation of inflammation and stress-associated genes, as well as autophagy, microgliosis, and heat shock signaling pathways, involving the regulation of cpr-5, epg-8, ced-7, ZC239.12, and hsp-16 genes. Overall, the results obtained in this study support the protective effects of epicatechin against Aβ-induced toxicity.

Investigation of genetic stress parameters in brain tissues of rats exposed to 1.8 GHz cell phone radiofrequency electromagnetic field

Heat Shock Proteins (HSPs) may induce various cellular processes, including replication, apoptosis, cell-cycle progression. Mitogen-activated protein kinase (MAPK) cascades are the primary mechanism that mediates the cellular stress response to extracellular stimuli and regulates transcriptional activity. It has been shown that mobile phone exposure can stimulate the Hsp27/p38MAPK stress pathway. In this study, twenty-seven mature female Wistar albino rats were exposed to 1.8 GHz radiofrequency electromagnetic field (RF-EMF) 2h/day for 8 weeks (SAR: 0.06 W/kg). Hsp27 and p38MAPK gene expressions were investigated in rat brains. Rats were divided into groups sham-exposed, cage control, and 1.8 GHz RF-EMF exposed. Hsp27 and p38MAPK gene expression levels were investigated from the brain. p38MAPK expression was found to be upregulated in RF-EMF exposed group (p=0.018) Hsp27 expressions were not altered (p=0.897). In conclusion, long-term exposure to 1.8 GHz cell phone radiation can activate the Hsp27/p38MAPK stress pathway. It may cause several cellular disorders and can affect brain function.

Exposure to heat stress leads to striking clone-specific nymph deformity in pea aphid.

Climatic changes, such as heatwaves, pose unprecedented challenges for insects, as escalated temperatures above the thermal optimum alter insect reproductive strategies and energy metabolism. While thermal stress responses have been reported in different insect species, thermo-induced developmental abnormalities in phloem-feeding pests are largely unknown. In this laboratory study, we raised two groups of first instar nymphs belonging to two clones of the pea aphid Acyrthosiphon pisum, on fava beans Vicia faba. The instars developed and then asexually reproduced under constant exposure to a sub-lethal heatwave (27°C) for 14 days. Most mothers survived but their progenies showed abnormalities, as stillbirths and appendageless or weak nymphs with folded appendages were delivered. Clone N116 produced more deceased and appendageless embryos, contrary to N127, which produced fewer dead and more malformed premature embryos. Interestingly, the expression of the HSP70 and HSP83 genes differed in mothers between the clones. Moreover, noticeable changes in metabolism, e.g., lipids, were also detected and that differed in response to stress. Deformed offspring production after heat exposure may be due to heat injury and differential HSP gene expression, but may also be indicative of a conflict between maternal and offspring fitness. Reproductive altruism might have occurred to ensure some of the genetically identical daughters survive. This is because maintaining homeostasis and complete embryogenesis could not be simultaneously fulfilled due to the high costs of stress. Our findings shine new light on pea aphid responses to heatwaves and merit further examination across different lineages and species.

Expression of Heat Shock Protein 30 in Talaromyces marneffei during Phase Transition and in Response to Heat and Oxidative Stresses

OBJECTIVE Heat shock protein 30 (Hsp30) has been identified as an immunogenic, yeast phase-specific protein in Talaromyces marneffei. The purpose of this study was to investigate how the hsp30 gene and Hsp30 protein are expressed during phase transition and in response to heat and oxidative stress exposure. METHODS Several sequence analysis tools were employed to predict hsp30 control elements and to determine the subcellular localization of Hsp30. In the phase transition experiment, Talaromyces marneffei conidia were cultivated at two different temperatures, 25 °C and 37 °C. Subsequently, stress response tests were conducted by subjecting the yeast cells to heat at 42 °C and by treating them with hydrogen peroxide. The levels of the hsp30 transcript and its protein were measured using real-time RT-PCR and western immunoblot analysis, respectively. RESULTS The sequence analysis revealed the presence of heat response element (HRE), stress responsive element (STRE), and xenobiotic responsive element (XRE), which are typically involved in regulating hsp genes. A web-based tool predicted that Hsp30 protein is localized in cytoplasm, nucleus, and cell membrane. The hsp30 transcript and Hsp30 protein were highly clearly detected in both yeast cells and conidia. Furthermore, the hsp30 transcript in yeast cells was upregulated following heat shock at 42° C and exposure to hydrogen peroxide. These findings indicate that Hsp30 plays a crucial role in assisting the yeast phase of T. marneffei to cope with heat and oxidative stresses. CONCLUSIONS Hsp30 is a protein specific to the conidial and yeast phases of T. marneffei. It likely performs a conserved chaperone function during yeast growth and plays a significant role in stress response by mitigating protein aggregation issues. KEYWORDS Talaromyces marneffei, heat shock protein 30, expression

GUMI-BEAR, a modular, unsupervised population barcoding method to track variants and evolution at high resolution.

Cellular lineage tracking provides a means to observe population makeup at the clonal level, allowing exploration of heterogeneity, evolutionary and developmental processes and individual clones' relative fitness. It has thus contributed significantly to understanding microbial evolution, organ differentiation and cancer heterogeneity, among others. Its use, however, is limited because existing methods are highly specific, expensive, labour-intensive, and, critically, do not allow the repetition of experiments. To address these issues, we developed gUMI-BEAR (genomic Unique Molecular Identifier Barcoded Enriched Associated Regions), a modular, cost-effective method for tracking populations at high resolution. We first demonstrate the system's application and resolution by applying it to track tens of thousands of Saccharomyces cerevisiae lineages growing together under varying environmental conditions applied across multiple generations, revealing fitness differences and lineage-specific adaptations. Then, we demonstrate how gUMI-BEAR can be used to perform parallel screening of a huge number of randomly generated variants of the Hsp82 gene. We further show how our method allows isolation of variants, even if their frequency in the population is low, thus enabling unsupervised identification of modifications that lead to a behaviour of interest.

Curcumin-mediated gene expression changes in Drosophila melanogaster

Background: Curcumin has been suggested to be useful in the treatment of numerous diseases, including autoinflammation, that has been implicated in some pathological conditions. Experimentally, autoinflammatory phenotypes were observed in the short-lived Peptidoglycan recognition protein LB (PGRP-LB) mutant of Drosophila melanogaster. Objective: This study aimed to determine the effect of curcumin on the expression of ageing-related genes in the autoinflammatory model of D. melanogaster. Method: This study was performed using five test groups including untreated control, solvent control, and three groups given a series of curcumin concentrations: 10 µM, 50 µM, and 250 µM, separately. Survival assay and gene expression studies were carried out on these test groups. Result: The results revealed that the lifespan of the curcumin-treated groups was significantly improved in comparison to the control groups. Such phenotype was accompanied by the increased expression of srl and hsp22 genes in most, if not all, of the curcumin-treated groups and elevated expression of tom40, pepck, and cat genes was specifically detectable only in groups treated with 250 µM curcumin. On the contrary, the expression of indy was significantly reduced upon the administration of curcumin at all given concentrations. Conclusion: Based on these results, it can be inferred that supplementation of curcumin can improve the lifespan of the PGRP-LB mutant flies and this might be related to the changes in the expression of ageing-related genes.

Transgenic overexpression of heat shock protein (HSP83) enhances protein kinase A activity, disrupts GP63 surface protease expression and alters promastigote morphology in Leishmania amazonensis

Leishmania parasites undergo morphological changes during their infectious life cycle, including developmental transitions within the sandfly vector, culminating in metacyclic stages that are pre-adapted for infection. Upon entering vertebrate host phagocytes, Leishmania differentiate into intracellular amastigotes, the form that is ultimately transmitted back to the vector to complete the life cycle. Although environmental conditions that induce these cellular transitions are well-established, molecular mechanisms governing Leishmania morphologic differentiation in response to these cues remain largely uncharacterized. Previous studies indicate a key role for HSP83 in both promastigote metacyclogenesis and amastigote differentiation. To further elucidate HSP83 functions in the Leishmania lifecycle, we examined the biological impact of experimentally elevating HSP83 gene expression in Leishmania. Significantly, HSP83 overexpression was associated with altered metacyclic morphology, increased protein kinase A (PKA) activity and decreased expression of the Leishmania major surface protease, GP63. Corroborating these findings, overexpression of the L. amazonensis PKA catalytic subunit resulted in a largely similar phenotype. Our findings demonstrate for the first time in Leishmania, a functional link between HSP83 and PKA in the control of Leishmania gene expression, replication and morphogenesis.

Comparison of Adjuvant Effects of Montanide ISA-720 and Heat Shock Protein 27 in Increasing Immunostimulatory Properties of HIV-1 Nef-Vif Fusion Protein Construct.

Effective T-cell-mediated immunity has emerged as an essential component of human immunodeficiency virus-1 (HIV-1) vaccination. Thus, inducing an immune response against HIV proteins such as Nef and Vif, two major accessory proteins with critical roles in HIV pathogenesis and immune evasion, may lead to an effective approach. Our goal is to evaluate and compare Montanide ISA-720 and heat shock protein 27 in increasing immunostimulatory properties of HIV-1 Nef-Vif fusion protein as a vaccine candidate. In this study, the nef-vif fusion gene with and without the heat shock protein 27 (hsp27) gene was cloned in the prokaryotic pET24a (+) vector. Then, the recombinant Nef-Vif and Hsp27-Nef- Vif proteins were generated in the E. coli system. Finally, their immunostimulatory properties were evaluated in mice. Indeed, the potency of Hsp27 as an endogenous natural adjuvant was investigated to enhance HIV-1 Nef-Vif antigen-specific immunity compared to Montanide ISA-720 as a commercial adjuvant in protein-based immunization strategy. Our results approved the role of Hsp27 as an effective adjuvant in the stimulation of B- and T-cell immunity. The linkage of Hsp27 to antigen could elicit higher levels of IgG1, IgG2a, IFN-γ, IL- 5 and Granzyme B than antigen mixed with Montanide ISA-720. Moreover, the ratios of IFN-γ/IL-5 and IgG2a/IgG1 were significantly increased in groups receiving Nef-Vif protein + Montanide ISA- 720 and Hsp27-Nef-Vif protein indicating the direction of the immune response pathway toward strong Th1 response. These ratios were higher in the group receiving Hsp27-Nef-Vif protein than in the group receiving Nef-Vif protein + Montanide ISA-720. Our findings suggest that Hsp27 can be used as an effective adjuvant to enhance antigenspecific immune responses in HIV-1 infectious models for therapeutic vaccine development.

Asphyxiation of Metarhizium robertsii during mycelial growth produces conidia with increased stress tolerance via increased expression of stress-related genes

Little is known about the impact of hypoxia and anoxia during mycelial growth on tolerance to different stress conditions of developing fungal conidia. Conidia of the insect-pathogenic fungus Metarhizium robertsii were produced on potato dextrose agar (PDA) medium under normoxia (control = normal oxygen concentrations), continuous hypoxia, and transient anoxia, as well as minimal medium under normoxia. The tolerance of the conidia produced under these different conditions was evaluated in relation to wet heat (heat stress), menadione (oxidative stress), potassium chloride (osmotic stress), UV radiation, and 4-nitroquinoline-1-oxide (=4-NQO genotoxic stress). Growth under hypoxic condition induced higher conidial tolerance of M. robertsii to menadione, KCl, and UV radiation. Transient anoxic condition induced higher conidial tolerance to KCl and UV radiation. Nutritional stress (i.e., minimal medium) induced higher conidial tolerance to heat, menadione, KCl, and UV radiation. However, neither of these treatments induced higher tolerance to 4-NQO. The gene hsp30 and hsp101 encoding a heat shock protein was upregulated under anoxic condition. In conclusion, growth under hypoxia and anoxia produced conidia with higher stress tolerances than conidia produced in normoxic condition. The nutritive stress generated by minimal medium, however, induced much higher stress tolerances. This condition also caused the highest level of gene expression in the hsp30 and hsp101 genes. Thus, the conidia produced under nutritive stress, hypoxia, and anoxia had greater adaptation to stress.

The tobacco phosphatidylethanolamine-binding protein NtFT4 increases the lifespan of Drosophila melanogaster by interacting with the proteostasis network.

Proteostasis reflects the well-balanced synthesis, trafficking and degradation of cellular proteins. This is a fundamental aspect of the dynamic cellular proteome, which integrates multiple signaling pathways, but it becomes increasingly error-prone during aging. Phosphatidylethanolamine-binding proteins (PEBPs) are highly conserved regulators of signaling networks and could therefore affect aging-related processes. To test this hypothesis, we expressed PEPBs in a heterologous context to determine their ectopic activity. We found that heterologous expression of the tobacco (Nicotiana tabacum) PEBP NtFT4 in Drosophila melanogaster significantly increased the lifespan of adult flies and reduced age-related locomotor decline. Similarly, overexpression of the Drosophila ortholog CG7054 increased longevity, whereas its suppression by RNA interference had the opposite effect. In tobacco, NtFT4 acts as a floral regulator by integrating environmental and intrinsic stimuli to promote the transition to reproductive growth. In Drosophila, NtFT4 engaged distinct targets related to proteostasis, such as HSP26. In older flies, it also prolonged Hsp26 gene expression, which promotes longevity by maintaining protein integrity. In NtFT4-transgenic flies, we identified deregulated genes encoding proteases that may contribute to proteome stability at equilibrium. Our results demonstrate that the expression of NtFT4 influences multiple aspects of the proteome maintenance system via both physical interactions and transcriptional regulation, potentially explaining the aging-related phenotypes we observed.

Physiological and molecular response of cotton (Gossypium hirsutum L.) to heat stress at the seedling stage

The ideal temperature range for the optimal growth and development of cotton is 25 °C–32 °C and high temperature adversely affects the metabolic activities of plant cells. This study was aimed to screen heat-tolerant cotton genotypes based on physiological and molecular parameters. Experiments were carried out during 2019–2020 at the MNS-University of Agriculture, Multan, Pakistan. The research comprised two parts. In the first experiment, 30 cotton genotypes were sown in a completely randomized design with three replications under laboratory conditions for the determination of cell membrane thermostability. Principal component analysis was performed, and four genotypes, i.e., two heat-tolerant (‘CRIS-5A’ and ‘VH-338’) and two heat-sensitive (‘FH-242’ and ‘VH-281’) genotypes, were selected. In the second experiment, the screened cotton genotypes were sown in pots in a factorial complete randomized design with three replications and two treatments (normal and heat treatment). Heat stress was applied at the seedling stage, and eight leaf samples (one from each experimental unit) were collected. Two genes were used for molecular analysis and were amplified in all eight cDNA samples. Molecular analysis indicated the presence of HSP70 and HSP26 genes in the cotton genotypes, and the expression of these genes was measured by using ImageJ software. The gene expression level of HSP70 was very high (16.41%) in ‘VH-281’, which is a heat-sensitive genotype under heat stress. The sensitive genotype ‘FH-242’ exhibited the highest gene expression level of HSP26 (20.32%) under normal conditions. A similar sequence of HSP70 gene of Agave sisalana was amplified for the first time in cotton. It is a good indicator for screening heat tolerant cotton genotypes at the molecular level.

Graphene oxide chronic exposure enhanced perfluorooctane sulfonate mediated toxicity through oxidative stress generation in freshwater clam Corbicula fluminea

Graphene oxide (GO), a frequently utilized graphene family nanomaterial, is inevitably released into the aquatic environment and interacts with organic pollutants, including perfluorooctane sulfonate (PFOS), a well-known persistent organic pollutant. To determine the adverse effects of GO chronic exposure on PFOS bioaccumulation and toxicity, adult freshwater bivalves, namely Asian clams (Corbicula fluminea) were treated for 28 days with PFOS (500 ng/L) and different concentrations of GO (0.2, 1, 5 mg/L) as PFOS single and GO single exposure groups, as well as PFOS-GO mixture exposure groups. Our results demonstrated that the bioaccumulation of PFOS was significantly enhanced by co-exposure in gills and visceral masses, which was 1.64–2.91 times higher in gills than in visceral masses. Both single, as well as co-exposure, caused a significant reduction in clams’ siphoning behavior, compared to the controls. Further, the co-exposure significantly increased the production of reactive oxygen species (ROS), exacerbating malondialdehyde (MDA) content, enhancing superoxide dismutase (SOD) and catalase (CAT), while decreasing glutathione reductase (GR) and glutathione S-transferase (GST) enzymatic activities in clam tissues. And co-exposure significantly altered the expressions of se-gpx, sod, cyp30, hsp40, and hsp22 genes (associated with oxidative stress and xenobiotic metabolism) both in gills and visceral masses. Moreover, co-exposure caused significant histopathological changes such as cilia degradation in the gills, expansion of tubule lumens in digestive glands, and oocyte shrinkage in gonads. Finally, the enhanced integrated biomarker response (EIBR) index revealed that co-exposure to 500 ng/L PFOS + 1 mg/L/5 mg/L GO was the most stressful circumstance. Overall, our findings suggested that the presence of GO increased PFOS bioaccumulation in tissues, inducing multifaceted negative implications at molecular and behavioral levels through oxidative stress generation in Asian clams.

Dynamics of heat shock proteins and heat shock factor expression during heat stress in daughter workers in pre-heat-treated (rapid heat hardening) Apis mellifera mother queens

Honeybees have a limited capacity to control their body temperature when exposed to thermal changes in the atmosphere. Environmental changes, such as thermal climate change, have an adverse effect on honeybee survival. Insects can be pre-heat-treated (rapid heat hardening) with a mild heat stressor to induce Hsp gene expression and protect them from future stresses. Sixty accepted mother queen (MQ) larvae at the age of 7 days were selected and divided into two incubation treatment groups (n = 30). The control group (non-heat-treated mother queens, nH-T MQ) was maintained at 34.5 °C for 15 min and 70% relative humidity (RH), and the pre-heat-treated (pre-heat-treated mother queens, pH-T MQ) group was subjected to 41 °C for 15 min and 70% RH. To evaluate the effect of larval pre-heat-treatment on thermotolerance acquisition of daughter workers, about 500 workers were collected from brood combs of each treatment group. The worker bees in their cages were incubated in digital-controlled thermo-incubators for 1 h under each of the following temperatures: 35, 40, 45, 50, 55, and 60 °C. The expression of Hsp40, Hsp60, Hsp70, HSC70-3, HSC70-4, HSC70-5, Hsp83, and Hsp90 genes in both head and thorax were evaluated by relative quantitative real-time qPCR (RT-qPCR). In general, the pH-T MQ workers exhibited a higher ability to tolerate temperature than nH-T MQ workers under extreme conditions. Furthermore, we reported for the first time that pre-heat treatment of the mother queen's larvae alters the basal and dynamic expression of heat shock proteins (Hsp40, Hsp60, Hsp70, and Hsp90) and heat shock factor (HSF) during thermoneutral conditions and during heat stress of daughter workers, probably indicating a substantial improvement of honeybees' thermotolerance acquisition in arid and semi-arid regions, and improvement of honeybee longevity and management strategies.

Antioxidant Enzymes and Heat-Shock Protein Genes of Green Peach Aphid (Myzus persicae) Under Short-Time Heat Stress

The management of insect pests under fluctuating temperatures has become an interesting area of study due to their ability to stimulate defense mechanisms against heat stress. Therefore, understanding insect’s physiological and molecular response to heat stress is of paramount importance for pest management. Aphids are ectothermic organisms capable of surviving in different climatic conditions. This study aimed to determine the effects of short-time heat stress on green peach aphid Myzus persicae under controlled conditions. In this study, short-time heat stress treatments at different temperatures 27, 30, 33, and 36°C with exposure times of 1, 3, 6, and 10 h, respectively, on the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and oxidants, such as malondialdehyde (MDA) and hydrogen peroxide (H2O2), were determined. The results showed that the short-time heat stress significantly increased the content of MDA of M. persicae by 71, 78, 81, and 86% at 36°C for the exposure times of 1, 3, 6, and 10 h, respectively, compared with control. The content of H2O2 increased by 75, 80, 85, and 88% at 36°C for the exposure times of 1, 3, 6, and 10 h, respectively, compared with the control. The SOD, POD, and CAT activities increased by 61, 76, and 77% for 1 h, 72, 83, and 84% for 3 h, 80, 85, and 86% for 6 h, and 87, 87.6, and 88% for 10 h at 36°C, respectively, compared with control. Again, under short-time heat stress, the transcription levels of Hsp22, Hsp23, Hsp27, SOD, POD, and CAT genes were upregulated compared with control. Our results suggest that M. persicae increased the enzymatic antioxidant activity and heat-shock gene expression as one of the defensive mechanisms in response to heat stresses.