ABSTRACT
Interspecies blastocyst complementation (IBC) provides a unique platform to study development and holds the potential to overcome worldwide organ shortages. Despite recent successes, brain tissue has not been achieved through IBC. Here, we developed an optimized IBC strategy based on C-CRISPR, which facilitated rapid screening of candidate genes and identified that Hesx1 deficiency supported the generation of rat forebrain tissue in mice via IBC. Xenogeneic rat forebrain tissues in adult mice were structurally and functionally intact. Cross-species comparative analyses revealed that rat forebrain tissues developed at the same pace as the mouse host but maintained rat-like transcriptome profiles. The chimeric rate of rat cells gradually decreased as development progressed, suggesting xenogeneic barriers during mid-to-late pre-natal development. Interspecies forebrain complementation opens the door for studying evolutionarily conserved and divergent mechanisms underlying brain development and cognitive function. The C-CRISPR-based IBC strategy holds great potential to broaden the study and application of interspecies organogenesis.
Subject(s)
Prosencephalon , Animals , Prosencephalon/metabolism , Prosencephalon/embryology , Mice , Rats , Blastocyst/metabolism , Female , CRISPR-Cas Systems/genetics , Transcriptome , Organogenesis , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , Male , Mice, Inbred C57BLABSTRACT
Competitive coevolution between microbes and viruses has led to the diversification of CRISPR-Cas defense systems against infectious agents. By analyzing metagenomic terabase datasets, we identified two compact families (775 to 803 amino acids (aa)) of CRISPR-Cas ribonucleases from hypersaline samples, named Cas13X and Cas13Y. We engineered Cas13X.1 (775 aa) for RNA interference experiments in mammalian cell lines. We found Cas13X.1 could tolerate single-nucleotide mismatches in RNA recognition, facilitating prophylactic RNA virus inhibition. Moreover, a minimal RNA base editor, composed of engineered deaminase (385 aa) and truncated Cas13X.1 (445 aa), exhibited robust editing efficiency and high specificity to induce RNA base conversions. Our results suggest that there exist untapped bacterial defense systems in natural microbes that can function efficiently in mammalian cells, and thus potentially are useful for RNA-editing-based research.
Subject(s)
CRISPR-Cas Systems , RNA Editing , RNA, Bacterial , Animals , Bacterial Proteins , Cell Line , Cloning, Molecular , Databases, Nucleic Acid , Dogs , Humans , Mice , RNA InterferenceABSTRACT
Common reference methods for COVID-19 variant diagnosis include viral sequencing and PCR-based methods. However, sequencing is tedious, expensive, and time-consuming, while PCR-based methods have high risk of insensitive detection in variant-prone regions and are susceptible to potential background signal interference in biological samples. Here, we report a loop-mediated interference reduction isothermal nucleic acid amplification (LM-IR-INA) strategy for highly sensitive single-base mutation detection in viral variants. This strategy exploits the advantages of nicking endonuclease-mediated isothermal amplification, luminescent iridium(III) probes, and time-resolved emission spectroscopy (TRES). Using the LM-IR-INA strategy, we established a luminescence platform for diagnosing COVID-19 D796Y single-base substitution detection with a detection limit of 2.01 × 105 copies/µL in a linear range of 6.01 × 105 to 3.76 × 108 copies/µL and an excellent specificity with a variant/wild-type ratio of significantly less than 0.0625%. The developed TRES-based method was also successfully applied to detect D796Y single-base substitution sequence in complicated biological samples, including throat and blood, and was a superior to steady-state technique. LM-IR-INA was also demonstrated for detecting the single-base substitution D614G as well as the multiple-base mutation H69/V70del without mutual interference, indicating that this approach has the potential to be used as a universal viral variant detection strategy.
ABSTRACT
Hibernation is a short-term survival strategy for ectotherms to cope with cold weather and food shortages. The energy sources stored before hibernation are used not only in the winter, but also in preparation for reproduction. Reproductive physiology and behavior are primarily regulated by the hypothalamus-pituitary-gonad (HPG) axis. In this study, we examined endocrine hormone changes in the HPG axis of female lizards (Eremias argus) after chlorantraniliprole insecticide (CAP) exposure during hibernation. The levels of gonadotropin-releasing hormone, luteinizing hormone, follicle-stimulating hormone and progesterone were significantly decreased and the level of testosterone (T) was significantly increased after 135d experiment. This study verified the possible endocrine disrupting effects of CAP. More energy material consumption was observed in CAP treated group. Female E. argus preferred to invest energy to present survival when exposed to CAP, rather than to reserve material for following reproductive activity.
Subject(s)
Hibernation , Insecticides , Lizards , Animals , Insecticides/metabolism , Insecticides/toxicity , ortho-AminobenzoatesABSTRACT
BACKGROUND AND AIMS: The decreasing Helicobacter pylori eradication rate and the increasing antibiotic resistance trend are of great concern. Therefore, new and effective therapies are needed for H. pylori infection. We conducted a systematic review and meta-analysis to assess the efficacy and safety of semisynthetic tetracycline regimens in H. pylori treatment. METHODS: PubMed, EMBASE, and the Cochrane library were searched. The outcome indicators were the eradication rate, risk ratio (RR, ie, the risk of the semisynthetic tetracycline regimen relative to the control), and 95% confidence interval (95% CI). Controls were patients undergoing any other treatment without semisynthetic tetracycline. RESULTS: Twenty-three studies with 5240 participants were included. The eradication rates of triple regimens with semisynthetic tetracyclines in most studies were less than 70% in both the intention-to-treat (ITT) and the per-protocol (PP) analyses. The pooled eradication rates of quadruple therapies with doxycycline and controls were 95% and 84% in the PP analyses, respectively. The pooled RR associated with efficacy in the quadruple therapy with doxycycline group compared with the control group was 1.12 (95% CI: 1.04-1.20) in the PP analysis. The pooled RR of side effects in the quadruple therapy with doxycycline group compared with the control group was 1.01 (95% CI: 0.65-1.55). CONCLUSION: Seven-day and ten-day quadruple therapy with doxycycline might be an optional first-line therapy. The safety of regimens containing semisynthetic tetracyclines was relatively satisfactory. However, the triple regimen is not recommended.
Subject(s)
Helicobacter Infections , Helicobacter pylori , Amoxicillin/therapeutic use , Anti-Bacterial Agents/adverse effects , Doxycycline/adverse effects , Drug Therapy, Combination , Helicobacter Infections/drug therapy , Humans , Minocycline/adverse effects , Treatment OutcomeABSTRACT
Effects of temperature on metabolism/biotransformation and toxicokinetics to lizards are significant, but frequently ignored in toxicology studies. Beta-cyfluthrin (BC) is a pyrethroid insecticide and has been widely used globally. The study aimed to understand the diverse adverse effects of BC to the lizard (Eremias argus) at different temperature regimes. We carried out a single oral BC treatment (20 mg/kg bw) for toxicokinetic study and a 7-day BC (10 mg/kg bw) gavage to look at toxicology by monitoring changes in the biomarkers HSP70, SOD, MDA, CarE, UDPGT, GST, cyp genes, and other metabolic responses. Results showed that BC was lethal to lizards, showing oxidative damages in the liver at ambient temperature (25 °C). Heat stress (35 °C) could exacerbate the oxidative damage (MDA increased) caused by BC, due to the disorder of the antioxidant defense system. The result of tissue distribution and toxicokinetic study also showed that temperature affected the BC biotransformation in lizards. The biotransformation of BC maybe relates to the activation of CarE and UDGPT by heat stress. However, the cyp system and GST didn't increase under BC or/and heat treatments. 1H-NMR metabolomics analysis showed that BC or/and heat stress interfered with energy and amino acid metabolism of the liver. Unlike acute lethal toxicity, the occurrence of the BC and heat stresses has detrimental effects on lizard individuals and populations on sub-lethal levels. Our results indicate that pollution and global warming (or some other extremely weather) may generate significant and harmful effects on lizards.
Subject(s)
Lizards , Pyrethrins , Administration, Oral , Animals , Biotransformation , Humans , Liver/metabolism , Mongolia , Nitriles , Pyrethrins/toxicity , Tissue DistributionABSTRACT
The rational use and the environmental safety of chiral pesticides have attracted significant research interest. Here, enantioselective toxic effects and the selective toxic mechanism of triticonazole (TRZ) against the aquatic microalgae Chlorella pyrenoidosa were studied. The 96h-EC50 values of rac-, (R)-(-)-, and (S)-(+)-TRZ were 1.939, 0.853, and 22.002 mg/L, respectively. At a concentration of 1 mg/L, the contents of photosynthetic pigments of C. pyrenoidosa exposed to (R)-(-)-TRZ were lower than if exposed to S-(+)-form and racemate. Transmission electron microscopic images showed that the R-(-)-form compromised the integrity of cells and disrupted the chloroplast structure. R-(-)-TRZ stimulated vast reactive oxygen species (ROS) and significantly increased superoxide dismutase (SOD) and catalase (CAT) activities, as well as malondialdehyde (MDA) content. For lipid accumulation experiments, nicotinamide adenine dinucleotide (NADH) and triacylglycerol (TAG) accumulations in algal cells treated with R-(-)-TRZ were 171.50% and 280.76%, respectively, compared with the control group. This far exceeded levels of algal cells treated with S-(+)- and rac-TRZ. Based on these data, R-(-)-TRZ was concluded to selectively affect the photosynthetic system, antioxidant system, and lipid synthesis of algal cells, thus causing enantioselective toxic effects of TRZ against C. pyrenoidosa, which indicating that the use of racemate may cause unpredictable environmental harm. Therefore, to reduce the hidden dangers of chiral pesticides for the ecological environment, the environmental risk of TRZ should be evaluated at the stereoselective level.
Subject(s)
Chlorella/drug effects , Cyclopentanes/toxicity , Fungicides, Industrial/toxicity , Microalgae/drug effects , Triazoles/toxicity , Water Pollutants, Chemical/toxicity , Antioxidants/metabolism , Chlorella/metabolism , Chlorella/ultrastructure , Chloroplasts/drug effects , Chloroplasts/metabolism , Cyclopentanes/chemistry , Fungicides, Industrial/chemistry , Malondialdehyde/pharmacology , Microalgae/metabolism , Microalgae/ultrastructure , Photosynthesis/drug effects , Reactive Oxygen Species/metabolism , Stereoisomerism , Superoxide Dismutase/metabolism , Triazoles/chemistry , Water Pollutants, Chemical/chemistryABSTRACT
Pesticides are proposed as one of the many causes for the global decline in reptile population. To understand the potential impact of alpha-cypermethrin (ACP) in reptiles, in the current study, we used a tri-trophic food web (plants - herbivores - natural enemies of predators) to examine the reproductive toxicity and biomarker changes. Based on the Maximum Residue Limit (MRL) of ACP in several agricultural products, we designed three concentrations 0, 2 (MRL), and 20â¯mg/kg wet weight as three treatment groups for this research. Male and female lizards were fed ACP contaminated or uncontaminated diets for eight weeks during the breeding phase. The number of deaths was different among the three groups, and a dose-dependent trend was found. Decreases in food consumption of 26.6% and 28.1% were observed in the low- and high-dose group, respectively. Dietary exposure significantly induced a dose-dependent decrease in body mass index in lizards. Significant variations in glutathione-S-transferaseb activities, catalase activities, and malondialdehyde levels in gonads, suggest that lizards were under oxidative stress. In addition, ACP exposure altered sexual hormone levels in males, reduced reproductive output of females, and induced histopathological changes in testes. These negative effects highlight that ACP dietary exposure is a potential threat to lizards' reproduction.
Subject(s)
Diet/veterinary , Lizards , Pesticides/toxicity , Pyrethrins/toxicity , Reproduction/drug effects , Animals , Biomarkers/blood , Catalase/blood , Dose-Response Relationship, Drug , Ecology , Estradiol/blood , Female , Male , Malondialdehyde/blood , Oxidative Stress/drug effects , Risk Assessment , Superoxide Dismutase/blood , Tenebrio , Testis/drug effects , Testosterone/bloodABSTRACT
In this study, two strains of symbiotic bacteria (SOB-1 and SOB-2) were isolated from Scenedesmus obliquus, and various algal-bacterial mutualistic systems were established under acetochlor (ACT) stress conditions. Following exposure to varying ACT concentrations from 2.0 to 25.0 µg/L, the capacity for co-cultured bacteria to degrade ACT was enhanced in 7 days by up to 226.9% (SOB-1) and 193.0% (SOB-2), compared with axenic algae, although bacteria exposed to higher ACT concentrations exacerbated algal metabolic stress, oxidative states, apoptosis and cellular lysis. ACT reduced carbohydrates in the phycosphere by up to 31.5%; compensatory nutrient plunder and structural damage by bacteria were the potential exploitation pathways determined based on the inhibition of bacterial infection using a glucanase inhibitor. The ACT-induced reduction in algal antimicrobial substances, including fatty acids and phenolics (by up to 58.1% and 56.6%, respectively), also facilitated bacterial exploitation of algae. ACT-dependent interspecific interaction coefficients between algae and bacteria generated from long-term symbiosis cultures implied that bacteria moved from mutualism (0 and 2.0 µg/L ACT) to exploitation (7.9 and 25.0 µg/L ACT). The population dynamic model under incremental ACT-concentration scenarios inferred that theoretical systematic extinction may occur in algal-bacterial systems earlier than in axenic algae. These outcomes provide interspecific insights into the distortion of algal-bacterial reciprocity due to the ecotoxicological effects of ACT.
Subject(s)
Chlorophyceae , Microalgae , Microalgae/metabolism , Symbiosis , BacteriaABSTRACT
The construction and investigation of dual-functional coordination polymers (CPs) with proton conduction and luminescence sensing is of great significance in clean energy and agricultural monitoring fields. In this work, an Mn-based coordination polymer (Mn-CP), namely, [Mn0.5(HL)] (H2L = HOOCC6H4C6H4CH2PO(OH)OCH3), was hydrothermally synthesized. Mn-CP has a one-dimensional (1D) chain structure, in which uncoordinated -COOH groups can serve as potential sites for fluorescence sensing. Moreover, Mn-CP shows good water and pH stabilities, offering the feasibility for proton conduction and sensing applications. Mn-CP displays comparatively high proton conductivity of 1.07 × 10-4 S cm-1 at 368 K and 95% relative humidity (RH), which is promising for proton conduction materials. Moreover, it can serve as a repeatable, highly selective, and visualized fluorescence sensor for detecting oxytetracycline (OTC). More importantly, Mn-CP reveals an amazing quantitative sensing of OTC in actual samples such as seawater, aquaculture freshwater, soil infiltration solutions, and tap water. This work proves the excellent application potential of dual-functional CPs in the field of clean energy and environmental protection, especially for the fluorescence detection of antibiotics in aquaculture systems.
ABSTRACT
Therapeutics for eradicating hepatitis B virus (HBV) infection are still limited and current nucleos(t)ide analogs (NAs) and interferon are effective in controlling viral replication and improving liver health, but they cannot completely eradicate the hepatitis B virus and only a very small number of patients are cured of it. The TCR-like antibodies recognizing viral peptides presented on human leukocyte antigens (HLA) provide possible tools for targeting and eliminating HBV-infected hepatocytes. Here, we generated three TCR-like antibodies targeting three different HLA-A2.1-presented peptides derived from HBV core and surface proteins. Bispecific antibodies (BsAbs) were developed by fuzing variable fragments of these TCR-like mAbs with an anti-CD3ϵ antibody. Our data demonstrate that the BsAbs could act as T cell engagers, effectively redirecting and activating T cells to target HBV-infected hepatocytes in vitro and in vivo. In HBV-persistent mice expressing human HLA-A2.1, two infusions of BsAbs induced marked and sustained suppression in serum HBsAg levels and also reduced the numbers of HBV-positive hepatocytes. These findings highlighted the therapeutic potential of TCR-like BsAbs as a new strategy to cure hepatitis B.
Subject(s)
Antibodies, Bispecific , Disease Models, Animal , Hepatitis B virus , Hepatitis B , Hepatocytes , Animals , Antibodies, Bispecific/immunology , Antibodies, Bispecific/pharmacology , Hepatocytes/virology , Hepatocytes/immunology , Mice , Humans , Hepatitis B virus/immunology , Hepatitis B virus/genetics , Hepatitis B/immunology , Hepatitis B/virology , HLA-A2 Antigen/immunology , Hepatitis B Surface Antigens/immunology , Receptors, Antigen, T-Cell/immunology , T-Lymphocytes/immunologyABSTRACT
Micro/Nano-scale particles are widely used as vaccine adjuvants to enhance immune response and improve antigen stability. While aluminum salt is one of the most common adjuvants approved for human use, its immunostimulatory capacity is suboptimal. In this study, we modified risedronate, an immunostimulant and anti-osteoporotic drug, to create zinc salt particle-based risedronate (Zn-RS), also termed particulate risedronate. Compared to soluble risedronate, micronanoparticled Zn-RS adjuvant demonstrated increased recruitment of innate cells, enhanced antigen uptake locally, and a similar antigen depot effect as aluminum salt. Furthermore, Zn-RS adjuvant directly and quickly stimulated immune cells, accelerated the formulation of germinal centers in lymph nodes, and facilitated the rapid production of antibodies. Importantly, Zn-RS adjuvant exhibited superior performance in both young and aged mice, effectively protecting against respiratory diseases such as SARS-CoV-2 challenge. Consequently, particulate risedronate showed great potential as an immune-enhancing vaccine adjuvant, particularly beneficial for vaccines targeting the susceptible elderly.
Subject(s)
Adjuvants, Vaccine , Vaccines , Animals , Mice , Humans , Aged , Risedronic Acid/therapeutic use , Aluminum , Adjuvants, Immunologic , Immunization , AntigensABSTRACT
Script event prediction aims to infer subsequent events given an incomplete script. It requires a deep understanding of events, and can provide support for a variety of tasks. Existing models rarely consider the relational knowledge between events, they regard scripts as sequences or graphs, which cannot capture the relational information between events and the semantic information of script sequences jointly. To address this issue, we propose a new script form, relational event chain, that combines event chains and relational graphs. We also introduce a new model, relational-transformer, to learn embeddings based on this new script form. In particular, we first extract the relationship between events from an event knowledge graph to formalize scripts as relational event chains, then use the relational-transformer to calculate the likelihood of different candidate events, where the model learns event embeddings that encode both semantic and relational knowledge by combining transformers and graph neural networks (GNNs). Experimental results on both one-step inference and multistep inference tasks show that our model can outperform existing baselines, indicating the validity of encoding relational knowledge into event embeddings. The influence of using different model structures and different types of relational knowledge is analyzed as well.
ABSTRACT
In this study, the temperature-dependent chemical toxicity of three insecticides and the resulting thermoregulatory (TR) behavior of the lizard Eremias argus have been consolidated into the current risk assessment framework. According to acute dermal toxicity assays, an increase of ambient temperature from 15 °C to 35 °C decreased the acute dermal toxicity of beta-cyfluthrin (BC) but increased the toxicity of chlorpyrifos (CPF). The toxicity of avermectin (AVM) did not show significant temperature-dependent responses. Based on thermal preference trials, lizards changed their body temperature via TR behavior to adaptively reduce toxicity under sub-lethal doses, which can be understood as a "self-rescue" behavior attenuating lethal effects. However, the risk quotient indicated that the effectiveness of this "self-rescue" behavior is limited. Metabolomics analysis showed that six different metabolites (i.e., creatine, glutamate, succinate, N-acetylaspartate, acetylcholine, and lactate) contributed to TR behavior changes. Biochemical assays and insecticide residue results demonstrated that the temperature-dependent toxicity of BC, CPF, and AVM affected lizards in the three aspects of biotransformation, oxidative stress, and neurometabolic interference. This work clarifies the ecotoxicological impacts of representative insecticides on reptiles from toxicological understanding to risk relevance. This knowledge may improve ecological predictions of agrochemical applications in the context of global climate change.
Subject(s)
Chlorpyrifos , Insecticides , Lizards , Animals , Insecticides/toxicity , Insecticides/metabolism , Prospective Studies , Temperature , Lizards/metabolism , Chlorpyrifos/toxicityABSTRACT
Biomimetic materials with complicated structures inspired by natural plants play a critical role in tissue engineering. The succulent plants, with complicated morphologies, show tenacious vitality in extreme conditions due to the physiological functions endowed by their unique anatomical structures. Herein, inspired by the macroscopic structure of succulent plants, succulent plant-like bioceramic scaffolds were fabricated via digital laser processing 3D printing of MgSiO3. Compared with conventional scaffolds with interlaced columns, the structures could prevent cells from leaking from the scaffolds and enhance cell adhesion. The scaffold morphology could be well regulated by changing leaf sizes, shapes, and interlacing methods. The succulent plant-like scaffolds show excellent properties for cell loading as well as cell distribution, promoting cellular interplay, and further enhancing the osteogenic differentiation of bone marrow stem cells. The in vivo study further illustrated that the succulent plant-like scaffolds could accelerate bone regeneration by inducing the formation of new bone tissues. The study suggests that the obtained succulent plant-like scaffold featuring the plant macroscopic structure is a promising biomaterial for regulating cell distribution, enhancing cellular interactions, and further improving bone regeneration.
Subject(s)
Osteogenesis , Tissue Scaffolds , Tissue Scaffolds/chemistry , Bone Regeneration , Biocompatible Materials/pharmacology , Biocompatible Materials/chemistry , Printing, Three-DimensionalABSTRACT
As the herbicide acetochlor (ACT) affects the plankton food web, this study investigated the effects of ACT and exocrine infochemicals from daphnids (after ACT exposure and/or starvation) on Scenedesmus obliquus growth, as well as the effects of ACT and starvation on life-history traits of Daphnia magna. Filtered secretions from daphnids increased algal ACT tolerance, dependent on different ACT exposure histories and food intake. Endogenous and secretory metabolite profiles of daphnids following ACT and/or starvation appear to be regulated by the fatty acid synthesis pathway and sulfotransferases and were related to energy allocation trade-offs. Oleic acid (OA) and octyl sulfate (OS), screened by secreted and somatic metabolomics, affected algal growth and ACT behavior in the algal culture in opposite ways. Trophic and non-trophic interspecific effects caused by ACT were observed in microalgae-daphnid microcosms, including algal growth inhibition, daphnid starvation, OA down-regulation, and OS up-regulation. Based on these findings, risk assessment of ACT on the freshwater plankton communities should take species interactions into account.
Subject(s)
Microalgae , Animals , Food Chain , Nutritional Status , DaphniaABSTRACT
BACKGROUND: In order to promote the green development of agriculture, it is important to study the enantioselective effect of chiral pesticides. The bioactivity of the chiral fungicide penthiopyrad (PEN) racemate and enantiomers against phytopathogens, toxicity to non-target organisms, effect on tomato fruit growth and maturation, and environmental fate in tomato cultivation were evaluated at an enantioselective level in this study. RESULTS: The results indicated that at the same efficacy, the optically pure S-(+)-PEN could lower the dosage of racemate by 20-96%. The S-enantiomer had low toxicity to earthworms. Besides, the S-(+)-PEN did not cause significant abiotic stress to the tomato and increased fruit fresh weight and size via modulating the contents of plant hormones. However, the content of hydrogen peroxide (H2 O2 ), superoxide (O2 - ) and malondialdehyde in the R-enantiomer treatment group was significantly higher than the control group. The effect of the racemate on tomato fruit was between the enantiomers. Furthermore, compared to R-(-)-PEN and racemate, the S-enantiomer degraded more quickly in tomato fruit, leaves, and soil, reducing the danger of human exposure. CONCLUSION: The S-enantiomer is highly effective and less toxic. The development of enantiomer pure S-(+)-PEN products might be an efficient and low-risk strategy. The results lay the foundation for comprehensive evaluation and proper application of PEN. © 2023 Society of Chemical Industry.
Subject(s)
Fungicides, Industrial , Pesticides , Solanum lycopersicum , Humans , Stereoisomerism , Pesticides/toxicity , Fungicides, Industrial/toxicity , Fungicides, Industrial/chemistryABSTRACT
The complex structure of rice straw is such that its bioconversion requires multiple physical and chemical pretreatment steps. In this study, it was found that a large amount of soluble polysaccharides (SPs) are formed during the pretreatment of straw. The yield of NaOH-based SPs (4.8%) was much larger than that of ball-milled SPs (1.5%) and H2SO4-based SPs (1.1%). For all the pretreatments, the ratio of phenolic compounds to saccharides (P/S) for each type of SPs increased upon increasing the concentration of ethanol in the order of 90% > 70% > 50%. The yield of NaOH-based SPs was much higher than that of acid-based and ball-milled SPs. The changes in the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power assay (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) of SPs follow the same rule, i.e., the higher the P/S ratio, the higher the antioxidant values of the SPs. The flow cytometry and laser scanning microscopy results show that the P/S ratio can significantly influence the effect of SPs on microbial growth and cell membrane permeability. Upon varying the ethanol concentration in the range of 50-90%, the P/S ratio increased from 0.02 to 0.17, resulting in an increase in the promoting effects of the SPs on yeast cell growth. Furthermore, H2O2, NAD+/NADH, and NADP+/NADPH assays indicate that SPs with a high P/S ratio can reduce intracellular H2O2 and change the intracellular redox status.
Subject(s)
Oryza , Oryza/chemistry , Antioxidants/chemistry , Fermentation , Hydrogen Peroxide , Sodium Hydroxide , Phenols/metabolism , Polysaccharides/metabolism , Ethanol/metabolismABSTRACT
Life-history theory suggests that organisms must distribute a limited share of their energetic resources among competing life-history trait demands. Therefore, the trade-off strategies individuals develop for particular life-history traits in a given environment may profoundly impact their environmental adaptability. In this study, lizards (Eremias. argus) were exposed to single and combined atrazine (4.0 mg·kg-1 and 20.0 mg·kg-1) and different temperatures (25 °C and 30 °C) for 8 weeks during the breeding season. The effects of atrazine and warming on the adaptability of lizards were explored by examining changes in trade-offs via several key life history traits (i.e., reproduction, self-maintenance, energy reserves, and locomotion). The results show that after atrazine exposure at 25 °C, both female and male lizards tended to allocate energy to self-maintenance by reducing energy allocation to reproductive process. The lower energy reserves of males are considered a "risky" life-history strategy and the observed higher mortality may be related to atrazine-induced oxidative damage. The retention of energy reserves by females not only ensured their current survival but also facilitated survival and reproduction in subsequent stages, which can be regarded as a "conservative" strategy. However, under high temperature and/or combined atrazine exposure, the "risky" strategy of males caused them to consume more energy reserves to invest in self-maintenance, which ensured their immediate survival, and profited from more rapid degradation of atrazine. In contrast, the "conservative" strategy of females could not meet their higher reproductive and self-maintenance demands under high temperatures, and the elevated reproductive oxidative and metabolic costs led to individual mortality. Gender differences in life-history trade-off strategies can directly lead to "winners" and "losers" from environmental stress within a species.