Generation of rat forebrain tissues in mice.

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.

A stable Mn(II) coordination polymer demonstrating proton conductivity and quantitative sensing of oxytetracycline in aquaculture.

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.

Micronanoparticled risedronate exhibits potent vaccine adjuvant effects.

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.

Effect of acetochlor on the symbiotic relationship between microalgae and bacteria.

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.

Past and projected future patterns of fractional vegetation coverage in China.

With the intensifying climate change and the strengthening ecosystem management, quantifying the past and predicting the future influence of these two factors on vegetation change patterns in China need to be analyzed urgently. By constructing a framework model to accurately identify fractional vegetation coverage (FVC) change patterns, we found that FVC in China from 1982 to 2018 mainly showed linear increase (29.5 %) or Gaussian decrease (27.4 %). FVC variation was mainly affected by soil moisture in the Qi-North region and by vapor pressure deficit in other regions. The influence of environmental change on FVC, except for Yang-Qi region in the southwest (-2.0 %), played a positive role, and weakened from the middle (Hu-Yang region: 2.7 %) to the northwest (Qi-North region: 2.4 %) to the east (Hu-East region: 0.8 %). Based on five machine learning algorithms, it was predicted that under four Shared Socioeconomic Pathways (SSPs, including SSP126、SSP245、SSP370、SSP585) from 2019 to 2060, FVC would maintain an upward trend, except for the east, where FVC would rapidly decline after 2039. FVC in the eastern region experienced a transition from past growth to future decline, suggesting that the focus of future ecosystem management should be on this region.

Glyphosate-based herbicide (GBH) challenged thermoregulation in lizards (Eremias argus), compensatory warming could mitigate this effect.

Chemical pollution and global warming are two major threats to reptiles, and these two factors can interact with each other. Glyphosate have attracted worldwide attention due to their ubiquitous occurrence, yet their impact on reptiles remains unknown. We designed a crossover experiment with different external GBH exposures (control/GBH) x different environmental temperatures (current climate treatment/warmer climate treatment) over 60 days to simulate environmental exposure in the Mongolian Racerunner lizard (Eremias argus). Preferred body temperature and active body temperature data were collected to calculate the accuracy of thermoregulation, while liver detoxification metabolic enzymes, oxidative stress system function, and the non-targeted metabolome of the brain tissue were assessed. Warmer-treated lizards adjusted their physiological levels and behavioral strategies in response to increased ambient temperatures and maintained body temperature homeostasis at moderate thermal perturbations. GBH-treated lizards suffered from oxidative damage to the brain tissue and abnormal histidine metabolism, thus their thermoregulatory accuracy reduced. Interestingly, at elevated ambient temperatures, GBH treatment did not affect on their thermoregulatory, possibly through several temperature-dependent detoxification mechanisms. Importantly, this data suggested that the subtle toxicological effects of GBH may threaten increasingly thermoregulation behavior of E. argus with species-wide repercussions, as climate change and exposure time extension.

Interspecific insights into direct and indirect effects of acetochlor on interactions between daphnids and microalgae: Toxic, trophic, and grazer-infochemical responses.

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.

Engineered CRISPR-OsCas12f1 and RhCas12f1 with robust activities and expanded target range for genome editing.

The type V-F CRISPR-Cas12f system is a strong candidate for therapeutic applications due to the compact size of the Cas12f proteins. In this work, we identify six uncharacterized Cas12f1 proteins with nuclease activity in mammalian cells from assembled bacterial genomes. Among them, OsCas12f1 (433 aa) from Oscillibacter sp. and RhCas12f1 (415 aa) from Ruminiclostridium herbifermentans, which respectively target 5' T-rich Protospacer Adjacent Motifs (PAMs) and 5' C-rich PAMs, show the highest editing activity. Through protein and sgRNA engineering, we generate enhanced OsCas12f1 (enOsCas12f1) and enRhCas12f1 variants, with 5'-TTN and 5'-CCD (D = not C) PAMs respectively, exhibiting much higher editing efficiency and broader PAMs, compared with the engineered variant Un1Cas12f1 (Un1Cas12f1_ge4.1). Furthermore, by fusing the destabilized domain with enOsCas12f1, we generate inducible-enOsCas12f1 and demonstate its activity in vivo by single adeno-associated virus delivery. Finally, dead enOsCas12f1-based epigenetic editing and gene activation can also be achieved in mammalian cells. This study thus provides compact gene editing tools for basic research with remarkable promise for therapeutic applications.

Develop a Compact RNA Base Editor by Fusing ADAR with Engineered EcCas6e.

Catalytically inactive CRISPR-Cas13 (dCas13)-based base editors can achieve the conversion of adenine-to-inosine (A-to-I) or cytidine-to-uridine (C-to-U) at the RNA level, however, the large size of dCas13 protein limits its in vivo applications. Here, a compact and efficient RNA base editor (ceRBE) is reported with high in vivo editing efficiency. The larger dCas13 protein is replaced with a 199-amino acid EcCas6e protein, derived from the Class 1 CRISPR family involved in pre-crRNA processing, and conducted optimization for toxicity and editing efficiency. The ceRBE efficiently achieves both A-to-I and C-to-U base editing with low transcriptome off-target in HEK293T cells. The efficient repair of the DMD Q1392X mutation (68.3±10.1%) is also demonstrated in a humanized mouse model of Duchenne muscular dystrophy (DMD) after AAV delivery, achieving restoration of expression for gene products. The study supports that the compact and efficient ceRBE has great potential for treating genetic diseases.

Integrating Relational Knowledge With Text Sequences for Script Event Prediction.

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.

The combined effects of atrazine and warming on environmental adaptability in lizards (Eremias argus) from the perspective of a life-history traits trade-off: Gender differences in trade-off strategies may reverse mortality risk.

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.

3D-Printing of succulent plant-like scaffolds with beneficial cell microenvironments for bone regeneration.

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.

Systemic enantioselectivity study of penthiopyrad: enantioselective bioactivity, acute toxicity, degradation and influence on tomato.

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.

Consolidation of temperature-dependent toxicity and thermoregulatory behavior into risk assessments of insecticides under thermal scenarios: A prospective study on Eremias argus.

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.

Influence of Different Pretreatment Steps on the Ratio of Phenolic Compounds to Saccharides in Soluble Polysaccharides Derived from Rice Straw and Their Effect on Ethanol Fermentation.

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.

Interference reduction isothermal nucleic acid amplification strategy for COVID-19 variant detection.

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.

High-fidelity Cas13 variants for targeted RNA degradation with minimal collateral effects.

CRISPR-Cas13 systems have recently been used for targeted RNA degradation in various organisms. However, collateral degradation of bystander RNAs has limited their in vivo applications. Here, we design a dual-fluorescence reporter system for detecting collateral effects and screening Cas13 variants in mammalian cells. Among over 200 engineered variants, several Cas13 variants including Cas13d and Cas13X exhibit efficient on-target activity but markedly reduced collateral activity. Furthermore, transcriptome-wide off-targets and cell growth arrest induced by Cas13 are absent for these variants. High-fidelity Cas13 variants show similar RNA knockdown activity to wild-type Cas13 but no detectable collateral damage in transgenic mice or adeno-associated-virus-mediated somatic cell targeting. Thus, high-fidelity Cas13 variants with minimal collateral effects are now available for targeted degradation of RNAs in basic research and therapeutic applications.

From the First to Third Generation of Neonicotinoids: Implication for Saving the Loss of Fruit Quality and Flavor by Pesticide Applications.

Neonicotinoids can control crop pests with high efficiency and low cost and have quickly swept one-fourth of the global insecticide market since the launch of imidacloprid in 1991. Imidacloprid and acetamiprid, the first generation of neonicotinoids, and dinotefuran, the representative of third generation of neonicotinoids, were applied on tomato plants individually to investigate neonicotinoid effects on tomato fruit quality, especially on appearance parameters, sugar, acid, and aroma compounds. Compared with the control, fewer differences in the transcriptome profile, sugar, acid, and volatile organic compound (VOC) contents, and sensory analysis results were shown in dinotefuran treatments than in the other two treatments. Therefore, dinotefuran was more recommended to control pests of tomatoes with less loss of fruit flavor and quality as well as lower ecological risks.