Nanomaterial-Encapsulated dsRNA-Targeting Chitin Pathway─A Potential Efficient and Eco-Friendly Strategy against Cotton Aphid, Aphis gossypii (Hemiptera: Aphididae).

The r-strategy pests are very challenging to effectively control because of their rapid population growth and strong resurgence potential and are more prone to developing pesticide resistance. As a typical r-strategy pest, the cosmopolitan cotton aphid, Aphis gossypii Glover, seriously impacts the growth and production of cucurbits and cotton. The present study developed a SPc/double-stranded RNA (dsRNA)/botanical strategy to enhance the control efficacy of A. gossypii. The results demonstrated that the expression of two chitin pathway genes AgCHS2 and AgHK2 notably changed in A. gossypii after treated by three botanical pesticides, 1% azadirachtin, 1% matrine, and 5% eucalyptol. SPc nanocarrier could significantly enhance the environmental stability, cuticle penetration, and interference efficiency of dsRNA products. The SPc/dsRNA/botanical complex could obviously increase the mortality of A. gossypii in both laboratory and greenhouse conditions. This study provides an eco-friendly control technique for enhanced mortality of A. gossypii and lower application of chemical pesticides. Given the conservative feature of chitin pathway genes, this strategy would also shed light on the promotion of management strategies against other r-strategy pests using dsRNA/botanical complex nanopesticides.

Side effects of X-ray irradiation on flight ability of Cydia pomonella moth.

BACKGROUND: The sterile insect technique (SIT) has proven to be an effective approach in managing the population of major invasive pests. Our previous studies showed that irradiation of Cydia pomonella males at a dosage of 366 Gy X-rays resulted in complete sterility. However, the mating competitiveness of sterilized males is significantly compromised, which can be attributed to a decline in their ability to fly. RESULTS: In this study, we examined the flight patterns of both male and female adults of C. pomonella. The results revealed significant variations in the average flight speed of both genders at different stages of maturity, with females displaying longer flight duration and covering greater distances. Effect of irradiation on the flight performance of 3-day-old male moths was further evaluated, as they demonstrated the longest flight distance. The findings indicated a significant decrease in flight distance, duration, and average speed, due to wing deformities caused by irradiation, which also limited the dispersal distance of moths in orchards, as indicated by the mark-and-recapture assay. Reverse-transcription quantitative polymerase chain reaction analysis revealed a down-regulation of flight-related genes such as Flightin, myosin heavy chain, and Distal-less following radiation exposure. CONCLUSION: These findings demonstrate that X-ray irradiation at a radiation dose of 366 Gy has a detrimental effect on the flight ability of male C. pomonella adults. These insights not only contribute to a better understanding of how radiation sterilization diminishes the mating competitiveness of male moths, but also aid in the development and improvement of SIT practices for the effective control of C. pomonella. © 2023 Society of Chemical Industry.

Red Blood Cell Lysis Pretreatment Can Significantly Improve the Yield of Treponema pallidum DNA from Blood.

PCR can be a supplement to Treponema serological testing. However, its sensitivity is not satisfactory for blood sample testing. The aim of this study was to investigate whether pretreatment with red blood cell (RBC) lysis could enhance the yield of Treponema pallidum subsp. pallidum DNA extraction from blood. We developed and verified the efficacy of a quantitative PCR (qPCR) assay that utilizes TaqMan technology to specifically detect T. pallidum DNA by targeting the polA gene. Simulation media with 106 to 100 treponemes/mL were prepared in normal saline (NS), whole blood, plasma, and serum, and RBC lysis pretreatment was performed on a portion of whole blood. Then, blood samples drawn from 50 syphilitic rabbits were divided in parallel into five groups, labeled whole blood, whole blood/lysed RBCs, plasma, serum, and blood cells/lysed RBCs. DNA extraction and qPCR detection were performed. The detection rate and copy number were compared among different groups. The polA assay showed good linearity and an excellent amplification efficiency of 102%. In the simulated blood samples, the detection limit of the polA assay reached 1 × 102 treponemes/mL in whole blood/lysed RBCs, plasma, and serum. However, the detection limit was only 1 × 104 treponemes/mL in NS and whole blood. Among the blood samples from syphilitic rabbits, whole blood/lysed RBCs showed the best detection rate (82.0%), while the detection rate for whole blood was only 6%. The copy number of whole blood/lysed RBCs was higher than that of whole blood. RBC lysis pretreatment can significantly improve the yield of T. pallidum DNA from whole blood, and the yield is better than that from whole blood, plasma, serum, and blood cells/lysed RBCs. IMPORTANCE Syphilis is a sexually transmitted disease caused by T. pallidum that can spread into the blood. T. pallidum DNA can be detected in blood by PCR but with low sensitivity. Few studies have applied RBC lysis pretreatment to blood T. pallidum DNA extraction. This study shows that the detection limit, detection rate, and copy number of whole blood/lysed RBCs were better than those of whole blood, plasma, and serum. After RBC lysis pretreatment, the yield of low concentrations of T. pallidum DNA was improved, and the low sensitivity of blood-based T. pallidum PCR was improved. Therefore, whole blood/lysed RBCs are the ideal sample for acquiring blood T. pallidum DNA.

Development and Evaluation of a Novel One-Step RT-qPCR Targeting the Vero Gene for the Identification of False-Positive Results Caused by Inactivated Virus Vaccine Contamination.

To identify false-positive SARS-CoV-2 test results caused by novel coronavirus inactivated vaccine contamination, a novel RT-qPCR targeting the ORF1ab and N genes of SARS-CoV-2 and Vero gene was developed. The amplification efficiency, precision, and lower limit of detection (LLOD) of the RT-qPCR assay were determined. A total of 346 clinical samples and 132 environmental samples were assessed, and the diagnostic performance was evaluated. The results showed that the amplification efficiency of the ORF1ab, N, and Vero genes was 95%, 97%, and 93%, respectively. The coefficients of variation of Ct values at a concentration of 3 × 104 copies/mL were lower than 5%. The LLOD for the ORF1ab, N, and Vero genes reached 8.0, 3.3, and 8.2 copies/reaction, respectively. For the 346 clinical samples, our RT-qPCR assay identified SARS-CoV-2-positive and SARS-CoV-2-negative samples with a sensitivity of 100.00% and a specificity of 99.30% and novel coronavirus inactivated vaccine-contaminated samples with a sensitivity of 100% and a specificity of 100%. For the environmental samples, our RT-qPCR assay identified novel coronavirus inactivated vaccine-contaminated samples with a sensitivity of 88.06% and a specificity of 95.38%. In conclusion, the RT-qPCR assay we established can be used to diagnose COVID-19 and, to a certain extent, false-positive results due to vaccine contamination.

Treponema pallidum protein Tp0136 promoting MMPs/TIMPs imbalance via PI3K, MAPK and NF-κB signalling pathways in HDVSMCs.

The invasive capability of Treponema. pallidum is central to its infection process. Matrix metalloproteinases (MMPs), which are specifically inhibited by the tissue inhibitors of metalloproteinases (TIMPs), play a pivotal role in promoting pathogenic invasion by destroying tissue barriers within the body. This study aimed to explore the effect of T. pallidum protein Tp0136 on the balance of MMPs/TIMPs in human dermal vascular smooth muscle cells (HDVSMCs) and the related underlying mechanisms. A number of in vitro studies were conducted to access the impact of recombinant Tp0136 protein on the balance of MMPs/TIMPs in HDVSMCs. The involvement of the PI3K, MAPK, and NF-κB signaling pathways in this process was also investigated. Tp0136 induced the mRNA and protein expressions of MMP1 in HDVSMCs in a concentration-dependent way. In addition, MMP1/TIMP1 and MMP1/TIMP2 ratios were also increased. Furthermore, the study demonstrated that treatment of HDVSMCs with Tp0136 activated the PI3K, MAPK, and NF-κB signaling pathways. Inhibition of PI3K, JNK, P38, and NF-κB, suppressed MMP1 expression and reduced the induction of MMP1/TIMP1 and MMP1/TIMP2 ratios by Tp0136. These findings demonstrate that Tp0136 enhanced the expression of MMP1 involving the PI3K, MAPK, and NF-κB signaling pathways in HDVSMCs, and thus generated the unbalance of MMPs/TIMP, which could contribute to the early spread of T. pallidum and pathogenesis of syphilis.

Cognitive process underlying ultimatum game: An eye-tracking study from a dual-system perspective.

According to the dual-system theories, the decisions in an ultimatum game (UG) are governed by the automatic System 1 and the controlled System 2. The former drives the preference for fairness, whereas the latter drives the self-interest motive. However, the association between the contributions of the two systems in UG and the cognitive process needs more direct evidence. In the present study, we used the process dissociation procedure to estimate the contributions of the two systems and recorded participants eye movements to examine the cognitive processes underlying UG decisions. Results showed that the estimated contributions of the two systems are uncorrelated and that they demonstrate a dissociated pattern of associations with third variables, such as reaction time (RT) and mean fixation duration (MFD). Furthermore, the relative time advantage (RTA) and the transitions between the two payoffs can predict the final UG decisions. Our findings provide evidence for the independent contributions of preference for fairness (System 1) and self-interest maximizing (System 2) inclinations to UG and shed light on the underlying processes.

Genetic variations in GABA metabolism and epilepsy.

Epilepsy is a paroxysmal brain disorder that results from an imbalance between neuronal excitation and inhibition. Gamma-aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the brain and plays an important role in the occurrence and development of epilepsy. Abnormalities in all aspects of GABA metabolism, including GABA synthesis, transport, genes encoding GABA receptors, and GABA inactivation, may lead to epilepsy. GABRA1, GABRA2, GABRA5, GABRB1, GABRB2, GABRB3, GABRG2 and GABBR2 are genes that encode GABA receptors and are commonly associated with epilepsy. Mutations of these genes lead to a variety of epilepsy syndromes with different clinical phenotypes, primarily by down regulating receptor expression and reducing the amplitude of GABA-evoked potentials. GABA is metabolized by GABA transaminase and succinate semi aldehyde dehydrogenase, which are encoded by the ABAT and ALDH5A1 genes, respectively. Mutations of these genes result in symptoms related to deficiency of GABA transaminase and succinate semi aldehyde dehydrogenase, such as epilepsy and cognitive impairment. Most of the variation in genes associated with GABA metabolism are accompanied by developmental disorders. This review focuses on advances in understanding the relationship between genetic variation in GABA metabolism and epilepsy to establish a basis for the accurate diagnosis and treatment of epilepsy.

Molecular typing of familial temporal lobe epilepsy.

The pathogenesis of temporal lobe epilepsy (TLE) was originally considered to be acquired. However, some reports showed that TLE was clustered in some families, indicating a genetic etiology. With the popularity of genetic testing technology, eleven different types of familial TLE (FTLE), including ETL1-ETL11, have been reported, of which ETL9-ETL11 had not yet been included in the OMIM database. These types of FTLE were caused by different genes/Loci and had distinct characteristics. ETL1, ETL7 and ETL10 were characterized by auditory, visual and aphasia seizures, leading to the diagnosis of familial lateral TLE. ETL2, ETL3 and ETL6 showed prominent autonomic symptom and automatism with or without hippocampal abnormalities, indicating a mesial temporal origin. Febrile seizures were common in FTLEs such as ETL2, ETL5, ETL6 and ETL11. ETL4 was diagnosed as occipitotemporal lobe epilepsy with a high incidence of migraine and visual aura. Considering the diversity and complexity of the symptoms of TLE, neurologists enquiring about the family history of epilepsy should ask whether the relatives of the proband had experienced unnoticeable seizures and whether there is a family history of other neurological diseases carefully. Most FTLE patients had a good prognosis with or without anti-seizure medication treatment, with the exception of patients with heterozygous mutations of the CPA6 gene. The pathogenic mechanism was diverse among these genes and spans disturbances of neuron development, differentiation and synaptic signaling. In this article, we describe the research progress on eleven different types of FTLE. The precise molecular typing of FTLE would facilitate the diagnosis and treatment of FTLE and genetic counseling for this disorder.

Influence of the Manner of Information Presentation on Risky Choice.

We are constantly faced with decisive situations in which the options are not presented simultaneously. How the information of options is presented might influence the subsequent decision-making. For instance, presenting the information of options in an alternative- or dimension-wise manner may affect searching patterns and thus lead to different choices. In this study, the effects of this manner of information presentation on risky choice according to two experiments (Experiment 1, N = 45; Experiment 2, N = 50) are systematically examined. Specifically, two tasks with different presentation are conducted. Participants could search the information of one option (alternative-wise task) or dimension (dimension-wise task) for each time. Results revealed that the participants assigned in the alternative-wise task exhibited more choices consistent with expected value theory and took a longer decision time than those in the dimension-wise task. Moreover, the effect of task on choice was mediated by the direction of information search. These findings suggest a relationship between information search pattern and risky choice and allow for a better understanding of the mechanisms and processes involved in risky choice.

Identification and Functional Characterization of a Sigma Glutathione S-Transferase CpGSTs2 Involved in λ-Cyhalothrin Resistance in the Codling Moth Cydia pomonella.

The codling moth, Cydia pomonella (L.), is a quarantine pest of global significance impacting pome fruits and walnuts. It has evolved resistance to many commonly used insecticides including λ-cyhalothrin. Glutathione S-transferases (GSTs) are multifunctional enzymes playing a crucial role in the detoxification of insecticides in insects. However, the role of specific GST gene in λ-cyhalothrin resistance in C. pomonella is unclear. In this study, we identified three sigma-class genes (CpGSTs1, CpGSTs2, and CpGSTs3). These genes were ubiquitously expressed at all developmental stages, and of these, the expression level of CpGSTs2 in the larval stage was significantly higher than in the egg, pupal, and adult stages. Moreover, CpGSTs2 was predominantly expressed in the fat body while lower levels in the cuticle. In addition to exposure of larvae to LD10 of λ-cyhalothrin elevating the expression level of CpGSTs2, mRNA levels of CpGSTs2 in a field population (ZW_R) from northeast China, which has developed moderate level resistance to λ-cyhalothrin, was significantly higher than that of susceptible strains. In vitro inhibition assays demonstrated that λ-cyhalothrin inhibited the conjugating activities of recombinant CpGSTs2, and metabolic assays indicated that λ-cyhalothrin could be depleted by recombinant CpGSTs2. These results bring evidence for the involvement of CpGSTs2 in C. pomonella in resistance to λ-cyhalothrin.

The power of last fixation: Biasing simple choices by gaze-contingent manipulation.

Among the established findings in eye movement during decision-making, decision-makers are likely to choose the last fixated option, and this phenomenon has proven robust. However, the causal link between last fixation and choices requires further examination. In Study 1 (N = 40), a gaze-contingent manipulation paradigm was developed by controlling the timing of decision prompts to manipulate the last fixation. The results showed that participants' value-based choices were biased toward the last fixated option. However, the manipulation in Study 1 may disturb their decision process, leading to an unnatural decision environment. In Study 2 (N = 40), the gaze-contingent paradigm was further developed to manipulate the last fixation by directing an additional fixation on the target option after the participants' decision prompts. The results showed that participants' choices were also biased in the uninterrupted decisions. Our findings suggest a causal link between last fixation and value-based choices.

Overexpression of Glutathione S-Transferase Genes in Field λ-Cyhalothrin-Resistant Population of Cydia pomonella: Reference Gene Selection and Expression Analysis.

Analysis of the glutathione S-transferase (GST) gene expression in an insecticide-resistant strain of Cydia pomonella using real-time quantitative polymerase chain reaction is a key step toward more mechanism studies that require suitable reference genes with stable expression. Here, nine commonly used reference genes were selected, and their expression stabilities were analyzed. Results showed that EF-1α was the most stable reference gene in all of the experimental sets. The combinations of EF-1α and 18S, EF-1α and RPL12, and EF-1α and GAPDH were sufficient for normalization of gene expression analysis accurately in developmental stages, tissues, and larvae exposed to sublethal dose of λ-cyhalothrin, respectively. Additionally, the suitability of particular reference genes was verified by analyzing the spatiotemporal and insecticide-induced expression profiles of CpGSTe3, CpGSTd3, and CpGSTd4, which were overexpressed in a λ-cyhalothrin-resistant population from northeast China. These genes were used to confer the practicability of reference genes chosen in this study.

The more involved in lead-zinc mining risk the less frightened: A psychological typhoon eye perspective.

In China, the current situation is that people under indirect threat from unprotected lead-zinc mining tends to oppose it, whereas people under direct threat are likely to 'sail close to the wind'. To understand this puzzle-like phenomenon, we surveyed 220 residents in a lead-zinc mining area located in Fenghuang County of China. We found that: 1) The degree of risk perception of villagers living around the mining site correlated inversely with their degree of involvement in mining risk. We refer to this as the ''involvement'' version of the psychological typhoon eye effect. 2) Perceived benefit and perceived harm provided a satisfactory explanation for this ''involvement'' version of the psychological typhoon eye effect. 3) Risk perception was negatively related to support for the relevant policy which we viewed as constituting a sort of voting behavior. The results may have implications for better understanding how benefited individuals respond to environmental health risks.

FRET-based system for probing protein-protein interactions between σR and RsrA from Streptomyces coelicolor in response to the redox environment.

Protein-protein interactions between sigma factor σ(R) and its corresponding zinc-binding anti-sigma (ZAS) protein RsrA trigger the thioredoxin system for maintaining cellular redox homeostasis in S. coelicolor. RsrA bound to zinc associates with σ(R), inhibiting its transcriptional activity in a reducing environment. During disulfide stress it forms intramolecular disulfide bonds, leading to zinc release and dissociation from σ(R), which initiates transcription to produce reductase and thioredoxin. We designed a fluorescence resonance energy transfer (FRET) based system for monitoring protein-protein interactions between σ(R) and RsrA to further understand how this redox switch regulates the thioredoxin system in S. coelicolor in response to its redox environment, especially various reactive oxygen species (ROS) derived from different metabolic pathways, and clarify the different response mechanisms between Zn-RsrA and apo-RsrA. By the use of the FRET approach described here, we showed that zinc protected thiols in RsrA and causes the σ(R)-RsrA complex to form a more compact structure. This system was also utilized to detect changes in redox status induced by ROS and diamide in real time in E. coli cells.

Quantitative monitoring of 2-oxoglutarate in Escherichia coli cells by a fluorescence resonance energy transfer-based biosensor.

2-Oxoglutarate (2OG) is a metabolite from the highly conserved Krebs cycle and not only plays a critical role in metabolism but also acts as a signaling molecule in a variety of organisms. Environmental inorganic nitrogen is reduced to ammonium by microorganisms, whose metabolic pathways involve the conversion of 2OG to glutamate and glutamine. Tracking of 2OG in real time would be useful for studies on cell metabolism and signal transduction. Here, we developed a genetically encoded 2OG biosensor based on fluorescent resonance energy transfer by inserting the functional 2OG-binding domain GAF of the NifA protein between the fluorescence resonance energy transfer (FRET) pair YFP/CFP. The dynamic range of the sensors is 100 µM to 10 mM, which appeared identical to the physiological range observed in E. coli. We optimized the peptide lengths of the binding domain to obtain a sensor with a maximal ratio change of 0.95 upon 2OG binding and demonstrated the feasibility of this sensor for the visualization of metabolites both in vitro and in vivo.

Imaging and tracing of intracellular metabolites utilizing genetically encoded fluorescent biosensors.

Intracellular metabolites play a crucial role in characterizing and regulating corresponding cellular activities. Tracking intracellular metabolites in real time by traditional means was difficult until the powerful toolkit of genetically encoded biosensors was developed. Over the past few decades, iterative improvements of these biosensors have been made, resulting in the effective monitoring of metabolites. In this review, we introduce and discuss the recent advances in the use of genetically encoded biosensors for tracking some key metabolites, such as ATP, cAMP, cGMP, NADH, reactive oxygen species, sugar, carbon monoxide, and nitric oxide. A brief phylogeny of fluorescent proteins and several typical construction modes for genetically encoded biosensors are also described. We also discuss the development of novel RNA-based sensors, which are genetically encoded biosensors active at the transcriptional level.