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BACKGROUND: Geographic differences exist in the antibiotic resistance patterns of Helicobacter pylori. Personalized treatment regimens based on local or individual resistance data are essential. We evaluated the current status of H. pylori resistance in Ningxia, analyzed resistance-related factors, and assessed the concordance of phenotypic and genotypic resistance. METHODS: Strains were isolated from the gastric mucosa of patients infected with H. pylori in Ningxia and relevant clinical information was collected. Phenotypic antibiotic susceptibility assays (Kirby-Bauer disk diffusion) and antibiotic resistance gene detection (Sanger sequencing) were performed. RESULTS: We isolated 1955 H. pylori strains. The resistance rates of H. pylori to amoxicillin, levofloxacin, clarithromycin, and metronidazole were 0.9%, 42.4%, 40.4%, and 94.2%, respectively. Only five tetracycline-resistant and one furazolidone-resistant strain were identified. Overall, 3.3% of the strains were sensitive to all six antibiotics. Multidrug-resistant strains accounted for 22.9%, of which less than 20% were from Wuzhong. Strains isolated from women and patients with nonulcerative disease had higher rates of resistance to levofloxacin and clarithromycin. Higher rates of resistance to metronidazole, levofloxacin, and clarithromycin were observed in the older age group than in the younger age group. The kappa coefficients of phenotypic resistance and genotypic resistance for levofloxacin and clarithromycin were 0.830 and 0.809, respectively, whereas the remaining antibiotics showed poor agreement. CONCLUSION: H. pylori antibiotic resistance is severe in Ningxia. Therefore, furazolidone, amoxicillin, and tetracycline are better choices for the empirical therapy of H. pylori infection in this region. Host sex, age, and the presence of ulcerative diseases may affect antibiotic resistance of the bacteria. Personalized therapy based on genetic testing for levofloxacin and clarithromycin resistance may be a future direction for the eradication therapy of H. pylori infection in Ningxia.
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Infecções por Helicobacter , Helicobacter pylori , Humanos , Feminino , Idoso , Claritromicina/farmacologia , Claritromicina/uso terapêutico , Metronidazol/farmacologia , Metronidazol/uso terapêutico , Levofloxacino/farmacologia , Levofloxacino/uso terapêutico , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/microbiologia , Estudos Retrospectivos , Furazolidona/uso terapêutico , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Amoxicilina/uso terapêutico , Tetraciclina/farmacologia , Tetraciclina/uso terapêutico , Resistência Microbiana a Medicamentos , Farmacorresistência BacterianaRESUMO
BACKGROUND: Long noncoding RNAs (lncRNAs) have emerged as an important class of transcriptional regulators in cellular processes. The past decades have witnessed great progress in lncRNA studies in a variety of organisms. The codling moth (Cydia pomonella L.) is an important invasive insect in China. However, the functional impact of lncRNAs in this insect remains unclear. In this study, an atlas of codling moth lncRNAs was constructed based on publicly available RNA-seq datasets. RESULTS: In total, 9875 lncRNA transcripts encoded by 9161 loci were identified in the codling moth. As expected, the lncRNAs exhibited shorter transcript lengths, lower GC contents, and lower expression levels than protein-coding genes (PCGs). Additionally, the lncRNAs were more likely to show tissue-specific expression patterns than PCGs. Interestingly, a substantial fraction of the lncRNAs showed a testis-biased expression pattern. Additionally, conservation analysis indicated that lncRNA sequences were weakly conserved across insect species, though additional lncRNAs with homologous relationships could be identified based on synteny, suggesting that synteny could be a more reliable approach for the cross-species comparison of lncRNAs. Furthermore, the correlation analysis of lncRNAs with neighbouring PCGs indicated a stronger correlation between them, suggesting potential cis-acting roles of these lncRNAs in the regulation of gene expression. CONCLUSIONS: Taken together, our work provides a valuable resource for the comparative and functional study of lncRNAs, which will facilitate the understanding of their mechanistic roles in transcriptional regulation.
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Mariposas , RNA Longo não Codificante , Animais , China , Regulação da Expressão Gênica , Masculino , Mariposas/genética , RNA Longo não Codificante/genética , SinteniaRESUMO
Endemic fluorosis in Guizhou Province, Southwest China was firstly reported by Lyth in 1946 and was extensively concerned since the early 1980s. Initially, the pathological cause of endemic fluorosis in Guizhou Province was instinctively ascribed to the drinking water. However, increasing evidences pointed that the major exposure route of fluorine for the local residents is via the roasted foodstuffs, especially the roasted pepper and corn. Source of fluorine in roasted foodstuffs was once blamed on the local coal and subsequently imputed to clay mixed in the coal. In fact, both are probably the source. Geogenic fluorine concentration in soil and clay is indeed high in Guizhou Province, but is not likely to be the direct cause for endemic fluorosis. The real culprit for endemic fluorosis in Guizhou Province is the unhealthy lifestyle of the local residents, who usually roasted their foodstuffs using local coal or briquettes (a mixture of coal and clay), resulting in the elevated fluorine in roasted foodstuffs. Nowadays, endemic fluorosis in Guizhou Province has substantially mitigated. Nevertheless, millions of confirmed cases of dental fluorosis remain left. In addition to endemic fluorosis, other health problems associated with domestic coal burning may also exist, because of the enrichment of toxic/harmful elements in the local coal. It is necessary to determine how serious the situation is and find out the possible solution. As people in other developing countries may suffer from similar health issues, same health issues around the world deserve more attention.
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Intoxicação por Flúor , Fluorose Dentária , China/epidemiologia , Carvão Mineral/toxicidade , Fluoretos/análise , Fluorose Dentária/epidemiologia , HumanosRESUMO
Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) with a rising incidence worldwide. The precise aetiology is unclear, but aberrant regulatory T cell (Treg) responses have been documented in active UC patients. Follicular regulatory T cell (Tfr) is a recently identified subset of Treg cells. In this study, the role of ICOS in Tfr cells, which is a costimulatory molecule shown to stabilize and promote Treg differentiation, was investigated in UC patients. We found that with increasing UC severity, the frequency of ICOS+ CD4 T cells was increased, but the level of ICOS expression by ICOS+ CD4 T cells was decreased. ICOS+ cells were highly enriched in follicular regulatory T cells (Tfr), which is a subset of Treg cells characterized by CD25+ CD127- CXCR5+ Foxp3+ phenotype. Anti-CD3, anti-CD3/CD28, or anti-CD3/ICOS had all significantly increased the expression of Foxp3 and IL-10, and among the three stimulation methods, anti-CD3/ICOS was most effective at enhancing Foxp3 and IL-10 expression. Moreover, anti-CD3/ICOS-stimulated Tfr cells could suppress conventional T cell proliferation in an IL-10-dependent manner. Interestingly, anti-CD3/ICOS stimulation was less effective in UC-Mild and UC-Active patients compared to that in healthy and UC-Remission patients. In addition, UC patients presented impairment in ICOS upregulation following anti-CD3 stimulation. Overall, these data indicated that ICOS+ Tfr cells were dysregulated in UC patients and the level of dysregulation was associated with the severity of UC, suggesting that ICOS+ Tfr cells could serve as a biomarker of the progression of UC.
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Linfócitos T ReguladoresRESUMO
OBJECTIVE: Gastric cancer (GC) has been become the second leading cause for cancer-associated death. This study aimed to investigate Orexin A levels and associated receptors in tumor tissues of GC patients. PATIENTS AND METHODS: Forty-six consecutive gastric cancer patients (GC, n=46) and 13 chronic atrophic gastritis patients (CAG, n=13) were recruited. Meanwhile, 18 health individuals visiting Medical Examination Department were involved as control (N group, n=18). ELISA was used to examine Orexin A concentration. Immunohistochemistry assay was used to examine OX1R and OX2R. HE staining was applied to evaluate inflammation. qRT-PCR was employed to detect OX1R, OX2R, prepro-Orexin mRNAs. Serum Helicobacter pylori (H. pylori) infection was measured. RESULTS: Orexin A expression in GC patients was significantly up-regulated compared to N group and CAG group (p<0.05). Orexin A expression was increased in CAG group compared to N group (p<0.05). Gastric cancer tissues exhibited significantly obvious inflammation compared to N group and CAG group (p<0.05). OX1R and OX2R expressions were significantly down-regulated in GC group compared to N group and CAG group (p<0.05). OX1R and OX2R were lower significantly in GC group compared to CAG group (p<0.05). Prepro-Orexin was significantly depleted in tumor tissues of GC group compared to N group and CAG group (p<0.05). Orexin A expression was un-associated with gender, age and differential grades (p>0.05). CAG and GC patients demonstrated higher H. pylori infection rates. CONCLUSION: Orexin A was associated with inflammation by interacting with OX1R/OX2R receptor and activating prepro-Orexin in tumor tissues of gastric cancer patients.
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Gastrite/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori , Proteínas de Neoplasias/fisiologia , Receptores de Orexina/fisiologia , Orexinas/fisiologia , Precursores de Proteínas/metabolismo , Neoplasias Gástricas/metabolismo , Feminino , Gastrite/complicações , Gastrite Atrófica/metabolismo , Regulação Neoplásica da Expressão Gênica , Infecções por Helicobacter/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Receptores de Orexina/biossíntese , Receptores de Orexina/genética , Orexinas/biossíntese , Orexinas/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologiaRESUMO
Extractable polycyclic aromatic hydrocarbons (EPAHs) and bound PAHs (BPAHs) were measured in a sediment core using conventional Soxhlet extraction and a more astringent extraction method, with the objectives of determining the influence of BPAHs on the historical reconstruction of PAHs and exploring the formation of BPAHs and long-term behaviors of PAHs in sediment. The results indicated that the formation of BPAHs was clearly sediment-depth and molecular-size dependent. BPAHs represents an important portion of PAHs in sediment and cannot be extracted by conventional Soxhlet extraction. This suggests that the previously developed vertical profile of PAHs is not the real chronology of PAHs and the plausible interpretation derived from the sedimentary records of PAHs needs reexamination. Based on the previous findings, a biphase model was proposed and the formation of BPAHs was predicted. Due to the different nature of geosorbents in sediment, redistribution of PAHs among these geosorbents logically leads to the formation of BPAHs and is kinetically favorable for smaller molecular PAHs. This is consistent with the obtained results. Many factors may influence the formation of BPAHs, such as the physicochemical structure of sediment and environmental conditions. There is still a long way to reveal the thermodynamical characteristics in action during the formation of BPAHs.
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Monitoramento Ambiental , Sedimentos Geológicos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análiseRESUMO
PBDEs are persistent organic pollutants, and have the capability to produce adverse effects on organisms. Aquatic piscivorous species at higher trophic levels have the greatest exposure risk. Information on the toxic potency of a commercial PBDE mixture, DE-71, to mink and American kestrel was reviewed, and dietary- and tissue-based TRVs were derived and evaluated for ecological risk assessment of aquatic piscivorous species inhabiting wetland areas in China. The effect on mink thyroid function was identified as the most appropriate and protective endpoint for deriving the TRV s for mammals. The TRV was based on dietary exposure, and wa s0.1 mg DE-71/kg (wm) or 0.01 mg DE-71/kg (bm)/day (ADI); for liver of mammals,the TRV was 1.2 mg LPBDEslkg (lm). For birds, reproductive effects on American kestrels were used to derive the TRVs, in which an overall UF of 3.0 was used. The TRV was based on dietary exposure, and was 0.1 mg DE-71/kg (wm) or 0.018 mg DE-71/kg (bm)/day (ADI); for eggs of birds, the TRV was 2.35 jlgLPBDEs/g (lm). Reported concentrations of PBDEs in livers of aquatic mammals found dead, and in fish and bird eggs from Chinese wetland areas were compiled and compared to the corresponding criteria values. Results indicated that TRV values reported in this study can be used as indicators for screening-level risk assessment of piscivorous species in Chinese aquatic systems. Furthermore, based on monitoring concentrations of PBDEs in fishes from two lakes (DCL and TL) in China and the dietary-based TRV of 0.1 mg DE-71/kg (wm), a screening-level risk assessment of PBDEs was performed for predatory birds and mammals. The results suggest that concentrations of PBDEs in these two areas would not be expected to cause any adverse effects on the local fish-eating wild birds and mammals.
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Éteres Difenil Halogenados/toxicidade , Lagos/análise , Medição de Risco , Poluentes Químicos da Água/toxicidade , Animais , Aves , China , Éteres Difenil Halogenados/farmacocinética , Vison , Nível de Efeito Adverso não Observado , Valores de ReferênciaRESUMO
The Middle East-Minor 1 cryptic species (MEAM1), Bemisia tabaci (Gennadius) is a globally invasive pest. It spreads widely due to its high fecundity and mutualistic interactions with the virus they vector. Feeding on virus (tomato yellow leaf curl China virus, TYLCCNV)-infected host plants improves their fecundity, however, the key factor regulating the signaling transduction in reproduction of whitefly remains to be identified. Here, we cloned a full length cDNA encoding an insulin-like peptide in MEAM1 (BtILP1) and investigated its expression profile, functions, and the expression induced by feeding on virus-infected tobacco plants. The full length cDNA of BtILP1 was 590 bps and encoded an open reading frame containing 149 amino acid residues. Multiple sequences alignment results showed BtILP1 contained the structural features typical of the insulin family. Expression dynamics associated with development showed the expression level of BtILP1 peaked at 5 days posteclosion (PE). During 1 to 3 days PE, BtILP1 was expressed highly in the head and abdomen of female adults and highly in the head during 5 to 7 days PE. Knockdown of the BtILP1 expression also impaired vitellogenin gene expression at both transcript and protein levels. Downregulating BtILP1 expression decreased fecundity of female adults and hatching rate of eggs. Feeding on virus-infected tobacco increased BtILP1 expression in MEAM1 female adults. We infer feeding on begomovirus-infected tobacco enhances the reproduction of MEAM1 by inducing BtILP1 expression. Our results give a new sight into the mutualistic interactions between virus and its insect vector.
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Regulação da Expressão Gênica , Hemípteros/fisiologia , Proteínas de Insetos/genética , Sequência de Aminoácidos , Animais , Begomovirus/fisiologia , DNA Complementar/genética , DNA Complementar/metabolismo , Comportamento Alimentar/fisiologia , Feminino , Fertilidade/fisiologia , Hemípteros/genética , Hemípteros/metabolismo , Hemípteros/virologia , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Dados de Sequência Molecular , Interferência de RNA , Alinhamento de Sequência , Nicotiana/fisiologia , Nicotiana/virologia , TranscriptomaRESUMO
Objective: Pancreatic carcinoma is characterised by high aggressiveness and a bleak prognosis; optimising related treatment decisions depends on the availability of reliable prognostic markers. This study was designed to compare various blood biomarkers, such as neutrophil/lymphocyte ratio (NLR), lymphocyte/monocyte ratio (LMR), platelet/lymphocyte ratio (PLR), C-reactive protein (CRP), albumin (Alb), plasma fibrinogen (PF), and CRP/Alb in patients with pancreatic carcinoma. Methods: Our study retrospectively reviewed 250 patients with pancreatic carcinoma diagnosed between July 2007 and December 2018. The Cutoff Finder application was used to calculate the optimal values of CRP/Alb and PF. The Chi-square test or Fisher's exact test was used to analyse the correlation of CRP/Alb and PF with other clinicopathological factors. Conducting univariate and multivariate analyses allowed further survival analysis of these prognostic factors. Results: Multivariate analysis revealed that, in a cohort of 232 patients with pancreatic ductal adenocarcinoma (PDAC), the PF level exhibited statistical significance for overall survival (hazard ratio (HR) = 0.464; p = 0.023); however, this correlation was not found in the entire group of 250 patients with pancreatic carcinoma. Contrastingly, the CRP/Alb ratio was demonstrated statistical significance in both the entire pancreatic carcinoma cohort (HR = 0.471; p = 0.026) and the PDAC subgroup (HR = 0.484; p = 0.034). CRP/Alb and PF demonstrated a positive association (r=0.489, p<0.001) as indicated by Spearman's rank correlation analysis. Additionally, in 232 PDAC patients, the combination of the CRP/Alb ratio and PF had synergistic effects on prognosis when compared with either the CRP/Alb ratio or the PF concentration alone. Conclusion: PF concentration is a convenient, rapid, and noninvasive biomarker, and its combination with the CRP/Alb ratio could significantly enhance the accuracy of prognosis prediction in pancreatic carcinoma patients, especially those with the most common histological subtype of PDAC.
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Insects have evolved effectors to regulate host defenses for efficient feeding, yet their impact on chewing insects, like the tomato leaf miner (Phthorimaea absoluta), a significant pest, is poorly understood. We used RNAi to target the REPAT38 gene in larvae, monitoring changes at 0.5, 1, 2, and 4 h in leaf stomata, plant hormone concentrations (jasmonic acid (JA), jasmonoyl-L-isoleucine (JA-Ile), salicylic acid (SA), ethylene (ET), and abscisic acid (ABA)), and 12 hormone-responsive genes to explore the molecular mechanism of REPAT38-mediated plant-insect interactions. The results showed that the effector induced stomatal closure at 0.5 h and inhibited the synthesis of JA, ET, and ABA at 1 h. Additionally, seven plant hormone-responsive genes-AOC, MYC2, ACS1A, PAL, PR1, EIL2, and SRK2E-were inhibited at various time points. Our data suggest that REPAT38, as an effector with conserved functions, can weaken tomato host defenses and conducive to insect adaptation to host plants.
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The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), which is native to tropical Africa, has invaded more than 100 countries and constitutes a risk to the citrus sector. Studying its potential geographical distribution (PGD) in the context of global climate change is important for prevention and control efforts worldwide. Therefore, we used the CLIMEX model to project and assess the risk of global invasion by C. capitata under current (1981-2010) and future (2040-2059) climates. In the prevailing climatic conditions, the area of PGD for C. capitata was approximately 664.8 × 105 km2 and was concentrated in South America, southern Africa, southern North America, eastern Asia, and southern Europe. Under future climate conditions, the area of PGD for C. capitata is projected to decrease to approximately 544.1 × 105 km2 and shift to higher latitudes. Cold stress was shown to affect distribution at high latitudes, and heat stress was the main factor affecting distribution under current and future climates. According to the predicted results, countries with highly suitable habitats for C. capitata that have not yet been invaded, such as China, Myanmar, and Vietnam, must strengthen quarantine measures to prevent the introduction of this pest.
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Invasive alien pests (IAPs) pose a major threat to global agriculture and food production. When multiple IAPs coexist in the same habitat and use the same resources, the economic loss to local agricultural production increases. Many species of the Diabrotica genus, such as Diabrotica barberi, Diabrotica undecimpunctata, and Diabrotica virgifera, originating from the USA and Mexico, seriously damaged maize production in North America and Europe. However, the potential geographic distributions (PGDs) and degree of ecological niche overlap among the three Diabrotica beetles remain unclear; thus, the potential coexistence zone is unknown. Based on environmental and species occurrence data, we used an ensemble model (EM) to predict the PGDs and overlapping PGD of the three Diabrotica beetles. The n-dimensional hypervolumes concept was used to explore the degree of niche overlap among the three species. The EM showed better reliability than the individual models. According to the EM results, the PGDs and overlapping PGD of the three Diabrotica beetles were mainly distributed in North America, Europe, and Asia. Under the current scenario, D. virgifera has the largest PGD ranges (1615 × 104 km2). In the future, the PGD of this species will expand further and reach a maximum under the SSP5-8.5 scenario in the 2050s (2499 × 104 km2). Diabrotica virgifera showed the highest potential for invasion under the current and future global warming scenarios. Among the three studied species, the degree of ecological niche overlap was the highest for D. undecimpunctata and D. virgifera, with the highest similarity in the PGD patterns and maximum coexistence range. Under global warming, the PGDs of the three Diabrotica beetles are expected to expand to high latitudes. Identifying the PGDs of the three Diabrotica beetles provides an important reference for quarantine authorities in countries at risk of invasion worldwide to develop specific preventive measures against pests.
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Besouros , Animais , Aquecimento Global , Reprodutibilidade dos Testes , Agricultura/métodos , Ecossistema , Zea maysRESUMO
Phthorimaea absoluta (Meyrick) is an invasive pest that has caused damage to tomatoes and other crops in China since 2017. Pest control is mainly based on chemical methods that pose significant threats to food safety and environmental and ecological security. Light-induced control, a green prevention and control technology, has gained attention recently. However, current light-trapping technology is non-specific, attracting targeted pests alongside natural enemies and non-target organisms. In this study, we characterized the phototactic behavior of tomato leaf miners for the development a specific light-trapping technology for pest control. In situ hybridization revealed opsin expression throughout the body. Furthermore, we investigated the tropism of pests (wild T. absoluta, Toxoptera graminum, and Bemisia tabaci) and natural enemies (Nesidiocoris tenuis and Trichogramma pintoi) using a wavelength-lamp tropism experiment. We found that 365 ± 5 nm light could accurately trap wild P. absoluta without trapping natural enemies and other insects. Finally, we analyzed the phototactic behavior of the mutant strains LW2(-/-) and BL(-/-). LW2 and BL mutants showed significant differences in phototactic behavior. The LW2(-/-) strain was attracted to light at 390 ± 5 nm and the BL(-/-) strain was unresponsive to any light. Our findings will help to develop specific light-trapping technology for controlling tomato leaf miners, providing a basis for understanding pest population dynamics and protecting crops against natural enemies.
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Spodoptera exempta, known as the black armyworm, has been extensively documented as an invasive agricultural pest prevalent across various crop planting regions globally. However, the potential geographical distribution and the threat it poses to host crops of remains unknown at present. Therefore, we used an optimized MaxEnt model based on 841 occurrence records and 19 bioclimatic variables to predict the potential suitable areas of S. exempta under current and future climatic conditions, and the overlap with wheat, rice, and maize planting areas was assessed. The optimized model was highly reliable in predicting potential suitable areas for this pest. The results showed that high-risk distribution areas for S. exempta were mainly in developing countries, including Latin America, central South America, central Africa, and southern Asia. Moreover, for the three major global food crops, S. exempta posed the greatest risk to maize planting areas (510.78 × 104 km2), followed by rice and wheat planting areas. Under future climate scenarios, global warming will limit the distribution of S. exempta. Overall, S. exempta had the strongest effect on global maize production areas and the least on global wheat planting areas. Our study offers a scientific basis for global prevention of S. exempta and protection of agricultural crops.
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In insects, vision is crucial in finding host plants, but its role in nocturnal insects is largely unknown. Vision involves responses to specific spectra of photon wavelengths and opsins plays an important role in this process. Long-wavelength sensitive opsin (LW opsin) and blue-sensitive opsin (BL opsin) are main visual opsin proteins and play important in behavior regulation.We used CRISPR/Cas9 technology to mutate the long-wavelength-sensitive and blue wavelength-sensitive genes and explored the role of vision in the nocturnal invasive pest Tuta absoluta. Light wave experiments revealed that LW2(-/-) and BL(-/-) mutants showed abnormal wavelength tropism. Both LW2 and BL mutations affected the preference of T. absoluta for the green environment. Mutations in LW2 and BL are necessary to inhibit visual attraction. The elimination of LW2 and BL affected the preference of leaf moths for green plants, and mutations in both induced a preference in moths for white plants. Behavioral changes resulting from LW2(-/-) and BL(-/-) mutants were not affected by sense of smell, further supporting the regulatory role of vision in insect behavior. To the best of our knowledge, this is the first study to reveal that vision, not smell, plays an important role in the host-seeking behavior of nocturnal insects at night, of which LW2 and BL opsins are key regulatory factors. These study findings will drive the development of the "vision-ecology" theory.
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Visão de Cores , Mariposas , Animais , Opsinas/genética , Opsinas/metabolismo , Espécies Introduzidas , Mariposas/genética , Mariposas/metabolismo , Insetos/metabolismoRESUMO
The role of sediment-bound organic phosphorus (Po) on lake eutrophication was studied using sequential extraction and enzymatic hydrolysis by collecting sediments from Dianchi Lake, China. Bioavailable Po species including labile monoester P, diester P, and phytate-like P were identified in the sequential extractions by H2O, NaHCO3, and NaOH. For the H2O-Po, 36.7% (average) was labile monoester P, 14.8% was diester P, and 69.9% was phytate-like P. In NaHCO3-Po, 19.9% was labile monoester P, 17.5% was diester P, and 58.8% was phytate-like P. For NaOH-Po, 25.6% was labile monoester P, 7.9% was diester P, and 35.9% was phytate-like P. Labile monoester P was active to support growth of algae to form blooms. Diester P mainly distributed in labile H2O and NaHCO3 fractions was readily available to cyanobacteria. Phytate-like P represents a major portion of the Po in the NaOH fractions, also in the more labile H2O and NaHCO3 fractions. Based on results of sequential extraction of Po and enzymatic hydrolysis, lability and bioavailability was in decreasing order as follows: H2O-Po > NaHCO3-Po > NaOH-Po, and bioavailable Po accounted for only 12.1-27.2% of total Po in sediments. These results suggest that the biogeochemical cycle of bioavailable Po might play an important role in maintaining the eutrophic status of lakes.
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Sedimentos Geológicos/química , Compostos Orgânicos/química , Fósforo/química , Disponibilidade Biológica , HidróliseRESUMO
Historical polycyclic aromatic hydrocarbon (PAH) pollution was explored through the sedimentary records of three lakes: Huguangyan Maar Lake (HGY) in South China, Mayinghai Lake (MYH) in North China, and Sihailongwan Lake (SHLW) in Northeast China. In these three lakes, the PAH concentrations in sediments are still rising, showing the different trend to lakes in developed countries. PAH pollution in South China occurred from 1850, much earlier than the increases since 1980 observed in North and Northeast China. The temporal trends of PAH concentrations in lake sediments are highly correlated with local economic development. Spatially, although the region where HGY is located has the highest gross domestic product, higher fluxes of PAHs were found in MYH sediments, indicating that atmospheric PAH pollution in North China might be more serious, and that PAH pollution is not fully correlated with economic development. Source analysis suggested that the PAHs in lake sediments are mainly derived from oil leaks, coal and biomass combustion, vehicle emissions, and diagenesis. Positive matrix factorization (PMF) model revealed that the contribution of vehicle emissions and coal combustion to PAHs has increased significantly in the past 40 years. Benzo(a)pyrene equivalent (BaPE) in the surface sediments of MYH and SHLW were similar and higher than in HGY. In HGY, vehicle emissions posed the highest toxic risk, followed by coal combustion. However, in MYH, the toxicity risk of vehicle emissions was close to that of coal and biomass combustion due to the highly developed coal industry in Shanxi Province. In SHLW, the contribution of fossil fuel combustion to BaPE was significantly higher than that of biomass combustion. This study provides important information for understanding PAH pollution affected by anthropogenic activities in the Anthropocene and provides a scientific basis for formulating PAH pollution control strategies.
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Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Desenvolvimento Econômico , Lagos/química , Emissões de Veículos/análise , Sedimentos Geológicos/química , Monitoramento Ambiental , China , Carvão Mineral/análiseRESUMO
BACKGROUND: Both arrhenotoky (sexual reproduction of females and asexual reproduction of males) and thelytoky (asexual reproduction of females) occur within the order Hymenoptera. The existence of both thelytokous and arrhenotokous strains within one species provides an opportunity to compare the biocontrol efficiency between two reproductive modes. The parasitoid Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae) has thelytokous and arrhenotokous strains with sympatric distributions. This parasitoid is used to control invasive leafminers through feeding, stinging, and parasitization. To compare the biocontrol efficiency of the two strains, we analyzed life tables and host-killing parameters of these two strains reared on the leafminer Liriomyza sativae Blanchard using the age-stage, two-sex life table and the CONSUME-MSChart software. RESULTS: Our results showed that the intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R0 ) of the thelytokous strain were significantly higher than those of the arrhenotokous strain. The thelytokous females also performed better than the arrhenotokous females for the net host-feeding rate, net host-stinging rate, and net host-killing rate, but not the finite parasitism rate. Conclusively, the finite host-killing rate of the thelytokous strain (0.8720 ± 0.0516) was significantly higher than that of the arrhenotokous strain (0.5914 ± 0.0832). CONCLUSION: We concluded that thelytokous N. formosa is a better candidate as a biocontrol agent than arrhenotokous N. formosa to control leafminers. Our results shed light on how to choose a better biocontrol agent for integrated pest management (IPM) based on biological control, especially for co-occurring thelytokous and arrhenotokous parasitoids. © 2022 Society of Chemical Industry.
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Himenópteros , Vespas , Animais , Feminino , Masculino , Taiwan , ReproduçãoRESUMO
Pine wilt disease (PWD), caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus), a destructive, invasive forest pathogen, poses a serious threat to global pine forest ecosystems. The global invasion of PWN has been described based on three successive phases, introduction, establishment, and dispersal. Risk assessments of the three successive PWN invasion phases can assist in targeted management efforts. Here, we present a risk assessment framework to evaluate the introduction, establishment, and dispersal risks of PWD in China using network analysis, species distribution models, and niche concepts. We found that >88 % of PWN inspection records were from the United States, South Korea, Japan, Germany, and Mexico, and 94 % of interception records were primarily from the Jiangsu, Shanghai, Shandong, Tianjin, and Zhejiang ports. Based on the nearly current climate, the areas of PWN overlap with its host Pinus species were primarily distributed in southern, eastern, Yangtze River Basin, central, and northeastern China regions. Areas of PWN overlap with its insect vector Monochamus alternatus were primarily distributed in southern, eastern, Yangtze River Basin, central, and northeastern China regions, and those of PWN overlap with the insect vector Monochamus saltuarius were primarily distributed in eastern and northeastern China. The niche between PWN and the insect vector M. alternatus was the most similar (0.68), followed by that between PWN and the insect vector M. saltuarius (0.47). Climate change will increase the suitable probabilities of PWN and its two insect vectors occurring at high latitudes, further increasing their threat to hosts in northeastern China. This risk assessment framework for PWD could be influential in preventing the entry of the PWN and mitigating their establishment and dispersal risks in China. Our study provides substantial clues for developing a framework to improve the risk assessment and surveillance of biological invasions worldwide.
Assuntos
Besouros , Nematoides , Pinus , Animais , Ecossistema , Doenças das Plantas , China , Insetos VetoresRESUMO
The southern armyworm (Spodoptera eridania), a polyphagous crop pest native to tropical America, has been found in Africa (2016) and India (2019), causing defoliation and damage to the reproductive structures of cassava, soybean, and tomato. The damage caused by this pest to crop systems has raised concerns regarding its potential risks. Therefore, we predicted the potential geographical distribution of S. eridania under climate change conditions using 19 bioclimatic variables based on an optimized MaxEnt model. The results showed that annual precipitation (bio12), mean temperature of the warmest quarter (bio10), and precipitation of the driest month (bio14) were important bioclimatic variables influencing the potential distribution. The prediction showed that the suitable habitat area was approximately 3426.43 × 104 km2, mainly concentrated in southern North America, South America, western Europe, central Africa, southern Asia, and eastern Oceania. In response to global climate change, suitable habitats for S. eridania will expand and shift to higher latitudes in the future, especially under the SSP5-8.5 scenario. Because of the current devastating effects on crop production, countries without S. eridania invasion, such as the European Union, Southeast Asian countries, and Australia, need to strengthen phytosanitary measures at border ports to prevent the introduction of this pest.