In this study, we isolated a virus strain （YN12031） from specimens of Armigeres subalbatus collected in the China-Laos border. BHK-21 cells infected with YN12031 exhibited an evident cytopathic effect （CPE） 32 h p...In this study, we isolated a virus strain （YN12031） from specimens of Armigeres subalbatus collected in the China-Laos border. BHK-21 cells infected with YN12031 exhibited an evident cytopathic effect （CPE） 32 h post-infection. The virus particles were spherical, 70 nm in diameter, and enveloped; they also featured surface fibers.展开更多
Japanese encephalitis(JE)was first discovered in Japan in 1871;in 1924,a major outbreak occurred,with 6,000 JE cases reported and a mortality rate of approximately 60%[1,2].Later studies showed that JE is caused by th...Japanese encephalitis(JE)was first discovered in Japan in 1871;in 1924,a major outbreak occurred,with 6,000 JE cases reported and a mortality rate of approximately 60%[1,2].Later studies showed that JE is caused by the Japanese encephalitis virus(JEV),which is spread by mosquitoes.展开更多
Objective Tick-borne encephalitis virus(TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis(TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease....Objective Tick-borne encephalitis virus(TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis(TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease. Methods A reverse-transcription recombinase-aided amplification(RT-RAA) assay was developed. This assay can be completed in one closed tube at 39℃ within 30 minutes. The sensitivity and specificity of RT-RAA were validated using non-infectious synthetic RNA representing a fragment of the NS5 region of the wild-type(WT) TBEV genome and the Senzhang strain. Additionally, 10 batches of tick samples were used to evaluate the performance of the RT-RAA assay. Results The analytical limit of detection of the assay was 20 copies per reaction of the TBEV synthetic transcript and 3 plaque-forming units(pfu) per reaction of TBEV titers. With the specific assay, no signal due to other arboviruses was observed. Of the 10 batches of tick samples obtained from the Changbai Mountains of China, three were TBEV-positive, which was consistent with the results of the quantitative real-time PCR assay. Conclusion A rapid, highly sensitive, specific, and easy-to-use method was developed for the detection of the TBEV Far-Eastern subtype.展开更多
A real-time RT-PCR （RT-qPCR） assay for the detection of Tahyna virus was developed to monitor Tahyna virus infection in field-collected vector mosquito samples. The targets selected for the assay were S segment sequ...A real-time RT-PCR （RT-qPCR） assay for the detection of Tahyna virus was developed to monitor Tahyna virus infection in field-collected vector mosquito samples. The targets selected for the assay were S segment sequences encoding the nucleocapsid protein from the Tahyna virus. Primers and probes were selected in conserved regions by aligning genetic sequences from various Tahyna virus strains available from GenBank. The sensitivity of the RT-qPCR approach was compared to that of a standard plaque assay in BHK cells. RT-qPCR assay can detect 4.8 PFU of titrated Tahyna virus. Assay specificities were determined by testing a battery of arboviruses, including representative strains of Tahyna virus and other arthropod-borne viruses from China. Seven strains of Tahyna virus were confirmed as positive; the other seven species of arboviruses could not be detected by RT-qPCR. Additionally, the assay was used to detect Tahyna viral RNA in pooled mosquito samples. The RT-qPCR assay detected Tahyna virus in a sensitive, specific, and rapid manner; these findings support the use of the assay in viral surveillance.展开更多
Rhododendron is a well-known genus consisting of commercially valuable ornamental woody plant species.Heat stress is a major environmental factor that affects rhododendron growth.Melatonin was recently reported to all...Rhododendron is a well-known genus consisting of commercially valuable ornamental woody plant species.Heat stress is a major environmental factor that affects rhododendron growth.Melatonin was recently reported to alleviate the effects of abiotic stress on plants.However,the role of melatonin in rhododendron plants is unknown.In this study,the effect of melatonin on rhododendron plants exposed to heat stress and the potential underlying mechanism were investigated.Analyses of morphological characteristics and chlorophyll a fluorescence indicated 200μmol L–1 was the optimal melatonin concentration for protecting rhododendron plants from heat stress.To elucidate how melatonin limits the adverse effects of high temperatures,melatonin contents,photosynthetic indices,Rubisco activity,and adenosine triphosphate(ATP)contents were analyzed at 25,35,and 40℃,respectively.Compared with the control,exogenous application of melatonin improved the melatonin contents,electron transport rate,photosystem II and I activities,Rubisco activity,and ATP contents under heat stress.The transcriptome analysis revealed many of the heat-induced differentially expressed genes were associated with the photosynthetic pathway;the expression of most of these genes was down-regulated by heat stress more in the melatonin-free plants than in the melatonin-treated plants.We identified Rh PGR5A,Rh ATPB,Rh LHCB3,and Rh Rbs A as key genes.Thus,we speculate that melatonin promotes photosynthetic electron transport,improves Calvin cycle enzyme activities,and increases ATP production.These changes lead to increased photosynthetic efficiency and CO_(2) assimilation under heat stress conditions via the regulated expression of specific genes,including Rh Rbs A.Therefore,the application of exogenous melatonin may increase the tolerance of rhododendron to heat stress.展开更多
Based on the Culex flavivirus (CxFV) E gene sequences in GenBank, CxFV-specific primers and probes were designed for real-time reverse transcription-polymerase chain reaction (RT-qPCR). The specificity test revealed t...Based on the Culex flavivirus (CxFV) E gene sequences in GenBank, CxFV-specific primers and probes were designed for real-time reverse transcription-polymerase chain reaction (RT-qPCR). The specificity test revealed that CxFV could be detected using RT-qPCR with the specific CxFV primers and probes; other species of arboviruses were not detected. The stability test demonstrated a coefficient of variation of <1.5%. A quantitative standard curve for CxFV RT-qPCR was established. Quantitative standard curve analysis revealed that the lower detection limit of the RT-qPCR system is 100 copies/mu L. Moreover, RT-qPCR was used to detect CxFV viral RNA in mosquito pool samples. In conclusion, we established a real-time RT-PCR assay for CxFV detection, and this assay is more sensitive and efficient than general RT-PCR. This technology may be used to monitor changes in the environmental virus levels.展开更多
基金supported by grants from National Natural Science Foundation of China(81290342 and 81501757)Development Grant of State Key Laboratory of Infectious Disease Prevention and Control(2014SKLID103)the Special National Project on Research and Development of Key Biosafety Technologies(2016YFC1201900),China
文摘In this study, we isolated a virus strain （YN12031） from specimens of Armigeres subalbatus collected in the China-Laos border. BHK-21 cells infected with YN12031 exhibited an evident cytopathic effect （CPE） 32 h post-infection. The virus particles were spherical, 70 nm in diameter, and enveloped; they also featured surface fibers.
基金supported by grants from the National Key Research and Development Program[2016YFD0500401](WH)the Development Grant of State Key Laboratory of Infectious Disease Prevention and Control[2014SKLID103](LG)and[2015SKLID505](WH)。
文摘Japanese encephalitis(JE)was first discovered in Japan in 1871;in 1924,a major outbreak occurred,with 6,000 JE cases reported and a mortality rate of approximately 60%[1,2].Later studies showed that JE is caused by the Japanese encephalitis virus(JEV),which is spread by mosquitoes.
基金supported by the National key research and development project [2017YFC1200505]the National Science and Technology Major Project of China [2018ZX10711001,2018ZX10101-002]the Development Grant of State Key Laboratory of Infectious Disease Prevention and Control [2015SKLID505,2014SKLID103]
文摘Objective Tick-borne encephalitis virus(TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis(TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease. Methods A reverse-transcription recombinase-aided amplification(RT-RAA) assay was developed. This assay can be completed in one closed tube at 39℃ within 30 minutes. The sensitivity and specificity of RT-RAA were validated using non-infectious synthetic RNA representing a fragment of the NS5 region of the wild-type(WT) TBEV genome and the Senzhang strain. Additionally, 10 batches of tick samples were used to evaluate the performance of the RT-RAA assay. Results The analytical limit of detection of the assay was 20 copies per reaction of the TBEV synthetic transcript and 3 plaque-forming units(pfu) per reaction of TBEV titers. With the specific assay, no signal due to other arboviruses was observed. Of the 10 batches of tick samples obtained from the Changbai Mountains of China, three were TBEV-positive, which was consistent with the results of the quantitative real-time PCR assay. Conclusion A rapid, highly sensitive, specific, and easy-to-use method was developed for the detection of the TBEV Far-Eastern subtype.
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2013ZX10004-101)
文摘A real-time RT-PCR （RT-qPCR） assay for the detection of Tahyna virus was developed to monitor Tahyna virus infection in field-collected vector mosquito samples. The targets selected for the assay were S segment sequences encoding the nucleocapsid protein from the Tahyna virus. Primers and probes were selected in conserved regions by aligning genetic sequences from various Tahyna virus strains available from GenBank. The sensitivity of the RT-qPCR approach was compared to that of a standard plaque assay in BHK cells. RT-qPCR assay can detect 4.8 PFU of titrated Tahyna virus. Assay specificities were determined by testing a battery of arboviruses, including representative strains of Tahyna virus and other arthropod-borne viruses from China. Seven strains of Tahyna virus were confirmed as positive; the other seven species of arboviruses could not be detected by RT-qPCR. Additionally, the assay was used to detect Tahyna viral RNA in pooled mosquito samples. The RT-qPCR assay detected Tahyna virus in a sensitive, specific, and rapid manner; these findings support the use of the assay in viral surveillance.
基金financially supported by the Shaoxing“Hometown of Celebrities”Talent Program,China(RC2022B05)the Talent Startup Program of Jiyang College of Zhejiang A&F University,China(RQ2020B15)the Scientific Research Training Program of Jiyang College of Zhejiang A&F University,China(JYKC2227)。
文摘Rhododendron is a well-known genus consisting of commercially valuable ornamental woody plant species.Heat stress is a major environmental factor that affects rhododendron growth.Melatonin was recently reported to alleviate the effects of abiotic stress on plants.However,the role of melatonin in rhododendron plants is unknown.In this study,the effect of melatonin on rhododendron plants exposed to heat stress and the potential underlying mechanism were investigated.Analyses of morphological characteristics and chlorophyll a fluorescence indicated 200μmol L–1 was the optimal melatonin concentration for protecting rhododendron plants from heat stress.To elucidate how melatonin limits the adverse effects of high temperatures,melatonin contents,photosynthetic indices,Rubisco activity,and adenosine triphosphate(ATP)contents were analyzed at 25,35,and 40℃,respectively.Compared with the control,exogenous application of melatonin improved the melatonin contents,electron transport rate,photosystem II and I activities,Rubisco activity,and ATP contents under heat stress.The transcriptome analysis revealed many of the heat-induced differentially expressed genes were associated with the photosynthetic pathway;the expression of most of these genes was down-regulated by heat stress more in the melatonin-free plants than in the melatonin-treated plants.We identified Rh PGR5A,Rh ATPB,Rh LHCB3,and Rh Rbs A as key genes.Thus,we speculate that melatonin promotes photosynthetic electron transport,improves Calvin cycle enzyme activities,and increases ATP production.These changes lead to increased photosynthetic efficiency and CO_(2) assimilation under heat stress conditions via the regulated expression of specific genes,including Rh Rbs A.Therefore,the application of exogenous melatonin may increase the tolerance of rhododendron to heat stress.
基金supported by grants from the Development Grant of State Key Laboratory of Infectious Disease Prevention and Control(2012SKLID204,2015SKLID505)the Ministry of Science and Technology of People’s Republic of China(No.2013ZX10004101)
文摘Based on the Culex flavivirus (CxFV) E gene sequences in GenBank, CxFV-specific primers and probes were designed for real-time reverse transcription-polymerase chain reaction (RT-qPCR). The specificity test revealed that CxFV could be detected using RT-qPCR with the specific CxFV primers and probes; other species of arboviruses were not detected. The stability test demonstrated a coefficient of variation of <1.5%. A quantitative standard curve for CxFV RT-qPCR was established. Quantitative standard curve analysis revealed that the lower detection limit of the RT-qPCR system is 100 copies/mu L. Moreover, RT-qPCR was used to detect CxFV viral RNA in mosquito pool samples. In conclusion, we established a real-time RT-PCR assay for CxFV detection, and this assay is more sensitive and efficient than general RT-PCR. This technology may be used to monitor changes in the environmental virus levels.
