With the implementation of the C-strain vaccine,classical swine fever(CSF) has been under control in China,which is currently in a chronic atypical epidemic situation.African swine fever(ASF) emerged in China in 2018 ...With the implementation of the C-strain vaccine,classical swine fever(CSF) has been under control in China,which is currently in a chronic atypical epidemic situation.African swine fever(ASF) emerged in China in 2018 and spread quickly across the country.It is presently occurring sporadically due to the lack of commercial vaccines and farmers’ increased awareness of biosafety.Atypical porcine pestivirus(APPV) was first detected in Guangdong Province,China,in 2016,which mainly harms piglets and has a local epidemic situation in southern China.These three diseases have similar clinical symptoms in pig herds,which cause considerable losses to the pig industry.They are difficult to be distinguished only by clinical diagnosis.Therefore,developing an early and accurate simultaneous detection and differential diagnosis of the diseases induced by these viruses is essential.In this study,three pairs of specific primers and Taq-man probes were designed from highly conserved genomic regions of CSFV(5’ UTR),African swine fever virus(ASFV)(B646L),and APPV(5’ UTR),followed by the optimization of reaction conditions to establish a multiplex real-time PCR detection assay.The results showed that the method did not cross-react with other swine pathogens(porcine circovirus type 2(PCV2),porcine reproductive and respiratory syndrome virus(PRRSV),foot-and-mouth disease virus(FMDV),pseudorabies virus(PRV),porcine parvovirus(PPV),and bovine viral diarrhea virus BVDV).The sensitivity results showed that CSFV,ASFV,and APPV could be detected as low as 1 copy μL–1;the repeatability results showed that the intra-assay and interassay coefficient of variation of ASFV,CSFV,and APPV was less than 1%.Twenty-two virus samples were detected by the multiplex real-time PCR,compared with national standard diagnostic and patented method assay for CSF(GB/T 27540–2011),ASF(GB/T 18648–2020),and APPV(CN108611442A),respectively.The sensitivity of this triple real-time PCR for CSFV,ASFV,and APPV was almost the same,and the compliance results were the same(100%).A total of 451 clinical samples were detected,and the results showed that the positive rates of CSFV,ASFV,and APPV were 0.22% (1/451),1.3%(6/451),and 0%(0/451),respectively.This assay provides a valuale tool for rapid detection and accurate diagnosis of CSFV,ASFV,and APPV.展开更多
Heterodera filipjevi continues to be a major threat to wheat production worldwide.Rapid detection and quantification of cyst nematodes are essential for more effective control against this nematode disease.In the pres...Heterodera filipjevi continues to be a major threat to wheat production worldwide.Rapid detection and quantification of cyst nematodes are essential for more effective control against this nematode disease.In the present study,a TaqManminor groove binder(TaqMan-MGB)probe-based fluorescence quantitative real-time PCR(qPCR)was successfully developed and used for quantifying H.filipjevi from DNA extracts of soil.The primers and probe designed from the obtained RAPD-SCAR marker fragments of H.filipjevi showed high specificity to H.filipjevi using DNA from isolatesconfirmed species of 23 Heterodera spp.,1 Globodera spp.and 3 Pratylenchus spp.The qPCR assay is highly sensitive and provides improved H.filipjevi detection sensitivity of as low as 4^(-3) single second-stage juvenile(J2)DNAs,10^(-3) female DNAs,and 0.01μgμL^(-1) genomic DNAs.A standard curve relating to the threshold cycle and log values of nematode numbers was generated and validated from artificially infested soils and was used to quantify H.filipjevi in naturally infested field soils.There was a high correlation between the H.filipjevi numbers estimated from 32 naturally infested field soils by both conventional methods and the numbers quantified using the qPCR assay.qPCR potentially provides a useful platform for the efficient detection and quantification of H.filipjevi directly from field soils and to quantify this species directly from DNA extracts of field soils.展开更多
Quantitative real-time PCR(qRT-PCR)has been widely used for gene expression analysis,and selection of reference genes is a key point to obtain accurate results.To find out optimal reference genes for qRT-PCR in Manila...Quantitative real-time PCR(qRT-PCR)has been widely used for gene expression analysis,and selection of reference genes is a key point to obtain accurate results.To find out optimal reference genes for qRT-PCR in Manila clam Ruditapes philippinarum in response to hypoxia,different tissues were used and compared to evaluate the stability of candidate reference genes under low oxygen stress(DO 0.5mgL^(−1) and DO 2.0mgL^(−1))and normal condition(DO 7.5mgL^(−1)).Seven candidate reference genes were selected to evaluate the stability of their expression levels.The reference genes were evaluated by Delta Ct,BestKeeper,NormFinder and geNorm,and then screened by RefFinder calculation.Under hypoxic stress of 0.5mgL^(−1),the most suitable reference gene for gill and hepatopancreas was RPL31,and the optimal reference genes for axe foot and adductor muscle were TUB and HIS,respectively.For hypoxic stress of 2.0mgL^(−1),the most stable reference gene for gill and hepatopancreas was RPL31,and the optimal reference genes for axe foot and adductor muscle were RPS23 and EF1A,respectively.At the normal condition,HIS and EF1A were identified as the optimal internal reference genes in gill and hepatopancreas respectively,and GFRP2 was the best internal reference gene for axe foot and adductor muscle.The present findings will provide important basis for the selection of reference genes for qRT-PCR analysis of gene expression level in bivalves under hypoxic stress,which might be helpful for the analysis of other molluscs too.展开更多
为建立灵敏、高效的登革病毒检测方法,本试验拟以包含登革病毒3′端保守序列的质粒pUC57-DENV为模板,建立检测DENV的荧光定量PCR方法。结果显示,该检测方法在4.88×10^1~4.88×10^9copies/μL范围内呈良好的线性关系,相关系数为...为建立灵敏、高效的登革病毒检测方法,本试验拟以包含登革病毒3′端保守序列的质粒pUC57-DENV为模板,建立检测DENV的荧光定量PCR方法。结果显示,该检测方法在4.88×10^1~4.88×10^9copies/μL范围内呈良好的线性关系,相关系数为0.999,斜率为-3.653。最低检测限度为4.88 copies/μL,对照组未出现特异性扩增,所有稀释度的标准品在80.20℃出现特异性熔解峰。组内和组间试验的变异系数均小于1%。本试验建立的SYBR Green Ⅰ荧光定量PCR方法,可为登革病毒早期检测提供技术支持。展开更多
为建立一种针对寨卡病毒的快速诊断方法,本研究根据寨卡病毒的3’端保守基因序列,设计合成1对引物,建立了检测寨卡病毒的荧光定量PCR方法。结果显示:所建立的检测方法的Ct值与标准品在1.41×10^1~1.41×10^10^ copies/μL具有...为建立一种针对寨卡病毒的快速诊断方法,本研究根据寨卡病毒的3’端保守基因序列,设计合成1对引物,建立了检测寨卡病毒的荧光定量PCR方法。结果显示:所建立的检测方法的Ct值与标准品在1.41×10^1~1.41×10^10^ copies/μL具有良好的线性关系,相关性为1,斜率为-3.502;灵敏性结果显示,该方法的检测限度为1.41×10^1 copies/μL,是普通PCR的10000倍;特异性结果显示,对CHIKV、DENV和JEV无特异性扩增,特异性强;重复性试验结果显示,组内和组间变异系数均小于1%,重复性好。本研究建立的SYBR Green I real-time PCR检测方法,可用于寨卡病毒感染的快速诊断。展开更多
基金supported by the National Natural Science Foundation of China (31872484) to Zhang Qianyithe Non-profit Key Program of Veterinary Drug Industry from China Institute of Veterinary Drug Control (GY202011) to Xia Yingju。
文摘With the implementation of the C-strain vaccine,classical swine fever(CSF) has been under control in China,which is currently in a chronic atypical epidemic situation.African swine fever(ASF) emerged in China in 2018 and spread quickly across the country.It is presently occurring sporadically due to the lack of commercial vaccines and farmers’ increased awareness of biosafety.Atypical porcine pestivirus(APPV) was first detected in Guangdong Province,China,in 2016,which mainly harms piglets and has a local epidemic situation in southern China.These three diseases have similar clinical symptoms in pig herds,which cause considerable losses to the pig industry.They are difficult to be distinguished only by clinical diagnosis.Therefore,developing an early and accurate simultaneous detection and differential diagnosis of the diseases induced by these viruses is essential.In this study,three pairs of specific primers and Taq-man probes were designed from highly conserved genomic regions of CSFV(5’ UTR),African swine fever virus(ASFV)(B646L),and APPV(5’ UTR),followed by the optimization of reaction conditions to establish a multiplex real-time PCR detection assay.The results showed that the method did not cross-react with other swine pathogens(porcine circovirus type 2(PCV2),porcine reproductive and respiratory syndrome virus(PRRSV),foot-and-mouth disease virus(FMDV),pseudorabies virus(PRV),porcine parvovirus(PPV),and bovine viral diarrhea virus BVDV).The sensitivity results showed that CSFV,ASFV,and APPV could be detected as low as 1 copy μL–1;the repeatability results showed that the intra-assay and interassay coefficient of variation of ASFV,CSFV,and APPV was less than 1%.Twenty-two virus samples were detected by the multiplex real-time PCR,compared with national standard diagnostic and patented method assay for CSF(GB/T 27540–2011),ASF(GB/T 18648–2020),and APPV(CN108611442A),respectively.The sensitivity of this triple real-time PCR for CSFV,ASFV,and APPV was almost the same,and the compliance results were the same(100%).A total of 451 clinical samples were detected,and the results showed that the positive rates of CSFV,ASFV,and APPV were 0.22% (1/451),1.3%(6/451),and 0%(0/451),respectively.This assay provides a valuale tool for rapid detection and accurate diagnosis of CSFV,ASFV,and APPV.
基金financially supported by the National Natural Science Foundation of China(31972247)the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences(ASTIP-2016-IPP-04)the Special Fund for Agro-scientific Research in the Public Interest,China(201503114)。
文摘Heterodera filipjevi continues to be a major threat to wheat production worldwide.Rapid detection and quantification of cyst nematodes are essential for more effective control against this nematode disease.In the present study,a TaqManminor groove binder(TaqMan-MGB)probe-based fluorescence quantitative real-time PCR(qPCR)was successfully developed and used for quantifying H.filipjevi from DNA extracts of soil.The primers and probe designed from the obtained RAPD-SCAR marker fragments of H.filipjevi showed high specificity to H.filipjevi using DNA from isolatesconfirmed species of 23 Heterodera spp.,1 Globodera spp.and 3 Pratylenchus spp.The qPCR assay is highly sensitive and provides improved H.filipjevi detection sensitivity of as low as 4^(-3) single second-stage juvenile(J2)DNAs,10^(-3) female DNAs,and 0.01μgμL^(-1) genomic DNAs.A standard curve relating to the threshold cycle and log values of nematode numbers was generated and validated from artificially infested soils and was used to quantify H.filipjevi in naturally infested field soils.There was a high correlation between the H.filipjevi numbers estimated from 32 naturally infested field soils by both conventional methods and the numbers quantified using the qPCR assay.qPCR potentially provides a useful platform for the efficient detection and quantification of H.filipjevi directly from field soils and to quantify this species directly from DNA extracts of field soils.
基金supported by research grants from the Science and Technology Innovation Program of the Laoshan Laboratory(No.LSKJ202203803)the National Natural Science Foundation of China(No.32273107)+2 种基金supported by the Central Public-Interest Scientific Institution Basal Research Fund,Yellow Sea Fisheries Research Institute,CAFS(No.20603022022001)the project of Putian Science and Technology Department(No.2021NJJ002)the Shinan District Science and Technology Plan Project(No.2022-2-026-ZH).
文摘Quantitative real-time PCR(qRT-PCR)has been widely used for gene expression analysis,and selection of reference genes is a key point to obtain accurate results.To find out optimal reference genes for qRT-PCR in Manila clam Ruditapes philippinarum in response to hypoxia,different tissues were used and compared to evaluate the stability of candidate reference genes under low oxygen stress(DO 0.5mgL^(−1) and DO 2.0mgL^(−1))and normal condition(DO 7.5mgL^(−1)).Seven candidate reference genes were selected to evaluate the stability of their expression levels.The reference genes were evaluated by Delta Ct,BestKeeper,NormFinder and geNorm,and then screened by RefFinder calculation.Under hypoxic stress of 0.5mgL^(−1),the most suitable reference gene for gill and hepatopancreas was RPL31,and the optimal reference genes for axe foot and adductor muscle were TUB and HIS,respectively.For hypoxic stress of 2.0mgL^(−1),the most stable reference gene for gill and hepatopancreas was RPL31,and the optimal reference genes for axe foot and adductor muscle were RPS23 and EF1A,respectively.At the normal condition,HIS and EF1A were identified as the optimal internal reference genes in gill and hepatopancreas respectively,and GFRP2 was the best internal reference gene for axe foot and adductor muscle.The present findings will provide important basis for the selection of reference genes for qRT-PCR analysis of gene expression level in bivalves under hypoxic stress,which might be helpful for the analysis of other molluscs too.
文摘为建立灵敏、高效的登革病毒检测方法,本试验拟以包含登革病毒3′端保守序列的质粒pUC57-DENV为模板,建立检测DENV的荧光定量PCR方法。结果显示,该检测方法在4.88×10^1~4.88×10^9copies/μL范围内呈良好的线性关系,相关系数为0.999,斜率为-3.653。最低检测限度为4.88 copies/μL,对照组未出现特异性扩增,所有稀释度的标准品在80.20℃出现特异性熔解峰。组内和组间试验的变异系数均小于1%。本试验建立的SYBR Green Ⅰ荧光定量PCR方法,可为登革病毒早期检测提供技术支持。
文摘为建立一种针对寨卡病毒的快速诊断方法,本研究根据寨卡病毒的3’端保守基因序列,设计合成1对引物,建立了检测寨卡病毒的荧光定量PCR方法。结果显示:所建立的检测方法的Ct值与标准品在1.41×10^1~1.41×10^10^ copies/μL具有良好的线性关系,相关性为1,斜率为-3.502;灵敏性结果显示,该方法的检测限度为1.41×10^1 copies/μL,是普通PCR的10000倍;特异性结果显示,对CHIKV、DENV和JEV无特异性扩增,特异性强;重复性试验结果显示,组内和组间变异系数均小于1%,重复性好。本研究建立的SYBR Green I real-time PCR检测方法,可用于寨卡病毒感染的快速诊断。
