An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system...An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system based on intergeneric conjugation was developed in Streptomyces rimosus M527,a bacterial strain which exhibits strong antagonistic activity against a broad range of plant-pathogenic fungi.Some experimental parameters involved in this procedure were optimized,including the conjugative media,ratio of donor to recipient,heat shock temperature,and incubation time of mixed culture.Under the optimal conditions,a maximal conjugation frequency of 3.05^10-5 per recipie nt was obtai ned.Subseque ntly,based on the above developed and optimized tran sformati on system,the synthetic promoters SPL-21 and SPL-57,a native promoter potrB,and a constitutive promoter permE commonly used for gene expression in streptomycetes were selected and their activity was analyzed using gusA as a reporter gene in S.rimosus M527.Among the four tested promoters,SPL-21 exhibited the strongest expression activity and gave rise to a 2.2-fold increase in p-glucuronidase(GUS)activity compared with the control promoter permE.Promoter SPL-57 showed activity comparable to that of permE.Promoter potrB,which showed the lowest activity,showed a 50%decrease in GUS activity compared with the control permE.The transformation system developed in this study and the tested promotors provide a basis for the further modification of S.rimosus M527.展开更多
A 1178 J near diffraction limited 527 nm laser is realized in a complete closed-loop adaptive optics(AO)controlled off-axis multi-pass amplification laser system.Generated from a fiber laser and amplified by the pre-a...A 1178 J near diffraction limited 527 nm laser is realized in a complete closed-loop adaptive optics(AO)controlled off-axis multi-pass amplification laser system.Generated from a fiber laser and amplified by the pre-amplifier and the main amplifier,a 1053 nm laser beam with the energy of 1900 J is obtained and converted into a 527 nm laser beam by a KDP crystal with 62%conversion efficiency,1178 J and beam quality of 7.93 times the diffraction limit(DL).By using a complete closed-loop AO configuration,the static and dynamic wavefront distortions of the laser system are measured and compensated.After correction,the diameter of the circle enclosing 80%energy is improved remarkably from 7.93DL to 1.29DL.The focal spot is highly concentrated and the 1178 J,527 nm near diffraction limited laser is achieved.展开更多
Hybrid rice significantly contributes to the food supply worldwide. Backbone parents play important roles in elite hybrid rice breeding systems. In this study, we performed pedigree-based analysis of the elite backbon...Hybrid rice significantly contributes to the food supply worldwide. Backbone parents play important roles in elite hybrid rice breeding systems. In this study, we performed pedigree-based analysis of the elite backbone parent rice variety, namely, Shuhui 527(SH527, Oryza sativa), to exploit key genome regions during breeding. Twenty-four cultivars(including SH527, its six progenitors and 17 derived cultivars) were collected and analyzed with high-density single nucleotide polymorphism(SNP) array. Scanning all these cultivars with genome-wide SNP data indicated the unique contributions of progenitors to the SH527 genome and identified the key genomic regions of SH527 conserved within all its derivatives. These findings were further supported by known rice yield-related genes or unknown QTLs identified by genome-wide association study. This study reveals several key regions for SH527 and provides insights into hybrid rice breeding.展开更多
位于Y染色体无精症因子区域(Azoospermia factor,AZF)的基因座位点DYS549、DYS527和DYS459在法医学鉴定和家系分析中被广泛应用。但是,在男性不育患者中,DYS549、DYS527和DYS459位点很可能会表现出特殊的基因型,对应用Y染色体短串联重...位于Y染色体无精症因子区域(Azoospermia factor,AZF)的基因座位点DYS549、DYS527和DYS459在法医学鉴定和家系分析中被广泛应用。但是,在男性不育患者中,DYS549、DYS527和DYS459位点很可能会表现出特殊的基因型,对应用Y染色体短串联重复序列(Y chromosome short tandem repeat,Y-STR)进行个体识别的结果产生干扰。因此,文章应用14个Y-STR基因座复合扩增体系和Y染色体AZFc区DAZ、CDY1基因的拷贝数检测等方法,探讨男性不育症中法医学相关的3个Y-STR基因座的异常分型,对个体识别和家系分析中的DNA检验异常结果提供合理的解释。在240例男性非梗阻性无精、严重少精、先天性双侧输精管缺如(CBVAD)患者中,采用改良的多重PCR体系进行AZF区域微缺失的序列标签位点(Sequence tagged sites,STSs)检测,发现AZF微缺失40例(AZFa:2例;AZFb:2例;AZFc:30例;AZFb+c:6例),AZF的总缺失率为16.67%。应用14 Y-STR复合扩增体系对上述AZF微缺失的阳性患者样本进行检测,发现所有AZFb缺失患者存在DYS549等位基因缺失,AZFc缺失患者存在DYS527、DYS459等位基因缺失,AZFb+c缺失患者存在DYS549、DYS527和DYS459等位基因缺失。在AZF微缺失阴性的不育症患者中,通过检测DAZ、CDY1基因拷贝数发现10例AZFc部分复制的患者(1例为先天性输精管缺如,2例非梗阻性无精症,7例严重少精子症),占所调查不育人群的4.17%。男性不育人群AZF区域3个Y-STR基因座多态性会造成等位基因缺失或者重复,这些异常分型是由于临床遗传缺陷造成的而不是实验偏差。阐明Y-STR在男性不育人群中的异质性可以更好地完善Y-STR数据库和解释STR实验结果。展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.31772213 and 31972320)the Excellent Youth Fund of Zhejiang Province,China(No.LR17C140002)
文摘An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system based on intergeneric conjugation was developed in Streptomyces rimosus M527,a bacterial strain which exhibits strong antagonistic activity against a broad range of plant-pathogenic fungi.Some experimental parameters involved in this procedure were optimized,including the conjugative media,ratio of donor to recipient,heat shock temperature,and incubation time of mixed culture.Under the optimal conditions,a maximal conjugation frequency of 3.05^10-5 per recipie nt was obtai ned.Subseque ntly,based on the above developed and optimized tran sformati on system,the synthetic promoters SPL-21 and SPL-57,a native promoter potrB,and a constitutive promoter permE commonly used for gene expression in streptomycetes were selected and their activity was analyzed using gusA as a reporter gene in S.rimosus M527.Among the four tested promoters,SPL-21 exhibited the strongest expression activity and gave rise to a 2.2-fold increase in p-glucuronidase(GUS)activity compared with the control promoter permE.Promoter SPL-57 showed activity comparable to that of permE.Promoter potrB,which showed the lowest activity,showed a 50%decrease in GUS activity compared with the control permE.The transformation system developed in this study and the tested promotors provide a basis for the further modification of S.rimosus M527.
基金the National Natural Science Foundation of China(Nos.61775199 and 61775112).
文摘A 1178 J near diffraction limited 527 nm laser is realized in a complete closed-loop adaptive optics(AO)controlled off-axis multi-pass amplification laser system.Generated from a fiber laser and amplified by the pre-amplifier and the main amplifier,a 1053 nm laser beam with the energy of 1900 J is obtained and converted into a 527 nm laser beam by a KDP crystal with 62%conversion efficiency,1178 J and beam quality of 7.93 times the diffraction limit(DL).By using a complete closed-loop AO configuration,the static and dynamic wavefront distortions of the laser system are measured and compensated.After correction,the diameter of the circle enclosing 80%energy is improved remarkably from 7.93DL to 1.29DL.The focal spot is highly concentrated and the 1178 J,527 nm near diffraction limited laser is achieved.
基金supported by the Sichuan Science and Technology Support Project, China (2016NZ0103)the National Natural Science Foundation of China (91435102 and 31570004)+1 种基金the Sichuan Provincial Founding for Distinguished Young Scholars, China (2015JQ0048)the Open Research Fund of State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, China (2016KF10)。
文摘Hybrid rice significantly contributes to the food supply worldwide. Backbone parents play important roles in elite hybrid rice breeding systems. In this study, we performed pedigree-based analysis of the elite backbone parent rice variety, namely, Shuhui 527(SH527, Oryza sativa), to exploit key genome regions during breeding. Twenty-four cultivars(including SH527, its six progenitors and 17 derived cultivars) were collected and analyzed with high-density single nucleotide polymorphism(SNP) array. Scanning all these cultivars with genome-wide SNP data indicated the unique contributions of progenitors to the SH527 genome and identified the key genomic regions of SH527 conserved within all its derivatives. These findings were further supported by known rice yield-related genes or unknown QTLs identified by genome-wide association study. This study reveals several key regions for SH527 and provides insights into hybrid rice breeding.
文摘位于Y染色体无精症因子区域(Azoospermia factor,AZF)的基因座位点DYS549、DYS527和DYS459在法医学鉴定和家系分析中被广泛应用。但是,在男性不育患者中,DYS549、DYS527和DYS459位点很可能会表现出特殊的基因型,对应用Y染色体短串联重复序列(Y chromosome short tandem repeat,Y-STR)进行个体识别的结果产生干扰。因此,文章应用14个Y-STR基因座复合扩增体系和Y染色体AZFc区DAZ、CDY1基因的拷贝数检测等方法,探讨男性不育症中法医学相关的3个Y-STR基因座的异常分型,对个体识别和家系分析中的DNA检验异常结果提供合理的解释。在240例男性非梗阻性无精、严重少精、先天性双侧输精管缺如(CBVAD)患者中,采用改良的多重PCR体系进行AZF区域微缺失的序列标签位点(Sequence tagged sites,STSs)检测,发现AZF微缺失40例(AZFa:2例;AZFb:2例;AZFc:30例;AZFb+c:6例),AZF的总缺失率为16.67%。应用14 Y-STR复合扩增体系对上述AZF微缺失的阳性患者样本进行检测,发现所有AZFb缺失患者存在DYS549等位基因缺失,AZFc缺失患者存在DYS527、DYS459等位基因缺失,AZFb+c缺失患者存在DYS549、DYS527和DYS459等位基因缺失。在AZF微缺失阴性的不育症患者中,通过检测DAZ、CDY1基因拷贝数发现10例AZFc部分复制的患者(1例为先天性输精管缺如,2例非梗阻性无精症,7例严重少精子症),占所调查不育人群的4.17%。男性不育人群AZF区域3个Y-STR基因座多态性会造成等位基因缺失或者重复,这些异常分型是由于临床遗传缺陷造成的而不是实验偏差。阐明Y-STR在男性不育人群中的异质性可以更好地完善Y-STR数据库和解释STR实验结果。
