The NDT detection of knobs of logs and timbers was conducted by using computer video technique.The key detection points were taken from these knobs for mathematics description. It can make the drawing ofthese knobs qu...The NDT detection of knobs of logs and timbers was conducted by using computer video technique.The key detection points were taken from these knobs for mathematics description. It can make the drawing ofthese knobs quantitatively and establish corresponding mathematics models. Using the grayness of pictures andcartoon if eatment made the mathemstics reappearance of the knobs become more access to video pictures.展开更多
IN 1964, the tomb of Hua Fang was excavated at a construction site in Beijing’s western suburbs. Hua Fang was the wife of Wang Jun, who was a prefectural governor of Youzhou (an ancient name for Beijing) during the W...IN 1964, the tomb of Hua Fang was excavated at a construction site in Beijing’s western suburbs. Hua Fang was the wife of Wang Jun, who was a prefectural governor of Youzhou (an ancient name for Beijing) during the Western Jin Dynasty. Found in the tomb were a bone ruler and a silver bell in good condition, as well as a packet of half-transparent pieces of glassware. The fragments were restored by experts in 1984 into a complete vessel, which is currently displayed in the Capital Museum.展开更多
FOR Wang Zhao and Ren Meiying, their marriage has a magic power pushing them towards a common cause. Wang and Ren met each other in 1983. At that time Wang was working with an oil company at Langfang, 58
酵母展示技术被广泛应用于抗体药物候选分子的发现与优化中,但传统酵母展示技术只能将抗体展示于表面,无法同时将抗体分泌至培养基的上清液进行亲和力测定。为克服此难点,将含Knob突变的抗体可结晶片断(Fc)展示于酵母表面作为“诱饵”,...酵母展示技术被广泛应用于抗体药物候选分子的发现与优化中,但传统酵母展示技术只能将抗体展示于表面,无法同时将抗体分泌至培养基的上清液进行亲和力测定。为克服此难点,将含Knob突变的抗体可结晶片断(Fc)展示于酵母表面作为“诱饵”,通过“Knob into Hole”的方式结合含Hole突变的免疫球蛋白(IgG)半分子,达到展示抗体的作用;同时,含Hole突变的IgG半分子自身可形成同源二聚体,形成IgG完整分子分泌至培养基中,实现酵母抗体展示与分泌的双重功能。结果发现:使用含Knob突变的重链恒定区3作为“诱饵”,展示抗体的效果最佳;双功能酵母展示与分泌系统经模拟文库验证,可高效筛选出占比极低的含高亲和力抗体序列的菌株;筛选出的菌株可将抗体同时分泌至培养基上清,直接用于亲和力测定。本研究结果充分说明,双功能酵母展示与分泌系统搭建成功并可用于抗体的亲和力成熟中,从而显著提高工作效率、缩短抗体亲和力成熟的周期。展开更多
The highly transformable maize inbred line LH244 represents an attractive model for gene discovery and genome engineering.However,the lack of a high-quality genome assembly has limited its utility in functional genomi...The highly transformable maize inbred line LH244 represents an attractive model for gene discovery and genome engineering.However,the lack of a high-quality genome assembly has limited its utility in functional genomics research.Here,we present a 2.29 Gb near-complete assembly of the LH244 maize genome,with an overall base accuracy of 99.998%.Except for five gaps associated with super-long thymine-adenine-guanine(TAG)repeat arrays,all the genome sequences were assembled from telomere to telomere(T2T).Comparative analysis revealed high genetic similarity between LH244 and B73,including 80.06% genome-wide synteny and 90.92% of genes nearly identical.The LH244 genome was also compared with the complete Mo17 genome and revealed extensive intraspecific genomic variations.A total of 14 megabase-scale structural variations(SVs)were identified,including a 3.15 Mb insertion,harboring 95 genes,within the 45S rDNA array of LH244 but not in the Mo17 genome.In addition,there were five knob arrays,with an average size of 21.76 Mb and the longest of 38.70 Mb,only existing in the LH244 genome.Despite the substantial variation in knob abundance,knob-6S and knob-8L were highly conserved between LH244 and Mo17,showing strong synteny and sequence identity,as well as consistent insertion patterns of genes and transposable elements(TEs).Overall,our study provides a near-complete reference genome of an important transformable maize germplasm,which will serve as a much-needed resource for functional genomics and genome editing of maize.展开更多
Knob-associated tandem repeats,180-bp repeats and TR-1 elements,together with 45S rDNA were located on mitotic chromosomes of Zea diploperennis(DP),maize inbred line F102 and their hybrid.In DP,knobs on the short arm ...Knob-associated tandem repeats,180-bp repeats and TR-1 elements,together with 45S rDNA were located on mitotic chromosomes of Zea diploperennis(DP),maize inbred line F102 and their hybrid.In DP,knobs on the short arm of chromosomes 1 and 4 and on the long arm ofthe chromosomes 4 and 5 are composed predominantly of the 180-bp repeats.In addition,180-bp repeats existed together with TR-1 elements were also detected on the short arm ofchromosomes 2 and 5 and on the long arm of the chromosomes 2,6,7,8 and 9.In maize inbred line F102,180-bp repeats were present in chromosomes 7S and one homologue of chromosomes 8L.TR-1 elements appeared on satellite of chromosome 6 and no detectable hybridization site co-located with 180-bp repeats was observed in maize F102.Polymorphism of size,number,and distribution of 180-bp and TR-1 signals were revealed among different chromosomes in these two species and heteromorphism existed between some homologous chromosomes in the same species.Using these excellent landmarks,the interspecific hybrid of maize and DP were identified.The results suggest that comparative analysis of 180-bp repeats and TR-1 elements may help understand the genome organization and the evolution in Zea.展开更多
Knobs are blocks of heterochromatin present on chromosomes of maize （Zea mays L.） and its relatives that have effects on the frequency of genetic recombination, as well as on chromosome behavior. Knob heterozygosity...Knobs are blocks of heterochromatin present on chromosomes of maize （Zea mays L.） and its relatives that have effects on the frequency of genetic recombination, as well as on chromosome behavior. Knob heterozygosity and instability in six maize inbred lines and one Z. diploperennis Iltis Doebley line were investigated using the fluorescence in situ hybridization （FISH） technique with knob-associated tandem repeats （180 bp and 350 bp （TR- 1）） as probes. Signals of seven heterozygous knobs containing 180- bp repeats and of one heterozygous knob containing TR- 1 were captured in chromosomes of all materials tested according to the results of FISH, which demonstrates that the 180-bp repeat is the main contributor to knob heterozygosity compared with the TR- 1 element. In addition, one target cell with two TR- 1 signals on one homolog of chromosome 2L, which was different from the normal cells in the maize inbred line GB57, was observed, suggesting knob duplication and an instability phenomenon in the maize genome.展开更多
文摘The NDT detection of knobs of logs and timbers was conducted by using computer video technique.The key detection points were taken from these knobs for mathematics description. It can make the drawing ofthese knobs quantitatively and establish corresponding mathematics models. Using the grayness of pictures andcartoon if eatment made the mathemstics reappearance of the knobs become more access to video pictures.
文摘IN 1964, the tomb of Hua Fang was excavated at a construction site in Beijing’s western suburbs. Hua Fang was the wife of Wang Jun, who was a prefectural governor of Youzhou (an ancient name for Beijing) during the Western Jin Dynasty. Found in the tomb were a bone ruler and a silver bell in good condition, as well as a packet of half-transparent pieces of glassware. The fragments were restored by experts in 1984 into a complete vessel, which is currently displayed in the Capital Museum.
文摘FOR Wang Zhao and Ren Meiying, their marriage has a magic power pushing them towards a common cause. Wang and Ren met each other in 1983. At that time Wang was working with an oil company at Langfang, 58
文摘酵母展示技术被广泛应用于抗体药物候选分子的发现与优化中,但传统酵母展示技术只能将抗体展示于表面,无法同时将抗体分泌至培养基的上清液进行亲和力测定。为克服此难点,将含Knob突变的抗体可结晶片断(Fc)展示于酵母表面作为“诱饵”,通过“Knob into Hole”的方式结合含Hole突变的免疫球蛋白(IgG)半分子,达到展示抗体的作用;同时,含Hole突变的IgG半分子自身可形成同源二聚体,形成IgG完整分子分泌至培养基中,实现酵母抗体展示与分泌的双重功能。结果发现:使用含Knob突变的重链恒定区3作为“诱饵”,展示抗体的效果最佳;双功能酵母展示与分泌系统经模拟文库验证,可高效筛选出占比极低的含高亲和力抗体序列的菌株;筛选出的菌株可将抗体同时分泌至培养基上清,直接用于亲和力测定。本研究结果充分说明,双功能酵母展示与分泌系统搭建成功并可用于抗体的亲和力成熟中,从而显著提高工作效率、缩短抗体亲和力成熟的周期。
基金supported by the Biological Breeding—Major Projects(2023ZD04074)the National Natural Science Foundation of China(32425041,32271541 and 32572347)+2 种基金Innovation Capabilities Construction Project of Beijing Academy of Agriculture and Forestry Sciences(KJCX20210410)the National Key Research and Development Program of China(2021YFD1200701)Joint Research on Maize Improvement of Henan(2022010202)。
文摘The highly transformable maize inbred line LH244 represents an attractive model for gene discovery and genome engineering.However,the lack of a high-quality genome assembly has limited its utility in functional genomics research.Here,we present a 2.29 Gb near-complete assembly of the LH244 maize genome,with an overall base accuracy of 99.998%.Except for five gaps associated with super-long thymine-adenine-guanine(TAG)repeat arrays,all the genome sequences were assembled from telomere to telomere(T2T).Comparative analysis revealed high genetic similarity between LH244 and B73,including 80.06% genome-wide synteny and 90.92% of genes nearly identical.The LH244 genome was also compared with the complete Mo17 genome and revealed extensive intraspecific genomic variations.A total of 14 megabase-scale structural variations(SVs)were identified,including a 3.15 Mb insertion,harboring 95 genes,within the 45S rDNA array of LH244 but not in the Mo17 genome.In addition,there were five knob arrays,with an average size of 21.76 Mb and the longest of 38.70 Mb,only existing in the LH244 genome.Despite the substantial variation in knob abundance,knob-6S and knob-8L were highly conserved between LH244 and Mo17,showing strong synteny and sequence identity,as well as consistent insertion patterns of genes and transposable elements(TEs).Overall,our study provides a near-complete reference genome of an important transformable maize germplasm,which will serve as a much-needed resource for functional genomics and genome editing of maize.
基金was supported by the National Natural Science Foundation of China(Grant No.39870423).
文摘Knob-associated tandem repeats,180-bp repeats and TR-1 elements,together with 45S rDNA were located on mitotic chromosomes of Zea diploperennis(DP),maize inbred line F102 and their hybrid.In DP,knobs on the short arm of chromosomes 1 and 4 and on the long arm ofthe chromosomes 4 and 5 are composed predominantly of the 180-bp repeats.In addition,180-bp repeats existed together with TR-1 elements were also detected on the short arm ofchromosomes 2 and 5 and on the long arm of the chromosomes 2,6,7,8 and 9.In maize inbred line F102,180-bp repeats were present in chromosomes 7S and one homologue of chromosomes 8L.TR-1 elements appeared on satellite of chromosome 6 and no detectable hybridization site co-located with 180-bp repeats was observed in maize F102.Polymorphism of size,number,and distribution of 180-bp and TR-1 signals were revealed among different chromosomes in these two species and heteromorphism existed between some homologous chromosomes in the same species.Using these excellent landmarks,the interspecific hybrid of maize and DP were identified.The results suggest that comparative analysis of 180-bp repeats and TR-1 elements may help understand the genome organization and the evolution in Zea.
文摘Knobs are blocks of heterochromatin present on chromosomes of maize （Zea mays L.） and its relatives that have effects on the frequency of genetic recombination, as well as on chromosome behavior. Knob heterozygosity and instability in six maize inbred lines and one Z. diploperennis Iltis Doebley line were investigated using the fluorescence in situ hybridization （FISH） technique with knob-associated tandem repeats （180 bp and 350 bp （TR- 1）） as probes. Signals of seven heterozygous knobs containing 180- bp repeats and of one heterozygous knob containing TR- 1 were captured in chromosomes of all materials tested according to the results of FISH, which demonstrates that the 180-bp repeat is the main contributor to knob heterozygosity compared with the TR- 1 element. In addition, one target cell with two TR- 1 signals on one homolog of chromosome 2L, which was different from the normal cells in the maize inbred line GB57, was observed, suggesting knob duplication and an instability phenomenon in the maize genome.
