[Objective] The paper aimed to construct a new T vector based on plasmid pUC19 digested with Xcm Ⅰ. [Method] Two complementary oligonucleotide chains containing two Xcm Ⅰ sites were synthesized. After denaturation a...[Objective] The paper aimed to construct a new T vector based on plasmid pUC19 digested with Xcm Ⅰ. [Method] Two complementary oligonucleotide chains containing two Xcm Ⅰ sites were synthesized. After denaturation and renaturation,the adaptor was cloned into plasmid pUC19 between the Hind Ⅲ and BamH Ⅰ sites. The new plasmid,pUC19-HB-T vector,was digested with Xcm Ⅰ to derive a T-vector with 3′ end overhanging a T base. [Result] The constructed pUC19-HB-T vector was efficient in cloning PCR products,with an efficiency of 95% at least. [Conclusion] A new Xcm Ⅰ-based pUC19-HB-T vector was constructed,which could be applied to cloning of PCR products and other microbiology operations.展开更多
It is obviously advantageous to use single-pattern cell ternary tree (T-gate)network to obtain ternary logic function. Many scholars at home and abroad have done much in minimization of T-gate realization of multiple-...It is obviously advantageous to use single-pattern cell ternary tree (T-gate)network to obtain ternary logic function. Many scholars at home and abroad have done much in minimization of T-gate realization of multiple-valued logic. It is generally acknowledged that it is necessary to try N! times in order to get an optimal result. However, using the Input Vector Map presented here, which is as simple and convenient as Binary Karnaugh Map, we can get an optimal result by trying only N times.展开更多
This review chronicles the development of the plant binary vectors of Ti plasmid in Agrobacterium tumefaciens during the last 30 years. A binary vector strategy was designed in 1983 to separate the T-DNA region in a s...This review chronicles the development of the plant binary vectors of Ti plasmid in Agrobacterium tumefaciens during the last 30 years. A binary vector strategy was designed in 1983 to separate the T-DNA region in a small plasmid from the virulence genes in avirulent T-DNA-less Ti plasmid. The small plant vectors with the T-DNA region have been simply now called binary Ti vectors. A binary Ti vector consist of a broad host-range replicon for propagation in A. tumeraciens, an antibiotic resistance gene for bacterial selection and the T-DNA region that would be transferred to the plant genome via the bacterial virulence machinery. The T-DNA region delimited by the right and left border sequences contains an antibiotic resistance gene for plant selection, reporter gene, and/or any genes of interest. The ColEI replicon was also added to the plasmid backbone to enhance the propagation in Escherichia coli. A general trend in the binary vector development has been to increase the plasmid stability during a long co-cultivation period of A. tumefaciens with the target host plant tissues. A second trend is to understand the molecular mechanism of broad host-range replication, and to use it to reduce the size of plasmid for ease in cloning and for higher plasmid yield in E. coli. The broad host-range replicon of VS1 was shown to be a choice of replicon over those of pRK2, pRi and pSA because of the superior stability and of small well-defined replicon. Newly developed plant binary vectors pLSU has the small size of plasmid backbone (4566 bp) consisting of VS1 replicon (2654 bp), ColE1 replicon (715 bp), a bacterial kanamycin (999 bp) or tetracycline resistance gene, and the T-DNA region (152 bp).展开更多
文摘[Objective] The paper aimed to construct a new T vector based on plasmid pUC19 digested with Xcm Ⅰ. [Method] Two complementary oligonucleotide chains containing two Xcm Ⅰ sites were synthesized. After denaturation and renaturation,the adaptor was cloned into plasmid pUC19 between the Hind Ⅲ and BamH Ⅰ sites. The new plasmid,pUC19-HB-T vector,was digested with Xcm Ⅰ to derive a T-vector with 3′ end overhanging a T base. [Result] The constructed pUC19-HB-T vector was efficient in cloning PCR products,with an efficiency of 95% at least. [Conclusion] A new Xcm Ⅰ-based pUC19-HB-T vector was constructed,which could be applied to cloning of PCR products and other microbiology operations.
文摘It is obviously advantageous to use single-pattern cell ternary tree (T-gate)network to obtain ternary logic function. Many scholars at home and abroad have done much in minimization of T-gate realization of multiple-valued logic. It is generally acknowledged that it is necessary to try N! times in order to get an optimal result. However, using the Input Vector Map presented here, which is as simple and convenient as Binary Karnaugh Map, we can get an optimal result by trying only N times.
文摘This review chronicles the development of the plant binary vectors of Ti plasmid in Agrobacterium tumefaciens during the last 30 years. A binary vector strategy was designed in 1983 to separate the T-DNA region in a small plasmid from the virulence genes in avirulent T-DNA-less Ti plasmid. The small plant vectors with the T-DNA region have been simply now called binary Ti vectors. A binary Ti vector consist of a broad host-range replicon for propagation in A. tumeraciens, an antibiotic resistance gene for bacterial selection and the T-DNA region that would be transferred to the plant genome via the bacterial virulence machinery. The T-DNA region delimited by the right and left border sequences contains an antibiotic resistance gene for plant selection, reporter gene, and/or any genes of interest. The ColEI replicon was also added to the plasmid backbone to enhance the propagation in Escherichia coli. A general trend in the binary vector development has been to increase the plasmid stability during a long co-cultivation period of A. tumefaciens with the target host plant tissues. A second trend is to understand the molecular mechanism of broad host-range replication, and to use it to reduce the size of plasmid for ease in cloning and for higher plasmid yield in E. coli. The broad host-range replicon of VS1 was shown to be a choice of replicon over those of pRK2, pRi and pSA because of the superior stability and of small well-defined replicon. Newly developed plant binary vectors pLSU has the small size of plasmid backbone (4566 bp) consisting of VS1 replicon (2654 bp), ColE1 replicon (715 bp), a bacterial kanamycin (999 bp) or tetracycline resistance gene, and the T-DNA region (152 bp).
