Abstract: A baculovirus vector and a use thereof in the preparation of a recombinant adeno-associated virus (rAAV) in an insect cell are provided. The baculovirus vector includes an exogenous gene expression cassette and a stable sequence. The stable sequence is located at a site 5 kb or less from the exogenous gene expression cassette, and the stable sequence is a conserved noncoding element (CNE) sequence or a nucleocapsid assembly-essential element (NAE) sequence. When an insect cell is infected with a recombinant baculovirus (rBV) constructed in this way, after multiple continuous passages, production levels of the rBV and the rAAV still remain relatively stable.

Abstract: The disclosure discloses an expression cassette for expressing a gene including overlapping open reading frames in an insect cell and an application thereof. The expression cassette includes from 5? to 3? and operably linked: a promoter capable of driving transcription in the insect cell; an artificially constructed sequence; the overlapping open reading frames missing only a first translation start codon; wherein the artificially constructed sequence includes a native or engineered intron with splicing activity in the insect cell, the intron includes ATG or the intron is located between any two adjacent nucleotides in ATG. A recombinant adeno-associated virus vector including the expression cassette of the disclosure regulates relative expressions of VP1, VP2, and VP3 proteins, and relative expressions of Rep78 and Rep52 proteins by using a designed intron sequence and through an intron splicing function for large-scale production of rAAV.

Abstract: An expression cassette containing overlapping open reading frames and an application thereof are provided. The overlapping open reading frames are overlapping open reading frames of a first ORF and a second ORF and include in sequence from a 5? end to a 3? end: a first promoter at least used to drive gene transcription of the first ORF; a 5? part of a gene of the first ORF; an intron; and a 3? part of a gene of the second ORF, the intron including a second promoter used only to drive gene transcription of the second ORF. By arranging two promoters in a single expression cassette in the disclosure, the two promoters are used to drive the expression of proteins of the overlapping reading frames and regulate the relative expression time and expression intensity of different proteins.

Abstract: Provided are a preparation method and system for a recombinant adeno-associated virus (rAAV) and a recombinant bacmid. The method comprises: first reconstructing a recombinant bacmid containing a recombinant baculovirus genome that produces essential functional elements for an rAAV, at least one of the essential functional elements being inserted into the N-terminal or C-terminal of a locus of an essential gene of the recombinant baculovirus genome; and then transfecting the obtained recombinant bacmid containing the recombinant baculovirus genome that produces the rAAV into a host cell line for culturing to prepare an rAAV. Compared with recombinant baculoviruses obtained by conventional Tn7 recombinant preparations of recombinant bacmid, the recombinant baculovirus obtained by inserting a core element containing Cap, Rep and ITR into two sides of a baculovirus essential gene has a more stable rAAV serial passage production level in a cell and has a higher rAAV yield.

Abstract: A baculovirus vector and a use thereof in the preparation of a recombinant adeno-associated virus (rAAV) in an insect cell are provided. The baculovirus vector includes an exogenous gene expression cassette and a stable sequence. The stable sequence is located at a site 5 kb or less from the exogenous gene expression cassette, and the stable sequence is a conserved noncoding element (CNE) sequence or a nucleocapsid assembly-essential element (NAE) sequence. When an insect cell is infected with a recombinant baculovirus (rBV) constructed in this way, after multiple continuous passages, production levels of the rBV and the rAAV still remain relatively stable.

Abstract: An expression cassette containing overlapping open reading frames and an application thereof are provided. The overlapping open reading frames are overlapping open reading frames of a first ORF and a second ORF and include in sequence from a 5? end to a 3? end: a first promoter at least used to drive gene transcription of the first ORF; a 5? part of a gene of the first ORF; an intron; and a 3? part of a gene of the second ORF, the intron including a second promoter used only to drive gene transcription of the second ORF. By arranging two promoters in a single expression cassette in the disclosure, the two promoters are used to drive the expression of proteins of the overlapping reading frames and regulate the relative expression time and expression intensity of different proteins.

Abstract: The disclosure discloses an expression cassette for expressing a gene including overlapping open reading frames in an insect cell and an application thereof. The expression cassette includes from 5? to 3? and operably linked: a promoter capable of driving transcription in the insect cell; an artificially constructed sequence; the overlapping open reading frames missing only a first translation start codon; wherein the artificially constructed sequence includes a native or engineered intron with splicing activity in the insect cell, the intron includes ATG or the intron is located between any two adjacent nucleotides in ATG. A recombinant adeno-associated virus vector including the expression cassette of the disclosure regulates relative expressions of VP1, VP2, and VP3 proteins, and relative expressions of Rep78 and Rep52 proteins by using a designed intron sequence and through an intron splicing function for large-scale production of rAAV.

Abstract: Provided are a preparation method and system for a recombinant adeno-associated virus (rAAV) and a recombinant bacmid. The method comprises: first reconstructing a recombinant bacmid containing a recombinant baculovirus genome that produces essential functional elements for an rAAV, at least one of the essential functional elements being inserted into the N-terminal or C-terminal of a locus of an essential gene of the recombinant baculovirus genome; and then transfecting the obtained recombinant bacmid containing the recombinant baculovirus genome that produces the rAAV into a host cell line for culturing to prepare an rAAV. Compared with recombinant baculoviruses obtained by conventional Tn7 recombinant preparations of recombinant bacmid, the recombinant baculovirus obtained by inserting a core element containing Cap, Rep and ITR into two sides of a baculovirus essential gene has a more stable rAAV serial passage production level in a cell and has a higher rAAV yield.

Abstract: Liver-specific promoters and application thereof are provided. A set of small-size recombinant nucleic acid sequences for regulating high specific expression of genes in a liver system are provided. Compared with the currently reported other sequences of similar size, the said recombinant regulatory sequence fragment has the advantage that the ability of driving expression of reporter gene and human coagulation factor FVIII in the liver system is significantly enhanced, thereby being suitable for recombinant adeno-associated virus (rAAV)-mediated gene therapy.

Abstract: Apparatus, systems and techniques that use a single laser to generate desired optical WDM comb frequencies.

Abstract: A stabilized single-longitudinal-mode laser where stabilization is performed through a pair of Bragg reflector mirrors slightly displaced in wavelength to either side of the longitudinal mode selected for operation. Transmitted signals through each Bragg reflector are detected and used in an electrical servo loop to control the relative positions of the longitudinal mode selected for operation and the peak wavelengths of the two Bragg reflector mirrors.

Abstract: An interferometer having semiconductor optical amplifiers in one or both arms of the interferometer converts information from a first wavelength to another predetermined wavelength. The original data signal (at the first wavelength) is coupled into the interferometer in such a way that it is confined to propagate, either co-directionally or contra-directionally, in only one arm of the interferometer together with the lightwave signal at the predetermined wavelength. This arm includes the semiconductor optical amplifier. In this way, the original data signal is utilized effectively to maximize the interference effect, which is required for wavelength conversion, while minimizing the problems associated with simultaneously saturating amplifiers in the interferometer structure.