171 results about "Essential gene" patented technology

The current invention provides methods to silence insect genes by using unpackaged dsRNA or siRNA, in one embodiment such dsRNA or siRNA is present in plant vascular tissue, preferably phloem, more particularly phloem sap, and the insect is a plant sap-sucking insect. Also provided are DNA sequences which when transcribed yield a double-stranded RNA molecule capable of reducing the expression of an essential gene of a plant sap-sucking insect, methods of using such DNA sequences and plants or plant cells transformed with such DNA sequences. Also provided is the use of cationic oligopeptides that facilitate the entry of dsRNA or siRNA molecules in insect cells, such as plant sap-sucking insect cells.

The invention discloses an insect bioreactor capable of expressing multiple exogenous genes, and a construction method and application thereof. The construction method comprises the following steps: (1) introducing multicopy high-efficiency bacteria DNA (deoxyribonucleic acid) replication initiator into chitinase and cysteine proteinase genes of a baculovirus genome to obtain a baculovirus shuttle plasmid; (2) replacing virus duplicated essential gene downstream the polyhedrosis gene of the baculovirus shuttle plasmid with antibiotic gene to obtain a baculovirus plasmid DNA; and (3) replacingother virus duplicated and infected nonessential genes in the baculovirus shuttle plasmid with reverse selection marker gene to obtain the insect bioreactor. The antibiotic gene or reverse selection marker gene in the insect bioreactor which is constructed by replacing the exogenous target genes can express multiple exogenous genes in a host insect or insect cell. The insect bioreactor disclosed by the invention can efficiently expressing one or more exogenous genes in an insect body at the same time, and can produce massive recombinant proteins at low cost.

Disclosed is an Environmentally Limited Viability System (ELVS) for microorganisms based on temperature differences between permissive and non-permissive environments. Viability of the microorganisms are limited to the permissive environment by specifically expressing one or more essential genes only in the permissive environment, or expressing one or more lethal genes only in the non-permissive environment. Environmentally Limited Viability Systems are also disclosed involving coordinate expression of a combination of required genes and lethal genes. Microorganisms containing an Environmentally Limited Viability System are useful for release into a permissive environment. Temperature regulated Environmentally Limited Viability Systems are particularly suited for use with recombinant avirulent Salmonella vaccines by limiting their growth to the warmer environment inside the host. Such vaccines can be administered to protect humans or warm-blooded animals against bacterial, viral, mycotic and parasitic pathogens, especially those that colonize on or invade through mucosal surfaces. This antigen delivery system can also be used for expression of gamete-specific antigens to induce immune responses to block fertilization, or to induce immune responses to tumor antigens. In the event that an individual sheds live vaccine into the environment, the presence of the ELVS prevents survival of the vaccine. When environmentally regulated lethal genes are present on an extrachromosomal element and are regulated by chromosomal genes, transfer of the extrachromosomal element to other microorganisms will be limited by unregulated expression of the lethal genes in the recipient microorganism.

The present invention provides for improved vectors for use in gene therapy. Utilizing the cancer specific DF3 / MUC1 promoter to drive a replication essential gene, vectors are made conditionally replication-competent, permitting wider infection and expression of tumor cells. In addition, therapeutic genes and adjunct therapies further increase anti-tumor efficacy.

The present invention provides C. neoformans genes that are essential and are potential targets for drug screening. The nucleotide sequence of the target genes can be used for various drug discovery purposes, such as expression of the recombinant protein, hybridization assay and construction of nucleic acid arrays. The uses of proteins encoded by the essential genes, and genetically engineered cells comprising modified alleles of essential genes in various screening methods are also encompassed by the invention. The present invention also provides methods and compositions that enable the experimental determination as to whether any gene in the genome of Cryptococcus neoformans is essential, and whether that gene is required for virulence or pathogenicity. The identification of essential genes and those genes critical to the development of virulent infections, provides a basis for the development of screens for new drugs against C. neoformans.

The present invention provides methods and compositions that enable the experimental determination as to whether any gene in the genome of a diploid pathogenic organism is essential, and whether it is required for virulence or pathogenicity. The methods involve the construction of genetic mutants in which one allele of a specific gene is inactivated while the other allele of the gene is placed under conditional expression. The identification of essential genes and those genes critical to the development of virulent infections, provides a basis for the development of screens for new drugs against such pathogenic organisms. The present invention further provides Candida albicans genes that are demonstrated to be essential and are potential targets for drug screening. The nucleotide sequence of the target genes can be used for various drug discovery purposes, such as expression of the recombinant protein, hybridization assay and construction of nucleic acid arrays. The uses of proteins encoded by the essential genes, and genetically engineered cells comprising modified alleles of essential genes in various screening methods are also encompassed by the invention.

The present invention provides methods and compositions that enable the experimental determination as to whether any gene in the genome of a diploid pathogenic organism is essential, and whether it is required for virulence or pathogenicity. The methods involve the construction of genetic mutants in which one allele of a specific gene is inactivated while the other allele of the gene is placed under conditional expression. The identification of essential genes and those genes critical to the development of virulent infections, provides a basis for the development of screens for new drugs against such pathogenic organisms. The present invention further provides Candida albicans genes that are demonstrated to be essential and are potential targets for drug screening. The nucleotide sequence of the target genes can be used for various drug discovery purposes, such as expression of the recombinant protein, hybridization assay and construction of nucleic acid arrays. The uses of proteins encoded by the essential genes, and genetically engineered cells comprising modified alleles of essential genes in various screening methods are also encompassed by the invention.

A mutant herpesvirus that can be used as a recombinant virus vector comprises (a) a mutation such that the mutant virus has a reduced ability in comparison with a parent type to cause lysis of an infected cell, and (b) an inactivating mutation in a gene essential for the production of infectious virus. An example is a HSV1 mutant lacking the essential glycoprotein gH gene and having a mutation impairing the function of gene product VP16. A heterologous gene can be carried at the site of the inactivated essential gene, e.g. a gene suitable for administering gene therapy. The vector has an increased margin of safety over known herpesvirus vectors in respect of incidence of cytopathic effects and / or risk of reversion.

The present invention concerns double stranded RNA compositions and transgenic plants capable of inhibiting expression of essential genes in parasitic nematodes, and methods associated therewith. Specifically, the invention relates to the use of RNA interference to inhibit expression of a target essential parasitic nematode gene, which is a parasitic nematode pas-5 gene, and relates to the generation of plants that have increased resistance to parasitic nematodes.

The present invention relates to main structure gene VP2 of artificial constructed pseudorabies virus, PrV and porcine parvovirus, PPV. In the pseudorabies virus genome in which the main toxicity gene (TK) and virus generation nonessential gene (gG) are deleted the VP2 gene of porcine parvovirus can be site-specifically inserted to make it be positioned in strong late promoter downstream of pseudorabies virus, and the inserted exogenous gene coded protein has good immunogenicity, and can stimulate swine to produce protective immune reaction for resisting two virulent challenges of porcine parvovirus and pseudorabies virus. Said invention also includes recombinant pseudorabies virus, Hzau AVL-PRppvV-VP2, vaccine prepared by using it and its preparation method.

One embodiment of the invention provides a genetically enhanced cyanobacterium producing a first chemical compound comprising:a genetically enhanced genome with a first gene inactivation in a first essential or conditionally essential gene of the cyanobacterium, anda first extrachromosomal plasmid harboring the first essential or conditionally essential gene and at least one first production gene for production of the first chemical compound,wherein the cyanobacterium lacks a functional gene conferring biocide resistance.These cyanobacteria can produce a first valuable chemical compound in long-term cultures without the need to employ genes conferring biocide resistance.

The present invention provides a herpes virus in which a non-essential gene for replication is inactivated. More particularly, the present invention provides a herpes virus in which a non-essential gene for replication present in a UL or US region is inactivated. More preferably, the non-essential gene for replication contains US3 or UL56. The herpes virus may be preferably a herpes simplex virus, and more preferably herpes simplex virus 1 or herpes simplex virus 2. The present invention provides a method, composition and use for treating various diseases or disorders including tumor and infectious diseases. The present invention also provides a method, composition and use for activating a prodrug.

The invention provides a recombinant adenovirus vector regulated by miRNA (micro Ribose Nucleic Acid) and capable of specifically proliferating in glioma cells. The recombinant adenovirus vector provided by the invention is characterized in that the target spot nucleotide sequence of at least one miRNA is inserted into the 3-untranslated region of at least one proliferation essential gene of the virus, the expression of miRNA is absent or reduced in glioma cells, but miRNA is normally expressed in nerve cells and glial cells so that the modified recombinant adenovirus specifically proliferate in the adenovirus in which the expression of miRNA is absent or reduced, but do not proliferate in normal cells in which the miRNA is normally expressed; and therefore, the recombinant adenovirus does not generate cytotoxicity to the normal cells.