Abstract: The present invention relates to a method of producing a cell comprising a conditionally active transgene in its genome, the method comprising (a) introducing into the cell a targeting vector, wherein the targeting vector comprises (i) a 5? recombinase recognition site specifically recognised by a first recombinase, wherein the first recombinase is endogenously present in the cell or wherein the first recombinase or a nucleic acid molecule encoding said first recombinase in expressible form is introduced into the cell; followed by (ii) a 5? recombinase recognition site specifically recognised by a second recombinase, wherein the second recombinase is not endogenously present or is not active in the cell; followed by (iii) a selection cassette comprising a positively selectable marker gene; followed by (iv) a 3? recombinase recognition site specifically recognised by a third recombinase, wherein the third recombinase is not endogenously present or is not active in the cell; followed by (v) the transgene; follo

Abstract: The present invention relates to a novel class of gene trap vector (enhanced gene trap vectors, eGTV) for efficiently identifying silent or weakly expressed target genes in mammalian genomes, methods of their production and methods for identifying and mutating target genes by using the enhanced gene trap vectors. The gene trap vectors of the present invention can also be used for inducing the expression of silent genes and enhancing the expression of weakly expressed genes. The use of the enhanced gene trap vectors for creating transgenic organisms to identify gene function and to validate pharmaceutical compounds prior to clinical applications is a further aspect of the present invention.

Abstract: The present invention relates to a method of producing a cell comprising a conditionally active transgene in its genome, the method comprising (a) introducing into the cell a targeting vector, wherein the targeting vector comprises (i) a 5? recombinase recognition site specifically recognised by a first recombinase, wherein the first recombinase is endogenously present in the cell or wherein the first recombinase or a nucleic acid molecule encoding said first recombinase in expressible form is introduced into the cell; followed by (ii) a 5? recombinase recognition site specifically recognised by a second recombinase, wherein the second recombinase is not endogenously present or is not active in the cell; followed by (iii) a selection cassette comprising a positively selectable marker gene; followed by (iv) a 3? recombinase recognition site specifically recognised by a third recombinase, wherein the third recombinase is not endogenously present or is not active in the cell; followed by (v) the transgene; follo

Abstract: The present invention relates to a novel class of gene trap vector (enhanced gene trap vectors, eGTV) for efficiently identifying silent or weakly expressed target genes in mammalian genomes, methods of their production and methods for identifying and mutating target genes by using the enhanced gene trap vectors. The gene trap vectors of the present invention can also be used for inducing the expression of silent genes and enhancing the expression of weakly expressed genes. The use of the enhanced gene trap vectors for creating transgenic organisms to identify gene function and to validate pharmaceutical compounds prior to clinical applications is a further aspect of the present invention.

Abstract: A new type of gene trap cassette, which can induce conditional mutations, relies on directional site-specific recombination systems, which can repair and re-induce gene trap mutations when activated in succession. After the gene trap cassettes are inserted into the genome of the target organism, mutations can be activated at a particular time and place in somatic cells. The gene trap cassettes also create multipurpose alleles amendable to a wide range of post-insertional modifications. Such gene trap cassettes can be used to mutationally inactivate all cellular genes temporally and/or spatially. Cells which contain the inventive gene trap cassette can be used for identification and/or isolation of genes and for the creation of transgenic organisms to study gene function at various developmental stages, including the adult, as well as for the creation of animal models of human disease useful for in vivo drug target validation.

Abstract: The invention relates to a method for the stable inversion of a DNA fragment upon recombinase-mediated rearrangements using two sets of two incompatible site-specific recombinase targeting sites (SSRTS) in the same order but in reverse orientation flanking the DNA fragment to be inverted. The invention also relates to a method for the stable inversion of the DNA fragment upon rearrangement mediated by a recombinase such as Cre recombinase. The invention also relates to a method for obtaining a transgenic cell of which at least one allele of a DNA sequence of interest is invalidated by a process of conditional deletion and the genome of which has a reporter gene inserted at the place of the DNA fragment deleted by the process of conditional deletion. A method to generate targeting sites to perform site-specific recombination mediated cassette exchange is also provided.

Abstract: The invention relates to a method for the stable inversion of a DNA fragment upon recombinase-mediated rearrangements using two sets of two incompatible site-specific recombinase targeting sites (SSRTS) in the same order but in reverse orientation flanking said DNA fragment to be inverted. The invention also relates to a method for the stable inversion of said DNA fragment upon rearrangement mediated by a recombinase such as Cre recombinase. The invention also relates to a method for obtaining a transgenic cell of which at least one allele of a DNA sequence of interest is invalidated by a process of conditional deletion and the genome of which comprises a reporter gene inserted at the place of the DNA fragment deleted by said processor conditional deletion. The invention also concerns a method to generate targeting sites to perform site-specific recombination mediated cassette exchange. The corresponding vectors, host cells, and transgenic animals are claimed.

Abstract: The invention relates to a method for the stable inversion of a DNA fragment upon recombinase-mediated rearrangements using two sets of two incompatible site-specific recombinase targeting sites (SSRTS) in the same order but in reverse orientation flanking said DNA fragment to be inverted. The invention also relates to a method for the stable inversion of said DNA fragment upon rearrangement mediated by a recombinase such as Cre recombinase. The invention also relates to a method for obtaining a transgenic cell of which at least one allele of a DNA sequence of interest is invalidated by a process of conditional deletion and the genome of which comprises a reporter gene inserted at the place of the DNA fragment deleted by said process of conditional deletion. The invention also concerns a method to generate targeting sites to perform site-specific recombination mediated cassette exchange. The corresponding vectors, host cells, and transgenic animals are claimed.