Abstract: The present invention discloses a method to construct eukaryotic cells having a target sequence in a chromosomal DNA sequence replaced by a replacement sequence of interest comprising: modifying a parent eukaryotic cell with a preference for NHR to provide a eukaryotic cell having an increased HR/NHR ratio as compared to the parent cell, providing two sets of DNA molecules of which the first set comprises DNA molecules each comprising a first non-functional fragment of the replacement sequence of interest flanked at its 5?-side by a DNA sequence substantially homologous to a sequence of the chromosomal DNA flanking the target sequence and the second set comprises DNA molecules each comprising a second non-functional fragment of the DNA replacement sequence of interest overlapping with the first non-functional fragment and flanked at its 3?-side by a DNA sequence substantially homologous to a sequence of the chromosomal DNA flanking the target sequence, wherein the first and second non-functional fragments

Abstract: A method to construct eukaryotic cells having a target sequence in a chromosomal DNA sequence replaced by a desired replacement sequence is disclosed.

Abstract: The present invention discloses a method to construct eukaryotic cells having a target sequence in a chromosomal DNA sequence replaced by a replacement sequence of interest comprising: modifying a parent eukaryotic cell with a preference for NHR to provide a eukaryotic cell having an increased HR/NHR ratio as compared to the parent cell, providing two sets of DNA molecules of which the first set comprises DNA molecules each comprising a first non-functional fragment of the replacement sequence of interest flanked at its 5?-side by a DNA sequence substantially homologous to a sequence of the chromosomal DNA flanking the target sequence and the second set comprises DNA molecules each comprising a second non-functional fragment of the DNA replacement sequence of interest overlapping with the first non-functional fragment and flanked at its 3?-side by a DNA sequence substantially homologous to a sequence of the chromosomal DNA flanking the target sequence, wherein the first and second non-functional fragments

Abstract: We disclose a method to construct eukaryotic cells having a target sequence in a chromosomal DNA sequence replaced by a desired replacement sequence, comprising: modifying a parent eukaryotic cell with a preference for NHR to provide a eukaryotic cell having an increased HR/NHR ratio as compared to the parent cell, providing a DNA molecule comprising a first DNA fragment comprising a desired replacement sequence flanked at its 5? and 3? sides by DNA sequences substantially homologous to sequences of the chromosomal DNA flanking the target sequence and a second DNA fragment comprising an expression cassette comprising a gene encoding a selection marker operably linked to regulatory sequences functional in the eukaryotic cell, transforming the modified eukaryotic cells with the DNA molecule, selecting transformed progeny cells having the DNA molecule inserted into the chromosome, deselecting transformed progeny cells having the DNA molecule inserted into the chromosome via NHR by expression of the selection mar