Method for the modification of expression characteristics of endogenous genes of certain cell lines or microorganisms

摘要

The following are claimed: (A) a method of activating a normally transcriptionally silent gene within the genome of a cell line or microorganism to enable the cell line or microorganism to express the gene prod. of the gene, comprising inserting a DNA construct into the genome by homologous recombination, the DNA construct comprising a DNA regulatory element capable of stimulating expression of the gene when operatively linked to it and a DNA targeting segment homologous to a region of the genome within or near to the gene, where the construct is inserted so regulatory segment is operatively linked to the gene of interest; (B) a genome having a DNA regulatory segment operatively linked with a naturally occurring gene at an insertion site characterised by a predetd. DNA sequence, etc.