Abstract: This invention provides a system for rapid determination of pharmacologic effects on target tissue types in cell populations cultured in vitro. The cells contain a promoter-reporter construct that reflects a toxicologic or metabolic change caused by the agent being screened. The promoter is taken from a gene known to be up- or down-regulated according to the metabolic state of the cell, and linked to a reporter gene that provides an external signal for monitoring promoter activity. The promoter-reporter cells may be produced by placing these genetic alterations into a line of human embryonic stem cells, bulking up the cells to any extent desired, and then differentiating the cells into the desired tissue type. This disclosure explains some of the powerful features of the promoter-reporter cells of this invention, and shows various ways the skilled reader can use the invention for pharmaceutical development and testing, or to monitor graft survival.

Abstract: This invention provides a system for rapid determination of pharmacologic effects on target tissue types in cell populations cultured in vitro. The cells contain a promoter-reporter construct that reflects a toxicologic or metabolic change caused by the agent being screened. The promoter is taken from a gene known to be up- or down-regulated according to the metabolic state of the cell, and linked to a reporter gene that provides an external signal for monitoring promoter activity. The promoter-reporter cells may be produced by placing these genetic alterations into a line of human embryonic stem cells, bulking up the cells to any extent desired, and then differentiating the cells into the desired tissue type. This disclosure explains some of the powerful features of the promoter-reporter cells of this invention, and shows various ways the skilled reader can use the invention for pharmaceutical development and testing, or to monitor graft survival.

Abstract: This invention provides a system for selecting a cell that has undergone genetic alteration by homologous recombination from amongst a population of cells that do not have the alteration. The successfully targeted cells are identified and separated according to surface glycosylation that has changed as a result of the homologous recombination. The recombination event may inactivate an endogenous gene, or introduce a transgene, either of which encodes a carbohydrate modulating enzyme, such as ?(1,3)galactosyltransferase or ?(1,2)fucosyltransferase. Altering carbohydrate modulating enzymes can be done for producing tissue with altered carbohydrate determinants, or as a means for tracking inactivation or insertion of other genetic elements for a variety of purposes.