cloning

Gene expression pinpoints multiple anomalies likely to lead to pregnancy failure for clones

Like great athletes and musicians, cells employed in cell-based assays or as expression systems for biopharmaceutical production are not born, but made. Cell lines that perform specifically and predictably arise from a population of cells that have undergone one or more genetic transformations (transfection) and are subsequently selected for desirable properties such as viability, protein or virus production; high culture density; or binding to drugs or antigens.

For years, researchers and patients have hoped that embryonic stem cells (ESCs)—capable of forming nearly any cell type in the body—could provide insight into numerous diseases perhaps even be used to treat them. Yet progress has been hampered by the inability to transfer research and tools from mouse ESC studies to their human counterparts, in part because human ESCs are “primed” and slightly less plastic than the mouse cells.