SELECTION OF HOST CELLS EXPRESSING PROTEIN AT HIGH LEVELS

摘要

The invention provides a DNA molecule comprising an open reading frame sequence that encodes a selectable marker polypeptide, wherein said DNA molecule in the coding strand comprises a translation start sequence for the selectable marker polypeptide having a GTG startcodon or a TTG startcodon, and wherein the open reading frame sequence that encodes the selectable marker protein has been mutated to replace at least half of its CpG dinucleotides as compared to the native open reading frame sequence that encodes the selectable marker protein.