Molecular cloning and expression of gerbil granulocyte/macrophage colony-stimulating factor

Using a combination of cross species reverse transcriptase-polymerase chain reaction and 3' rapid amplification of cDNA ends techniques, we cloned the cDNA encoding gerbil granulocyte/macrophage colony-stimulating factor (GM-CSF). The open reading frame had 81% nucleotide identity with its mouse counterpart, while the mature protein had 80% homology with mature mouse GM-CSF. COS-7 cells transfected with gerbil GM-CSF cDNA secreted high levels of bioactive GM-CSF, as their supernatant stimulated gerbil bone-marrow cell proliferation and colony formation in semi-solid medium.