Generation of transgenic chickens that produce bioactive human granulocyte-colony stimulating factor

We report here the generation of transgenic chickens that produce human granulocyte-colony stimulating factor (hG-CSF) using replication-defective Moloney murine leukemia virus (MoMLV)-based vectors packaged with vesicular stomatitis virus G glycoprotein (VSV-G). The recombinant retrovirus was injected beneath the blastoderm of nonincubated chicken embryos (stage X). Out of 140 injected eggs, 17 chicks hatched after 21 days of incubation and all hatched chicks were found to express vector-encoded hG-GSF gene. The biological activity of the recombinant hG-CSF was significantly higher than its commercially derived E. coli-derived counterpart. Successful germline transmission of the transgene was also confirmed in G(1) transgenic chicks produced from the cross of Go transgenic roosters with nontransgenic hens, but most of the G(1) progeny were dead within 1 month of hatching.