Production of germline transgenic chickens expressing enhanced green fluorescent protein using a MoMLV-based retrovirus vector

The Moloney murine leukemia virus (MoMLV)-based retrovirus vector system has been used most often in gene transfer work, but has been known to cause silencing of the imported gene in transgenic animals. In the present study, using a MoMLV-based retrovirus vector, we successfully generated a new transgenic chicken line expressing high levels of enhanced green fluorescent protein (eGFP). The level of eGFP expression was conserved after germline transmission and as much as 100 mu g of eGFP could be detected per 1 mg of tissue protein. DNA sequencing showed that the transgene had been integrated at chromosome 26 of the G(1) and G(2) generation transgenic chickens. Owing to the stable integration of the transgene, it is now feasible to produce G(3) generation of homozygous eGFP transgenic chickens that will provide 100% transgenic eggs. These results will help establish a useful transgenic chicken model system for studies of embryonic development and for efficient production of transgenic chickens as bioreactors.