375 PRODUCTION OF GERMLINE TRANSGENIC CHICKENS USING MURINE LEUKEMIA VIRUS-BASED RETROVIRUS VECTOR SYSTEM

Abstract

We report here successful generation of germline transgenic chickens expressing the enhanced green fluorescence protein (EGFP) gene throughout whole bodies. The founder chickens were produced by injecting replication-defective recombinant retroviruses encapsulated with the vesicular stomatitis virus G glycoprotein (VSV-G)-pseudotyped retrovirus vector system beneath the blastoderm of non-incubated chicken embryos (stage X). Of 129 injected eggs, 13 chickens hatched. These 13 chickens were analyzed at 6-16 weeks post-hatching and all were found to emit green fluorescence in at least one part of the body. One cock of the 13 Go chimeric founder cockerels was mated with several non-transgenic hens, and one of 102 G1 siblings was found to emit a green fluorescent signal in its whole body. Successful germline transmission of the EGFP transgene was further confirmed in the G2 generation chickens: Crossing of the G1 cock and several non-transgenic hens resulted in about 50% (18/37) of the G2 cockerels being transgenic. The results of this study would be very helpful in establishing a useful transgenic chicken model system for generation of transgenic chickens as bioreactors producing therapeutic proteins, as well as for studies on embryo development.