Foreign gene expression by in vivo gene electroporation in the quail testis

To investigate whether or not foreign gene expression is attained in the testis of living Japanese quails, a firefly luciferase reporter gene was transfected by in vivo electroporation (EP), and transcriptional activity of different promoters was compared. In addition, the effect of the Epstein-Barr virus self-replication sequence was also tested. The results showed that luciferase activity in the testis reached almost a plateau value at 50 V. Under this EP condition, no difference was found in transcriptional activity between the simian virus 40 (SV40) and miw promoters. The reporter gene expression in the quail testis was observed over 28 days after in vivo gene EP, although the activity gradually decreased, and the presence of the Epstein-Barr virus self-replication sequence in the SV40 promoter did not significantly prolong the luciferase activity. These results suggest that in vivo gene EP confers strong, though transient, foreign gene expression in the Japanese quail, and it may provide a new powerful approach for studies on transcriptional regulation of genes during proliferation and differentiation of spermatogenic cells in the quail testis.