SCNT-TG embryos express eGFP when cultured in the presence of doxycycline.

(A) SCNT was performed using eGFP-positive pFF. The resulting embryos were cultured in the presence of doxycycline for 1 to 7 days and were examined by bright field and fluorescence microscopy. eGFP expression was detected in embryos at the 1-cell, 2–4-cell, and blastocyst stages. (B) SCNT-TG embryos were cultured in the presence of doxycycline for 3 days and then in the absence of doxycycline for a further 4 days. The embryos were examined by bright field and fluorescence microscopy. eGFP fluorescence appeared when embryos were cultured in the presence of doxycycline and gradually disappeared when embryos were cultured in the absence of doxycycline.