Research Article

Supplementation of fructose in chemically defined protein-free medium enhances the in vitro development of bovine transgenic cloned embryos

M.M. Uddin Bhuiyan^a1 c1, S-K. Kang^a2 and B-C. Lee^a2

^a1 Department of Surgery and Obstetrics, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.

^a2 Laboratory of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Republic of Korea.

Summary

The present study evaluated the possible embryotrophic role of fructose supplementation in chemically defined protein-free KSOM on in vitro development of bovine transgenic cloned embryos. Bovine fetal fibroblasts transfected with expression plasmids for bovine prion protein (PrP) mutant gene with GFP marker gene were used as donor nuclei for reconstruction of slaughterhouse-derived in vitro matured oocytes. The reconstructed oocytes were cultured in KSOM supplemented with 0.01% PVA (KSOM–PVA) at 39 °C in a humidified atmosphere of 5% CO₂, 5% O₂ and 90% N₂ for 192 h. In Experiment 1, when reconstructed oocytes were cultured in KSOM–PVA supplemented with glucose (0.2 mM), fructose (1.5 mM) or combined glucose and fructose (0.2 and 1.5 mM, respectively), significantly (p < 0.05) higher blastocyst (19.2%) and hatching/hatched blastocyst (13.1%) formation rates were obtained in combined fructose and glucose supplemented medium than glucose supplemented counterpart (10.0% and 5.7%, respectively). In Experiment 2, when reconstructed oocytes were cultured in KSOM–PVA supplemented with 0.0, 0.2, 1.5, 3.0 and 5.6 mM fructose in combination with 0.2 mM glucose, the blastocyst formation rate was significantly higher (17.6%) in 1.5 mM fructose supplemented group than that of no fructose supplemented counterpart (9.7%; p > 0.05). In conclusion, supplementation of combined fructose (1.5 mM) and glucose (0.2 mM) in chemically defined protein-free KSOM enhances the in vitro development of bovine transgenic cloned embryos.

(Received March 13 2006)

(Accepted February 15 2007)

Keywords:

• Bovine embryos;
• Fructose;
• KSOM;
• Nuclear transfer;
• Transgenic

Correspondence:

^c1 All correspondence to: M.M. Uddin Bhuiyan, Department of Surgery and Obstetrics, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh. Tel: +880 1715 020254. Fax: +880 91 55810. e-mail: mmubhuiyan@hotmail.com