BLG Gene in Production of Transgenic Sheep

Introduction

Transgenic animals are produced for various reasons where gene manipulation is carried out to improve certain traits, or produce recombinant chemicals, for instance proteins and hormones. Transgenic animal production focuses on gene transfer where desired genes are introduced into animal cells or embryos through a microinjection, virus or other desirable gene transfer techniques. Over time, scientists have produced transgenic sheep, which has high production capacity for milk. BLG gene is the main contributor to the success of this scientific approach where it assists in the expression of the human IX gene within the mammary gland of sheep.

The desired gene is introduced to the pronuclei of the sheep through pronuclear microinjection (Nancarrow, Marshall & Ward 1993). Once injection is completed, the embryos are allowed to develop to the blastocyst stage within the sheep’s oviduct. The embryos that reach the blastocyst stage are then transferred to the synchronous recipient through a non-surgical method. Successful pregnancies are allowed to develop within 60-65 days of gestation after which the fetus are taken out surgically together with a placental tissue sample (Shenoy, 2007).

BLG gene allowed specific expression of the introduced gene in sheep’s mammary gland thus allowing the sheep to secrete human factor IX in sheep’s milk. Factor IX is essential in blood clotting in the human body and assist in treatment of individuals with hemophilia (Shenoy, 2007). Transgenic sheep may also allow enrichment of sheep’s milk for human consumption, as well as augmenting an animal’s milk production and overall quality. Ovine BLG gene promoter blended with the ha₁ gene produced a biological activity identical to that of human plasma obtained from antitrypsin (Shenoy, 2007). High production of the protein is useful in the manufacture of sheep bioreactor.

Conclusion

However, the transgenic animals are considered to be GMOs, which offers considerable debate on utilization of these animals in the production of human foods due to safety concerns. Scientist fear that some potent microorganism utilized in the transfer of the desirable gens may express themselves within the human bodies causing harm. Nevertheless, the success of these biotechnological improvements has provided considerable help to patients with hemophilia and other diseases that require production of specific hormones or proteins in transgenic animals.