Gene transfer experiments in cattle.

Area of Science:

• Animal Biotechnology
• Molecular Biology
• Reproductive Biology

Background:

• Gene transfer techniques are crucial for genetic improvement in livestock.
• Developing efficient methods for introducing foreign DNA into bovine zygotes is essential for agricultural applications.

Purpose of the Study:

• To evaluate the efficiency of different gene constructs for gene transfer in cattle.
• To determine the optimal timing for bovine zygote collection for gene injection.

Main Methods:

• Four gene constructs were prepared: bovine papilloma virus DNA, Drosophila melanogaster alcohol dehydrogenase gene, and human/bovine growth hormone genes.
• Bovine zygotes were collected 78-82 hours post-prostaglandin treatment and injected with foreign DNA.
• Embryos were transferred to recipient heifers, and gene transfer efficiency was assessed using dot-blot hybridization.

Main Results:

• Gene transfer efficiencies were 3.2% for construct 1 (bovine papilloma virus DNA) and 6.9% for construct 2 (alcohol dehydrogenase gene).
• Construct 4 (bovine growth hormone gene) resulted in a 0.8% gene transfer efficiency, with 14 calves born from 43 transferred embryos.
• The optimal time for zygote collection was identified, and successful pregnancies were achieved.

Conclusions:

• The study highlights varying efficiencies of different gene constructs for gene transfer in cattle.
• The alcohol dehydrogenase gene construct showed the highest efficiency among those tested.
• Optimized zygote collection and transfer protocols are vital for successful bovine gene transfer.