Improved efficiency of bovine somatic cell nuclear transfer by optimizing operational procedures

Area of Science:

• Animal Biotechnology
• Reproductive Biology
• Developmental Biology

Background:

• Somatic cell nuclear transfer (SCNT) is crucial for bovine reproductive technologies.
• Improving the efficiency of SCNT remains a significant challenge in animal breeding.

Purpose of the Study:

• To optimize key procedural steps in bovine SCNT to enhance overall efficiency.
• To evaluate the impact of pronase treatment, activation methods, and culture conditions on SCNT outcomes.

Main Methods:

• Donor cells were treated with pronase to assess its effect on fusion rates.
• Fused embryos were activated using chemical (ionomycin + CHX) or electrical + CHX methods.
• Reconstructed embryos were cultured in either ACM + MEF or B2 + GC media.

Main Results:

• Pronase treatment significantly increased the fusion rate (78.3% vs. 53.9%).
• Chemical activation resulted in comparable cleavage and blastocyst rates to electrical activation but with lower mortality.
• ACM + MEF culture medium yielded significantly higher blastocyst (46.7%), pregnancy (36.1%), and newborn (25.9%) rates compared to B2 + GC.

Conclusions:

• Optimized bovine SCNT procedures enhance efficiency.
• Pronase treatment, chemical activation, and specific culture media are critical for successful SCNT.