Influence of epidermal growth factor on in vitro maturation of equine oocytes.

The research paper discusses the impact of epidermal growth factor (EGF) on the in vitro maturation of horse oocytes (eggs). The findings suggest that EGF is an effective substitute for crude equine gonadotrophin in improving the maturation rate of these oocytes.

Summary of Research Methodology

• The study was conducted in two experiments: one using oocytes collected from abattoirs and another using oocytes obtained through ultrasound-guided follicular puncture in vivo.
• The collected oocytes that had a compact or expanded cumulus were cultured for 30 hours in four different mediums: medium 1 (comprising TCM199, fetal calf serum, crude equine gonadotrophin, oestradiol, and antibiotics), medium 2 (containing TCM199 and EGF), medium 3 (medium 1 without FCS but with EGF), and medium 4 (medium 1 without CEG but with EGF).

Findings from Experiment 1

• In the first experiment, 84% (37/44) and 87% (40/46) of oocytes demonstrated cumulus expansion in mediums 1 and 2 respectively—there was no significant statistical difference.
• However, a significant variation was observed in the nuclear maturation rate, with 39% (22/57) of oocytes showing nuclear maturation in medium 1 as compared to only 9% (5/57) in medium 2.

Findings from Experiment 2

• In the second experiment, cumulus expansion was observed in all oocytes cultured in mediums 1, 3, and 4.
• A lower rate of nuclear maturation was observed in medium 3 (6%, 2/36) compared to medium 1 (43%, 16/37); the difference was statistically significant.
• The nuclear maturation rate was higher in medium 4 (64%, 25/39) than in medium 1, but the difference was not statistically significant.

Conclusion

• The study concluded that 50 ng EGF ml(-1) alone was an effective substitute for crude equine gonadotrophin.
• The presence of EGF improves the nuclear maturation rate of equine oocytes. This finding has potential implications for improving in vitro fertilization practices in the equine sector.