Zinc Chloride Supplementation During In Vitro Fertilization Reduces Polyspermic Fertilization of Porcine Oocytes

Area of Science:

• Reproductive Biology
• Animal Science
• Biochemistry

Background:

• Zinc is crucial for sperm and oocyte fertilization competency.
• Understanding zinc's role in assisted reproductive technologies like in vitro fertilization (IVF) is important for optimizing outcomes.

Purpose of the Study:

• To investigate the impact of zinc chloride (ZnCl2) supplementation during porcine IVF on oocyte fertilization and embryo development.
• To determine the optimal ZnCl2 concentration for improving IVF success rates.

Main Methods:

• Porcine oocytes and frozen-thawed boar spermatozoa were used for IVF.
• ZnCl2 was supplemented at concentrations of 0, 1, 10, and 20 μg/mL.
• Sperm quality, fertilization rates (including polyspermy), and embryo development were assessed. Effects of metal chelators Ca-EDTA and Zn-EDTA were also examined.

Main Results:

• ZnCl2 supplementation did not affect the quality of frozen-thawed boar spermatozoa after 5 hours of culture.
• 1 μg/mL ZnCl2 significantly decreased polyspermic fertilization compared to 0 and 20 μg/mL groups.
• While 1 μg/mL ZnCl2 increased blastocyst formation rate in some cases, it did not consistently improve overall embryo development across different boar spermatozoa.
• Zn-EDTA co-incubation reduced polyspermic fertilization, similar to ZnCl2.

Conclusions:

• Supplementation with 1 μg/mL ZnCl2 during porcine IVF effectively reduces polyspermic fertilization.
• The positive effect of ZnCl2 on fertilization does not always translate to improved embryo development, suggesting complex interactions.
• Further research is needed to elucidate the precise mechanisms and optimize ZnCl2 use in IVF.