Effect of cumulus cell removal and sperm pre-incubation with progesterone on in vitro fertilization of equine gametes in the presence of oviductal fluid or cells.

This study explores the effect and possible enhancement of the equine in vitro fertilization (IVF) process through a particular set of conditions: the removal of cumulus cells from the oocyte, sperm pre-incubation with oviductal fluid, or in the presence of oviductal cells, and sperm pre-incubation with progesterone. It found that while certain procedures presented a slight increase in the fertilization percentage, none had a significant influence on the overall fertilization rate. However, the results encouragingly showed that pre-incubating fresh sperm with progesterone resulted in the formation of two 3-4 cell stage zygotes.

Objective and Methodology

• The objective of this research was to study and increase the efficiency of equine IVF by investigating potential enhancements to the process. These enhancements included the removal of cumulus cells from the oocyte and sperm pre-incubation with progesterone, porcine oviductal fluid, or in the presence of oviductal cells.
• The study was divided into four experiments. In the first two experiments, IVF was performed with porcine oviduct epithelial cells; in the latter two experiments, sperm was pre-incubated with porcine oviductal fluid.

Results

• The first two experiments showed that removing cumulus cells from equine oocytes after in vitro maturation had a positive but not statistically significant effect when fresh sperm was used, but there was no effect with frozen sperm. Pre-incubating equine sperm with progesterone had no significant influence on the fertilization rate for both fresh and frozen sperm.
• The latter two experiments mirrored the results of the first two, showing a slight but not significant increase in fertilization percentage when cumulus cells were removed and fresh sperm was used. Again, sperm pre-incubation with progesterone showed no noticeable effect on the fertilization rate whether fresh or frozen sperm was used.
• However, an encouraging result was found during the latter half of the study, where fresh sperm pre-incubated with progesterone resulted in the creation of two 3-4 cell stage zygotes. This suggests a potential method for stimulating early embryo development within the equine IVF procedure.

Conclusion

• By and large, the study found that the tested methods had no significant overall influence on the fertilization rate during the equine IVF process.
• However, the result of successfully producing multiple 3-4 cell stage zygotes through sperm pre-incubation with progesterone suggests potential for future research and possible enhancements to the equine IVF technique.