Implication of the estrogen receptors GPER, ESR1, ESR2 in post-testicular maturations of equine spermatozoa.

The research article investigates the role of estrogen receptors (ESR1, ESR2, and GPER) on horse sperm and their impact on post-testicular maturation factors such as motility, capacitation, and acrosome reaction.

Objective of the Study

• This research aims to understand the presence and role of estrogen receptors ESR1, ESR2, and GPER on mature ejaculated horse sperm. This includes analyzing whether exposaure to high estrogen levels in both male and female genital tracts influences these post-testicular sperm maturation processes, with a specific focus on the role of 17β-estradiol.
• Additionally, the research seeks to understand any seasonal variations in the presence of these estrogen receptors on horse sperm, correlating this to the horse’s breeding status.

Findings of the Study

• The study found that these estrogen receptors are present on stallion sperm more during the breeding season.
• In terms of 17β-estradiol’s role during post-testicular maturation, it was found that capacitation and acrosome reaction — essential processes for successful fertilization — remain unaffected by this estrogenic compound.
• However, estrogen does slightly influence the motility (movement) of the sperm. This effect aligns with the presence of GPER, but not ESR1 and ESR2 receptors in the sperm cells. This corresponds with GPER’s subcellular localization in the neck of the sperm.

Implications and Conclusions

• The results suggest that estrogens may not play a significant role in regulating sperm maturations that take place in the mare’s genital tract, but could potentially influence maturation processes during the epididymal phase.
• This study advances our understanding of the influence of estrogen and its receptors on horse sperm, which can be instrumental in improving the controlled breeding practices in horses.