Exposure of progesterone receptors on the plasma membranes of stallion spermatozoa as a parameter for prediction of fertility.

The study examines the connection between the fertility of stallions and the presence of progesterone receptors on their sperm. More specifically, the research found a strong correlation between the proportion of sperm with exposed progesterone receptors and the fertility of the stallion, suggesting that these receptors could be a useful indicator of fertility.

Objective of the Study

• This research aimed at evaluating the possibility of using the proportion of stallion sperm with exposed progesterone receptors on their plasma membranes as a predictive parameter for fertility. The objective was to draw a correlation between stallion fertility and the presence of these receptors.

Study Methodology

• The study was conducted on semen from Dutch Warmblood and Friesian stallions. The fertility of these stallions was determined based on first cycle foaling rate and first cycle non-return rate, which indicate the fertility success in the first breeding cycle.
• The researchers used a specific type of progesterone receptor probe (Progesterone 3-(o-carboxymethyl)oxime-BSA) coupled with fluorescein isothiocyanate to detect the presence and exposure of progesterone receptors on the sperm plasma membrane. Ethidium homodimer was used as a supravital stain, a live cell staining technique that enables visualization of cellular structures.

Key Findings

• The study found a strong correlation (r > 0.70; P < 0.01) between the proportion of spermatozoa with exposed progesterone receptors and the fertility of the stallion.
• This correlation suggests that the membrane exposure of progesterone receptors on stallion sperm can serve as a potential parameter for predicting fertility in these animals.

Significance of the Research

• The findings of this research provide a potential approach to assess the fertility of stallions using a biological marker – the exposure of progesterone receptors on the spermatozoa.
• This could be beneficial for breeding programs, helping to select high fertility stallions, and potentially improve the efficiency and success rate of equine reproductive operations.