Abstract

Background:
The extracellular matrix glycoprotein osteopontin (OPN) is highly phosphorylated.

Aim:
This study investigates the expression and localization of OPN in the vas deferens, prostate, and bulbourethral glands throughout the rutting season to better understand its role in dromedary camels.

Methods:
Tissue samples were collected from the vas deferens (beginning, middle, and ampullary sections), prostate (corpus and disseminated regions), and bulbourethral glands of 12 adult male camels. Immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine the distribution and expression levels of OPN protein and mRNA.

Results:
IHC revealed strong OPN expression in the epithelial cells of the ampullary part of the vas deferens and the disseminated prostate. Moderate immunoreactivity was observed in the corpus prostate and the vas deferens’ beginning and middle sections. Among all examined regions, the bulbourethral gland exhibited the lowest expression levels. The qRT-PCR results showed that OPN mRNA expression was significantly higher (p < 0.05) in the ampullary part of the vas deferens and the disseminated prostate than in other sections of the vas deferens and the compact prostate gland. The lowest mRNA expression was detected in the bulbourethral gland.

Conclusion:
OPN expression in the vas deferens and male accessory glands of the dromedary camel may facilitate sperm immigration through these organs. Additionally, the secretion of OPN into the seminal fluid by the accessory glands may influence sperm function within the female reproductive tract. Therefore, OPN could serve as a potential breeding selection marker.

Key words: Accessory glands; Immunohistochemistry; OPN; qRT-PCR; Vas deferens.