Uterotubal Junction of the Bovine (Bos taurus) vs. the Dromedary Camel (Camelus dromedarius): Histological and Histomorphometry Analysis

Abstract

This study compares the histomorphology differences of cattle uterotubal junction (CUTJ) and dromedary camels uterotubal junction papilla (CUTJP). UTJ were dissected from eight cows and twelve camels with dominant follicles, and processed for H&E staining for morphology, histology, and histomorphometry examination. The results showed that the CUTJP existed only in camels and was completely absent in cattle. Histologically, CUTJ appears with a star-shaped lumen, and the mucosa lined by a simple columnar epithelium containing ciliated and non-ciliated cells, superficial (SG), and deep glands (D G) were abundant in the submucosa. CUTJP is a fibrous conical structure, it has a pale yellowish color and 0.5 ± 0.2 cm height and 0.3 ± 0.1 cm width. C UTJP, the lumen is wider, and the mucosa showed large multiple folds lined with ciliated and non-ciliated pseudostratified columnar epithelium. The submucosa showed no endometrial glands. Lumen area, lumen epithelial height, luminal epithelial density, the thickness of the muscular layer, number of folds, folds height, epithelial height, fold area, and epithelial perimeter were higher in CUTJP (P < 0.001) than CUTJ. While the total endometrial area and glandular epithelial density were lower in UTJP (P < 0.001) than in CUTJ. In conclusion, the epithelial lining, absence of glands, and the thick layer of tunica muscularis might indicate that camel CUTJP could play a mechanical role in selecting spermatozoa and assisting the hatching of blastocysts during their passage through it.