The expression and localization of V-ATPase and cytokeratin 5 during postnatal development of the pig epididymis

Abstract

Objective: We examined the localization and expression of H<sup>+ pumping vacuolar ATPase (V-ATPase) and cytokeratin 5 (KRT5) in the epididymis of pigs, expressed in clear and basal cells, respectively, during postnatal development.Methods: Epididymides were obtained from pigs at 1, 7, 21, 60, 120, and 180 days of age; we observed the localization and expression patterns of V-ATPase and KRT5 in the different regions of these organs, namely, the caput, corpus, and cauda. The differentiation of epididymal epithelial cells was determined by immunofluorescence labeling using cell-type-specific markers and observed using confocal microscopy.Results: At postnatal day 5 (PND5), the localization of clear cells commenced migration from the cauda toward the caput. Although at PND120, goblet-shaped clear cells were detected along the entire length of the epididymis, those labeled for V-ATPase had disappeared from the corpus to cauda and were maintained only in the caput epididymis in adult pigs. In contrast, whereas basal cells labeled for KRT5 were only present in the vas deferens at birth, they were detected in all regions of the epididymis at PND60. These cells were localized at the base of the epithelium; however, no basal cells characterized by luminally extending cell projections were observed in any of the adult epididymides examined.Conclusion: The differentiation of clear and basal cells progressively initiates in a retrograde manner from the cauda to the caput epididymis. The cell-type-specific distribution and localization of the epithelial cells play important roles in establishing a unique luminal environment for sperm maturation and storage in the pig epididymis.

Development and Differentiation of Epididymal Epithelial Cells in Korean Native Black Goat

“…Finally, after differentiation, BCs were hemispherical and their nuclei were located at the base of the epithelium ( Figure 3 and Figure 5 ). These observations are in agreement with those of previous studies on the pig epididymis [ 15 ]. The shapes of BCs in the epididymis varies greatly among species.…”

“…Clear cells were columnar, narrow, and goblet shaped ( Figure 6) during epithelial development, but only goblet-shaped CCs were present in the caput and corpus of the epididymis after differentiation. These results are consistent with those of a previous study showing that CCs show different morphologies in the developing epididymis, but only one shape in the differentiated epididymis of pigs [15]. In contrast, rodent CCs show different shapes, such as pencil-, cuboidal-, and goblet-shaped, across the epididymal regions [7,17].…”

“…Thus, the hematoxylin and eosin staining procedure is limited to observing the development and differentiation of epididymal epithelial cells, particularly in the early stages when there are no localization differences among the multiple cell types, including PCs, CCs, and BCs ( Figure 6). Using a KRT5 antibody that specifically labels BCs in a range of species, including mice [13], rats [22], bats [23], and pigs [15], we were able to distinguish different types of epididymal epithelial cells. Furthermore, dynamic morphological changes in BCs were observed with age and across regions of the epididymis.…”

“…The shapes of BCs in the epididymis varies greatly among species. In rodents, the projected BCs are maintained after completion of their differentiation and play an important role in scanning the luminal environment [12,24], whereas in other species, such as bats [23] and pigs [15], they disappear. These results suggest that BCs' regulation and function may be species-specific.…”

“…Recently, we reported that in pigs, the development and differentiation of the epididymal epithelium are determined by cell-specific mechanisms during postnatal development and that the establishment of an appropriate environment via the interaction of CCs and BCs is essential for sperm maturation and storage [15]. However, information regarding the development and differentiation of epididymal epithelium in goats is limited.…”