Morphological changes of telocytes in camel efferent ductules in response to seasonal variations

What is it about?

Telocytes (TCs) are a distinct stromal cell type described in many organs. The present study investigated the existence of TCs within the efferent ductules in camel and the changes that occur in their morphology and activity during active and inactive reproductive seasons. TCs in the camel had a cell body and multiple telopodes (TPs), and most TCs had indented nuclei that exhibited prominent intranucleolar chromatin. TCs exhibited seasonal differences which were evaluated by histochemistry, immunohistochemistry (IHC), Transimition electron microscopy (TEM) and scanning electron microscopy (SEM). The presence of TCs in camel efferent ductules has been confirmed by CD34 positive immunostaing. In addition to the expression of the vascular endothelial growth factor (VEGF) which was stronger in the summer season. TCs exhibited stronger immunoreactivity for progesterone and oestrogen alpha receptors (ESR1) in the spring than in the summer. In addition, TCs showed strong positive immunostaining for both vimentin and androgen receptor (AR). Several ultrastructural changes were observed in TCs during the two seasons. TPs in the summer season had delicate ramifications whereas, in the spring, TPs displayed fine arborization and became more corrugated. TCs acquired signs of exaggerated secretory activities in the spring; TPs became expanded and packed with secretory vesicles. Thus, we conclude that, hormonal alterations during the reproductive cycle impact the morphology and secretory behavior of TCs.

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Why is it important?

In conclusion, seasonal differences in TCs morphology and behavior are likely regard to hormonal variations between the two seasons. Hormonal alternations during the reproductive cycle may influence the TCs morphology and secretory behavior. The results of the present study support the hypothesis that TCs are affected by microenvironmental changes. TCs gain additional short TPs in an environment characterized by oxidative stress. Intranucleolar chromatin was observed in TCs as well as lymphocytes. The structural organization of intranucleolar chromatin is associated with seasonal and hormonal variation. This finding suggests that the intranucleolar chromatin may act as a temporarily inactive gene that is activated when necessary to satisfy the functional demand in the reproductive cycle particularly the secretory function.