Differential expression and localization of thermosensitive Transient Receptor Potential Vanilloid (TRPV) channels in the mature sperm of white pekin duck (Anas platyrhynchos)

Sperm cells have the ability of precise chemotactic and thermotactic movement which is crucial for fertilization, yet the key molecules involved in the detection of different chemical and physical stimuli and guide the sperm cells for proper navigation are not known. This aspect is more complex as each species have their own reproductive identity. Never-the-less, Ca2+-signaling and thus a series of Ca2+-channels seem to coordinate in order to regulate different functions mediated by sperm cells. However, such aspects are controlled by different Ca2+ channels and have species-specific differences. In this work we explored if TRPV channels are endogenously expressed in the mature spermatozoa obtained from avian species. We have used the sperm cells of white pekin duck (Anas platyrhynchos) as a representative avian species to explore the endogenous expression and localization of different TRPV channels. Western blot analysis (WB), flow cytometry, confocal imaging and super resolution imaging was performed for the characterization. Our results strongly suggest the expression and distinct localization of different TRPV channels in the sperm cells. All these TRPV channels are mainly absent in the head region. Only TRPV3 and TRPV4 are sparsely present in the neck region enriched with mitochondria. All these channels (TRPV1-6) are present in the tail region. The differential localization of TRPVs in duck sperm indicate their respective functions relevant in fertilization process of avian sperm. These findings may also have commercial importance in poultry production, cryopreservation of sperm as well as conservation of endangered species through artificial insemination.