Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea; Department of Social Informatics, Kyoto University, Kyoto, Japan
Kibum Nam
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
Byeong Eun Lee
Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
Yundon Jeong
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
Seunghun Lee
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
Jeongmo Kim
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
In most murine species, spermatozoa exhibit a falciform apical hook at the head end. The function of the sperm hook is not yet clearly understood. In this study, we investigate the role of the sperm hook in the migration of spermatozoa through the female reproductive tract in Mus musculus (C57BL/6), using a deep tissue imaging custom-built two-photon microscope. Through live reproductive tract imaging, we found evidence indicating that the sperm hook aids in the attachment of spermatozoa to the epithelium and facilitates interactions between spermatozoa and the epithelium during migration in the uterus and oviduct. We also observed synchronized sperm beating, which resulted from the spontaneous unidirectional rearrangement of spermatozoa in the uterus. Based on live imaging of spermatozoa-epithelium interaction dynamics, we propose that the sperm hook plays a crucial role in successful migration through the female reproductive tract by providing anchor-like mechanical support and facilitating interactions between spermatozoa and the female reproductive tract in the house mouse.
