MYH14 and Abnormal sperm morphology: The sperm head and tail are bridged by the connecting piece, which not only serves as a physical linkage but also participates in sperm motility.77, 78 ‘Decapitated sperm', or ‘acephalic sperm', a type of human teratozoospermia, refers to the condition in which the ejaculate contains mostly sperm tails without heads.79, 80, 81 To date, several proteins that interact with myosin (an actin-based motor protein) have been reported to contribute to the connection between the sperm head and tail (Figure 3; left).