SPATA6 and Abnormal sperm morphology: Ablation of Spata6 (spermatogenesis-associated 6 gene) completely disrupts formation of the connecting piece, leading to acephalic spermatozoa and male sterility in mice.87, 88 Interaction between SPATA6 and myosin light and heavy chain subunits (e.g., MYL6) strongly suggests that SPATA6 is involved in myosin-based microfilament transport during connecting piece formation.88 Further identification of spermatid-specific factors that control the connection of the sperm head and tail and mutation screening in human teratozoospermia patients remain to be investigated.