Summary. One of the major events that characterize spermiogenenesis is the formation of the acrosome. Acrosome-less spermatozoa are infertile; in human, globozoospermia is a rare but severe disorder in male infertility. The acrosome formation is far more complicated than has been so far proposed. Here we address attention to the ubiquitin-dependent protein/vesicle sorting during acrosomogenesis, with a particular focus to the early endosome compartment and retrograde traffic. The acrosome shares features with lysosome-related organelles (LROs), the biogenesis of which employs a common machinery whose genetic defects can affect all LROs or only an individual LRO. The Wobbler mouse, an animal mutant characterized by motor neuron disorders and male infertility