KRT5 and Globozoospermia: Acroplaxome is a cytoskeletal scaffold that contains F-actin and Keratin 5, which anchors the developing acrosome to the nuclear envelope,35 and acroplaxome formation defects also cause the malformation of the acrosome and globozoospermia.35, 36, 37 The expression of Keratin 5 was analyzed by immunofluorescence.