Defects in spermiogenesis in Sam68−/− testis. Motility is impaired in spermatozoa from Sam68 knockout mice (∼50% of the animals tested). The few Sam68−/− spermatozoa that maintained reduced motility in culture were completely infertile even under in vitro fertilization conditions. Images were taken from an inverted microscope (DMI6000B; Leica) using a Pan-Neofluar 40×/0.75 objective lens. Images were acquired at room temperature using an RT-slider camera (Diagnostic Instruments, Inc.) and LIF software (Leica). The display rate is 5 frames per second.
