In sac^MB11257 homozygous males, mature sperm fail to be loaded into the seminal vesicles (in 14 days old adults). There fewer and more abnormal actin cones. Immediately after meiosis there is increased mitochondrial aggregation. Onion stage spermatids show nuclei that are enlarged and of heterogeneous size. Elongation stage spermatids show abnormal axonemal plasma membrane in many cells; both the mitochondrial derivatives are small; there are fewer accessory microtubules associated with the minor derivative.