Homozygous mutants are viable and female fertile, but male sterile.

Mutant males do no have gross defects in testis organisation or spermatid elongation, but they have empty seminal vesicles, indicating defects in spermiogenesis. The waste bag that is normally formed from cytoplasm discarded at the distal end of spermatids as the individualisation complex moves along the developing spermatid is completely absent in mutant testes. The investment cones form normally above spermatid nuclei in mutant testes, however, the nuclei fail to remain tightly clustered and are displaced distally along the cyst. Although investment cones progress away from the nuclei in the mutant testis, investment cone coupling within individualisation complexes is lost and cones never progress the full length of the mutant spermatids.