Probable E3 ubiquitin-protein ligase involved in either protein trafficking or in the distribution of cellular structures. Required for spermatozoon maturation and fertility, and for the removal of the cytoplasmic droplet of the spermatozoon. E3 ubiquitin-protein ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfer it to targeted substrates. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Protein modification; protein ubiquitination. Ubiquitously expressed, highest expression is found in testis during spermiogenesis. It is specifically found in spermatogonia, spermatocytes, and spermatids with little or no expression detectable in the spermatozoa, or interstitial cells. Highly expressed in testis during spermiogenesis. Expression was almost undetectable in testes at postnatal day 14 (P14). However, by P23, a strong increase in mRNA levels was observed with expression persisting to P40 when spermatozoa were first observed. Up-regulated in the uterine luminal epithelium at the time of embryo implantation. Disruption causes defects in spermatozoon maturation and impaired fertility in males; females display normal fertility. Males produce litter sizes some 50% smaller, as well 50% of mature spermatozoa have reduced mobility. T.wilfordii induces abnormal expression of spermiogenesis genes including Herc4, the spermatogenic cells in the convoluted seminiferous tubules decrease and the lumen is obstructed by large deciduous spermatogenic cells. T.wilfordii has apparent antifertility effects.