title: Failure to assemble the peri-nuclear structures in GOPC deficient spermatids as found in round-headed spermatozoa.
abstract: Deletion of the GOPC gene encoding mouse GOPC (Golgi-associated PDZ- and coiled-coil motif-containing protein) causes infertile round-headed spermatozoa, which have acrosome-less round heads and deformed tails (Yao et al, 2002). This study investigated how GOPC deficient spermatids fail to assemble the peri-nuclear structures in round-headed spermatozoa during spermiogenesis in GOPC knockout mouse testes. In step 1-8 spermatids, Golgi-derived proacrosomal vesicles that are transported to the perinuclear region formed acrosome-like vesicles of various sizes, called pseudoacrosomes. The marginal ring of the acroplaxome, which is generally formed between the descending edge of a developing acrosome and nuclear envelope in a wild spermatid, was poorly formed between the pseudoacrosome and nuclear envelope. In step 9-11 elongating spermatids, a majority of pseudoacrosomes were detached from the nucleus and disappeared from the perinuclear region by spermiation. Concomitantly, several failures occurred on the nucleus, manchette, postacrosomal sheath (perinuclear theca), and posterior ring. Ectoplasmic specializations were poorly formed, and did not always associate with developing spermatids. Consequently, spermatid nuclear elongation to form round-headed spermatozoa developed was impaired. In addition to these sequential failures, the posterior ring deficiency was attributed to the tail deformation destined to occur during epididymal maturation as reported in an accompanying paper (Suzuki-Toyota et al, 2004 in this issue), its eventual phenotype being reminiscent of the round-headed spermatozoa of human infertile globozoospermia.
authors.affiliation: Department of Anatomy and Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Chizuru
authors.initials: C
authors.lastname: Ito
authors.forename: Fumie
authors.initials: F
authors.lastname: Suzuki-Toyota
authors.forename: Mamiko
authors.initials: M
authors.lastname: Maekawa
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Toyama
authors.forename: Ryoji
authors.initials: R
authors.lastname: Yao
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Noda
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Toshimori
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D002467:Cell Nucleus / Q000648:ultrastructure*; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D000077614:Golgi Matrix Proteins; D007150:Immunohistochemistry; D007248:Infertility, Male / Q000209:etiology; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D008954:Models, Biological; D010503:Periodic Acid-Schiff Reaction; D013087:Spermatids / Q000648:ultrastructure*; D013091:Spermatogenesis; D013094:Spermatozoa / Q000002:abnormalities* / Q000648:ultrastructure*; D013737:Testis / Q000166:cytology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D000077614:Golgi Matrix Proteins; C435484:Gopc protein, mouse; D047908:Intracellular Signaling Peptides and Proteins