title: A novel stage-specific antigen is expressed only in early stages of spermatogonia in Japanese eel, Anguilla japonica testis.
abstract: We produced an antibody that recognized only early stages of spermatogonia in Japanese eel testis. This antibody (anti-spermatogonia-specific antigen-1, anti-SGSA-1) recognized a band of about 38 kDa in Western blot analysis of extracts from eel testis. This antigen was observed by immunohistochemistry only in type-A and early type-B spermatogonia and could not be seen in the late type-B spermatogonia, which appeared after the initiation of spermatogenesis by a single injection of human chorionic gonadotropin. Immunoreactive SGSA-1 was absent in spermatocytes, spermatids, spermatozoa, Sertoli cells, and interstitial Leydig cells. Similarly, this antigen was also detected only in type-A/primary spermatogonia in the testes of two species of teleosts, medaka (Oryzias latipes) and tilapia (Oreochromis niloticus), as well as a toad (Xenopus laevis). These results imply that the disappearance of SGSA-1 in late type-B/secondary spermatogonia is a critical step in the progression of spermatogenesis, and indicate that anti-SGSA-1 is a useful marker for analysis of the molecular mechanism controlling the differentiation of spermatogonia in lower vertebrates.
authors.affiliation: Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: H
authors.initials: H
authors.lastname: Kajiura-Kobayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Nagahama
mesh_terms: D000595:Amino Acid Sequence; D000811:Anguilla / Q000276:immunology*; D000818:Animals; D007106:Immune Sera / Q000276:immunology; D016256:Lewis X Antigen / Q000032:analysis / Q000276:immunology*; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D013091:Spermatogenesis / Q000276:immunology; D013093:Spermatogonia / Q000254:growth & development / Q000276:immunology*; D013252:Steroid 11-beta-Hydroxylase / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D013737:Testis / Q000276:immunology*; D017210:Tilapia; D014982:Xenopus laevis
chemical_list: D007106:Immune Sera; D016256:Lewis X Antigen; D010446:Peptide Fragments; D013252:Steroid 11-beta-Hydroxylase