title: Lymphocyte antigen 75 (Ly75/CD205) is a surface marker on mitotic germ cells in rainbow trout.
abstract: In mammals, several cell surface molecular markers have been characterized in order to identify the mitotic germ cells. However, little is known in fish about their cell surface antigen. In this study, we identified lymphocyte antigen 75 (Ly75/CD205) as a germ cell-specific cell surface marker by combination expressed sequence tag analysis of purified type A spermatogonia (A-SG) from immature testis, in silico prediction of membrane proteins, and expression studies. The ly75 transcripts were abundant in the testis and gills, and weak signals were detected in the head kidney and brain. In addition, ly75 mRNA was predominantly localized in the primordial germ cells of newly hatched embryos, A-SG in testis, oogonia, and chromatin nucleolus-stage oocytes in the ovary. In contrast, ly75 mRNA was not detected in spermatocytes, spermatids, spermatozoa, vitellogenic oocytes, or gonadal somatic cells from either males or females. The expression profile of Ly75 protein was similar to that of the mRNA. Furthermore, identification of various fish homologs of ly75 confirmed that their amino acid sequences are well conserved. Therefore, Ly75 may be appropriate for use as a versatile cell surface marker for mitotic germ cells in fish.
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan.
authors.forename: Kazue
authors.initials: K
authors.lastname: Nagasawa
authors.forename: Shinya
authors.initials: S
authors.lastname: Shikina
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Goro
authors.initials: G
authors.lastname: Yoshizaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D015152:Blotting, Northern / Q000662:veterinary; D003001:Cloning, Molecular; D005260:Female; D005819:Genetic Markers; D007150:Immunohistochemistry; D017403:In Situ Hybridization / Q000662:veterinary; D037181:Lectins, C-Type / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D015778:Minor Histocompatibility Antigens; D008938:Mitosis / Q000502:physiology; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism* / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D013093:Spermatogonia / Q000378:metabolism* / Q000502:physiology
chemical_list: D015703:Antigens, CD; C093569:DEC-205 receptor; D005819:Genetic Markers; D037181:Lectins, C-Type; D015778:Minor Histocompatibility Antigens; D012333:RNA, Messenger; D011956:Receptors, Cell Surface