title: Manipulation of fish germ cell: visualization, cryopreservation and transplantation.
abstract: Germ-cell transplantation has many applications in biology and animal husbandry, including investigating the complex processes of germ-cell development and differentiation, producing transgenic animals by genetically modifying germline cells, and creating broodstock systems in which a target species can be produced from a surrogate parent. The germ-cell transplantation technique was initially established in chickens using primordial germ cells (PGCs), and was subsequently extended to mice using spermatogonial stem cells. Recently, we developed the first germ-cell transplantation system in lower vertebrates using fish PGCs and spermatogonia. During mammalian germ-cell transplantation, donor spermatogonial stem cells are introduced into the seminiferous tubules of the recipient testes. By contrast, in the fish germ-cell transplantation system, donor cells are microinjected into the peritoneal cavities of newly hatched embryos; this allows the donor germ cells to migrate towards, and subsequently colonize, the recipient genital ridges. The recipient embryos have immature immune systems, so the donor germ cells can survive and even differentiate into mature gametes in their allogeneic gonads, ultimately leading to the production of normal offspring. In addition, implanted spermatogonia can successfully differentiate into sperm and eggs, respectively, in male and female recipients. The results of transplantation studies in fish are improving our understanding of the development of germ-cell systems during vertebrate evolution.
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Okutsu
authors.forename: Ayaka
authors.initials: A
authors.lastname: Yano
authors.forename: Kazue
authors.initials: K
authors.lastname: Nagasawa
authors.forename: Shinya
authors.initials: S
authors.lastname: Shikina
authors.forename: Terumasa
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Goro
authors.initials: G
authors.lastname: Yoshizaki
mesh_terms: D000818:Animals; D001709:Biotechnology / Q000379:methods; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D005260:Female; D005854:Germ Cells / Q000502:physiology* / Q000637:transplantation*; D008297:Male; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000502:physiology*; D030781:Organisms, Genetically Modified / Q000235:genetics / Q000502:physiology