• 1
    Dixon, K. E., 1981. The origin of the primordial germ cells in the Amphibia. Netherlands J. Zool., 31, 537.
  • 2
    Humphrey, R. R., 1925. The primordial germ cells of Hemidactylium and other Amphibia. J. Morph. Physiol., 41, 143.
  • 3
    Ijiri, K. and N. Egami, 1975. Mitotic activity of germ cells during normal development of Xenopus laevis tadpoles. J. Embryol. exp. Morph., 34, 687694.
  • 4
    Ikenishi, K., M. Kotani and K. Tanabe, 1974. Ultrastructural changes associated with UV irradiation in the ‘germinal plasm’ of Xenopus laevis. Develop. Biol., 36, 155168.
  • 5
    Ikenishi, K. and M. Kotani, 1979. Ultraviolet effects on presumptive primordial germ cells (pPGCs) in Xenopus laevis after the cleavage stage. Develop. Biol., 69, 237246.
  • 6
    Ikenishi, K., T. Okuda and S. Nakazato, 1984. Differentiation of presumptive primordial germ cell (pPGC)-like cells in explants into PGCs in experimental tadpoles. Develop. Biol., 103, 258262.
  • 7
    Ikenishi, K., K. Itoh and M. Furusawa, 1992. Subcellular localization and molecular nature of the no. 48 antigen found in Xenopus germ plasm by fluorescence microscopy. Zool. Sci., 9, 1187.
  • 8
    Kamimura, M., K. Ikenishi, M. Kotani and T. Matsuno, 1976. Observations on the migration and proliferation of gonocytes in Xenopus laevis. J. Embryol. exp. Morph., 36, 197207.
  • 9
    Kotani, M., K. Ikenishi and K. Tanabe, 1973. Cortical granules remaining after fertilization in Xenopus laevis. Develop. Biol., 30, 228232.
  • 10
    Kotani, M., K. Ikenishi, E. Torii, E. Amemiya and M. Kadowaki, 1994. Comparison of the number of primordial germ cells and the total volume of germinal granules between the periodic albino and the wild type of Xenopus laevis. Bull. Osaka Women's Univ., 31, 115.
  • 11
    Nakazato, S. and K. Ikenishi, 1989. Monoclonal antibody production against a subcellular fraction of vegetal pole cytoplasm containing the germ plasm of Xenopus 2-cell eggs. Cell Differ. Develop., 27, 163174.
  • 12
    Nieuwkoop, P. D. and J. Faber, 1967. “Normal Table of Xenopus laevis (Daudin),” 2nd ed. North-Holland, Amsterdam .
  • 13
    Smith, L. D., 1966. The role of a ‘germinal plasm’ in the formation of primordial germ cells in Rana pipiens. Develop. Biol., 14, 330347.
  • 14
    Smith, L. D. and M. A. Williams, 1979. Germinal plasm and germ cell determinants in anuran amphibians. In Maternal Effects in Development: British Society for Developmental Biology, Symposium 4 (Eds. D. R.Newth and M.Balls), pp. 167197. Cambridge University Press, Cambridge .
  • 15
    Subtelny, S, 1980. Migration and replication of the germ cell line in Rana pipiens. In Differentiation and Neoplasia, (Eds. R. D.McKinnel, M. A.DiBerardino, M.Blumenfeld and R. D.Bergad), pp. 157165. Springer, Berlin , Heidelberg , New York .
  • 16
    Tanabe, K. and M. Kotani, 1974. Relationship between the amount of the germinal plasm and the number of primordial germ cells in Xenopus laevis. J. Embryol. exp. Morph., 31, 8993.
  • 17
    Thomas, J., J. Heasman, C, Ford, D. Nagajski and C. C. Wylie, 1983. Further analysis of the effect of ultra-violet irradiation on the formation of the germ line in Xenopus laevis. J. Embryol. exp. Morph., 76, 6781.
  • 18
    Williams, M. A. and L. D. Smith, 1984. Ultravioletirradiation of Rana pipiens embryos delays the migration of primordial germ cells into the genital ridges. Differentiation., 26, 220226.
  • 19
    Wylie, C. C., J. Heasman, A. Snape, M. O'Driscoll and S. Holwill, 1985. Primordial germ cells of Xenopus laevis are not irreversibly determined early in development. Develop. Biol., 112, 6672.
  • 20
    Züst, B. and K. E. Dixon, 1975. The effect of u.v. irradiation of the vegetal pole of Xenopus laevis eggs on the presumptive primordial germ cells. J. Embryol. exp. Morph., 34, 209220.
  • 21
    Züst, B. and K. E. Dixon, 1977. Events in the germ cell lineage after entry of the primordial germ cells into the genital ridges in normal and UV-irradiated Xenopus laevis. J. Embryol. exp. Morph., 41, 3346.