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Direct Evidence for the Presence of Germ Cell Determinant in Vegetal Pole Cytoplasm of Xenopus laevis and in a Subcellular Fraction of It
Author(s) -
IKENISHI KOHJI,
NAKAZATO SAKIKO,
OKUDA TAKASHI
Publication year - 1986
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1986.00563.x
Subject(s) - xenopus , cytoplasm , biology , neurula , embryo , tadpole (physics) , blastomere , somatic cell , microbiology and biotechnology , germ plasm , salientia , polarity in embryogenesis , cell , notochord , anatomy , embryogenesis , genetics , gastrulation , physics , particle physics , gene
To test for the presence of germ cell determinant in Xenopus embryos, vegetal pole cytoplasm containing the “germ plasm”, or a subcellular fraction of it, was microinjected into single somatic blastomeres isolated from 32‐cell embryos. Injected or non‐injected (control) blastomeres were cultured in 3 H‐thymidine until normal control embryos reached the neurula stage. The labeled explants were then implanted into unlabeled host neurulae, which were allowed to develop to the tadpole stage. Labeled PGCs of explant origin in the genital ridges of the experimental tadpoles were examined by autoradiography. Isolated blastomeres were injected with vegetal pole cytoplasm of 32‐cell embryos or with a 20,000 g pellet made from vegetal pole cytoplasm of 2‐cell embryos. Labeled PGCs were found in 7.6% and 2.3% of the experimental tadpoles, respectively. No labeled PGCs were found in the control tadpoles, except for one tadpole in the first experiment. These results strongly suggest that the vegetal pole cytoplasm and its subcellular fractions act as germ cell determinant.