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Takashi Okamoto


Ph.D. in Science, Department of Biological Sciences, Tokyo Metropolitan University, 1998

Current position

Professor, Department of Biological Sciences, Tokyo Metropolitan University, Japan

Publications (since 2005)

  1. Ohnishi, Y. and Okamoto, T. (2015). Karyogamy in rice zygotes: Actin filament-dependent migration of sperm nucleus, chromatin dynamics, and de novo gene expression. Plant Signal Behav 10(2): e989021.
  2. Ohnishi, Y., Hoshino, R. and Okamoto, T. (2014). Dynamics of male and female chromatin during karyogamy in rice zygotes. Plant Physiol 165(4): 1533-1543.
  3. Abiko, M., Furuta, K., Yamauchi, Y., Fujita, C., Taoka, M., Isobe, T. and Okamoto, T. (2013). Identification of proteins enriched in rice egg or sperm cells by single-cell proteomics. PLoS One 8(7): e69578.
  4. Abiko, M., Maeda, H., Tamura, K., Hara-Nishimura, I. and Okamoto, T. (2013). Gene expression profiles in rice gametes and zygotes: identification of gamete-enriched genes and up- or down-regulated genes in zygotes after fertilization. J Exp Bot 64(7): 1927-1940.
  5. Okamoto, T. (2011). In vitro fertilization with isolated rice gametes: production of zygotes and zygote and embryo culture. Methods Mol Biol 710: 17-27.
  6. Ohnishi, T., Takanashi, H., Mogi, M., Takahashi, H., Kikuchi, S., Yano, K., Okamoto, T., Fujita, M., Kurata, N. and Tsutsumi, N. (2011). Distinct gene expression profiles in egg and synergid cells of rice as revealed by cell type-specific microarrays. Plant Physiol 155(2): 881-891.
  7. Takeuchi, K., Gyohda, A., Tominaga, M., Kawakatsu, M., Hatakeyama, A., Ishii, N., Shimaya, K., Nishimura, T., Riemann, M., Nick, P., Hashimoto, M., Komano, T., Endo, A., Okamoto, T., Jikumaru, Y., Kamiya, Y., Terakawa, T. and Koshiba, T. (2011). RSOsPR10 expression in response to environmental stresses is regulated antagonistically by jasmonate/ethylene and salicylic acid signaling pathways in rice roots. Plant Cell Physiol 52: 1686–1696.
  8. Okamoto, T. (2010). Gamete fusion site on the egg cell and autonomous establishment of cell polarity in the zygote. Plant Signal Behav 5(11): 1464-1467.
  9. Nakajima, K., Uchiumi, T. and Okamoto, T. (2010). Positional relationship between the gamete fusion site and the first division plane in the rice zygote. J. Exp. Bot. 61: 3101-3105.
  10. Sato, A., Toyooka, K. and Okamoto, T. (2010). Asymmetric cell division of rice zygotes located in embryo sac and produced by in vitro fertilization. Sex Plant Reprod 23(3): 211-217.
  11. Uchiumi, T. and Okamoto, T. (2010). Rice fruit development is associated with an increased IAA content in pollinated ovaries. Planta 232: 579-592.
  12. Takanashi, H., Ohnishi, T., Mogi, M., Okamoto, T., Arimura, S. and Tsutsumi, N. (2010). Studies of mitochondrial morphology and DNA amount in the rice egg cell. Curr Genet 56(1): 33-41.
  13. Wang, S. and Okamoto, T. (2009). Involvement of polypyrimidine tract-binding protein (PTB)-related proteins in pollen germination in Arabidopsis. Plant Cell Physiol 50(2): 179-190.
  14. Kranz, E., Hoshino, Y. and Okamoto, T. (2008). In vitro fertilization with isolated higher plant gametes. Methods Mol Biol 427: 51-69.
  15. Uchiumi, T., Uemura, I. and Okamoto, T. (2007). Establishment of an in vitro fertilization system in rice (Oryza sativa L.). Planta 226(3): 581-589.
  16. Uchiumi, T., Shinkawa, T., Isobe, T. and Okamoto, T. (2007). Identification of the major protein components of rice egg cells. J Plant Res 120(4): 575-579.
  17. Uchiumi, T., Komatsu, S., Koshiba, T. and Okamoto, T. (2006). Isolation of gametes and central cells from Oryza sativa L. Sex Plant Reprod. 19: 37-45.
  18. Okamoto, T., Scholten, S., Lörz, H. and Kranz, E. (2005). Identification of genes that are up- or down-regulated in the apical or basal cell of maize two-celled embryos and monitoring their expressions during zygote development by a cell manipulation- and PCR-based approach. Plant Cell Physiol 46: 332-338.
Protocols by Takashi Okamoto
  1. Microscopic Observation, Three-dimensional Reconstruction, and Volume Measurements of Sperm Nuclei