Home ＞GCOE Researchers ＞Tetsuya HIGASHIYAMA

GCOE Researchers

Tetsuya HIGASHIYAMA

Affiliation
/Position		 Graduate School of Science, Division of Biological Science, Professor
Doctorate Doctor of Science
Research interests Plant molecular cell biology, intercellular signaling in plant reproduction
address higashi＠bio.nagoya-u.ac.jp
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+81-52-747-6404
  Laboratory

Outline of research

Among biological phenomena, reproduction is one of the most intriguing events. Higher plants have evolved a unique reproduction mechanism called double fertilization. Double fertilization is not only a fascinating and sophisticated biological phenomenon, but is also directly important to human beings, for example, in crop production. Its molecular mechanism, however, is not well understood. Our laboratory seeks to clarify the key molecular events required to achieve reproduction in plants, and thus to elucidate universal biological mechanisms pertaining to intercellular communication, heredity and development.

One major focus of our group has been our contribution to the search for the "pollen tube attractant," which has been underway for over 140 years. By ablating individual cells using a micro-laser, we demonstrated that pollen tube attractant definitely exists, and that two cells (called synergid cells) located next to the egg cell secrete the attractant. These results, which were published in the journal Science, attracted global attention and led to a race to find the attractant. Our research group succeeded in identifying potential candidates by analyzing molecules from individual synergid cells picked from Torenia fournieri. We are currently trying to conclusively verify candidate molecules, using a laser microinjector specifically designed for this purpose. How is the pollen tube guidance prevailing nano-machines and control of elongation direction of pollen tube achieved? Following the discovery of the key players responsible for pollen tube guidance and the development of such novel microscopic cell manipulation and imaging techniques, we believe that pollen tube guidance could someday be understood as an integrated complex system.

References

  1. Berger F. et al. (2008) Double fertilization - caught in the act. Trends Plant Sci., 13: 437-443.
  2. Higashiyama T., & Hamamura Y. (2008) Gametophytic pollen tube guidance. Sex. Plant Reprod., 21: 17-26.
  3. Ingouff M. et al. (2007) Distinct dynamics of HISTONE3 variants between the two fertilization products in plants. Curr. Biol., 17: 1032-1037.
  4. Mori T. et al. (2006) GENERATIVE CELL SPECIFIC 1 is essential for angiosperm fertilization. Nat. Cell Biol., 8: 64-71.
  5. Nishimura Y. et al. (2006) Active digestion of sperm mitochondrial DNA in single living sperm revealed by optical tweezers. Proc. Natl. Acad. Sci. USA, 103: 1382-1387.
  6. Higashiyama T. et al. (2006) Species preferentiality of he pollen tube attractant derived from the synergid cell of Torenia fournieri. Plant Physiol., 142: 481-491.
  7. Matsuzaki M. et al. (2004) Genome sequence of the ultra-small unicellular red alga Cyanidioschyzon merolae 10D. Nature, 428: 653-657.
  8. Sasaki N. et al. (2003) Glom is a novel mitochondrial DNA packaging protein in Physarum polycephalum and causes intense chromatin condensation without suppressing DNA functions. Mol. Biol. Cell, 14: 4758-4769.
  9. Nishimura Y. et al. (2002) An mt+ gamete-specific nuclease that targets mt- chloroplasts during sexual reproduction in C. reinhardtii. Genes Dev., 16: 1116-1128.
  10. Higashiyama T. et al. (2001) Pollen tube attraction by the synergid cell. Science, 293: 1480-1483.

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