Biological Sciences in Space
Online ISSN : 1349-967X
Print ISSN : 0914-9201
ISSN-L : 0914-9201
16 巻, 4 号
選択された号の論文の2件中1~2を表示しています
  • Mami Sugano, Yoshio Ino, Teruko Nakamura
    2002 年 16 巻 4 号 p. 242-244
    発行日: 2002年
    公開日: 2006/01/31
    ジャーナル フリー
    The photosynthetic rate, the leaf characteristics related to photosynthesis, such as the chlorophyll content, chlorophyll ab ratio and density of the stomata, the leaf area and the dry weight in seedlings of Japanese flowering cherry grown under normal gravity and simulated microgravity conditions were examined. No significant differences were found in the photosynthetic rates between the two conditions. Moreover, leaf characteristics such as the chlorophyll content, chlorophyll ab ratio and density of the stomata in the seedlings grown under the simulated microgravity condition were not affected. However, the photosynthetic product of the whole seedling under the simulated microgravity condition increased compared with the control due to its leaf area increase. The results suggest that dynamic gravitational stimulus controls the partitioning of the products of photosynthesis.
  • 山下 雅道, 内藤 富夫, Wassersug Richard J.
    2002 年 16 巻 4 号 p. 245-270
    発行日: 2002年
    公開日: 2006/01/31
    ジャーナル フリー
    We review here the scientific significance of the use of amphibians for research in gravitational biology. Since amphibian eggs are quite large, yet develop rapidly and externally, it is easy to observe their development. Consequently amphibians were the first vertebrates to have their early developmental processes investigated in space. Though several deviations from normal embryonic development occur when amphibians are raised in microgravity, their developmental program is robust enough to return the organisms to an ostensibly normal morphology by the time they hatch. Evolutionally, amphibians were the first vertebrate animal to come out of the water and onto land. Subsequently they diversified and have adaptively radiated to various habitats. They now inhabit aquatic, terrestrial, arboreal and fossorial niches. This diversity can be used to help study the biological effects of gravity at the organismal level, where macroscopic phenomena are associated with gravitational loading. By choosing different amphibian models and using a comparative approach one can effectively identify the action of gravity on biological systems, and the adaptation that vertebrates have made to this loading. Advances in cellular and molecular biology provide powerful tools for the study in many fields, including gravitational biology, and amphibians have proven to be good models for studies at those levels as well. The low metabolic rates of amphibians make them convenient organisms to work with (compared to birds and mammals) in the difficult and confined spaces on orbiting research platforms. We include here a review of what is known about and the potential for further behavioral and physiological researches in space using amphibians.
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