著者

長沼 毅 岩月 輝希 小林 憲正

出版者

Japanese Society for Biological Sciences in Space

雑誌

宇宙生物科学 = Biological sciences in space (ISSN:09149201)

巻号頁・発行日

vol.19, no.1, pp.8-24, 2005-03-01

被引用文献数

1

著者

Mituo Ikenaga Isao Yoshikawa Moto Kojo Toshikazu Ayaki Haruko Ryo Kanji Ishizaki Tomohisa Kato Hanako Yamamoto Ryujiro Hara

出版者

Japanese Society for Biological Sciences in Space

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.11, no.4, pp.346-350, 1997 (Released:2006-02-01)

参考文献数

18

被引用文献数

40 50

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To examine the possible effects of space radiation on living organisms, fruit flies Drosophila melanogaster were loaded on the US Space Shuttle Endeavour, and after the flight we have analyzed two types of mutations, sex-linked recessive lethal mutations induced in male reproductive cells and somatic mutations which give rise to morphological changes in hairs growing on the surface of wing epidermal cells. Wild type strains and a radiation-sensitive strain mei-41 were used. The frequencies of sex-linked recessive lethal mutations in flight groups were 2 and 3 times higher for wild type Canton-S and mei-41 strains, respectively, than those in ground control groups. By contrast, the frequencies of wing-hair somatic mutations differed little between flight and control groups. The possibility that the space environment causes mutations in certain types of cells such as male reproductive cells, is discussed.

著者

Kazuma Emoto Yoshinori Takao Hitoshi Kuninaka

出版者

Japanese Society for Biological Sciences in Space

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.32, pp.1-5, 2018 (Released:2018-04-28)

参考文献数

13

被引用文献数

4

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We propose radiation shielding using Martian magnetic anomalies to protect human crews on the Martian surface. We have simulated the trajectories of energetic protons using the Buneman-Boris method to measure how magnetic anomalies affect the impact rate on the Martian surface. Protons from the west can be completely eliminated, while those from the east are concentrated on the area between the magnetic poles. This would mean crews would need to concern themselves about radiation from the vertex and east only. A Martian magnetic anomaly can therefore be used to realize continuous and efficient radiation shielding.

著者

Natsuhiro Takahashi Masamichi Takami Masahiro Chatani

出版者

Japanese Society for Biological Sciences in Space

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.35, pp.24-31, 2021 (Released:2021-09-01)

参考文献数

18

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Bones are important organs for body resistance against force produced by gravity, though the influence of gravity on bone development is unclear. To examine the effects of gravity on osteogenesis, medaka larvae were reared in water or gel under various conditions. For determining the effects on bone development in a state of motion, larvae were reared in water under normal gravity (1g) or hypergravity (5g) conditions. Also, to examine the direct effect of gravity on bone mineralization, larvae were embedded in low melting agarose gel containing alizarin complexone (ALC) and reared for three days under a normal gravity (1g), simulated-microgravity (s-μg) with use of a clinostat device, or 5g condition. Medaka reared in water under the 5g condition showed forward protruding jaws and spreading of the mineralized area of jaw teeth as compared to those reared under the 1g control condition. In addition, the direction of growth of the notochord in the fin region was changed upward in those reared under the 5g condition, accompanied by a part of acetylated tubulin-positive nerves also localized upward, while positive signals for DsRed, expressed by an osterix promoter, in osteoblasts were increased in the fin region. On the other hand, in medaka reared in gel, ALC signals in the fin ray of those in the s-μg condition were increased as compared to those in the 5g condition. Changes noted in medaka larvae over three days indicated osteogenesis adaptation to the specific gravity environment. The present results obtained with an experimental system are considered useful for examinations in the future regarding changes of osteogenesis, which will be needed to clarify the mechanism of the effects of gravity on bone development.

著者

Masamichi Yamashita Akemi Izumi-Kurotani Yoshihiro Mogami Makoto Okuno Tomio Naitoh Richard J. Wassersug

出版者

Japanese Society for Biological Sciences in Space

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.11, no.4, pp.313-320, 1997 (Released:2006-02-01)

参考文献数

32

被引用文献数

11 17

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The “Frog in Space” (FRIS) experiment marked a major step for Japanese space life science, on the occasion of the first space flight of a Japanese cosmonaut. At the core of FRIS were six Japanese tree frogs, Hyla japonica, flown on Space Station Mir for 8 days in 1990. The behavior of these frogs was observed and recorded under microgravity. The frogs took up a “parachuting” posture when drifting in a free volume on Mir. When perched on surfaces, they typically sat with their heads bent backward. Such a peculiar posture, after long exposure to microgravity, is discussed in light of motion sickness in amphibians. Histological examinations and other studies were made on the specimens upon recovery. Some organs, such as the liver and the vertebra, showed changes as a result of space flight; others were unaffected. Studies that followed FRIS have been conducted to prepare for a second FRIS on the International Space Station. Interspecific diversity in the behavioral reactions of anurans to changes in acceleration is the major focus of these investigations. The ultimate goal of this research is to better understand how organisms have adapted to gravity through their evolution on earth.

著者

Kenichi Ijiri

出版者

Japanese Society for Biological Sciences in Space

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.9, no.1, pp.3-16, 1995 (Released:2006-02-01)

被引用文献数

33 49

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The code name ‘MEDAKA’ was given to the fish experiment in the IML-2 (the second International Microgravity Laboratory), a Space-shuttle mission (STS-65) carried out in July 1994. Medaka is the Japanese name for a small fresh-water fish, Oryzias latipes. This experiment titled ‘Mating behavior of the fish Medaka and development of their eggs in space’ aimed to present data for designing the future fish-culture in space. The Medaka experiment accomplished its objectives to the point of 100 %. The fish mated, laid eggs in space, and these eggs developed normally to hatching (coming out as a baby fish) under microgravity. Its success totally depended on selection of the four fish sent to space. This paper describes the aims of the IML-2 Medaka fish experiment and how it was prepared, together with a brief report on what were achieved in space.

著者

Masahiro Chatani Aiko Mitsuhashi Yusuke Dodo Nobuhiro Sakai Masamichi Takami

出版者

Japanese Society for Biological Sciences in Space

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.33, pp.12-17, 2019 (Released:2019-09-10)

参考文献数

18

被引用文献数

3

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Teleost fish live under a constant force derived from gravity, with hard tissues playing important roles to help maintain body balance. However, the mechanism of hard tissue formation induced by gravity remains unclear. To examine the effects of gravity in aquatic animals, we performed experiments with medaka fish reared in a hypergravity environment, in which the force of gravity exceeded that present on the surface of the Earth, and analyzed hard tissue formation. Medaka fish were reared for 6 months under a normal gravitational force (1G) or that 5.29 times greater than normal (5.29G) using a centrifuge designated for small fish rearing. Micro-CT analysis results showed that hypergravity induced a vertebral curvature towards the dorsal side and asymmetric formation of otoliths in which the cross-sectional area was increased. Our findings indicate that the process of adaptation to a hypergravity environment results in spinal and otolith deformation in medaka fish.

著者

Yinjie Yang Shin-ichi Yokobori Akihiko Yamagishi

出版者

Japanese Society for Biological Sciences in Space

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.23, no.3, pp.151-163, 2009 (Released:2010-08-06)

参考文献数

133

被引用文献数

12 17

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Microbiology at the high altitude atmosphere is important for assessing the chances and limits of microbial transfer from the earth to extraterrestrial bodies. Among the microorganisms isolated from the high-atmospheric samples, spore formers and vegetative Deinococci were highly resistant against harsh environment at high altitude. From limited knowledge available to date, it is suggested that terrestrial microorganisms may have had chances to be ejected and transferred to outer space. Survival of these organisms during their space travel and proliferation on other planets might be also feasible. Directed Panspermia from Earth to extraterrestrial bodies is discussed on the basis of findings reported in literatures.

著者

Monika Fejtek Michel Delorme Richard Wassersug

出版者

Japanese Society for Biological Sciences in Space

雑誌

Biological Sciences in Space (ISSN:09149201)

巻号頁・発行日

vol.9, no.2, pp.77-81, 1995 (Released:2006-02-01)

参考文献数

18

被引用文献数

1 1

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As part of an ongoing survey of the behavioral responses of vertebrates to abrupt changes in gravity, we report here on the reactions of bats (Carollia perspicillata) exposed to altered gravity during parabolic aircraft flight. In microgravity, mammals typically behave as if they were upside-down and exhibit repetitive righting reflexes, which often lead to long axis rolling. Since bats, however, normally rest upside-down, we hypothesized that they would not roll in microgravity. Only one of three specimens attempted to fly during microgravity. None rolled or performed any righting maneuvers. During periods of microgravity the bats partially extended their forearms but kept their wings folded and parallel to the body. Between parabolas and occasionally during microgravity the bats groomed themselves. Both the extended limbs and autogrooming may be stress responses to the novel stimulus of altered gravity. This is the first behavioral record of Chiroptera in microgravity.