著者
薮田 ひかる
出版者
生命の起原および進化学会
雑誌
Viva Origino (ISSN:09104003)
巻号頁・発行日
vol.36, no.2, pp.20-43, 2008 (Released:2022-01-18)
参考文献数
128

This review (in Japanese) highlights the results on the Stardust mission organics preliminary examination of the returned Comet 81P/Wild 2 particles, based on the Science article published in December 15, 2006. The recent developments of studies on organics in chondritic meteorites and/or interstellar dust particles using modern instruments are also described for seeking relations of organic characteristics among the three extraterrestrial samples. In addition, potential chemistry for which cometary and meteoritic organics were responsible as a source of exogenous delivery to the early Earth is discussed.
著者
山岸 明彦 矢野 創 小林 憲正 横堀 伸一 橋本 博文 山下 雅道 田端 誠 河合 秀幸
出版者
生命の起原および進化学会
雑誌
Viva Origino (ISSN:09104003)
巻号頁・発行日
vol.36, no.4, pp.72-76, 2008 (Released:2022-01-18)
参考文献数
23

たんぽぽ(蒲公英,dandelion)は綿毛のついた種子を風に乗せて頒布し,その生息域を広げる多年草である.我々は,この名前のもと,国際宇宙ステーション-JEM(日本実験棟)上での微生物と生命材料となり得る有機化合物の天体間の移動の可能性の検討と微小隕石の検出および解析実験を提案する.我々は,超低密度エアロゲルを用いることで,微小隕石やその他の微粒子を捕集することが可能であると考えている.低軌道上で超低密度エアロゲルを一定期間曝露することで宇宙空間で微粒子を捕集する.エアロゲル表面と衝突トラックの顕微観察の後,エアロゲルの様々な解析を行う.衝突トラックの詳細な検討により,国際宇宙ステーション周辺のデブリのサイズと速度が明らかにできると期待される.エアロゲル中に残存した粒子に関して,鉱物学的,有機化学的,及び微生物学的な検討を行う.一方,宇宙環境下での微生物の生存可能性について検討するため,微生物を直接宇宙空間に曝露する実験も行う.同様に,宇宙環境下での有機化合物の変性の可能性を検討するため,有機化合物の宇宙空間への直接曝露実験も行う.これらの実験を行うための装置はすべて受動的な装置であり,そのための装置の基本構造,装置回収後の解析法も,既に確立されている.
著者
布村 渉
出版者
一般社団法人 日本血液学会
雑誌
臨床血液 (ISSN:04851439)
巻号頁・発行日
vol.57, no.7, pp.933-943, 2016 (Released:2016-08-05)
参考文献数
50

地球が誕生して46億年,地球上に原始生命体が登場してから約38億年の歴史からすれば,Homo sapiens(ヒト属ヒト)の繁栄十数万年は点ほどにしかならない。原始的な生命体の営みによって地球上に酸素がもたらされ,多くの生物は酸素を利用することで,より効率のよいエネルギー産生系を確立してきた。好気的呼吸をする生物にとって酸素は不可欠であり,酸素運搬の担い手である赤血球は,その進化と共に機能や形状を巧みに変化させてきた。私達の興味は,哺乳類だけが他の脊椎動物と異なりエネルギーを使って核を放出すること,つまり,脱核することにある。生物の進化は偶然の重なりの結果であるが,その偶然によって子孫を残すに至ったことには相応の意味があるはずだ。赤芽球の脱核のメカニズムと生物学的意義について,進化学的視点に立ち,哺乳類と恐竜類が共に進化した中生代約2億年とヒトの赤芽球・赤血球の知見を統合して考察したい。
著者
小林 憲正
出版者
生命の起原および進化学会
雑誌
Viva Origino (ISSN:09104003)
巻号頁・発行日
vol.36, no.4, pp.77-82, 2008 (Released:2022-01-18)
参考文献数
34

A great number of experiments have been done to examine possible prebiotic formation of bioorganic compounds such as amino acids in possible primitive environments. There are two scenario of prebiotic formation of bioorganic compounds: An endogenous formation scenario and an exogenous formation scenario. The latter scenario was supported by the facts that a wide variety of organic compounds were detected in meteorites and comets. It is now suggested that organic compounds in extraterrestrial bodies were originally formed in extremely cold environments such as in molecular clouds. Laboratory experiments showed that complex precursors of amino acids could be formed from simulated interstellar media by irradiation with high-energy particles. It was suggested that such extraterrestrial organic compounds were delivered mainly by cosmic dusts. We have, however, very limited information on organic compounds in cosmic dusts since they are captured within terrestrial environments. We proposed a novel astrobiology mission “Tanpopo” by utilizing the international space station. In the mission, cosmic dusts will be collected with ultra-low-density aerogel, and organic compounds in them will be analyzed. In the mission, organic compounds simulating extraterrestrial organics will be directly exposed to solar ultraviolet light and cosmic rays at the same time to study the fate of organic compounds in cosmic dusts near the Earth orbit.
著者
小池 惇平
出版者
生態工学会
雑誌
CELSS JOURNAL (ISSN:09154353)
巻号頁・発行日
vol.8, no.1, pp.27-32, 1995-09-30 (Released:2010-12-16)
参考文献数
11

We have studied on the ability of living organisms to survive under simulated extraterrestrial condition. The subject is not restricted to an academic curiosity, but concerns problems to prevent the contamination of extraterrestrial circumstance with terrestrial microorganisms carried by spaceprobes. Some species of terrestrial microorganisms can survive even after the exposure under a simulated space conditions.Samples of microb were harvested from air and wall surface in Mir station by Progress M-26 on Feb. 15, 1995. The population of microorganisms and resistace to proton radiation by accelerator and ultra violet were examined.
著者
山岸 明彦
出版者
生命の起原および進化学会
雑誌
Viva Origino (ISSN:09104003)
巻号頁・発行日
vol.49, no.2, pp.6, 2021 (Released:2021-11-25)
参考文献数
87

In my college age, I read the Japanese translation of “The Origin of Life” written by Oparin, though understood a little. During graduate school and postdoctoral position in Japan and USA, I started the research experience in the field of photosynthesis. After returning back to Japan, I started the research career in Tokyo Institute of Technology, where I started the research on the structure of genomic DNA of archaebacteria. We analyzed the characteristics of the last universal common ancestor, which we named Commonote commonote, and found that the species was hyper-thermophilic, based on the experimental results obtained by reproducing an enzyme possessed by C. commonote, in Tokyo University of Pharmacy and Life Sciences. Then, we started the research on microbiota in deep see hydrothermal system as well as high atmosphere. Later, we started the space experiment Tanpopo on the International Space Station. The research field is now called Astrobiology.   There are ample of research results related to the RNA-origin of life. The ribonucleotides were produced nonbiologically in aqueous media by a reaction process with drying steps. The ribonucleotides were polymerized without biological catalyst. RNA-replicating ribozyme with the length of 200 nucleotides capable of replicating 200-nucleotide-long template has been reported. The process from the protocell containing self-replicating ribozyme surrounded by lipid membrane to the last universal common ancestor Commonote commonote is proposed.