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C. elegans flight experiment using Chinese recovery satellite was carried out September 2006. This flight experiment was conducted by Chinese research team composed of researchers of Beihang university, and C. elegans samples recovered from space were shared with Chinese and Japanese research teams. There was no problem in survival of C. elegans and the population size of worms was increased four to five times during spaceflight. However we need environmental data of worms culture, especially temperature log both in-flight and in-transit for control experiment, and then we are now making a request for the monitoring log data to Chinese research team and proceeding with the preparations for analysis.

The space environment contains two main biologically important factors, i.e. space radiations and microgravity. Space radiations are well known to contain heavy particles which induce serious damage in organisms with high relative biological effectiveness as compared with low LET (Linear Energy Transfer) radiations such as X-rays and gamma-rays. Therefore, study of the biological effects of space radiations is very important when we aim to stay long term in space. In 2005, we organized the WG of 'the study of biological effects by space radiations in ISS (International Space Station)' including radiation biologists and physicists in Japan. We discussed the next stage of space experiments. On the other hand PI of this WG will carry out of space experiment 'RadGene' program in 2008. In 'RadGene' program, the PI propose to investigate the gene expression of p53-regulated genes in mammalian cultured cells (human lymphoblastoid TK6 cells carrying wild-type p53 and WTK1 cells, a sub-clone of TK6 carrying mutant p53) after exposure to space environment. The tumor suppressor gene product p53 is generally thought to contribute to the genetic stability of DNA (DeoxyriboNucleic Acid)-damaged cells through p53-centered signal transduction pathways. Then, the members of this WG will discuss the additional experiments using 'RadGene' samples. We expect that the data from this proposal will contribute to protect biological and physiological effects for human body from space radiations during long stays in space.

すでにこの研究グループはすでに宇宙飛行したラットの皮膚には癌抑制遺伝子p53の産物が誘導されること、また宇宙飛行した金魚のいくつかの臓器においてストレスタンパク質遺伝子HSP72の産物が誘導されていることを知った。そこで「培養細胞・個体での各種環境変化によるストレスタンパク質・癌関連遺伝子の形質発現誘導とそのしくみ」を明らかにすることを目的とした。, NASDA Special Publication, 宇宙開発事業団特別報告

Accepted: 2006-03-27