Experiment

Increasingly evident effects of a long-term culture in the space environment on Medaka fish genes

An experiment rearing Medaka fish* (Oryzias latipes) was conducted for two months from October 2012 in the Aquatic Habitat (AQH) on the Japanese Experiment Module ("Kibo") of the International Space Station (ISS). The research intends to clarify the mechanisms of bone metabolism in microgravity.

* Effect of microgravity on osteoclasts and analysis of the gravity sensing system in medaka (Medaka osteoclast)

Principal Investigator (PI): Akira Kudo, Professor, Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology

The results of the study have been published in an academic journal by the Tokyo Institute of Technology and JAXA.^*1 This time, another joint research group headed by Professor Hiroshi Mitani of Tokyo University and Professor Shuji Terai of Niigata University analyzed the gene expression of medaka cultured on the ISS, with the results being published in PLOS ONE, ^*2 a U.S. scientific journal.

The team conducted a comprehensive analysis of the six kinds of tissues in juvenile medaka cultured on the ISS for two months, and found that multiple genes are expressed differently than those on the ground. In addition, some genes showed common expression changes in all tissues cultured on the ISS.

Finding how such changes in gene expression occur will help prevent or solve health problems that astronauts may face during prolonged space travel.

*1 Microgravity promotes osteoclast activity in medaka fish reared on the International Space Station Scientific Reports, 21 September 2015

*2 Histological and Transcriptomic Analysis of Adult Japanese Medaka Sampled Onboard the International Space Station PLOS ONE, October 1, 2015

*All times are Japan Standard Time (JST)