[Embryo Rad]
Life time heritable effect of space radiation on mouse germ cells and embryos preserved for a long-term in ISS

RESEARCH OVERVIEW

• One of major concerns of human health during prolonged stay in space environment, such as a space station increment or manned exploration-class Mission, is carcinogenic and trans-generational effects after exposure to the space radiation.
• In order to study the influence of the space radiation on the whole human body, mouse embryos are installed in ISS for a long duration stay in a frozen condition. After return to Earth, they are thawed and allowed to develop and to live throughout their lifetime. The mice are then studied for longevity, cancer development, and mutations in their genes (chromosome aberration and point mutations).
• Several mice strains are used, including wild-type, DNA-repair-deficient mice, and cancer prone knockout mice. The DNA damages to the mice induced by the space radiation is then studied, which can be detected during fetal stage and after birth. The study of whole body effects by the space radiation using mice as a model is an indispensable means of providing the basic radiation exposure data for humans.

DESCRIPTION

One of the major concerns of human health during prolonged stay in space environment, such as long duration manned flight beyond low earth orbit, or a stay in a space station, is carcinogenesis and trans-generational effects after exposure to space radiation. Therefore, the study of the effects of space radiation on the whole body using mice is an indispensable means to provide the basic data for humans. However, at present mice cannot be launched to ISS. To research for whole body effect, researchers suggest a new system is proposed that utilizes frozen embryos of mice. Consequently, the following approaches are planned in present study to clarify the influence of the space radiation.

1. Mouse embryos are stored on the ISS for a certain period of time in a frozen condition. After return to Earth, the embryos are unfrozen to generate “Space mice” and be allowed to live their lives. Then, longevity, cancer development, and the gene mutations (chromosome aberration and point mutations) are analyzed. As a control group, ‘Earth mice” will be set, of which embryos are kept under an equal condition within ISS.
2. Several mice strains are to be used, including wild-type, DNA-repair-deficient mice and cancer prone knockout mice.
3. Since methods have already established for cancer analysis, it is possible to complete most of studies, except lifespan, within one year after returning to Earth.
4. The consequences of the DNA damage induced by space radiation are to be analyzed, and can be detected during fetal stage and after birth.

SPACE APPLICATIONS

Results from the Embryo Rad investigationcan help scientists better understand how space radiation exposure could cause cancer, and it allows a unique way to study potential trans-generational effects of the radiation exposure. The investigation helps researchers determine radiation exposure risk, and it can be used to design new radiation protection measures for future space missions.

EARTH APPLICATIONS

Radiation is frequently applied in therapeutic settings, especially for treatment of cancer. Proton and neutron therapies, which use particles to target cancer cells, is increasingly common. But little is known about the secondary cancer risk that may result from exposure to high-energy particles. Studying the potential cancer risk from space-based radiation, which includes high-energy particles from the sun and deep space, could help scientists to better understand the risks involved in ground-based radiation therapy.

OPERATIONAL REQUIREMENTS AND PROTOCOLS

Cold Stowage requirement: Embryo Rad Sample Case stored at -95°C until return.

Please provide temperature data of On-orbit.

The Embryo Rad Sample Case containing Mouse embryos is set to launch at -95°C on SpaceX.

The Sample Case should be kept at -95°C in MELFI on board for about 6 months. On board operation is only to keep samples at-95°C in MELFI.

The Sample Case should be returned at -95°C on SpaceX.