Experiment

Objective

Although the best method to investigate the effect of space environment on mammalian cells is to actually breed small animals, such as mice, in the ISS for a long period of time, it is not feasible from the perspective of the time, effort, and equipment required. Accordingly, Professor Takashi Morita and Associate Professor Kayo Yoshida plan to examine the effects of time spent in space on embryonic stem (ES) cells, a type of pluripotent cells.

ES cells are useful in analyzing chromosome aberrations because they have normal chromosomes. Like fertilized embryonic cells in the early developmental stage, ES cells also have the potential to differentiate into various cell types. The ES cells make it possible to examine the early developmental processes of cells and to implant an embryo into the uterus of a pseudopregnant mouse to produce a mouse pup (Figure 1). The results obtained from this experiment will be useful for developmental experiments and estimation of the influence of time spent in space on the next generation, which are difficult to determine in human beings. We also aim to improve the estimation of the health risks attendant on long-term stays in space, development of safety standards, and development of protective measures.

Figure 1 Mouse ES cells and development after microinjection (implanted on Earth)