Description
The establishment of extraterrestrial multigenerational colonies of animals and humans requires the capability for sexual reproduction, and normal embryonic development is essential for producing healthy individuals. Early embryogenesis, including germ layer formation, axis establishment, and organogenesis (including gonad development), is highly sensitive to external stressors that may disrupt developmental processes and lead to developmental abnormalities or embryonic death. In the space environment, one of the most adverse factors affecting living organisms is cosmic radiation. Because high-energy protons constitute a major component of cosmic radiation, understanding their biological impact on early embryonic development is critical. The chicken embryo was used as a well-established vertebrate developmental model to evaluate the effects of proton irradiation on early embryos at stage X (blastoderm) and on embryos incubated for 24 hours. Early embryos were exposed to ~23 MeV protons at doses up to 3–4 Gy using the L3 ELIMAIA–ELIMED beamline. After irradiation, samples were cultured under controlled conditions for the required period and subsequently evaluated. This experiment represents our first irradiation study at the L3 ELIMAIA–ELIMED beamline using chicken embryos and served as a pilot investigation to familiarize the team with the ELIMAIA–ELIMED facility, optimize handling procedures, and identify technical constraints and troubleshooting requirements associated with irradiation, sample positioning, post-exposure culture conditions, and embryo post-processing. The study therefore provided essential operational experience in addition to biological observations. Biological response was primarily assessed by evaluating embryo viability, while analysis of cell death is currently ongoing to determine whether the applied doses induce programmed cell death in irradiated embryos. This pilot study forms part of the preparatory activities of the ZOE (Zero-gravity and Cosmic Radiation in-Orbit Embryogenesis) project under an ESA-STAR contract for the Czech Astronaut Mission, and the results contribute to defining radiation tolerance thresholds compatible with successful embryogenesis.
