With the development of deep-space exploration and long-term manned missions, understanding the effects of space environments on life and reproductive health has become increasingly important. Whether very low-dose radiation affects early embryonic development in mammals, and how to mitigate such risks, remain critical questions in space life sciences.

A study published in Space: Science & Technology and led by LEI Xiaohua's team from the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences uncovered how chronic, extremely low-dose ionizing radiation—simulating deep-space conditions—harms early embryonic development in mice, and proposed a dual-target intervention strategy.

Researchers demonstrated that chronic low-dose radiation adversely impacts embryonic development. In vitro, mouse one-cell embryos exposed to a cumulative 2 mGy dose exhibited impaired blastocyst development and abnormal expression of genes associated with oxidative stress and developmental regulation. In vivo, pregnant mice exposed to a cumulative 10 mGy dose gave birth to offspring with reduced litter size, lower birth weight, and shorter body length.

Moreover, researchers found that the intervention with apocynin, an NADPH oxidase inhibitor, combined with vitamin C effectively alleviated developmental defects and partially reversed associated molecular abnormalities, which highlights the pivotal role of oxidative stress and epigenetic modifications.

These findings indicate that chronic, extremely low-dose ionizing radiation cannot be considered harmless and exerts a dose-dependent effect on early embryonic development.

The work provides crucial evidence for assessing reproductive risks in space, protecting astronautic fertility, and guiding the development of effective countermeasures. It also offers insights for evaluating reproductive safety in terrestrial contexts involving low-dose radiation exposure.