Effects of Selected Environmental Agents on Biodiversity: A Case Study of Ionizing Radiation

摘要

The biological effects of ionizing radiation have been a focal point of research interest after the discovery of X ray more than a century ago. However, the effects of ionizing radiation on host-associated microbiota, especially in the contaminated zones following nuclear accidents, remain largely unknown. This dissertation aims to examine the impact of ionizing radiation on different layers of biodiversity -- species, genes, ecosystems, and their interactions, with a focus on the gut microbiome. First of all, gut microbiome profiles from a range of wild animal hosts were gathered and comparatively analyzed, providing insights into key factors that could influence the gut microbiome diversity in natural populations. Secondly, mutational effects of ionizing radiation were evaluated with meta-analysis, and potential factors that may influence the effects of ionizing radiation on the genetic material were examined. Finally, a working model depicting effects of ionizing radiation on the gut microbiota was established, elucidating host-commensal interactions in the gut micro-ecosystem, providing a theoretical framework for studying ionizing radiation and its impact on the host-microbial consortia. The present study also proposes a future research effort in exploring certain intestinal microbes as biomarkers of radiation exposure, with application to the subject of wild animals.