Understanding the effects of chronic exposure to pollutants over generations is of primary importance for the protection of humans and the environment; however, to date, knowledge on the molecular mechanisms underlying multigenerational adverse effects is scarce. We employed a systems biology approach to analyze effects of chronic exposure to gamma radiation at molecular, tissue and individual levels in the nematode Caenorhabditis elegans. Our data show a decrease of 23% in the number of offspring on the first generation F0 and more than 40% in subsequent generations F1, F2 and F3. To unveil the impact on the germline, an in-depth analysis of reproductive processes involved in gametes formation was performed for all four generations. We measured a decrease in the number of mitotic germ cells accompanied by increased cell-cycle arrest in the distal part of the gonad. Further impact on the germline was manifested by decreased sperm quantity and quality. In order to obtain insight in the molecular mechanisms leading to decreased fecundity, gene expression was investigated via whole genome RNA sequencing. The transcriptomic analysis revealed modulation of transcription factors, as well as genes involved in stress response, unfolded protein response, lipid metabolism and reproduction. Furthermore, a drastic increase in the number of differentially expressed genes involved in defense response was measured in the last two generations, suggesting a cumulative stress effect of ionizing radiation exposure. Transcription factor binding site enrichment analysis and the use of transgenic strain identified daf-16/FOXO as a master regulator of genes differentially expressed in response to radiation. The presented data provide new knowledge with respect to the molecular mechanisms involved in reproductive toxic effects and accumulated stress resulting from multigenerational exposure to ionizing radiation.

了解几代人长期接触污染物的影响对于保护人类和环境至关重要；然而，迄今为止，关于多代不良影响背后的分子机制的知识很少。我们采用系统生物学方法分析长期暴露于伽马辐射对线虫秀丽隐杆线虫分子、组织和个体水平的影响. 我们的数据显示，第一代 F0 的后代数量减少了 23%，随后的 F1、F2 和 F3 代减少了 40% 以上。为了揭示对生殖系的影响，对所有四代都进行了对配子形成所涉及的生殖过程的深入分析。我们测量了有丝分裂生殖细胞数量的减少，伴随着性腺远端细胞周期停滞的增加。对生殖系的进一步影响表现为精子数量和质量的下降。为了深入了解导致生育力下降的分子机制，通过全基因组 RNA 测序研究了基因表达。转录组学分析揭示了转录因子以及参与应激反应、未折叠蛋白反应、脂质代谢和繁殖的基因的调节。此外，在最后两代中测量到参与防御反应的差异表达基因的数量急剧增加，表明电离辐射暴露的累积压力效应。转录因子结合位点富集分析和转基因菌株的使用将 daf-16/FOXO 鉴定为响应辐射而差异表达的基因的主要调节因子。所提供的数据提供了关于涉及生殖毒性效应和多代电离辐射暴露累积压力的分子机制的新知识。转录因子结合位点富集分析和转基因菌株的使用将 daf-16/FOXO 鉴定为响应辐射而差异表达的基因的主要调节因子。所提供的数据提供了关于涉及生殖毒性效应和多代电离辐射暴露累积压力的分子机制的新知识。转录因子结合位点富集分析和转基因菌株的使用将 daf-16/FOXO 鉴定为响应辐射而差异表达的基因的主要调节因子。所提供的数据提供了关于涉及生殖毒性效应和多代电离辐射暴露累积压力的分子机制的新知识。