Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China.
Appl Microbiol Biotechnol. 2020 May;104(9):4043-4057. doi: 10.1007/s00253-020-10464-8. Epub 2020 Mar 6.
Heavy-ion beam (HIB) irradiation has been widely used in microbial mutation breeding. However, a global cellular response to such radiation remains mostly uncharacterised. In this study, we used transcriptomics to analyse the damage repair response in Saccharomyces cerevisiae following a semi-lethal HIB irradiation (80 Gy), which induced a significant number of DNA double-strand breaks. Our analysis of differentially expressed genes (DEGs) from 50 to 150 min post-irradiation revealed that upregulated genes were significantly enriched for gene ontology and Kyoto encyclopaedia of genes and genomes terms related to damage repair response. Based on the number of DEGs, their annotation, and their relative expression, we established that the peak of the damage repair response occurred 75 min post-irradiation. Moreover, we exploited the data from our recent study on X-ray irradiation-induced repair to compare the transcriptional patterns induced by semi-lethal HIB and X-ray irradiations. Although these two radiations have different properties, we found a significant overlap (> 50%) for the DEGs associated with five typical DNA repair pathways and, in both cases, identified homologous recombination repair (HRR) as the predominant repair pathway. Nevertheless, when we compared the relative enrichment of the five DNA repair pathways at the key time point of the repair process, we found that the relative enrichment of HRR was higher after HIB irradiation than after X-ray irradiation. Additionally, the peak stage of HRR following HIB irradiation was ahead of that following X-ray irradiation. Since mutations occur during the DNA repair process, uncovering detailed repair characteristics should further the understanding of the associated mutagenesis features.
重离子束（HIB）辐照已广泛应用于微生物诱变育种。然而，这种辐射对细胞的整体反应在很大程度上仍未被描述。在这项研究中，我们使用转录组学分析了酿酒酵母在半致死 HIB 辐照（80 Gy）后的损伤修复反应，该辐照诱导了大量的 DNA 双链断裂。我们对辐照后 50 至 150 分钟的差异表达基因（DEGs）进行分析，结果表明，上调基因在与损伤修复反应相关的基因本体论和京都基因与基因组百科全书术语中显著富集。基于 DEGs 的数量、注释和相对表达水平，我们确定损伤修复反应的峰值出现在辐照后 75 分钟。此外，我们利用我们最近关于 X 射线辐照诱导修复的研究数据，比较了半致死 HIB 和 X 射线辐照诱导的转录模式。尽管这两种辐射具有不同的特性，但我们发现与五种典型 DNA 修复途径相关的 DEGs 有很大的重叠（>50%），并且在两种情况下，都发现同源重组修复（HRR）是主要的修复途径。然而，当我们比较修复过程关键时间点的五种 DNA 修复途径的相对富集程度时，我们发现 HRR 在 HIB 辐照后的相对富集程度高于 X 射线辐照后。此外，HIB 辐照后 HRR 的峰值阶段早于 X 射线辐照后。由于突变发生在 DNA 修复过程中，因此揭示详细的修复特征应该有助于进一步了解相关的诱变特征。
