A precise understanding of differences in genomic mutations according to the mutagenic mechanisms detected in mutagenicity data is required to evaluate the carcinogenicity of environmental mutagens. Recently, we developed a highly accurate genome sequencing method, ‘Hawk-Seq™’, that enables the detection of mutagen-induced genome-wide mutations. However, its applicability to detect various mutagens and identify differences in mutational profiles is not well understood. Thus, we evaluated DNA samples from Salmonella typhimurium TA100 exposed to 11 mutagens, including alkylating agents, aldehydes, an aromatic nitro compound, epoxides, aromatic amines and polycyclic aromatic hydrocarbons (PAHs). We extensively analysed mutagen-induced mutational profiles and studied their association with the mechanisms of mutagens. Hawk-Seq™ sensitively detected mutations induced by all 11 mutagens, including one that increased the number of revertants by approximately 2-fold in the Ames test. Although the sensitivity for less water-soluble mutagens was relatively low, we increased the sensitivity to obtain high-resolution spectra by modifying the exposure protocol. Moreover, two epoxides indicated similar 6- or 96-dimensional mutational patterns; likewise, three SN1-type alkylating agents indicated similar mutational patterns, suggesting that the mutational patterns are compound category specific. Meanwhile, an SN2 type alkylating agent exhibited unique mutational patterns compared to those of the SN1 type alkylating agents. Although the mutational patterns induced by aldehydes, the aromatic nitro compound, aromatic amines and PAHs did not differ substantially from each other, the maximum total base substitution frequencies (MTSFs) were similar among mutagens in the same structural groups. Furthermore, the MTSF was found to be associated with the carcinogenic potency of some direct-acting mutagens. These results indicate that our method can generate high-resolution mutational profiles to identify characteristic features of each mutagen. The detailed mutational data obtained by Hawk-Seq™ can provide useful information regarding mutagenic mechanisms and help identify its association with the carcinogenicity of mutagens without requiring carcinogenicity data.

中文翻译：

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Hawk-Seq™ 可区分由暴露于 Ames 测试阳性诱变剂引起的鼠伤寒沙门氏菌 TA100 菌株的各种突变

需要根据诱变数据中检测到的诱变机制准确了解基因组突变的差异，以评估环境诱变剂的致癌性。最近，我们开发了一种高度准确的基因组测序方法“Hawk-Seq™”，可以检测诱变剂诱导的全基因组突变。然而，它在检测各种诱变剂和识别突变谱差异方面的适用性尚不清楚。因此，我们评估了暴露于 11 种诱变剂的鼠伤寒沙门氏菌 TA100 的 DNA 样本，包括烷化剂、醛类、芳香族硝基化合物、环氧化物、芳香胺和多环芳烃 (PAH)。我们广泛分析了诱变剂诱导的突变谱，并研究了它们与诱变剂机制的关联。Hawk-Seq™ 敏感地检测到由所有 11 种诱变剂诱导的突变，其中一种在 Ames 测试中将回复体的数量增加了大约 2 倍。尽管对水溶性较差的诱变剂的敏感性相对较低，但我们通过修改曝光协议提高了获得高分辨率光谱的敏感性。此外，两个环氧化物显示出相似的 6 维或 96 维突变模式。同样，三种 SN1 型烷化剂显示出相似的突变模式，表明突变模式是化合物类别特异性的。同时，与SN1 型烷化剂相比，SN2 型烷化剂表现出独特的突变模式。尽管由醛、芳香族硝基化合物引起的突变模式，芳香胺和多环芳烃之间没有显着差异，最大总碱基取代频率（MTSFs）在相同结构组的诱变剂中相似。此外，发现 MTSF 与某些直接作用的诱变剂的致癌效力有关。这些结果表明，我们的方法可以生成高分辨率突变谱来识别每种诱变剂的特征。Hawk-Seq™ 获得的详细突变数据可以提供有关诱变机制的有用信息，并有助于确定其与诱变剂致癌性的关联，而无需致癌性数据。发现 MTSF 与某些直接作用的诱变剂的致癌效力有关。这些结果表明，我们的方法可以生成高分辨率突变谱来识别每种诱变剂的特征。Hawk-Seq™ 获得的详细突变数据可以提供有关诱变机制的有用信息，并有助于确定其与诱变剂致癌性的关联，而无需致癌性数据。发现 MTSF 与某些直接作用的诱变剂的致癌效力有关。这些结果表明，我们的方法可以生成高分辨率突变谱来识别每种诱变剂的特征。Hawk-Seq™ 获得的详细突变数据可以提供有关诱变机制的有用信息，并有助于确定其与诱变剂致癌性的关联，而无需致癌性数据。