The melanized yeast Exophiala dermatitidis is resistant to many environmental stresses and is used as a model for understanding the diverse roles of melanin in fungi. Here, we describe the extent of resistance of E. dermatitidis to acute γ-radiation exposure and the major mechanisms it uses to recover from this stress. We find that melanin does not protect E. dermatitidis from γ-radiation. Instead, environmental factors such as nutrient availability, culture age and culture density are much greater determinants of cell survival after exposure. We also observe a dramatic transcriptomic response to γ-radiation that mobilizes pathways involved in morphological development, protein degradation and DNA repair, and is unaffected by the presence of melanin. Together, these results suggest that the ability of E. dermatitidis to survive γ-radiation exposure is determined by the prior and the current metabolic state of the cells as well as DNA repair mechanisms, and that small changes in these conditions can lead to large effects in radiation resistance, which should be taken into account when understanding how diverse fungi recover from this unique stress.

中文翻译：

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变黑的酵母皮肤病外来酵母对γ射线辐射的响应。

黑色素化的酵母皮肤癣菌对许多环境压力具有抵抗力，并被用作了解黑色素在真菌中的多种作用的模型。在这里，我们描述了皮炎埃希氏菌对急性γ辐射暴露的抵抗程度以及它用来从这种压力中恢复的主要机制。我们发现黑色素不能保护皮肤炎埃希氏菌免受γ辐射。取而代之的是，诸如养分利用率，培养年龄和培养密度等环境因素是暴露后细胞存活的更大决定因素。我们还观察到了对γ辐射的戏剧性转录反应，该反应调动了参与形态发育，蛋白质降解和DNA修复的途径，并且不受黑色素的影响。综合起来，这些结果表明了E的能力。