ABSTRACT: During evolution, microorganisms exposed to high amounts of UV-B irradiation developed fine-tuned photo-enzymes called ‘photolyases’ to cope with DNA damage caused by UV-B. These photoreceptors, belonging to the cryptochrome/photolyase family (CPF), have been well characterized at the genomic and proteomic level in bacteria isolated from a wide range of environments. In this work, we go further towards studying the abundance of CPF in aquatic microbial communities from different geographic regions across the globe. Metagenomics data combined with geo-referenced solar irradiation measurements indicated that the higher the UV-B level in the microbiome’s environment, the higher the abundance of CPF genes and lower the microbial diversity. A connection between CPF abundance and radiation intensity/photoperiod was found. Likewise, cryptochrome-like genes were found to be abundant in most exposed microbiomes, indicating a complementary role to standard photolyases. We observed that CPFs are more likely to be present in dominant taxa of the highly irradiated microbiomes, suggesting an evolutionary force for survival and dominance under extreme solar exposure. This work reports 3 novel CPF clades, proving the potential of global metagenomic analyses in detecting novel proteins.

中文翻译：

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在暴露于多种UV-B方式的水生生物群落中发现隐色素/光解酶基因多样性

摘要：在进化过程中，暴露于大量UV-B辐射的微生物形成了微调的光酶，称为“光解酶”，以应对UV-B引起的DNA损伤。这些属于隐色染料/光裂解酶家族（CPF）的感光细胞，在从广泛的环境中分离出的细菌中，在基因组和蛋白质组学水平上都得到了很好的表征。在这项工作中，我们将进一步研究来自全球不同地理区域的水生微生物群落中CPF的丰度。元基因组学数据与地理参考太阳辐射测量结果相结合，表明微生物组环境中的UV-B含量越高，CPF基因的丰度越高，微生物多样性越低。发现CPF丰度与辐射强度/光周期之间存在联系。同样 发现隐色样基因在大多数暴露的微生物群落中含量丰富，表明与标准光裂解酶具有互补作用。我们观察到，CPFs更有可能出现在高度辐射的微生物群落的主要类群中，这表明在极端阳光照射下生存和优势的进化力。这项工作报告了3个新颖的CPF进化枝，证明了全球宏基因组学分析在检测新颖蛋白中的潜力。