Selenium (Se) is an essential trace element for many organisms, which is required in the biosynthesis of proteins with selenocysteine, tRNAs with selenouridine, and certain enzymes with Se as a cofactor. Recent large-scale metagenomics projects provide a unique opportunity for studying the global trends of Se utilization in marine environments. Here, we analyzed samples from different marine microbial communities, revealed by the Tara Oceans project, to characterize the Se utilization traits. We found that the selenophosphate synthetase gene, which defines the overall Se utilization, and Se utilization traits are present in all samples. Regions with samples rich and poor in Se utilization traits were categorized. From the analysis of environmental factors, the mesopelagic zone and high temperature (> 15°C) of water are favorable, while geographical location has little influence on Se utilization. All Se utilization traits showed a relatively independent occurrence. The taxonomic classification of Se traits shows that most of the sequences corresponding to Se utilization traits belong to the phylum Proteobacteria. Overall, our study provides useful insights into the general features of Se utilization in ocean samples and may help to understand the evolutionary dynamics of Se utilization in different marine environments.

中文翻译：

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不同海洋环境中硒利用性状的比较基因组分析

硒（Se）是许多生物必不可少的微量元素，这是生物合成含硒代半胱氨酸的蛋白质，含硒基尿苷的tRNA和含硒作为辅因子的某些酶的生物合成所必需的。最近的大规模宏基因组学项目为研究海洋环境中硒利用的全球趋势提供了独特的机会。在这里，我们分析了塔拉海洋项目揭示的来自不同海洋微生物群落的样本，以表征硒的利用特征。我们发现硒磷酸盐合成酶基因（定义了总体硒利用）和硒利用特性均存在于所有样品中。对样品中硒利用特性丰富和较差的区域进行了分类。从环境因素的分析来看，水的近中生带和高温（> 15°C）是有利的，地理位置对硒的利用影响不大。所有硒利用特征均表现出相对独立的发生。硒性状的分类学分类表明，与硒利用性状相对应的大多数序列都属于门氏杆菌属。总体而言，我们的研究为海洋样品中硒利用的一般特征提供了有用的见解，并可能有助于了解不同海洋环境中硒利用的演变动态。