Huang Jiao-Mei, Wang Yong
Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hai Nan, China; University of Chinese Academy of Sciences, Beijing, China.
Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hai Nan, China.
Mar Genomics. 2020 Apr;50:100699. doi: 10.1016/j.margen.2019.100699. Epub 2019 Jul 10.
Marinimicrobia are widespread from the marine surface to the hadal zone. Major clades of Marinimicrobia have evolved to different ecotypes along with energy gradients, but their genomes in deeper waters and sediments have rarely been studied. Here we obtained 11 Marinimicrobia draft genomes from the water column in the full-ocean depth and the hadal sediments in the Mariana Trench. All the predicted genomic capabilities of the metagenome-assembled genomes (MAGs) are indicative of heterotrophic lifestyle. The MAGs from the hadal depths are distinct from those from the mesopelagic and bathypelagic depths by enrichment of the genes involved in amino acids metabolism and mismatch repair. Compared with the MAGs from waters, those from the sediments were dramatically expanded by acquiring the genes responsible for chemotaxis, mobility and the two-component systems. Marinimicrobia were apparently differentiated in the environments with different depths, organic matters and electronic acceptors. Our results also posit a potential evolutionary relationship between the species inhabiting the waters and sediments, indicating the occurrence of allopatric speciation in Marinimicrobia.
海生微生物在从海洋表层到超深渊带广泛分布。海生微生物的主要进化枝已随着能量梯度演化为不同的生态型，但其在更深水域和沉积物中的基因组鲜有研究。在此，我们从全球海洋深度的水柱和马里亚纳海沟的超深渊沉积物中获得了11个海生微生物草图基因组。所有宏基因组组装基因组（MAG）预测的基因组功能均表明其为异养生活方式。超深渊深度的MAG与中层和深层中层深度的MAG不同，其参与氨基酸代谢和错配修复的基因有所富集。与来自水体的MAG相比，来自沉积物的MAG通过获得负责趋化性、移动性和双组分系统的基因而显著扩展。海生微生物在不同深度、有机物和电子受体的环境中明显分化。我们的结果还提出了栖息于水体和沉积物中的物种之间潜在的进化关系，表明海生微生物中发生了异域物种形成。
