Gura Colby, Rogers Scott O
Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA.
Biology (Basel). 2020 Mar 16;9(3):55. doi: 10.3390/biology9030055.
A combined metatranscriptomic and metagenomic study of Vostok (Antarctica) ice core sections from glacial, basal, and lake water accretion ice yielded sequences that indicated a wide variety of species and possible conditions at the base of the glacier and in subglacial Lake Vostok. Few organisms were in common among the basal ice and accretion ice samples, suggesting little transmission of viable organisms from the basal ice meltwater into the lake water. Additionally, samples of accretion ice, each of which originated from water in several locations of the shallow embayment, exhibit only small amounts of mixing of species. The western-most portion of the embayment had very low numbers of organisms, likely due to biologically challenging conditions. Increasing numbers of organisms were found progressing from west to east, up to approximately 7 km into the embayment. At that point, the numbers of unique sequences and sequence reads from thermophilic, thermotolerant, psychrophilic, and psychrotolerant organisms increased dramatically, as did sequences from alkaliphilic, alkalitolerant, acidophilic, and acidotolerant sequences. The number of unique and total sequences were positively associated with increases in concentrations of Na, Ca, Mg, SO, Cl, total amino acids, and non-purgeable organic carbon. The numbers of unique sequences from organisms reported from soil, sediment, ice, aquatic, marine, animal, and plant (probably pollen) sources also peaked in this region, suggesting that this was the most biologically active region. The confluence of the high numbers of organisms, physiologies, and metabolic capabilities suggests the presence of energy and nutrient sources in the eastern half of the embayment. Data from the main basin suggested a cold oligotrophic environment containing fewer organisms. In addition to bacteria, both the basal ice and accretion ice contained sequences from a diverse assemblage of eukaryotes, as well as from bacteria that are known to be associated with multicellular eukaryotes.
对来自沃斯托克（南极洲）冰芯不同部分（冰川冰、底部冰和湖水堆积冰）进行的宏转录组学和宏基因组学联合研究，得到了一系列序列，这些序列揭示了冰川底部和沃斯托克湖下存在的多种物种以及可能的环境状况。底部冰和堆积冰样本中共同存在的生物很少，这表明活生物体从底部冰融水进入湖水的传播很少。此外，堆积冰样本（每个样本都源自浅湾几个位置的水）仅显示出少量的物种混合。浅湾最西部的生物体数量非常少，可能是由于生物学上具有挑战性的条件。从西向东，随着进入浅湾约7公里，发现的生物体数量不断增加。此时，嗜热、耐热、嗜冷和耐冷生物体的独特序列和序列读数数量急剧增加，嗜碱、耐碱、嗜酸和耐酸序列的数量也急剧增加。独特序列和总序列的数量与钠、钙、镁、硫酸根、氯、总氨基酸和不可吹扫有机碳浓度的增加呈正相关。来自土壤、沉积物、冰、水生、海洋、动物和植物（可能是花粉）来源的生物体的独特序列数量在该区域也达到峰值，这表明该区域是生物活性最高的区域。大量生物体、生理特征和代谢能力的汇聚表明，浅湾东半部存在能量和营养源。主盆地的数据表明存在一个寒冷的贫营养环境，生物体较少。除细菌外，底部冰和堆积冰都包含来自多种真核生物以及已知与多细胞真核生物相关的细菌的序列。
