Genetic Diversity Affects the Daily Transcriptional Oscillations of Marine Microbial Populations

Marine microbial communities are genetically diverse but have robust synchronized daily transcriptional patterns at the genus level that are similar across a wide variety of oceanic regions. We developed a microarray-inspired gene-centric approach to resolve transcription of closely-related but distinct strains/ecotypes in high-throughput sequence data. Applying this approach to the existing metatranscriptomics datasets collected from two different oceanic regions, we found unique and variable patterns of transcription by individual taxa within the abundant picocyanobacteria Prochlorococcus and Synechococcus, the alpha Proteobacterium Pelagibacter and the eukaryotic picophytoplankton Ostreococcus. The results demonstrate that marine microbial taxa respond differentially to variability in space and time in the ocean. These intra-genus individual transcriptional patterns underlie whole microbial community responses, and the approach developed here facilitates deeper insights into microbial population dynamics.

海洋微生物群落虽具有丰富的遗传多样性，但在属水平上呈现出稳定且同步的每日转录模式，且该模式在各类海洋区域中均保持相似。我们开发了一种受基因芯片（microarray）技术启发的以基因为中心的研究方法，用于解析高通量测序数据中亲缘关系相近但功能型各异的菌株/生态型的转录情况。将该方法应用于从两个不同海洋区域采集的现有宏转录组学（metatranscriptomics）数据集后，我们发现丰度较高的超微型蓝细菌原绿球藻（Prochlorococcus）、聚球藻（Synechococcus），α-变形菌门的远洋杆菌属（Pelagibacter），以及真核超微型浮游植物奥氏藻（Ostreococcus）中，各分类单元的转录模式兼具独特性与变异性。研究结果表明，海洋微生物类群对海洋环境的空间与时间变异存在差异化响应。这些属内个体特异性转录模式构成了整个微生物群落响应的基础，而本研究开发的分析方法有助于更深入地解析微生物种群动态。