自然界典型微生物群落一般由少量丰富种和大量稀少种构成。丰富种基于丰度优势，通常在能量流动和物质循环中起重要作用，历来被认为是生态系统的重要组成部分。近年来，随着高通量测序技术的发展，逐渐揭示出海洋微生物群落中稀少种也具备重要生态功能。另一方面，丰富种和稀少种子群落由于内在物种组成差异，构建机制可能不同。

黄邦钦教授团队以东海和南海的微微型真核浮游生物群落为研究对象，采用454高通量测序技术，揭示了这两大边缘海上层水体中微微型真核生物丰富种与稀少种子群落差异性分布模式。在表层水体，丰富种较多受到扩散限制，而稀少种较多受到环境过滤影响；在次表层水体，二者均较少体现环境过滤，而较多受到扩散限制影响。此外，丰富种和稀少种子群落均显示出明显季节性差异分布模式。

该成果展示了微微型真核生物不同功能类群的差异性群落构建机制，近期发表在Environmental Microbiology期刊。第一作者为吴文学博士，黄邦钦教授和台湾大学海洋研究所谢志豪教授为共同通讯作者。

Principal coordinate analysis (PCoA) of abundant and rare sub-communities in the surface (A and B) and subsurface (C and D) layers using an unweighted UniFrac distance metric. The results are based on the average of 100 bootstraps.

Abstract:

In this work, they compared patterns of abundant and rare picoeukaryotic sub-communities in the epipelagic waters (surface and 40–75 m depth subsurface layers) of the East and South China Seas across seasons via 454 pyrosequencing of the V4 region of 18S rDNA. They also examined the relative effects of environmental filtering, dispersal limitations, and seasonality on community assembly. Their results indicated that (i) in the surface layer, abundant taxa are primarily influenced by dispersal limitations and rare taxa are primarily influenced by environmental filtering, whereas (ii) in the subsurface layer, both abundant and rare sub-communities are only weakly influenced by environmental filtering but are strongly influenced by dispersal limitations. Moreover, (iii) abundant taxa exhibit stronger temporal variability than rare taxa. They also found that abundant and rare sub-communities display similar spatial richness patterns that are negatively correlated with latitude and chlorophyll a and positively correlated with temperature. In summary, environmental filtering and dispersal limitations have different effects on abundant and rare picoeukaryotic sub-communities in different layers. Thus, depth appears as an essential variable that governs the structuring patterns of picoeukaryotic communities in the oceans and should be thoroughly considered to develop a more comprehensive understanding of oceanic microbial assemblages.

Reference:

Wu W, Logares R, Huang B, Hsieh C. (2017). Abundant and rare picoeukaryotic sub-communities present contrasting patterns in the epipelagic waters of marginal seas in the northwestern Pacific Ocean. Environ Microbiol, 19: 287–300.

Link:

http://onlinelibrary.wiley.com/doi/10.1111/1462-2920.13606/abstract