Center for Environmental Diagnostics and Bioremediation, University of West Florida, 11000 University Parkway, Bldg 58. Rm70, Pensacola, FL, 32514, USA.
Virginia Institute of Marine Science Eastern Shore Laboratory, 40 Atlantic Ave., Wachapreague, VA, 23480, USA.
Microb Ecol. 2020 Feb;79(2):511-515. doi: 10.1007/s00248-019-01413-8. Epub 2019 Aug 7.
A latitudinal biodiversity gradient has captivated ecologists for years, and has become a widely recognized pattern in biogeography, manifest as an increase in biodiversity from the poles to the tropics. Oceanographers have attempted to discern whether these distribution patterns are shared with marine biota, and a lively debate has emerged concerning the global distribution of microbes. Limitations in sampling resolution for such large-scale assessments have often prohibited definitive conclusions. We evaluated microbial planktonic communities along a ~ 15,400-km Pacific Ocean transect with DNA from samples acquired every 2 degrees of latitude within a 3-month period between late August and early November 2003. Next-generation sequencing targeting the Bacteria, Archaea, and Eukarya yielded ~ 10.8 million high-quality sequences. Beta-analysis revealed geographic patterns of microbial communities, primarily the Bacteria and Archaea domains. None of the domains exhibited a unimodal pattern of alpha-diversity with respect to latitude. Bacteria communities increased in richness from Arctic to Antarctic waters, whereas Archaea and Eukarya communities showed no latitudinal or polar trends. Based on our analyses, environmental factors related to latitude thought to influence various macrofauna may not define microplankton diversity patterns of richness in the global ocean.
多年来，纬度生物多样性梯度一直吸引着生态学家的注意，并已成为生物地理学中广泛认可的模式，表现为从极地到热带的生物多样性增加。海洋学家试图辨别这些分布模式是否与海洋生物群共享，关于微生物的全球分布出现了激烈的争论。对于这种大规模评估，采样分辨率的限制常常禁止得出明确的结论。我们评估了 2003 年 8 月下旬至 11 月初的三个月内，在太平洋约 15400 公里的航线上采集的每 2 度纬度的微生物浮游生物群落的 DNA。针对细菌、古菌和真核生物的下一代测序获得了约 1080 万个高质量序列。β分析揭示了微生物群落的地理模式，主要是细菌和古菌域。没有一个域表现出与纬度有关的单一模式的α多样性。细菌群落从北极水域到南极水域的丰富度增加，而古菌和真核生物群落没有显示出纬度或极地趋势。根据我们的分析，与纬度有关的环境因素被认为会影响各种大型动物，但它们可能无法定义全球海洋中微生物丰富度的浮游生物多样性模式。
