對太平洋中兩個相鄰的深海熱液噴口中微生物的基因組普查揭示,，其中的細菌和古生菌種群的多樣性極高、而且種類比過去估計的多得多,。雖然這兩個噴口相隔小于3公里,，每個噴口有不同的化學和不同的微植物群。每個噴口包括了來自海底深部,、噴口各個地方,、以及附近海水中的生物。研究人員用新的DNA測序技術編目了這些微生物群體的廣泛性和多樣性,，提供了比過去更多的細節(jié),。Julie A. Huber和同事用一種技術檢驗了在所有微生物中都有的核糖體RNA基因的超過90萬個字母的序列。他們用該基因一個多變的短區(qū)域中的微小差異編目了這兩個噴口中生命的多樣性,。其中古生菌的多樣性比細菌的低,，而且古生菌多樣性的普遍模式是幾個明顯的種群占主導地位，多樣性主要來自幾千個低數(shù)量的種群,。
美國海洋生物學家在太平洋的俄勒岡州沿海的深海熱液噴口發(fā)現(xiàn)了上千種微生物新物種,。參與該項研究的科學家來自于緬因州的伍茲霍爾海洋生物實驗室以及華盛頓大學的大氣和海洋聯(lián)合研究所。
利用一種被稱為“454標簽測序法”的新型分析技術,，科學家們分析了微生物和古生菌的1百萬個DNA序列,。這些DNA取自于太平洋軸向海山深?；鹕降膬蓚€熱液出口處的微生物樣本。研究人員最終發(fā)現(xiàn)那些地區(qū)存在3000種不同的古生菌,，微生物的種類更是超過了37000種,。
該篇文章的主要作者、海洋生物實驗室的Julie Huber表示：這些細菌大多數(shù)此前從未見報道過,，其中有上百種與我們?nèi)缃袼奈⑸锵嗖钌踹h,，以至于只能判斷其所屬門類。很明顯,，繼續(xù)取樣進行研究以確定其所屬的種類是必不可少的,。
該項研究結果發(fā)表在《科學》雜志上。
原始出處:
Science 5 October 2007:
Vol. 318. no. 5847, pp. 97 - 100
DOI: 10.1126/science.1146689
Microbial Population Structures in the Deep Marine Biosphere
Julie A. Huber,1* David B. Mark Welch,1 Hilary G. Morrison,1 Susan M. Huse,1 Phillip R. Neal,1 David A. Butterfield,2 Mitchell L. Sogin1
The analytical power of environmental DNA sequences for modeling microbial ecosystems depends on accurate assessments of population structure, including diversity (richness) and relative abundance (evenness). We investigated both aspects of population structure for microbial communities at two neighboring hydrothermal vents by examining the sequences of more than 900,000 microbial small-subunit ribosomal RNA amplicons. The two vent communities have different population structures that reflect local geochemical regimes. Descriptions of archaeal diversity were nearly exhaustive, but despite collecting an unparalleled number of sequences, statistical analyses indicated additional bacterial diversity at every taxonomic level. We predict that hundreds of thousands of sequences will be necessary to capture the vast diversity of microbial communities, and that different patterns of evenness for both high- and low-abundance taxa may be important in defining microbial ecosystem dynamics.
1 Josephine Bay Paul Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA.
2 Joint Institute for the Study of Atmosphere and Ocean, University of Washington, Post Office Box 354925, Seattle, WA 98105, USA.
* To whom correspondence should be addressed. E-mail: [email protected]
