Nicol Graeme W, Tscherko Dagmar, Chang Lisa, Hammesfahr Ute, Prosser James I
School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen, AB24 3UU, UK.
Environ Microbiol. 2006 Aug;8(8):1382-93. doi: 10.1111/j.1462-2920.2006.01031.x.
Non-thermophilic Crenarchaeota are recognized as ubiquitous and abundant components of soil microbial communities. Previous studies of the foreland of the receding Rotmoosferner glacier in the Austrian Central Alps have demonstrated that crenarchaeal communities in soil at different stages of development are distinct from each other, with Group 1.1b crenarchaeal populations dominating throughout the successional gradient, while Group 1.1c crenarchaea are present in mature soils only. To determine whether this highly structured succession was unique to the Rotmoosferner glacier foreland, 1.1b and 1.1c communities were compared with those present along a successional gradient at Odenwinkelkees glacier, 125 km away, by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA reverse transcription polymerase chain reaction products. Similarities in community structure were observed; 1.1b communities were present throughout both successional gradients (though lacking the defined structure at Odenwinkelkees) and 1.1c communities were present only in mature soil. Comigration of bands on DGGE gels indicated that a number of similar crenarchaeal populations were present at both sites. To compare populations, and examine microscale diversity, 16S rRNA genes and complete 16S-23S internal transcribed spacer (ITS) regions representing six major band positions in DGGE analysis were amplified, cloned and sequenced and represented four 1.1b and two 1.1c lineages. The data provide no evidence of endemism, but large differences in the rate of sequence divergence in the ITS region (relative to that in 16S rRNA genes) were observed. Two of the 1.1b lineages (each possessing > 98% 16S rRNA gene similarity) had relatively long and highly divergent ITS sequences. In contrast, two other 1.1b and two 1.1c lineages (each possessing > 99% 16S rRNA gene similarity) exhibited markedly less variation in their respective 16S-23S ITS regions. The results reveal common patterns in the ecology and assembly of crenarchaeal communities in spatially separated soil systems and may indicate different evolutionary rates between soil crenarchaea lineages.
非嗜热泉古菌被认为是土壤微生物群落中普遍存在且数量丰富的组成部分。此前对奥地利中部阿尔卑斯山退缩的罗特莫斯费尔纳冰川前沿地带的研究表明，处于不同发育阶段土壤中的泉古菌群落彼此不同，在整个演替梯度中，1.1b组泉古菌种群占主导地位，而1.1c组泉古菌仅存在于成熟土壤中。为了确定这种高度结构化的演替是否是罗特莫斯费尔纳冰川前沿地带所特有的，通过对16S rRNA逆转录聚合酶链反应产物进行变性梯度凝胶电泳（DGGE），将1.1b和1.1c群落与相距125公里的奥登温克尔凯斯冰川沿演替梯度的群落进行了比较。观察到群落结构的相似性；在两个演替梯度中都存在1.1b群落（尽管在奥登温克尔凯斯缺乏明确的结构），而1.1c群落仅存在于成熟土壤中。DGGE凝胶上条带的共迁移表明，两个地点存在一些相似的泉古菌种群。为了比较种群并研究微观尺度的多样性，对代表DGGE分析中六个主要条带位置的16S rRNA基因和完整的16S - 23S内部转录间隔区（ITS）区域进行了扩增、克隆和测序，代表了四个1.1b和两个1.1c谱系。数据没有提供特有性的证据，但观察到ITS区域的序列分歧率（相对于16S rRNA基因）存在很大差异。两个1.1b谱系（每个谱系的16S rRNA基因相似度> 98%）具有相对较长且高度分歧的ITS序列。相比之下，另外两个1.1b和两个1.1c谱系（每个谱系的16S rRNA基因相似度> 99%）在各自的16S - 23S ITS区域表现出明显较少的变异。结果揭示了空间上分离的土壤系统中泉古菌群落的生态和组装的共同模式，并可能表明土壤泉古菌谱系之间不同的进化速率。
