A Few Cosmopolitan Phylotypes Dominate Planktonic Archaeal Assemblages in Widely Different Oceanic Provinces
AUTOR(ES)
Massana, Ramon
FONTE
American Society for Microbiology
RESUMO
We compared the phylogenetic compositions of marine planktonic archaeal populations in different marine provinces. Samples from eight different environments were collected at two depths (surface and aphotic zone), and 16 genetic libraries of PCR-amplified archaeal 16S rRNA genes were constructed. The libraries were analyzed by using a three-step hierarchical approach. Membrane hybridization experiments revealed that most of the archaeal clones were affiliated with one of the two groups of marine archaea described previously, crenarchaeotal group I and euryarchaeotal group II. One of the 2,328 ribosomal DNA clones analyzed was related to a different euryarchaeal lineage, which was recently recovered from deep-water marine plankton. In temperate regions (Pacific Ocean, Atlantic Ocean, and Mediterranean Sea) both major groups were found at the two depths investigated; group II predominated at the surface, and group I predominated at depth. In Antarctic and subantarctic waters group II was practically absent. The clonal compositions of archaeal libraries were investigated by performing a restriction fragment length polymorphism (RFLP) analysis with two tetrameric restriction enzymes, which defined discrete operational taxonomic units (OTUs). The OTUs defined in this way were phylogenetically consistent; clones belonging to the same OTU were closely related. The clonal diversity as determined by the RFLP analysis was low, and most libraries were dominated by only one or two OTUs. Some OTUs were found in samples obtained from very distant places, indicating that some phylotypes were ubiquitous. A tree containing one example of each OTU detected was constructed, and this tree revealed that there were several clusters within archaeal group I and group II. The members of some of these clusters had different depth distributions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=101412Documentos Relacionados
- Comparative Genomic Analysis of Archaeal Genotypic Variants in a Single Population and in Two Different Oceanic Provinces
- Molecular evidence of cryptic speciation in planktonic foraminifers and their relation to oceanic provinces
- Phylogenetic Composition of Arctic Ocean Archaeal Assemblages and Comparison with Antarctic Assemblages
- Seasonal and Spatial Variability of Bacterial and Archaeal Assemblages in the Coastal Waters near Anvers Island, Antarctica
- An epitope of elongation factor Tu is widely distributed within the bacterial and archaeal domains.