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Newly identified and diverse plastid-bearing branch on the eukaryotic tree of life
- Source :
- Proceedings of the National Academy of Sciences of the United States of America (PNAS), 108 (4). pp. 1496-1500.
- Publication Year :
- 2011
- Publisher :
- Proceedings of the National Academy of Sciences, 2011.
-
Abstract
- The use of molecular methods is altering our understanding of the microbial biosphere and the complexity of the tree of life. Here, we report a newly discovered uncultured plastid-bearing eukaryotic lineage named the rappemonads. Phylogenies using near-complete plastid ribosomal DNA (rDNA) operons demonstrate that this group represents an evolutionarily distinct lineage branching with haptophyte and cryptophyte algae. Environmental DNA sequencing revealed extensive diversity at North Atlantic, North Pacific, and European freshwater sites, suggesting a broad ecophysiology and wide habitat distribution. Quantitative PCR analyses demonstrate that the rappemonads are often rare but can form transient blooms in the Sargasso Sea, where high 16S rRNA gene copies mL −1 were detected in late winter. This pattern is consistent with these microbes being a member of the rare biosphere, whose constituents have been proposed to play important roles under ecosystem change. Fluorescence in situ hybridization revealed that cells from this unique lineage were 6.6 ± 1.2 × 5.7 ± 1.0 μm, larger than numerically dominant open-ocean phytoplankton, and appear to contain two to four plastids. The rappemonads are unique, widespread, putatively photosynthetic algae that are absent from present-day ecosystem models and current versions of the tree of life.
- Subjects :
- 0106 biological sciences
Rare biosphere
Lineage (evolution)
Molecular Sequence Data
Fresh Water
DNA, Ribosomal
010603 evolutionary biology
01 natural sciences
Evolution, Molecular
Haptophyte
03 medical and health sciences
Algae
Phylogenetics
RNA, Ribosomal, 16S
RNA, Ribosomal, 18S
Seawater
Environmental DNA
Plastids
14. Life underwater
Plastid
Atlantic Ocean
Ribosomal DNA
In Situ Hybridization, Fluorescence
Phylogeny
030304 developmental biology
Genetics
0303 health sciences
Pacific Ocean
Multidisciplinary
biology
fungi
Eukaryota
Genetic Variation
Sequence Analysis, DNA
Biological Sciences
biology.organism_classification
RNA, Ribosomal, 23S
Microscopy, Fluorescence
Evolutionary biology
Seasons
Water Microbiology
Subjects
Details
- ISSN :
- 10916490 and 00278424
- Volume :
- 108
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences
- Accession number :
- edsair.doi.dedup.....946c4c735cadbd04d81c414814f17dcb