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DOI: 10.1038/ismej.2010.141
¤ OpenAccess: Bronze
This work has “Bronze” OA status. This means it is free to read on the publisher landing page, but without any identifiable license.

Quantitative analysis of a deeply sequenced marine microbial metatranscriptome

Scott M. Gifford,Shalabh Sharma,Johanna M. Rinta-Kanto,Mary Ann Moran

Biology
Ammonia monooxygenase
Bacterioplankton
2010
Abstract The potential of metatranscriptomic sequencing to provide insights into the environmental factors that regulate microbial activities depends on how fully the sequence libraries capture community expression (that is, sample-sequencing depth and coverage depth), and the sensitivity with which expression differences between communities can be detected (that is, statistical power for hypothesis testing). In this study, we use an internal standard approach to make absolute (per liter) estimates of transcript numbers, a significant advantage over proportional estimates that can be biased by expression changes in unrelated genes. Coastal waters of the southeastern United States contain 1 × 1012 bacterioplankton mRNA molecules per liter of seawater (∼200 mRNA molecules per bacterial cell). Even for the large bacterioplankton libraries obtained in this study (∼500 000 possible protein-encoding sequences in each of two libraries after discarding rRNAs and small RNAs from >1 million 454 FLX pyrosequencing reads), sample-sequencing depth was only 0.00001%. Expression levels of 82 genes diagnostic for transformations in the marine nitrogen, phosphorus and sulfur cycles ranged from below detection (<1 × 106 transcripts per liter) for 36 genes (for example, phosphonate metabolism gene phnH, dissimilatory nitrate reductase subunit napA) to >2.7 × 109 transcripts per liter (ammonia transporter amt and ammonia monooxygenase subunit amoC). Half of the categories for which expression was detected, however, had too few copy numbers for robust statistical resolution, as would be required for comparative (experimental or time-series) expression studies. By representing whole community gene abundance and expression in absolute units (per volume or mass of environment), ‘omics’ data can be better leveraged to improve understanding of microbially mediated processes in the ocean.
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    Quantitative analysis of a deeply sequenced marine microbial metatranscriptome” is a paper by Scott M. Gifford Shalabh Sharma Johanna M. Rinta-Kanto Mary Ann Moran published in 2010. It has an Open Access status of “bronze”. You can read and download a PDF Full Text of this paper here.