Metatranscriptomes reveal functional variation in diatom communities from the Antarctic Peninsula
© 2015 International Society for Microbial Ecology All rights reserved. Functional genomics of diatom-dominated communities fromthe Antarctic Peninsula was studied using comparative metatranscriptomics. Samples obtained from diatom-rich communities in the Bransfield Strait, the western Weddell Sea a...
Published in: | The ISME Journal |
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Main Authors: | , , , , , , , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Nature Publishing Group
2015
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Subjects: | |
Online Access: | http://hdl.handle.net/10261/126061 https://doi.org/10.1038/ismej.2015.40 https://doi.org/10.13039/501100001871 https://doi.org/10.13039/501100003329 |
Summary: | © 2015 International Society for Microbial Ecology All rights reserved. Functional genomics of diatom-dominated communities fromthe Antarctic Peninsula was studied using comparative metatranscriptomics. Samples obtained from diatom-rich communities in the Bransfield Strait, the western Weddell Sea and sea ice in the Bellingshausen Sea/Wilkins Ice Shelf yielded more than 500K pyrosequencing reads that were combined to produce a global metatranscriptome assembly. Multi-gene phylogenies recovered three distinct communities, and diatom-assigned contigs further indicated little read-sharing between communities, validating an assembly-based annotation and analysis approach. Although functional analysis recovered a core of abundant shared annotations that were expressed across the three diatom communities, over 40% of annotations (but accounting for <10% of sequences) were community-specific. The two pelagic communities differed in their expression of N-metabolism and acquisition genes, which was almost absent in post-bloom conditions in the Weddell Sea community, while enrichment of transporters for ammonia and urea in Bransfield Strait diatoms suggests a physiological stance towards acquisition of reduced N-sources. The depletion of carbohydrate and energy metabolism pathways in sea ice relative to pelagic communities, together with increased light energy dissipation (via LHCSR proteins), photorespiration, and NO 3 - uptake and utilization all pointed to irradiance stress and/or inorganic carbon limitation within sea ice. Ice-binding proteins and cold-shock transcription factors were also enriched in sea ice diatoms. Surprisingly, the abundance of gene transcripts for the translational machinery tracked decreasing environmental temperature across only a 4 °C range, possibly reflecting constraints on translational efficiency and protein production in cold environments. This work was supported by grants 'SOPA' from the Portuguese Science Foundation (FCT; PTDC/MAR/72630) to GAP and is a contribution to the ATOS ... |
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