3-domain Metabarcoding and its Application to Arctic Time-Series Data

2022-06-24 Meeting AWI-USC

 

  1. Provide overview of 3-domain metabarcoding approach, and the unique information it provides
  2. Describe how these types of data can inform global models, and the importance of Simons CMAP for this work
  3. Present our vision for a paper comparing 18S community profiles from specific and 3-domain approaches, using FRAM RAS data
  4. Propose that AWI could become involved in a "global paper"
    • Describing patterns from globally-distributed, unfractionated (>0.2µm) microbiome profiles
    • AWI would provide critical coverage in Arctic for a truly global perspective

Meeting plan

Microbe art: @claudia_traboni

p16S

e16S

18S

  • Comprehensive community data from single PCR assay:
    • p(rokaryotic)16S
    • e(ukaryotic)16S
    • Eukaryotic 18S

(1) 3-domain Metabarcoding: A holistic picture

Microbe art: @claudia_traboni

18S

p16S

e16S

  • Comprehensive community data from single PCR assay:
    • p(rokaryotic)16S
    • e(ukaryotic)16S
    • Eukaryotic 18S

(1) 3-domain Metabarcoding: A holistic picture

Craig Carlson, Elisa Halewood, UCSB

Fraction of 18S amplicon sequences

16S

plastid 16S

18S

 Jan-Feb 2005

 

Feb-Mar 2006

With deep sequencing, good coverage for all 3 domains

(1) 3-domain Metabarcoding: A holistic picture

An in silico global phytoplankton model (DARWIN project, MIT)

  • How robust are model predictions?
  • What is the function of  microbial "black box"?
  • Can models and data help predict consequences of climate change?

(2) Metabarcoding data and global models

Model-data intercomparison (Yubin Raut, USC)

Modelling marine heterotrophs (Emily Zakem, Carnegie Inst.)

(2) Metabarcoding data and global models

(3) Application to FRAM data

  • July 2016 - July 2017 from remote access sampler (RAS); >0.2µm fraction
  • Scientific questions:
    • How does the performance of 18S-specific primers compare with 3-domain primers?
    • Which taxa may be under- or over-estimated by each primer set?
    • What new biological insights can we gain from a holistic dataset?
      • "Cross-domain" interactions unique to Arctic ecosystems
      • Changing ratio of PROK:EUK across extreme seasonal cycle

(3) Application to FRAM data: Comparison

Differences to be investigated with MGPrimerEval pipeline using TARA TOPC metagenomes as "ground truth"

  • Not just saying "they're different", but which is more accurate

(3) Application to FRAM data: Holistic picture

  • Blue = all EUK-originating SSU rRNA
  • Orange = all free-living PROK rRNA

Transition from PROK-dominated system to a higher contribution of EUKs

in silico method optimization

3-domain metabarcoding primers work almost* perfectly across global oceans (including for Arctic based on TOPC)

Data for global paper from many collaborators

Global metagenomes

Over 800 globally-distributed barcode samples allow model-data intercomparison but we lack coverage in Arctic!

(4) Where does FRAM data fit in to global picture?

  • FRAM data have already been processed through our standard pipeline, making them ready for Simons CMAP database
    • Sets stage for AWI to be involved with "global paper"
      • Aiming for high impact, including collaborators from USA, UK
    • Having datasets accessible on CMAP allows for broader collaborations (e.g. network analysis)
      • Will be stored as a unique dataset with its own landing page, e.g.:
      • cmap.readthedocs.io/en/latest/catalog/datasets/ESV.html
      • Re-use and citation of FRAM study by non-molecular ecologists more likely

(4) Where does FRAM data fit in to global picture?

plastid

16S

mito 16S

nuclear 18S

Space / time

Abundance

A eukaryotic phytoplankter

Broader collaborations: network analysis

MOSAiC metagenomes, phyloFlash profiles

220624_Katja_Jed_Matthias

By jcmcnch

220624_Katja_Jed_Matthias

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