Dataset: Non-cyanobacterial diazotroph nifH-qPCR-based abundances collected from various cruises in the global ocean between 2000-2019

This is a formal meta analysis of all available NDC qPCR datasets published between 2000 and 2019. Seawater DNA and RNA samples were collected using two main field approaches, via Niskin bottles attached to rosettes with CTDs, are using the ship's underway seawater systems). Samples were collected by numerous different research groups. DNA and RNA samples were generally filtered through 0.2 µm filers, using a variety of materials, and in some cases, size fractionated samples were collected (e.g. 3 µm and 0.2 µm filters in series). DNA and RNA samples were typically extracted using on column purification-based kits, and in the case where nifH transcription was quantified cDNA (derived from RNA) was typically generated using Superscript reverse transcriptase kits.  Purified DNA/RNA/cDNA were typically stored at -80oC prior to analysis. Quantitative PCR assays (55 total), were developed by multiple different groups, and his database only includes data generated using qPCR using Taqman(R) chemistry.

This dataset was compiled/formatted for CMAP by Mary R Gradoville and Kendra Turk-Kubo from the Zehr Research Group at the University of California Santa Cruz. 

Data sources:  Individual dataset sources are listed in the "source_data" column for each observation (from 59 published studies).  Column "source_doi" is the DOI for the reference provided in "source_data."  Additional details about the specific data used are provided in the "source_location_of_data" column (e.g., specific tables, figures, whether data provided by the authors, or databases).   

Cruise description: This dataset is a compilation of multiple cruises, collectively carried out by numerous research groups, not all funded by NSF. The original citations are provided in the metadata for the dataset.