Picoplankton 18S rRNA genes from the tropical and sub-tropical global-ocean sampled during the Malaspina-2010 expedition

Sampling

Surface global ocean eukaryotic picoplankton from the Malaspina-2010 expedition: Surface waters (3m depth) from a total of 122 globally-distributed stations located in the tropical and sub-tropical global ocean were sampled from December 2010 to July 2011 as a part of the Malaspina-2010 expedition (Duarte 2015; Estrada, et al. 2016). Water samples were obtained with Niskin bottles attached to a CTD profiler that included sensors for conductivity, temperature, oxygen, fluorescence and turbidity. About 12L of seawater were sequentially filtered through a 20m nylon mesh, followed by a 3m and 0.2m polycarbonate filters of 142mm diameter (Isopore, Millipore). Only the picoplankton size-fraction (0.2-3 m) was used for sequencing. DNA was extracted using a standard phenol-chloroform protocol (Massana, et al. 1997). The V4 region of the 18S (~380 bp) was amplified with the primers TAReuk454FWD1 and TAReukREV3 (Stoeck, et al. 2010). Duarte CM. 2015. Seafaring in the 21St Century: The Malaspina 2010 Circumnavigation Expedition. Limnology and Oceanography Bulletin 24:11-14.Estrada M, Delgado M, Blasco D, Latasa M, Cabello AM, Benitez-Barrios V, Fraile-Nuez E, Mozetic P, Vidal M. 2016. Phytoplankton across Tropical and Subtropical Regions of the Atlantic, Indian and Pacific Oceans. PLoS One 11:e0151699.Massana R, Murray AE, Preston CM, DeLong EF. 1997. Vertical distribution and phylogenetic characterization of marine planktonic Archaea in the Santa Barbara Channel. Applied and environmental microbiology 63:50-56.Stoeck T, Bass D, Nebel M, Christen R, Jones MD, Breiner HW, Richards TA. 2010. Multiple marker parallel tag environmental DNA sequencing reveals a highly complex eukaryotic community in marine anoxic water. Molecular ecology 19 Suppl 1:21-31.

Method steps

1. Pipeline used: https://www.ebi.ac.uk/metagenomics/pipelines/5.0