Microbiobial eukaryote community composition during early phytoplankton blooms in the naturally iron-fertilized Kerguelen area (Southern Ocean)
The 31 DNA samples were amplified using one set of universal eukaryote primers 18S-82F (5’-GAAACTGCGAATGGCTC-3’, Lopez-Garcia et al. 2003) and Euk-516r (5’-ACCAGACTTGCCCTCC-3’, Amman et al. 1990). These primers have been designed to amplify a domain around 470-480 bp corresponding to the variable V2 and V3 eukaryote 18S rDNA regions. Two “sff” files, HS3LA6A03.sff and HS3LA6A04.sff, were produced containing all the amplified sequences. A 4-bp TCAG key and a 31-bp adapter for the GS FLX technology were added to the primers. PCR was carried out according to standard conditions for Platinum Taq High-Fidelity DNA Polymerase (Invitrogen, Carlsbad, CA, USA), with 10 ng of environmental DNA as template. The library was prepared following the procedures described by Roche (Basel, Switzerland) and used in two ¼ plate run on a 454 GS FLX Titanium sequencer.   This study was carried out during the KEOPS2 cruise from October 15th to November 20th 2011. Water samples were collected from eight stations in the bloom area above and off the Kerguelen plateau: R ( -50.4°N, 66.7°E); FL (-48.6°N, 74.8°E); E4W (-48.8°N, 71.4°E); A3-2 (-50.6°N, 72.1°E); E1 (-48.5°N, 72.2°E); E3 (-48.7°N, 72°E); E4E (-48.7°N, 72.6°E); E5 (-48.4°N, 71.9°E). Four sampling depths were chosen at each station.    MID sequences: R (20 m) CGTCTAGTAC, R (60 m) TCACGTACTA, R (150 m) ATACGACGTA, R (300 m) CGAGAGATAC, FL (20 m) AGCACTGTAG, FL (65 m) AGACGCACTC, FL (180 m) ACGCTCGACA, FL (300 m) ACGAGTGCGT, E4W (30 m) AGCGTCGTCT, E4W (80 m) AGACTATACT, E4W (150 m) ACTGTACAGT, E4W (300 m) ACTACTATGT, A3-2 (20m) ACGCGAGTAT, A3-2 (80 m) AGACTATACT, A3-2 (160 m) TGTACTACTC, A3-2 (300 m) TCTACGTAGC, E1 (80 m) TACACGTGAT, E1 (150 m) TACACACACT, E1 (300 m) CGACGTGACT, E3 (20 m) TACTGAGCTA, E3 (65 m) TGATACGTCT, E3 (180 m) TCTCTATGCG, E3 (300 m) TAGTATCAGC, E4E (30 m) CTCGCGTGTC, E4E (80 m) CGTGTCTCTA, E4E (150 m)  ATATCGCGAG, E4E (300 m) ATCAGACACG, E5 (20 m) CAGTAGACGT, E5 (80 m) TCGATCACGT, E5 (150 m) ATAGAGTACT, E5 (300 m) AGTACGCTAT