Metabarcoding of abyssal zooplankton
DNA metabarcoding on the bulk zooplankton sample was performed using a modified protocol for the E.Z.N.A Blood Maxi Kit (OMEGA Bio-Tek, Georgia, USA. The first elution was concentrated using the DNA Clean & Concentrator kit (Zymo Research, CA, USA), and the V7-V8 region of the nuclear 18S rRNA gene (18S V7-V8) using primers 3F: 5' GYGGTGCATGGCCGTTSKTRGTT 3' and 5' GTGTGYACAAAGGBCAGGGAC 3' (∼325 bp; (Machida and Knowlton 2012) was amplified using polymerase chain reaction (PCR)was amplified using polymerase chain reaction (PCR). PCR amplification was conducted in duplicate and products were pooled for library preparation. Pooled amplicons were purified using AMPure® XP beads (Beckman Coulter®), quantified using a Qubit® 1X dsDNA High Sensitivity Fluorescence kit (Thermofisher Scientific), and normalized to a concentration of 4ng/µL with molecular grade H20 prior to sequencing. Full methods description is reported at publication in Supplementary file S1.