Planktonic 16S rRNA gene sequences (V4/V5 region) from water samples collected inside the northern coral-reef lagoon of Mo'orea (French Polynesia) and 4 km offshore, in the tropical open ocean.
In this work, surface water samples (2L) were collected at two sampling points: one located 4 km offshore in the open ocean (OO) over a depth of 1200 m; and the other located in the back-reef (BR) lagoon, over a depth of ~2.5 m. Samples for DNA collection were done every 6 h over a period of 34 h on April 12-13 (BR) and April 19-20 (OO) from the surface (0-50 cm) using a small boat. Sampling times were 04:00, 10:00, 16:00, 22:00, 04:00, 10:00, and 14:00 (13:00 at OO) local time. The microbial biomass was then collected on 0.2 µm pore-size, 47 mm diameter polycarbonate filters using a peristaltic pump. The filters were flash frozen in liquid N2 and stored at -80°C. Total DNA was extracted using the phenol-chloroform protocol as described in Massana et al. (1997). Prokaryotic diversity was determined by amplicon sequencing of the V4/V5 regions of the 16S rDNA genes using the Illumina MiSeq platform and paired-end reads (2 x 250 bp). PCR amplifications were done using the prokaryotic universal primers 515F-Y (5'- GTGYCAGCMGCCGCGGTAA-3') and 926R (5'-CCGYCAATTYMTTTRAGTTT-3') (Parada et al. 2016). All samples were sequenced at the Research and Testing Laboratories (RTL, Lubbock, TX, USA).  References:   Massana, R., Murray, A. E., Preston, C. M., and DeLong, E. 1302 F. (1997). Vertical distribution and phylogenetic characterization of marine planktonic Archaea in the Santa Barbara Channel. Appl. Environ. Microbiol. 63, 50–56.   Parada, A. E., Needham, D. M., and Fuhrman, J. A. (2016). Every base matters: assessing small subunit rRNA primers for marine microbiomes with mock communities, time series and global field samples: Primers for marine microbiome studies. Environ. Microbiol. 18, 1403–1414.