PR2_V9, a SSU V9 rDNA reference database with functional annotations.

The present data set provides a tab separated text file compressed in a gzip archive. The file includes 63,401 18S V9 rDNA reference sequences for 44,084 unique eukaryotic taxa and 9,759 16S V9 rDNA references sequences for 9,661 unique prokaryotic taxa. It includes the following fields : sequence = nucleic acid sequence of reference; lineage = taxonomic path of the reference sequence; refs = original accession numbers corresponding to the reference sequence; name = reference sequence identifier; taxogroup = high-taxonomic level assignation of the reference sequence. The file also includes six categories of functional annotations: (1) chloroplast: yes, presence of permanent chloroplast; no, absence of permanent chloroplast ; NA, undetermined. (2) symbiont (small partner): parasite, the species is a parasite; commensal, the species is a commensal; mutualist, the species is a mutualist symbiont, most often a microalgal taxon involved in photosymbiosis; no the species is not involved in a symbiosis as small partner; NA, undetermined. (3) symbiont (host): photo, the host species relies on a mutualistic microalgal photosymbiont to survive (obligatory photosymbiosis); photo_falc, same as photo, but facultative relationship; photo_klep, the host species maintains chloroplasts from microalgal prey(s) to survive; photo_klep_falc, same as photo_klep, but facultative; Nfix, the host species must interact with a mutualistic symbiont providing N2 fixation to survive; Nfix_falc, same as Nfix, but facultative; no, the species is not involved in any mutualistic symbioses; NA, undetermined. (4) silicification; yes, the species has a silicified skeleton; no, it does not; NA, undetermined. (5) calcification; yes, the species has a calcified skeleton; no, it does not; NA, undetermined. (6) strontification; yes, the species has a skeleton made of strontium; no, it does not; NA, undetermined.