UCYN-A3, a newly characterized open ocean sublineage of the symbiotic N2 -fixing cyanobacterium Candidatus Atelocyanobacterium thalassa.
Environ Microbiol
; 21(1): 111-124, 2019 01.
Article
de En
| MEDLINE
| ID: mdl-30255541
ABSTRACT
The symbiotic unicellular cyanobacterium Candidatus Atelocyanobacterium thalassa (UCYN-A) is one of the most abundant and widespread nitrogen (N2 )-fixing cyanobacteria in the ocean. Although it remains uncultivated, multiple sublineages have been detected based on partial nitrogenase (nifH) gene sequences, including the four most commonly detected sublineages UCYN-A1, UCYN-A2, UCYN-A3 and UCYN-A4. However, very little is known about UCYN-A3 beyond the nifH sequences from nifH gene diversity surveys. In this study, single cell sorting, DNA sequencing, qPCR and CARD-FISH assays revealed discrepancies involving the identification of sublineages, which led to new information on the diversity of the UCYN-A symbiosis. 16S rRNA and nifH gene sequencing on single sorted cells allowed us to identify the 16S rRNA gene of the uncharacterized UCYN-A3 sublineage. We designed new CARD-FISH probes that allowed us to distinguish and observe UCYN-A2 in a coastal location (SIO Pier; San Diego) and UCYN-A3 in an open ocean location (Station ALOHA; Hawaii). Moreover, we reconstructed about 13% of the UCYN-A3 genome from Tara Oceans metagenomic data. Finally, our findings unveil the UCYN-A3 symbiosis in open ocean waters suggesting that the different UCYN-A sublineages are distributed along different size fractions of the plankton defined by the cell-size ranges of their prymnesiophyte hosts.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Cyanobactéries
/
Fixation de l'azote
Type d'étude:
Prognostic_studies
Pays/Région comme sujet:
America do norte
Langue:
En
Journal:
Environ Microbiol
Sujet du journal:
MICROBIOLOGIA
/
SAUDE AMBIENTAL
Année:
2019
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique