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UCYN-A3, a newly characterized open ocean sublineage of the symbiotic N2 -fixing cyanobacterium Candidatus Atelocyanobacterium thalassa.

A new interesting article has been published in Environ Microbiol. 2018 Sep 25. doi: 10.1111/1462-2920.14429. and titled:

UCYN-A3, a newly characterized open ocean sublineage of the symbiotic N2 -fixing cyanobacterium Candidatus Atelocyanobacterium thalassa.

Authors of this article are:
Cornejo-Castillo FM Del Carmen Muñoz-Marin M Turk-Kubo KA Royo-Llonch M Farnelid H Acinas SG Zehr JP.

A summary of the article is shown below:
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. This article is protected by copyright. All rights reserved.

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This article is a good source of information and a good way to become familiar with topics such as: n/a.

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