Skip to Main content Skip to Navigation
Journal articles

Cyanobacterial symbionts diverged in the late Cretaceous towards lineage-specific nitrogen fixation factories in single-celled phytoplankton

Abstract : The unicellular cyanobacterium UCYN-A, one of the major contributors to nitrogen fixation in the open ocean, lives in symbiosis with single-celled phytoplankton. UCYN-A includes several closely related lineages whose partner fidelity, genome-wide expression and time of evolutionary divergence remain to be resolved. Here we detect and distinguish UCYN-A1 and UCYN-A2 lineages in symbiosis with two distinct prymnesiophyte partners in the South Atlantic Ocean. Both symbiotic systems are lineage specific and differ in the number of UCYN-A cells involved. Our analyses infer a streamlined genome expression towards nitrogen fixation in both UCYN-A lineages. Comparative genomics reveal a strong purifying selection in UCYN-A1 and UCYN-A2 with a diversification process B91 Myr ago, in the late Cretaceous, after the low-nutrient regime period occurred during the Jurassic. These findings suggest that UCYN-A diversified in a co-evolutionary process, wherein their prym-nesiophyte partners acted as a barrier driving an allopatric speciation of extant UCYN-A lineages.
Complete list of metadata

Cited literature [53 references]  Display  Hide  Download

https://hal.sorbonne-universite.fr/hal-01295207
Contributor : Gestionnaire 2 HAL-UPMC Connect in order to contact the contributor
Submitted on : Wednesday, March 30, 2016 - 3:22:51 PM
Last modification on : Thursday, March 17, 2022 - 10:08:40 AM
Long-term archiving on: : Monday, November 14, 2016 - 9:40:57 AM

File

ncomms11071.pdf
Publication funded by an institution

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Citation

Francisco M. Cornejo-Castillo, Ana M. Cabello, Guillem Salazar, Patricia Sánchez-Baracaldo, Gipsi Lima-Mendez, et al.. Cyanobacterial symbionts diverged in the late Cretaceous towards lineage-specific nitrogen fixation factories in single-celled phytoplankton. Nature Communications, Nature Publishing Group, 2016, 7, pp.11071. ⟨10.1038/ncomms11071⟩. ⟨hal-01295207⟩

Share

Metrics

Record views

2662

Files downloads

137