Co-occurring Synechococcus ecotypes occupy four major oceanic regimes defined by temperature, macronutrients and iron

Authors

Jill A. Sohm, University of Southern California
Nathan A. Ahlgren, University of Southern CaliforniaFollow
Zachary J. Thomson, University of Washington School of Oceanography
Cheryl Williams, University of Washington School of Oceanography
James W. Moffett, University of Southern California
Mak A. Saito, Woods Hole Oceanographic Institution
Eric A. Webb, University of Southern California
Gabrielle Rocap, University of Washington School of Oceanography

Document Type

Article

Abstract

Marine picocyanobacteria, comprised of the genera Synechococcus and Prochlorococcus, are the most abundant and widespread primary producers in the ocean. More than 20 genetically distinct clades of marine Synechococcus have been identified, but their physiology and biogeography are not as thoroughly characterized as those of Prochlorococcus. Using clade-specific qPCR primers, we measured the abundance of 10 Synechococcus clades at 92 locations in surface waters of the Atlantic and Pacific Oceans. We found that Synechococcus partition the ocean into four distinct regimes distinguished by temperature, macronutrients and iron availability. Clades I and IV were prevalent in colder, mesotrophic waters; clades II, III and X dominated in the warm, oligotrophic open ocean; clades CRD1 and CRD2 were restricted to sites with low iron availability; and clades XV and XVI were only found in transitional waters at the edges of the other biomes. Overall, clade II was the most ubiquitous clade investigated and was the dominant clade in the largest biome, the oligotrophic open ocean. Co-occurring clades that occupy the same regime belong to distinct evolutionary lineages within Synechococcus, indicating that multiple ecotypes have evolved independently to occupy similar niches and represent examples of parallel evolution. We speculate that parallel evolution of ecotypes may be a common feature of diverse marine microbial communities that contributes to functional redundancy and the potential for resiliency.

Publication Title

ISME Journal

Publication Date

2-1-2016

Volume

10

Issue

2

First Page

333

Last Page

345

ISSN

1751-7362

DOI

10.1038/ismej.2015.115

Repository Citation

Sohm, Jill A.; Ahlgren, Nathan A.; Thomson, Zachary J.; Williams, Cheryl; Moffett, James W.; Saito, Mak A.; Webb, Eric A.; and Rocap, Gabrielle, "Co-occurring Synechococcus ecotypes occupy four major oceanic regimes defined by temperature, macronutrients and iron" (2016). Biology. 69.
https://commons.clarku.edu/faculty_biology/69