Sponsor
Portland State University. Department of Biology
First Advisor
Anne Thompson
Term of Graduation
Summer 2026
Date of Publication
9-21-2026
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Biology
Department
Biology
Language
English
Subjects
picocyanobacteria, Synechococcus
Physical Description
1 online resource (viii, 56 pages)
Abstract
Picocyanobacteria are a globally important group of microorganisms that contribute significantly to marine food webs and biogeochemical cycles. One lineage of picocyanobacteria, Synechococcus, is abundant and globally distributed in the oceans. Its abundance and ability to live in a wide variety of marine habitats make it an important contributor to biogeochemical cycles and source of food for grazers in the ocean, especially in habitats where picocyanobacteria dominate phytoplankton communities. Synechococcus is known to have several distinct, plastic (i.e. flexible) morphologies and cellular arrangements that give it survival advantages like evading predators, such as the ability to form microcolonies and type IV pili. This work aims to quantify and image the diversity of Synechococcus cellular arrangements across multiple clades in the lineage, quantify and screen the diversity of Synechococcus cellular arrangements in wild populations, and test how the different Synechococcus cellular arrangements change under changing culture conditions to determine when each cellular arrangement is most abundant. Results suggest that Synechococcus cellular arrangements are more varied than previously known. Out of 19 distinct strains screened, 17 were observed to have a previously undocumented filament cellular arrangement. Prevalence of filaments are stable over the growth curve and no filaments were observed in natural populations. These results suggest that Synechococcus are a more morphologically plastic group of picocyanobacteria than previously thought. Understanding the details of Synechococcus filamentation may change our understanding of its role as prey for higher trophic levels, a primary producer, and its role in carbon export to the deep ocean.
Rights
© 2026 Darian Madere
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Persistent Identifier
https://archives.pdx.edu/ds/psu/45165
Recommended Citation
Madere, Darian, "Novel Cellular Arrangements of Marine Synechococcus" (2026). Dissertations and Theses. Paper 7224.