Date of Award

Spring 5-12-2017

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Masters of Science in Bioscience (MSB)

Department

Marine Biology

Advisor

Susan H. Brawley

Second Committee Member

Lee Karp-Boss

Third Committee Member

John Singer

Additional Committee Members

Toshiki Uji

Abstract

The marine red alga Porphyra umbilicalis (Rhodophyta, Bangiaceae) has ideal traits to allow it to become a model organism, including its economic value, reproduction in the northwestern Atlantic through asexual neutral spores (NS), and availability of fully-sequenced nuclear and organelle genomes. Research on the bacterial component of the Porphyra microbiome is ongoing. To advance model organism development and support microbial studies, data on natural reproductive trends and early embryonic development are needed, along with a system for genetic transformation, and ways of visualizing the attached microbial community. To meet these needs, two years of phenological data were analyzed, revealing seasonal reproductive trends and some location-based effects. Early development of P. umbilicalis from neutral spores is mostly linear. Blades bearing neutral spores were frozen (-20 ºC) for 4 weeks to determine if freezing influences early development. Freezing had minor effects on early development compared to the rate and pattern of germination from NS in untreated controls. Attempted genetic transformation of P. umbilicalis using biolistics was successful, but whether it was a stable transformation is unknown; hygromycin B was demonstrated to be an effective antibiotic to use in selection of transformants. Use of scanning electron microscopy (SEM) revealed that microbial communities on the surface of P. umbilicalis are often diverse, complex, and vary between different groups of specimens. Together, these studies support continuing development of P. umbilicalis as a model organism and a valuable aquaculture crop.

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