Lipid biomarkers of coral stress : calibration and exploration

Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2011.

Bibliographic Details
Main Author: Kneeland, Jessie M. (Jessie Mary)
Other Authors: Konrad A. Hughen.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2012
Subjects:
Online Access:http://hdl.handle.net/1721.1/68888
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author Kneeland, Jessie M. (Jessie Mary)
author2 Konrad A. Hughen.
author_facet Konrad A. Hughen.
Kneeland, Jessie M. (Jessie Mary)
author_sort Kneeland, Jessie M. (Jessie Mary)
collection MIT
description Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2011.
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spelling mit-1721.1/688882022-01-14T19:09:20Z Lipid biomarkers of coral stress : calibration and exploration Kneeland, Jessie M. (Jessie Mary) Konrad A. Hughen. Woods Hole Oceanographic Institution. Joint Program in Oceanography/Applied Ocean Science and Engineering Woods Hole Oceanographic Institution Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Joint Program in Oceanography/Applied Ocean Science and Engineering. Earth, Atmospheric, and Planetary Sciences. Woods Hole Oceanographic Institution. Corals Effect of stress on Zooxanthellate corals Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2011. Cataloged from PDF version of thesis. Includes bibliographical references. Corals are increasingly threatened by warming sea surface temperatures and other anthropogenic changes. The delicate symbiosis between corals and their algal endosymbionts (zooxanthellae) is easily disrupted by thermal stress, leading to bleaching and eventual mortality. The use of lipid ratios as biomarkers of environmental conditions is well established. Coral biomass contains abundant lipids, and the potential of lipid parameters to diagnose thermal tolerance in zooxanthellae has been previously suggested. In this thesis, I explore the response of specific fatty acids, sterols, and thylakoid membrane lipids to thermal and disease stress in zooxanthellae grown in culture, as well as those isolated from living corals. I present the discovery of a bioactive thylakoid lipid within zooxanthellae cells, and show how this compound is selectively mobilized in thermally stressed cells. I present a plausible mechanism for the breakdown of this compound into products that may cause apoptosis and disrupt the coral-algal symbiosis, eventually causing bleaching. I present two new lipid biomarkers of thermal stress in zooxanthellae, the C18 fatty acid unsaturation ratio, and the fatty acid to sterol ratio. I calibrate the decline of these two parameters to levels of thermal stress comparable to those needed to cause bleaching. I further show that these parameters are sensitive to pathogen stress as well. In several case studies of diseased and thermally stressed corals, I demonstrate that these lipid biomarkers of coral stress may be applied to zooxanthellae isolated from environmental samples. I show that these same compounds are preserved within coral aragonite, which opens up the potential to retrieve lipid-based historical records of coral health from annual layers of coral skeleton. This work demonstrates the value of using lipid biomarkers to assess coral health and better understand the biochemical mechanisms of coral bleaching. by Jessie Mary Kneeland. Ph.D. 2012-01-30T16:57:40Z 2012-01-30T16:57:40Z 2011 2011 Thesis http://hdl.handle.net/1721.1/68888 773366640 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 136 p. application/pdf Massachusetts Institute of Technology
spellingShingle Joint Program in Oceanography/Applied Ocean Science and Engineering.
Earth, Atmospheric, and Planetary Sciences.
Woods Hole Oceanographic Institution.
Corals Effect of stress on
Zooxanthellate corals
Kneeland, Jessie M. (Jessie Mary)
Lipid biomarkers of coral stress : calibration and exploration
title Lipid biomarkers of coral stress : calibration and exploration
title_full Lipid biomarkers of coral stress : calibration and exploration
title_fullStr Lipid biomarkers of coral stress : calibration and exploration
title_full_unstemmed Lipid biomarkers of coral stress : calibration and exploration
title_short Lipid biomarkers of coral stress : calibration and exploration
title_sort lipid biomarkers of coral stress calibration and exploration
topic Joint Program in Oceanography/Applied Ocean Science and Engineering.
Earth, Atmospheric, and Planetary Sciences.
Woods Hole Oceanographic Institution.
Corals Effect of stress on
Zooxanthellate corals
url http://hdl.handle.net/1721.1/68888
work_keys_str_mv AT kneelandjessiemjessiemary lipidbiomarkersofcoralstresscalibrationandexploration