Molecular Physiological Evolution: Steroid Hormone Receptors and Antifreeze Proteins
For my dissertation research I explored the diversity and functional evolution of steroid hormone receptors (SRs) in animals and the physiological implications of the evolution of antifreeze proteins in Antarctic notothenioid fishes. For the former, I discovered multiple new SRs from the vast and un...
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University of Oregon
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ftunivoregonsb:oai:scholarsbank.uoregon.edu:1794/18733 2023-05-15T14:02:48+02:00 Molecular Physiological Evolution: Steroid Hormone Receptors and Antifreeze Proteins Cziko, Paul Cresko, William 2015-01-14 application/pdf http://hdl.handle.net/1794/18733 en_US eng University of Oregon http://hdl.handle.net/1794/18733 All Rights Reserved. Antifreeze proteins Endocrinology Molecular evolution Polar marine biology Protein evolution Steroid hormone receptors Electronic Thesis or Dissertation 2015 ftunivoregonsb 2022-12-19T13:50:58Z For my dissertation research I explored the diversity and functional evolution of steroid hormone receptors (SRs) in animals and the physiological implications of the evolution of antifreeze proteins in Antarctic notothenioid fishes. For the former, I discovered multiple new SRs from the vast and under-sampled swath of animal diversity known as invertebrates. I used the sequences of these and other newly discovered related receptors in combination with genomic data and molecular phylogenetic techniques to revise the understanding of the evolutionary history of this important gene family. While previous studies have suggested that vertebrate SR diversity arose from a gene duplication in an ancestor of all bilaterian animals, my work presents strong evidence that this duplication occurred much later, at the base of the chordates. Furthermore, to determine the implications of added diversity and a revised phylogeny on inferences of the functional evolution of SRs, I functionally characterized heretofore-unknown SRs from hemichordates, an acoelomate flatworm, and a chaetognath and statistically reconstructed and functionally characterized ancestral SRs. My results expand the known sequence and functional repertoire of SRs in animals while reinforcing the previous inference that all SRs evolved from an estrogen-sensitive ancestral receptor. I also explored the consequences of the evolution of antifreeze proteins in Antarctic notothenioid fishes, a crucial adaptation to their icy, polar environment. These special proteins adsorb to ice crystals that enter a fish's body and prevent further growth, thereby averting death. I discovered that, in addition to their lifesaving growth-inhibiting ability, AFPs also prevent the melting of internal ice crystals at temperatures above the expected equilibrium melting point. Together with a decade-long temperature record of one of the coldest fish habitats on earth, my experimental results show that the evolution and expression of antifreeze proteins is accompanied by a potentially ... Thesis Antarc* Antarctic University of Oregon Scholars' Bank Antarctic |
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University of Oregon Scholars' Bank |
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ftunivoregonsb |
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English |
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Antifreeze proteins Endocrinology Molecular evolution Polar marine biology Protein evolution Steroid hormone receptors |
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Antifreeze proteins Endocrinology Molecular evolution Polar marine biology Protein evolution Steroid hormone receptors Cziko, Paul Molecular Physiological Evolution: Steroid Hormone Receptors and Antifreeze Proteins |
topic_facet |
Antifreeze proteins Endocrinology Molecular evolution Polar marine biology Protein evolution Steroid hormone receptors |
description |
For my dissertation research I explored the diversity and functional evolution of steroid hormone receptors (SRs) in animals and the physiological implications of the evolution of antifreeze proteins in Antarctic notothenioid fishes. For the former, I discovered multiple new SRs from the vast and under-sampled swath of animal diversity known as invertebrates. I used the sequences of these and other newly discovered related receptors in combination with genomic data and molecular phylogenetic techniques to revise the understanding of the evolutionary history of this important gene family. While previous studies have suggested that vertebrate SR diversity arose from a gene duplication in an ancestor of all bilaterian animals, my work presents strong evidence that this duplication occurred much later, at the base of the chordates. Furthermore, to determine the implications of added diversity and a revised phylogeny on inferences of the functional evolution of SRs, I functionally characterized heretofore-unknown SRs from hemichordates, an acoelomate flatworm, and a chaetognath and statistically reconstructed and functionally characterized ancestral SRs. My results expand the known sequence and functional repertoire of SRs in animals while reinforcing the previous inference that all SRs evolved from an estrogen-sensitive ancestral receptor. I also explored the consequences of the evolution of antifreeze proteins in Antarctic notothenioid fishes, a crucial adaptation to their icy, polar environment. These special proteins adsorb to ice crystals that enter a fish's body and prevent further growth, thereby averting death. I discovered that, in addition to their lifesaving growth-inhibiting ability, AFPs also prevent the melting of internal ice crystals at temperatures above the expected equilibrium melting point. Together with a decade-long temperature record of one of the coldest fish habitats on earth, my experimental results show that the evolution and expression of antifreeze proteins is accompanied by a potentially ... |
author2 |
Cresko, William |
format |
Thesis |
author |
Cziko, Paul |
author_facet |
Cziko, Paul |
author_sort |
Cziko, Paul |
title |
Molecular Physiological Evolution: Steroid Hormone Receptors and Antifreeze Proteins |
title_short |
Molecular Physiological Evolution: Steroid Hormone Receptors and Antifreeze Proteins |
title_full |
Molecular Physiological Evolution: Steroid Hormone Receptors and Antifreeze Proteins |
title_fullStr |
Molecular Physiological Evolution: Steroid Hormone Receptors and Antifreeze Proteins |
title_full_unstemmed |
Molecular Physiological Evolution: Steroid Hormone Receptors and Antifreeze Proteins |
title_sort |
molecular physiological evolution: steroid hormone receptors and antifreeze proteins |
publisher |
University of Oregon |
publishDate |
2015 |
url |
http://hdl.handle.net/1794/18733 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://hdl.handle.net/1794/18733 |
op_rights |
All Rights Reserved. |
_version_ |
1766273210088685568 |