Thesis advisor: Jeffrey H. Chuang / Gene regulation is perhaps least understood among vertebrate species, where cell differentiation, tissue-types and body-plans indicate a complexity in need of careful coordination to achieve such hierarchical design. Recent studies reveal the intricacy of vertebrate gene regulation through diverse events including transcriptional regulatory histone modifications and non-coding DNA [1-5]. Almost 98% of the human genome is noncoding DNA, much of which may be actively involved in regulating healthy and disease-state gene expression and environmental response [6]. Conserved noncoding elements (CNEs) are sequences of noncoding DNA that are known to regulate gene expression [7-9]. The CNEs identified thus far are a small percentage of the total noncoding DNA in the human genome, and many identified CNEs still lack experimental characterization [10]. Thus, there is a need for functional characterization and streamlined identification of CNEs in order to more fully annotate vertebrate genomes and understand gene expression. The work in this thesis identified over 6000 CNEs and experimentally characterized over 150 CNEs conserved between zebrafish and human (> 60% DNA sequence conservation), using the experimental model Danio rerio (zebrafish). Functional, tissue and time-specific CNEs were identified through analysis of conservation, accelerated evolution, distance, GC content, motifs, transcription factors and gene function. In addition, a searchable database and website was created to host data and facilitate collaborative research between experimental and computational labs. While non-coding DNA is an important area of discovery for gene regulation, protein-coding DNA also has the potential to contain non-coding transcriptional information. DNA is typically conceptualized as either noncoding or protein coding. An underlying assumption to this framework assumes that the function of noncoding DNA is "regulatory" and coding DNA is "protein coding." Consequently, the potential for DNA to harbor both types of information in one sequence has been minimally researched. For the second-half of this thesis, I identified and experimentally tested 31 conserved coding exons ( > 60% zebrafish and human DNA sequence conservation) in zebrafish. To improve annotation of live embryonic expression, a novel voice-recognition expression analysis system was developed that allows quick comparison and annotation of embryonic expression at the microscope. In addition, a website and webtool to calculate significant expression was created as a resource for experimental research on anatomical analysis in whole organisms. The experimental results show that a large number of protein-coding DNA sequences can act as non-coding enhancers. This knowledge may impact methods to identify noncoding signals and, further, the scientific conceptualizations of coding and noncoding DNA in the genome. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.
| Identifer | oai:union.ndltd.org:BOSTON/oai:dlib.bc.edu:bc-ir_101922 |
| Date | January 2011 |
| Creators | Ritter, Deborah Irene |
| Publisher | Boston College |
| Source Sets | Boston College |
| Language | English |
| Detected Language | English |
| Type | Text, thesis |
| Format | electronic, application/pdf |
| Rights | Copyright is held by the author, with all rights reserved, unless otherwise noted. |
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