- Title
- Genomic characterisation of small RNA-mediated post-transcriptional gene regulation
- Creator
- Carroll, Adam
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2013
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- microRNA (miRNA) are small non-coding RNA molecules that function to guide the miRNA-induced silencing complex (miRISC) to regions of complementarity within mRNA transcripts, thereby mediating sequence-specific post-transcriptional gene silencing (PTGS). This form of gene regulation is vital to a variety of biological processes in animals, from fundamental developmental functions including cellular proliferation and differentiation, to more complex and specialised roles such as long-term potentiation and synapse-specific modifications in neurons. While the complementarity of miRNA-mRNA interactions enables bioinformatic algorithms to predict potential target genes, the capacity for miRNA to interact with their targets through elements of only partial complementarity renders high false discovery rates to these predictions. With the discovery of increased cortical miRNA expression in schizophrenia, biological evidence was therefore required to investigate the function of schizophrenia-associated miRNA including miR-181b, miR-107, and members of the miR-15 and miR-17 families. Functional genomic techniques were established with genome-wide expression analysis and miRNA reporter-gene assays to characterise the biology of these miRNA in a variety of cellular contexts. In vitro characterisation of miR-181b revealed target gene regulation through interactions at both conserved and non-conserved MREs, with primary and secondary effects of miRNA modulation affecting many genes enriched within neurodevelopmental pathways vital to synaptic plasticity, including a number of schizophrenia candidate genes. Surprisingly, comparisons of miR-181b and miR-107 function against target prediction frameworks revealed a subset of predicted targets displaying positive correlation with cognate miRNA expression. Context-specific functional pleiotropy was also observed in different cellular environments, and this was further explored through miR-17/20a in T lymphocyte activation, and through miR-16 in cell cycle progression. Ultimately, substantial evidence was obtained to establish biological plausibility for miR-181b dysregulation as a potential aetiological factor in the development of schizophrenia, though the emergent theme of context-specific miRNA function requires future methodological developments and experiments to consider this functional pleiotropy when exploring miRNA function in normal developmental and pathophysiological states.
- Subject
- miRNA; schizophrenia; thesis by publication; target identification; luciferase assay; miR-181b; miR-107; miR-17; miR-20a; miR-16; expression
- Identifier
- http://hdl.handle.net/1959.13/1037796
- Identifier
- uon:13486
- Rights
- Copyright 2013 Adam Carroll
- Language
- eng
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| View Details Download | ATTACHMENT02 | Thesis | 23 MB | Adobe Acrobat PDF | View Details Download |