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Full-Text Articles in Life Sciences
Investigating The Impact Of Transcription On Mutation Rates, Sarah Patterson
Investigating The Impact Of Transcription On Mutation Rates, Sarah Patterson
Theses and Dissertations
tRNA genes are highly transcribed and perform one of the most fundamental cellular functions. Although a universal pattern observed across all three domains of life is that highly transcribed genes tend to evolve slowly, tRNA genes have been shown previously to evolve rapidly. This rapid sequence evolution could result from relaxed selection, increased mutation rate, or a combination of both. Here, we use mutation-accumulation line sequencing data to show that tRNA genes accumulate more mutations than other gene types. Our results indicate that this elevated mutation rate is a consequence of both elevated transcription-associated mutagenesis and a lack of transcription-coupled …
Genome Evolution In The Salicaceae: Genetic Novelty, Horizontal Gene Transfer, And Comparative Genomics, Timothy Yates
Genome Evolution In The Salicaceae: Genetic Novelty, Horizontal Gene Transfer, And Comparative Genomics, Timothy Yates
Doctoral Dissertations
Genome evolution is a powerful force which shapes genomes over time through processes like mutation, horizontal transfer, and sexual reproduction. Although questions which aim to explore genome evolution are broad, they are all understood through the discovery and comparison of genetic variation. For example, genetic diversity may explain differences in phenotypes, etiology of disease, and is essential for phylogenomic analysis. Recently, the democratization of next generation and third generation DNA sequencing technologies have allowed for genomics to produce large amounts of sequence data. This has facilitated the capture of genetic variation at species and population scales.
Populus and Salix are …
Discovering Mechanisms Driving Adaptive Evolution In The Cross-Kingdom Fungal Pathogen Fusarium Oxysporum, Dilay Hazal Ayhan
Discovering Mechanisms Driving Adaptive Evolution In The Cross-Kingdom Fungal Pathogen Fusarium Oxysporum, Dilay Hazal Ayhan
Doctoral Dissertations
Fusarium oxysporum is a cross-kingdom pathogenic fungus that can cause vascular wilt disease in many economically important plants and local or disseminated infections in humans. Although it lacks a sexual stage in its life cycle, F. oxysporum can adapt to a wide range of hosts because of accessory chromosomes (ACs) which are enriched in host-specific genes and repeat content. This dissertation investigates the mechanisms that drive the adaptive evolution in the cross-kingdom pathogen F. oxysporum using comparative genomics and an experimental evolution approach. The first chapter compares phenotypes and genomes of a plant pathogenic isolate F. oxysporum f. sp. lycopersici …
Investigation Into The Evolution Of Heterogeneity Within Secondary Replicons And Their Maintenance In Genus Variovorax, Christopher Ne Ville
Investigation Into The Evolution Of Heterogeneity Within Secondary Replicons And Their Maintenance In Genus Variovorax, Christopher Ne Ville
Electronic Theses, Projects, and Dissertations
Approximately 10% of all bacterial genomes sequenced thus far contain a secondary replicon. This considerable genetic reservoir contains many potentially mobilizable elements, allowing for the formation of many unique secondary replicons. This property of bacterial populations vastly increases the genomic diversity available to species that effectively take up and maintain these replicons. Members of the genus Variovorax have extensive heterogeneity in genome architecture, including sequenced isolates containing plasmids, megaplasmids, and chromids. Using available Illumina data on the NCBI database, we have completed these assemblies using 3rd generation sequencing methods on 17 members of this genus. We have sequenced, assembled, …