Life Sciences Commons^™

The Introduction Of Nursery Seedlings And Their Fungi To A Spruce-Fir Forest In Newfoundland, Alicia G. Banwell

Electronic Thesis and Dissertation Repository

A few species of boreal trees form symbiotic relationships with many ectomycorrhizal (ECM) fungi that allow trees to thrive on nutrient poor soils in Canada. A small number of ECM species grow on tree seedlings raised in nurseries for reforestation of clearcut sites. The native ECM fungal community composition of a mixed spruce-fir forest in Newfoundland was determined through next generation sequencing. With the introduction of nursery seedlings, the transfer of native ECM fungi to seedlings and nursery-established ECM fungi to roots was investigated over 20 months. ECM community composition was found to be similar to that of other boreal …

Molecular Identification And Characterization Of Viral Pathogens Infecting Sweet Cherry, Aaron J. Simkovich

Electronic Thesis and Dissertation Repository

Stone fruits are a valuable crop grown worldwide, however pathogens such as viruses threaten fruit production by reducing tree health and fruit yield. In an orchard within the Niagara region of Ontario, symptoms typical of viral infection such as chlorosis and leaf deformation were seen on sweet cherry (Prunus avium L.) trees. Next generation sequencing was performed on symptomatic and asymptomatic leaves and four viruses were identified. On the tree displaying the most severe symptoms, Prune dwarf virus (PDV), was the only virus detected. A survey conducted during this work showed 42% of cherry trees on a single …

Efficient Alignment Algorithms For Dna Sequencing Data, Nilesh Vinod Khiste

Electronic Thesis and Dissertation Repository

The DNA Next Generation Sequencing (NGS) technologies produce data at a low cost, enabling their application to many ambitious fields such as cancer research, disease control, personalized medicine etc. However, even after a decade of research, the modern aligners and assemblers are far from providing efficient and error free genome alignments and assemblies respectively. This is due to the inherent nature of the genome alignment and assembly problem, which involves many complexities. Many algorithms to address this problem have been proposed over the years, but there still is a huge scope for improvement in this research space.

Many new genome …

Measuring The Human Gut Microbiome: New Tools And Non Alcoholic Fatty Liver Disease, Ruth G. Wong

Electronic Thesis and Dissertation Repository

With the advent of next generation DNA and RNA sequencing, scientists can obtain a more comprehensive snapshot of the bacterial communities on the human body (known as the `human microbiome'), leading to information about the bacterial composition, what genes are present, and what proteins are produced. The scientific community is in a phase of developing the experiments and accompanying statistical techniques to investigate the mechanisms by which the human microbiome affects health and disease. In this thesis, I explore alternatives to the standard weighted and unweighted UniFrac distance metric that measure the difference between microbiome samples. These alternative weightings allow …

Translesion Synthesis And Mutations: On The Mutagenic Properties Of The Two Dna Lesions, 8-Oxo-G And Pt-Gg, And The Functions Of Y-Family Dna Polymerases And Rev3l On The Bypass Of Each Of The Dna Lesions In Mammalian Cells, Lizhen Guo

Electronic Thesis and Dissertation Repository

I studied the capabilities of the two DNA lesions 8-oxo-guanine and cisplatin intrastrand crosslinked 1,2-d(GpG) or Pt-GG to cause mutations in mammalian cells. Using isogenic cell lines generated from mice with selective gene knockouts of distinct DNA polymerases as models, I deduced the biological functions of the translesion DNA polymerases Pol eta, Pol kappa, Pol iota, Rev1 and Rev3L on bypassing each of the lesions 8-oxo-G and Pt-GG. My study takes advantage of the Next Generation Sequencing (NGS) technology to determine mutagenic effects of the DNA lesions in vivo and effects of translesion DNA polymerases on bypassing the lesions. Through …

Epigenetics Of Stress Adaptation In Arabidopsis: The Case Of Histone Modifications, Behnaz Najafi Majdabadi Farahani

Electronic Thesis and Dissertation Repository

Changes in the epigenetic status of plants, which contribute to changes in gene expression, in response to abiotic stress are well documented. However, their stability and transmission to subsequent generations, and their incorporation into plant stress adaptation are still a matter for debate. Using chromatin immuno-precipitation and Next Generation Sequencing (ChIP-seq), we compared genome wide enrichment of two histone marks, H3K9ac and H3K4me2, in the progeny of salt stressed and control Arabidopsis plants. Data showed less enrichment of the H3K9ac in the chromatin of the progeny of salt stressed plants, but no changes were detected in the enrichment of the …