Life Sciences Commons^™

Telomere Length Variation In Preschool Children: Associations With Chronic Family Stress, Maternal Depression, And Cortisol Reactivity, Aditi Thakur

Electronic Thesis and Dissertation Repository

Telomeres are repetitive nucleotide repeats of TTAGGG sequences located at the two ends of each chromosome. Telomeres protect DNA from degradation and maintain genomic stability. Shorter telomeres are implicated in different diseases and disorders including psychiatric disorders. I measured buccal cell telomere length (TL) in 384 pre-school children (3-4 years), from Southwestern Ontario using monochrome multiplex qPCR method. I assessed the associations between TL and family, child-specific variables. I did not find a significant correlation between TL and maternal depression, chronic family stress, or age and sex of the children. However, I found a significant positive correlation between TL and …

Multi-Gene Resistance To Neonicotinoids In The Colorado Potato Beetle, Leptinotarsa Decemlineata, Emine Kaplanoglu

Electronic Thesis and Dissertation Repository

The Colorado potato beetle, Leptinotarsa decemlineata, is a significant pest of potato, and its impact on agriculture is measured on a global scale. The beetle is mainly controlled by neonicotinoid insecticides, however, resistance development is a growing concern. Resistance to neonicotinoids is thought to involve elevated activity of detoxifying enzymes and xenobiotic transporters that break-down and excrete insecticide molecules. Here, using mRNA sequencing, I identified multiple detoxifying enzyme and xenobiotic transporter genes transcriptionally up-regulated in a neonicotinoid resistant strain of beetles. I then used RNA interference to knock down the transcript levels of the ten most promising genes in …

Iron Acquisition Strategies Employed By Staphylococcus Lugdunensis, Jeremy R. Brozyna

Electronic Thesis and Dissertation Repository

Iron is crucial for many cellular processes including DNA synthesis and respiration. The majority of iron in mammals is in heme within hemoproteins, inside cells, or transported through circulation by the glycoprotein transferrin, which constitutes the greatest iron source in serum. Limiting iron availability is an important facet of nutritional immunity to help prevent infection.

Staphylococcus lugdunensis is a human skin commensal and opportunistic pathogen capable of causing a variety of infections, including particularly aggressive endocarditis. It is an emerging pathogen with elevated virulence compared to other species of coagulase-negative staphylococci. The versatility of S. lugdunensis to infect multiple niches …

Nucleoporin-Mediated Regulation Of The Kcnq1ot1 Imprinted Domain, Saqib Sachani

Electronic Thesis and Dissertation Repository

Genomic imprinting is an epigenetic phenomenon that restricts gene expression to one parental allele while the other copy is silent. How this duality is regulated is not fully understood. Using the Kcnq1ot1 imprinted domain as a model, previous work in the laboratory identified nucleoporin 107 as a candidate regulator of imprinted domain regulation. Within the Kcnq1ot1 domain resides the imprinting control region, the paternally expressed Kcnq1ot1 (Kcnq1 opposite transcript 1) noncoding RNA, nine maternal-expressed protein-coding genes, as well as genes that escape imprint regulation. On the maternal allele, the Kcnq1ot1 imprinting control region is methylated, silencing the embedded Kcnq1ot1 …

Assisted Reproductive Technologies Disrupt Genomic Imprinting In Human And Mitochondria In Mouse Embryos, Carlee R. White

Electronic Thesis and Dissertation Repository

Infertile couples worldwide use assisted reproductive technologies (ARTs) to help conceive their own biological child. Due to the rising use of ARTs, there is continual emergence of new techniques implemented in human fertility clinics. When treatment is successful, there is an increased risk even within singletons for perinatal complications including preterm birth, intrauterine growth restriction, low and high birth weight and genomic imprinting disorders Beckwith Wiedemann Syndrome, Angelman Syndrome, and Silver-Russel Syndrome. Consequently, there is a need to investigate the effects of these treatments on the manipulated oocyte and preimplantation embryo. To address this, I first analyzed the combined effects …

Gene Discovery In Mendelian And Complex Diseases, Sali Farhan

Electronic Thesis and Dissertation Repository

Through the Finding of Rare Disease Genes in Canada (FORGE Canada) initiative, individuals affected with rare Mendelian diseases were clinically ascertained with a goal of identifying the genetic origin of their disease. Herein, I describe the methods for identifying the genetic basis of four Mendelian diseases. The application of next generation sequencing led to the discovery of non-synonymous variation in the DNA of individuals affected by rare diseases. The effects of the candidate variants were assessed using a series of functional experiments to complement the human genetics data. The variants observed in patients’ cells are extremely rare, were consistently predicted …

Glucan Synthase-Like 8: A Key Player In Early Seedling Development In Arabidopsis, Behnaz Saatian

Electronic Thesis and Dissertation Repository

Plants’ cell walls have unique chemical composition and features which enable them to play essential roles during plant development as shaping the cells and providing intercellular communication between adjacent cells. Polysaccharides, including callose, and glycoproteins are known as the main constituents of the cell wall. Callose, a linear β-1,3-glucan polymer, is accumulated at the cell plate during cytokinesis, in plasmodesmata, where it regulates cell-to-cell communication, in dormant phloem, where it seals sieve plates after mechanical injury and pathogen attack, and in male and female gametophytes. GLUCAN SYNTHASE-LIKE (GSL) genes in Arabidopsis comprise a family of 12 members. A …

Inheritance, Differential Expression, And Candidate Gene Analyses For Avr2 In Phytophthora Sojae, Chelsea S. Ishmael

Electronic Thesis and Dissertation Repository

Phytophthora sojae is an oomycete responsible for seed, root and stem rot of soybean plants. Managing this disease relies on growing soybean cultivars with race-specific resistance (Rps) genes that deliver complete host immunity in the presence of corresponding pathogen avirulence (Avr) effector proteins. The aims of this study were to characterize virulence towards Rps2 among different P. sojae strains, track the inheritance of this trait, and attempt to identify an Avr2 gene. Fifteen P. sojae strains were tested for virulence towards Rps2 and crosses were performed between selected virulent and avirulent strains to follow the inheritance of virulence. …