Genomics Commons^™

Chromatin Accessibility Dynamics In The Arabidopsis Root Epidermis And Endodermis During Cold Acclimation, Shawn Hoogstra

Electronic Thesis and Dissertation Repository

Understanding cell-type specific transcriptional responses to environmental conditions is limited by a lack of knowledge of transcriptional control due to epigenetic dynamics. Additionally, cell-type analyses are limited by difficulties in applying current technologies to single cell-types. A novel DNase-seq protocol and analysis procedure, deemed DNase-DTS, was developed to identify DHSs in the Arabidopsis epidermis and endodermis under control and cold acclimation conditions. Results identified thousands of DHSs within each cell-type and experimental condition. DHSs showed strong association to gene expression, DNA methylation, and histone modifications. A priori mapping of existing DNA binding motifs within accessible genes and the cold C-repeat/dehydration …

Gene Expression Changes In The Mushroom Body Of Drosophila Melanogaster During A Time Course Of Long-Term Memory Formation And Maintenance, Spencer G. Jones

Electronic Thesis and Dissertation Repository

Long-term memory (LTM) requires gene transcription. However, there is still much to learn about which genes are transcriptionally regulated during LTM and the biological roles they play. Here, gene expression changes were characterized in Drosophila melanogaster over a time course of LTM formation and maintenance in neurons of the mushroom body (MB), a structure required for normal learning and memory. I identified 120 genes differentially expressed (q < 0.2, fold change > 1.3) 24h after LTM induction. Among these were 13 potential downstream targets for RNA localization by the known memory genes pumilo, staufen and oskar, several genes encoding chromatin regulators and seven genes with …

Amelioration Of Prenatal Alcohol Effects By Environmental Enrichment In A Mouse Model Of Fasd, Aniruddho Chokroborty-Hoque

Electronic Thesis and Dissertation Repository

Maternal alcohol consumption during pregnancy results in a spectrum of behavioural and cognitive deficits collectively known as Fetal Alcohol Spectrum Disorders (FASD). Currently, little is know about if and how the external environment may modulate these deficits. I have used C57BL/6 mice to study this interaction between prenatal alcohol exposure and the postnatal environment. Alcohol exposure during synaptogenesis produces high levels of anxiety-like traits and decreased memory performance. Alcohol-exposed mice (and matched unexposed controls) were put in 'environmentally-enriched' conditions of voluntary exercise, physical activities and cognitive stimulation to ascertain the effects of a positive postnatal environment. The results show that …

Transcriptional Regulation Of Cell-Type Specific Expression In The Arabidopsis Root, Keegan M. Leckie

Electronic Thesis and Dissertation Repository

Characterizing transcription factor interactions with their corresponding binding sites is crucial for understanding how gene expression is regulated by DNA sequence. A more comprehensive understanding of this process could have benefits in synthetic promoter design and creation of genetically modified organisms. Herein, the promoters of genes exhibiting cell-type specific expression within a single layer of the Arabidopsis root are analyzed to identify cis-regulatory motifs implicated in cell-type specific expression. De novo motif prediction identifies multiple motif candidates overly represented in the promoter sequences of co-expressed genes specific for epidermal, cortex, and endodermal expression. Several endodermal specific putative motifs are …

Unravelling Organelle Genome Transcription Using Publicly Available Rna-Sequencing Data, Matheus Sanita Lima

Electronic Thesis and Dissertation Repository

The study of organelles helped forge theories of genome evolution because of their unconventional genomes and gene expression regimes. The organelle genomics field (~35 years old) has seen the development of next generation sequencing (NGS) techniques and the consequent skyrocketing of genomic and transcriptomic data. However, these data are being underused in the studies of organelle genome transcription. My thesis investigates how NGS has affected the field of organelle genomics at both the DNA and RNA levels. First, I demonstrate that although organelle genomes are being sequenced as never before, they are un-characterized as they are published mostly as “organelle …

Evolutionary Genetic Aspects Of Host Association In Generalist Ectoparasites, Benoit Talbot

Electronic Thesis and Dissertation Repository

Despite the use of the host for dispersal by most parasite species, the extremely loose relationship typical between highly mobile hosts and generalist ectoparasites may lead to very different gene flow patterns between the two, leading in turn to different spatial genetic structure, and potentially different demographic history. I examined how similar gene flow patterns are between Cimex adjunctus, a generalist ectoparasite of bats present throughout North America, and two of its key bat hosts. I first analyzed the continent-scale genetic structure and demographic history of C. adjunctus and compared it to that of two of its hosts, the …

Hippocampal Epigenetic Changes In A Mouse Model Of Fetal Alcohol Spectrum Disorders, Eric J. Chater-Diehl

Electronic Thesis and Dissertation Repository

Fetal alcohol spectrum disorders (FASD) refers to the neurological, developmental, and behavioural abnormalities arising from in utero ethanol exposure. These abnormities included attention deficit, anxiety, and learning and memory impairment persisting into adulthood. The molecular mechanisms of such persistent behavioural changes remain unknown and are an area of intense research. In this thesis, mice were exposed to ethanol during the third trimester equivalent, the peak of synaptic development. Following this exposure, genome-wide epigenetic and gene expression and changes in the hippocampus were assessed in adult (70 day old) mice.

In the first experiment, genome-wide trimethylation of histone H3 at histone …

Discovery And Validation Of Information Theory-Based Transcription Factor And Cofactor Binding Site Motifs., Ruipeng Lu, Eliseos J Mucaki, Peter K Rogan

Biochemistry Publications

Data from ChIP-seq experiments can derive the genome-wide binding specificities of transcription factors (TFs) and other regulatory proteins. We analyzed 765 ENCODE ChIP-seq peak datasets of 207 human TFs with a novel motif discovery pipeline based on recursive, thresholded entropy minimization. This approach, while obviating the need to compensate for skewed nucleotide composition, distinguishes true binding motifs from noise, quantifies the strengths of individual binding sites based on computed affinity and detects adjacent cofactor binding sites that coordinate with the targets of primary, immunoprecipitated TFs. We obtained contiguous and bipartite information theory-based position weight matrices (iPWMs) for 93 sequence-specific TFs, …

P08. Unravelling Organelle Genome Evolution Architecture Using Rna-Sequencing Data, Matheus Sanita Lima, David Roy Smith

Western Research Forum

Background: Mitochondria genomes vary from 11 Mb to 6 kb, while plastids can vary from 1 Mb to 30 kb. Non-coding DNA accounts for most of this size variation, but the mechanistic and evolutionary reasons for that are still unknown. Next generation sequencing has generated unprecedented amounts of genomic and transcriptomic data that can be used for organelle genome evolution studies. However, most of these data is used only for the study of cell nucleus. Therefore, I decided to use these untapped data source to investigate the transcription of organelle genomes in plastid-bearing protists.

Methods: I mapped the transcriptomes over …

Microbial Repopulation Following In Situ Star Remediation, Gavin Overbeeke

Electronic Thesis and Dissertation Repository

In situ STAR (Self-sustaining Treatment for Active Remediation) is an emerging remediation technology which uses smouldering combustion to destroy nonaqueous phase liquid (NAPL) contamination in the subsurface. Since STAR smouldering travels through contaminated soils slowly (~0.5 to 5 m/day) and subjects them to high temperatures (400–1000°C), it is expected that this technology will thoroughly dry and sterilize the zones which it treats. Further, soils surrounding the treatment zone which are not smouldered will be heated, although not smouldered, by virtue of their proximity to STAR, impacting microbial communities within them. Therefore, the objectives of this work are to quantify the …