Life Sciences Commons^™

The Detection Of Putative Recessive Lethal Haplotypes In Irish Sheep Populations, Rory Mcauley

ORBioM (Open Research BioSciences Meeting)

In livestock populations, recessive lethal alleles are a known contributor to poor reproductive performance due to embryonic death in homozygous individuals. Despite their lethal effect in the recessive form, these alleles may be maintained at high frequencies among carrier animals because of their positive pleiotropic effects on economically important traits. Although several such recessive alleles have been identified in cattle and pig populations, limited studies have been completed in sheep, and none within Irish sheep populations. Genotype data for 69,034 animals from five major Irish sheep breeds genotyped on a variety of panels was available for this study. Only animals …

Annotation Of Non-Model Species’ Genomes, Taiya Jarva

Master's Theses

The innovations in high throughput sequencing technologies in recent decades has allowed unprecedented examination and characterization of the genetic make-up of both model and non-model species, which has led to a surge in the use of genomics in fields which were previously considered unfeasible. These advances have greatly expanded the realm of possibilities in the fields of ecology and conservation. It is now possible to the identification of large cohorts of genetic markers, including single nucleotide polymorphisms (SNPs) and larger structural variants, as well as signatures of selection and local adaptation. Markers can be used to identify species, define population …

The Genomics Of Autism-Related Genes Il1rapl1 And Il1rapl2: Insights Into Their Cortical Distribution, Cell-Type Specificity, And Developmental Trajectories, Jacob Weaver

MUSC Theses and Dissertations

Neuropsychiatric disorders have a significant impact on modern society. These disorders affect a large percentage of the population: schizophrenia has a world-wide prevalence of 1% and autism spectrum disorders (ASD) affects 1 in 59 school-aged children in the US. There is substantial evidence that most neuropsychiatric disorders have a genetic component. Thus, with the advent of high throughput sequencing much effort has gone into identifying genetic variants associated with these disorders. The emerging picture from these studies is a complex one where hundreds of genes with small effects interact with a varied landscape of common variants to result in disease. …

Dfhic: A Dilated Full Convolution Model To Enhance The Resolution Of Hi-C Data, Bin Wang, Kun Liu, Yaohang Li, Jianxin Wang

Computer Science Faculty Publications

Motivation: Hi-C technology has been the most widely used chromosome conformation capture(3C) experiment that measures the frequency of all paired interactions in the entire genome, which is a powerful tool for studying the 3D structure of the genome. The fineness of the constructed genome structure depends on the resolution of Hi-C data. However, due to the fact that high-resolution Hi-C data require deep sequencing and thus high experimental cost, most available Hi-C data are in low-resolution. Hence, it is essential to enhance the quality of Hi-C data by developing the effective computational methods.

Results: In this work, we propose …

Identification Of Dna Methylation Episignatures For Classification And Phenotype/Genotype Correlation In Mendelian Neurodevelopmental Disorders, John Reilly

Electronic Thesis and Dissertation Repository

ABSTRACT: Diagnosis for neurodevelopmental disorders poses numerous challenges, related to the lack of specific findings and limited understanding of clinical impact of the majority of genetic variation. Epigenomics mechanisms involve chemical modifications in DNA that involve a range of cellular mechanisms. DNA methylation is an epigenetic mechanism involving addition and removal of methyl groups to cytosine residues. These methylation signals form episignatures; patterns of methylation that can be used as biomarkers capable of differentiating neurodevelopmental disorders. EpiSigns have enabled molecular diagnosis of a number of genetic conditions, classification of variants of unknown significance, and provided insights into the pathophysiology of …

The Low Abundance Of Cpg In The Sars-Cov-2 Genome Is Not An Evolutionarily Signature Of Zap, Ali Afrasiabi, Hamid Alinejad-Rokny, Azad Khosh, Mostafa Rahnama, Nigel Lovell, Zhenming Xu, Diako Ebrahimi

Plant Pathology Faculty Publications

The zinc finger antiviral protein (ZAP) is known to restrict viral replication by binding to the CpG rich regions of viral RNA, and subsequently inducing viral RNA degradation. This enzyme has recently been shown to be capable of restricting SARS-CoV-2. These data have led to the hypothesis that the low abundance of CpG in the SARS-CoV-2 genome is due to an evolutionary pressure exerted by the host ZAP. To investigate this hypothesis, we performed a detailed analysis of many coronavirus sequences and ZAP RNA binding preference data. Our analyses showed neither evidence for an evolutionary pressure acting specifically on CpG …

Identifying The Cell Composition And Clonal Diversity Of Supratentorial Ependymoma Using Single Cell Rna-Sequencing, James He

University Scholar Projects

Ependymoma is a primary solid tumor of the central nervous system. Supratentorial ependymoma (ST-EPN), a subtype of ependymomas, is driven by an oncogenic fusion between the ZFTA and RELA genes in 70% of cases. We introduced this fusion into neural progenitor cells of mice embryos via in utero electroporation of a non-viral binary piggyBac transposon system containing ZFTA-RELA. From preliminary data in the LoTurco lab, inducing the expression of ZFTA-RELA into different neural progenitor cells produces tumors of varying lethality and cellular composition. To define the cellular composition and subclonal diversity of ST-EPN tumors, we used single cell RNA-sequencing to …

Analysis Of Subtelomeric Rextal Assemblies Using Quast, Tunazzina Islam, Desh Ranjan, Mohammad Zubair, Eleanor Young, Ming Xiao, Harold Riethman

Computer Science Faculty Publications

Genomic regions of high segmental duplication content and/or structural variation have led to gaps and misassemblies in the human reference sequence, and are refractory to assembly from whole-genome short-read datasets. Human subtelomere regions are highly enriched in both segmental duplication content and structural variations, and as a consequence are both impossible to assemble accurately and highly variable from individual to individual. Recently, we developed a pipeline for improved region-specific assembly called Regional Extension of Assemblies Using Linked-Reads (REXTAL). In this study, we evaluate REXTAL and genome-wide assembly (Supernova) approaches on 10X Genomics linked-reads data sets partitioned and barcoded using the …

Composition And Homology In The Taxonomic Classification Of Escherichia Coli, Tanya Irani

Theses and Dissertations (Comprehensive)

As new techniques have been introduced, specifically the possibility of complete genome sequencing, better methods of defining bacterial species have also been proposed. One of the most recently proposed methods, using bioinformatic techniques, is to calculate the average nucleotide identity (ANI) between the homologous genome segments of different isolates. Another method for species discrimination that has been tested successfully is the similarity of DNA compositional signatures. However, in a recent update, DNA signatures split the available Escherichia coli complete genomes into three groups. To check if this result was consistent with such genomes belonging to different species, we tested methods …

Evolutionary And Ecological Determinism Of Host Specificity In Arthropod Parasites, Joseph Levey

UCARE Research Products

Understanding why some diseases infect more species than others is crucial for predicting where and when disease will spread, which can inform the management of wildlife, agriculture, and human health. Currently, large scale patterns of host-parasite dynamics are being studied to understand where to look for and how to manage emerging human diseases (Leroy 2005; Benelli 2018). Previous research has used the Global Mammal Parasite Database (GMPD) to look at host breadth—the number and diversity of species a pathogen can infect—for various groups of parasites, e.g. helminths, arthropods, fungi, etc., from a host-centric perspective (Stephens et al. 2017; Park et …

Chasing The Genetics Of Ascites In Broilers Using Whole Genome Resequencing, Alia Parveen

Graduate Theses and Dissertations

We are using whole genome resequencing to identify chromosomal regions associated with resistance or susceptibility to ascites, a form of pulmonary hypertension syndrome, meat-type chickens. Previous Genome Wide Association Studies (GWAS) based on Single Nucleotide Polymorphisms (SNPs) have identified regions on chromosomes 2, 9 and Z. Despite several GWAS and further genotyping, there are no reliable or potential markers for ascites phenotype. We have completed screening of Copy Number Variations (CNVs) and Single Nucleotide Polymorphisms in ascites resistant and susceptible birds from the relaxed, REL, line derived from a commercial elite broiler line. DNA samples from resistant and susceptible birds …

Phylogenetic History Of The Amy Gene Cluster In Catarrhines, Christian M. Gagnon

Theses and Dissertations

This study phylogenetically analyzed 30 AMY-related genes from 11 primates. The results show the gradual expansion of the AMY gene family which could have allowed primates to adapt to various ecological landscapes and maximize energy intake from starch-rich foods in periods of food scarcity.

Genome-Wide Systems Genetics Of Alcohol Consumption And Dependence, Kristin Mignogna

Theses and Dissertations

Widely effective treatment for alcohol use disorder is not yet available, because the exact biological mechanisms that underlie this disorder are not completely understood. One way to gain a better understanding of these mechanisms is to examine the genetic frameworks that contribute to the risk for developing this disorder. This dissertation examines genetic association data in combination with gene expression networks in the brain to identify functional groups of genes associated with alcohol consumption and dependence.

The first study took advantage of the behavioral complexity of human samples, and experimental capabilities provided by mouse models, by co-analyzing gene expression networks …

Gene-Based Association Study For Lipid Traits In Diverse Cohorts Implicates Bace1 And Sidt2 Regulation In Triglyceride Levels, Angela Andaleon, Lauren S. Mogil, Heather Wheeler

Bioinformatics Faculty Publications

Plasma lipid levels are risk factors for cardiovascular disease, a leading cause of death worldwide. While many studies have been conducted on lipid genetics, they mainly focus on Europeans and thus their transferability to diverse populations is unclear. We performed SNP- and gene-level genome-wide association studies (GWAS) of four lipid traits in cohorts from Nigeria and the Philippines and compared them to the results of larger, predominantly European meta-analyses. Two previously implicated loci met genome-wide significance in our SNP-level GWAS in the Nigerian cohort, rs34065661 in CETP associated with HDL cholesterol (P = 9.0 × 10⁻¹⁰) and …

Unseen Science: Modern Discoveries Too Far Away Or Tiny For Human Eyes, Lucy Huang

Capstones

As science has progressed, scientists have realized that evidence goes beyond the realms of physical sight. Whether it is too small or difficult to find, scientists have developed different ways to get around this problem. We see this in cancer genomics and in extrasolar planetary research. Scientists use what they know and what they measure to validate their work.

https://lucy-huang-9tge.squarespace.com/

Crispr-Cas9 Nuclear Dynamics And Target Recognition In Living Cells, Hanhui Ma, Li-Chun Tu, Ardalan Naseri, Maximiliaan Huisman, Shaojie Zhang, David Grünwald, Thoru Pederson

David Grünwald

The bacterial CRISPR-Cas9 system has been repurposed for genome engineering, transcription modulation, and chromosome imaging in eukaryotic cells. However, the nuclear dynamics of clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) guide RNAs and target interrogation are not well defined in living cells. Here, we deployed a dual-color CRISPR system to directly measure the stability of both Cas9 and guide RNA. We found that Cas9 is essential for guide RNA stability and that the nuclear Cas9-guide RNA complex levels limit the targeting efficiency. Fluorescence recovery after photobleaching measurements revealed that single mismatches in the guide RNA seed sequence …

Isolation And Comparative Genomic Analysis Of Final Third Of Satis Genome, Kelly Hartigan, Nicole Curnutt, Matthew Mcdermut

Undergraduate Research Symposium Posters

A highly novel Streptomyces phage, Satis, was isolated from a direct environmental sample collected from outside Danforth House on the Washington University campus. Satis infects bacterial species Streptomyces lividans producing pinpoint, cloudy plaques less than 1mm in diameter. Electron microscope data shows rare atypical physical features. Rather than the common octahedral capsid shape, Satis has a prolate head with visible cross-linked hexagonal protein structure and average measurements of 285 nm by 47 nm with a long, flexible tail measuring 268 nm. Upon sequencing, it was found that Satis contains the longest phage genome discovered to date through the SEA-PHAGE program …

Hybridization Dynamics Of A Newly Discovered Parrotfish Swarm In The Tropical Eastern Pacific, Robert Barron

Honors Projects

Hybrid zones and their dynamics are important in the understanding of the genetic basis of reproductive isolation and speciation. This study seeks to investigate the hybridization dynamics of a Scarus hybrid swarm within the Tropical Eastern Pacific (TEP) that includes four phenotypically distinct species: S. perrico, S. ghobban, S. rubroviolaceus, and S. compressus. Genetic and population structure analyses of four nuclear loci and a mitochondrial locus revealed that one of the four species, S. compressus, was the result of two different hybrid crosses: S. perrico ✕ S. rubroviolaceus and S. perrico ✕ S. ghobban. A …

A Longitudinal Cline Characterizes The Genetic Structure Of Human Populations In The Tibetan Plateau, Choongwon Jeong, Benjamin M. Peter, Buddha Basnyat, Maniraj Neupane, Geoff Childs, Sienna Craig, John Novembre, Anna Di Rienzo

Dartmouth Scholarship

Indigenous populations of the Tibetan plateau have attracted much attention for their good performance at extreme high altitude. Most genetic studies of Tibetan adaptations have used genetic variation data at the genome scale, while genetic inferences about their de- mography and population structure are largely based on uniparental markers. To provide genome-wide information on population structure, we analyzed new and published data of 338 individuals from indigenous populations across the plateau in conjunction with world- wide genetic variation data. We found a clear signal of genetic stratification across the east- west axis within Tibetan samples. Samples from more eastern locations …

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 …

Functional Analysis Of Synthetic Gene Circuits Controlling A Protein Pump In Yeast, Junchen Diao

Dissertations & Theses (Open Access)

Synthetic biology aims to build biological devices to understand living systems and explore new applications. Synthetic gene circuits such as genetic switches, oscillators and logic gates are at the core of many synthetic biology applications. These gene circuits often include a sensor/regulator protein capable to detect small molecules and then transduce them into a regulatory signal to generate measurable output. Similar signal transduction networks are also abundant in nature. However, in many natural and engineered scenarios, the output also affects the regulator/sensor protein. How such interactions between the regulator/sensor and the output affect synthetic gene circuit function has not been …

Systems Level Analysis Of Systemic Sclerosis Shows A Network Of Immune And Profibrotic Pathways Connected With Genetic Polymorphisms, J. Matthew Mahoney, Jaclyn Taroni, Viktor Martyanov, Tammara A. A. Wood, Casey S. Greene, Patricia A. Pioli, Monique E. Hinchcliff, Michael L. Whitfield

Dartmouth Scholarship

Systemic sclerosis (SSc) is a rare systemic autoimmune disease characterized by skin and organ fibrosis. The pathogenesis of SSc and its progression are poorly understood. The SSc intrinsic gene expression subsets (inflammatory, fibroproliferative, normal-like, and limited) are observed in multiple clinical cohorts of patients with SSc. Analysis of longitudinal skin biopsies suggests that a patient's subset assignment is stable over 6-12 months. Genetically, SSc is multi-factorial with many genetic risk loci for SSc generally and for specific clinical manifestations. Here we identify the genes consistently associated with the intrinsic subsets across three independent cohorts, show the relationship between these genes …

Phenotypic Robustness And The Assortativity Signature Of Human Transcription Factor Networks, Dov A. Pechenick, Joshua L. Payne, Jason H. Moore

Dartmouth Scholarship

Many developmental, physiological, and behavioral processes depend on the precise expression of genes in space and time. Such spatiotemporal gene expression phenotypes arise from the binding of sequence-specific transcription factors (TFs) to DNA, and from the regulation of nearby genes that such binding causes. These nearby genes may themselves encode TFs, giving rise to a transcription factor network (TFN), wherein nodes represent TFs and directed edges denote regulatory interactions between TFs. Computational studies have linked several topological properties of TFNs - such as their degree distribution - with the robustness of a TFN's gene expression phenotype to genetic and environmental …

Structural Features Of The Pseudomonas Fluorescens Biofilm Adhesin Lapa Required For Lapg-Dependent Cleavage, Biofilm Formation, And Cell Surface Localization, Chelsea D. Boyd, T. Jarrod Smith, Sofiane El-Kirat-Chatel, Peter D. Newell, Yves F. Dufrêne, George A. O'Toole

Dartmouth Scholarship

The localization of the LapA protein to the cell surface is a key step required by Pseudomonas fluorescens Pf0-1 to irreversibly attach to a surface and form a biofilm. LapA is a member of a diverse family of predicted bacterial adhesins, and although lacking a high degree of sequence similarity, family members do share common predicted domains. Here, using mutational analysis, we determine the significance of each domain feature of LapA in relation to its export and localization to the cell surface and function in biofilm formation. Our previous work showed that the N terminus of LapA is required for …

Creating A Package In R, Brit Schneiders, Eric Archer

STAR Program Research Presentations

In a time of increasingly efficient technology and data production, scientists are producing data faster than it can be analyzed. Therefore, user accessibility to data analysis is becoming more and more critical. In general, researchers have a set of raw data and want an efficient means to their final analysis. A package serves as that means by creating a set of functions and making them accessible to the user. Often, a user has a small piece of code to run (a single R script, for example), and that script requires the use of certain functions, which are contained in a …

Key Genes For Modulating Information Flow Play A Temporal Role As Breast Tumor Coexpression Networks Are Dynamically Rewired By Letrozole, Nadia M. Penrod, Jason H. Moore

Dartmouth Scholarship

Genes do not act in isolation but instead as part of complex regulatory networks. To understand how breast tumors adapt to the presence of the drug letrozole, at the molecular level, it is necessary to consider how the expression levels of genes in these networks change relative to one another. Using transcriptomic data generated from sequential tumor biopsy samples, taken at diagnosis, following 10-14 days and following 90 days of letrozole treatment, and a pairwise partial orrelation statistic, we build temporal gene coexpression networks. We characterize the structure of each network and identify genes that hold prominent positions for maintaining …

Transcriptomic Characterization Of A Synergistic Genetic Interaction During Carpel Margin Meristem Development In Arabidopsis Thaliana, April N. Wynn, Elizabeth E. Rueschhoff, Robert G. Franks

Biological Sciences Research

In flowering plants the gynoecium is the female reproductive structure. In Arabidopsis thalianaovules initiate within the developing gynoecium from meristematic tissue located along the margins of the floral carpels. When fertilized the ovules will develop into seeds. SEUSS (SEU) and AINTEGUMENTA (ANT) encode transcriptional regulators that are critical for the proper formation of ovules from the carpel margin meristem (CMM). The synergistic loss of ovule initiation observed in the seu ant double mutant suggests that SEU and ANT share overlapping functions during CMM development. However the molecular mechanism underlying this synergistic interaction is unknown. Using …

Minimum Description Length Measures Of Evidence For Enrichment, Zhenyu Yang, David R. Bickel

COBRA Preprint Series

In order to functionally interpret differentially expressed genes or other discovered features, researchers seek to detect enrichment in the form of overrepresentation of discovered features associated with a biological process. Most enrichment methods treat the p-value as the measure of evidence using a statistical test such as the binomial test, Fisher's exact test or the hypergeometric test. However, the p-value is not interpretable as a measure of evidence apart from adjustments in light of the sample size. As a measure of evidence supporting one hypothesis over the other, the Bayes factor (BF) overcomes this drawback of the p-value but lacks …

Powerful Snp Set Analysis For Case-Control Genome Wide Association Studies, Michael C. Wu, Peter Kraft, Michael P. Epstein, Deanne M. Taylor, Stephen J. Chanock, David J. Hunter, Xihong Lin

Harvard University Biostatistics Working Paper Series

No abstract provided.

A Decomposition Of The Pure Parsimony Problem, Allen Holder, Thomas M. Langley

Mathematical Sciences Technical Reports (MSTR)

We partially order a collection of genotypes so that we can represent the problem of inferring the least number of haplotypes in terms of substructures we call g-lattices. This representation allows us to prove that if the genotypes partition into chains with certain structure, then the NP-Hard problem can be solved efficiently. Even without the specified structure, the decomposition shows how to separate the underlying integer programming model into smaller models.