Life Sciences Commons^™

Multivariate Adaptive Shrinkage Improves Cross-Population Transcriptome Prediction And Association Studies In Underrepresented Populations, Daniel Araujo, Chris Nguyen, Xiaowei Hu, Anna V. Mikhaylova, Christopher R. Gignoux, Kristin Ardlie, Kent D. Taylor, Peter Durda, Yongmei Liu, George Papanicolaou, Michael H. Cho, Stephen S. Rich, Jerome I. Rotter, Nhlbi Topmed Consortium, Hae Kyung Im, Ani Manichaikul, Heather Wheeler

Biology: Faculty Publications and Other Works

Transcriptome prediction models built with data from European-descent individuals are less accurate when applied to different populations because of differences in linkage disequilibrium patterns and allele frequencies. We hypothesized that methods that leverage shared regulatory effects across different conditions, in this case, across different populations, may improve cross-population transcriptome prediction. To test this hypothesis, we made transcriptome prediction models for use in transcriptome-wide association studies (TWASs) using different methods (elastic net, joint-tissue imputation [JTI], matrix expression quantitative trait loci [Matrix eQTL], multivariate adaptive shrinkage in R [MASHR], and transcriptome-integrated genetic association resource [TIGAR]) and tested their out-of-sample transcriptome prediction accuracy …

Incorporating Sex Chromosomes In Transcriptome Prediction Models And Improving Cross-Population Prediction Performance, Daniel S. Araujo

Master's Theses

Transcriptome prediction models built with data from European-descent individuals are less accurate when applied to different populations because of differences in linkage disequilibrium patterns and allele frequencies. We hypothesized multivariate adaptive shrinkage may improve cross-population transcriptome prediction, as it leverages effect size estimates across different conditions - in this case, different populations. To test this hypothesis, we made transcriptome prediction models for use in transcriptome-wide association studies (TWAS) using different methods (Elastic Net, Matrix eQTL and Multivariate Adaptive Shrinkage in R (MASHR)) and tested their out-of-sample transcriptome prediction accuracy in population-matched and cross-population scenarios. Additionally, to evaluate model applicability in …

Analysis Of Structural Variation And Mtdna Copy Number In Finns, Liron Ganel

Arts & Sciences Electronic Theses and Dissertations

Cardiovascular disease (CVD) is a complex disease responsible for more deaths worldwide than any other cause according to the World Health Organization. Genetic association studies for CVD and related risk factors have successfully identified hundreds of loci associated with these complex diseases and traits, although much of their heritability remains unexplained. Structural variants (SVs) - including insertions, deletions, duplications, and inversions - are an understudied class of genomic variation that have the potential to explain much of the missing heritability of CVD and other complex traits. Here, we discuss advances emerging from the study of SVs in the context of …

Rising Rural Body-Mass Index Is The Main Driver Of The Global Obesity Epidemic In Adults, Con Burns, Tara Coppinger, Janette Walton, Et Al

Publications

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities1,2. This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity3,4,5,6. Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to …

Lncrna Ak001796 Is Essential For The Survival Of Aggressive Breast Cancer Cells, Sumayya Adib Al-Chalabi

Legacy Theses & Dissertations (2009 - 2024)

Abstract:

Refining Associations Between Targeted Genes And The Development Of Substance Use Disorders, Emily Olfson

Arts & Sciences Electronic Theses and Dissertations

Recent genome-wide association studies (GWAS) provide strong evidence for the contribution of a few specific genes to alcohol and nicotine dependence. Chapter 2 explores numerous previously identified candidate genes for alcohol dependence using a publicly available GWAS. I found that many candidate loci do not replicate, highlighting the utility of GWAS for focusing on disease associated genes. Chapters 3-5 dissect associations between three genome-wide significant genes and substance use disorders. Chapter 3 focuses on a functional variant in alcohol dehydrogenase (ADH) 1B. Through examining 1,550 adolescent drinkers in the Collaborative Study on the Genetics of Alcoholism (COGA), I extended adult …

Genetic Variations Affecting Serum Carcinoembryonic Antigen Levels And Status Of Regional Lymph Nodes In Patients With Sporadic Colorectal Cancer From Southern China, Yu Liang, Weizhong Tang, Tiquiang Huang, Yong Gao, Aihua Tan, Xiaobo Yang, Haiying Zhang, Yanling Hu, Xue Qin, Shan Li, Shijun Zhang, Linjian Mo, Zhenjia Liang, Deyi Shi, Zhang Huang, Yingyong Guan, Jicheng Zhou, Cheryl Winkler, Stephen J. O'Brien, Jianfeng Xu, Zengnan Mo, Tao Peng

Marine & Environmental Sciences Faculty Articles

Background: Serum carcinoembryonic antigen (sCEA) level might be an indicator of disease. Indeed, an elevated sCEA level is a prognostic factor in colorectal cancer (CRC) patients. However, the genetic determinants of sCEA level in healthy and CRC population remains unclear. Thus we investigated the genetic markers associated with elevated serum sCEA level in these two populations and its clinical implications.

Methods and Findings: Genome-wide association study (GWAS) was conducted in a cohort study with 4,346 healthy male adults using the Illumina Omni 1 M chip. Candidate SNPs associated with elevated sCEA levels were validated in 194 CRC patients on ABI …

Combined Metagenomic And Phenomic Approaches Identify A Novel Salt Tolerance Gene From The Human Gut Microbiome, Eamon Culligan, Julian R. Marchesi, Colin Hill, Roy D. Sleator

Department of Biological Sciences Publications

In the current study, a number of salt-tolerant clones previously isolated from a human gut metagenomic library were screened using Phenotype MicroArray (PM) technology to assess their functional capacity. PM's can be used to study gene function, pathogenicity, metabolic capacity and identify drug targets using a series of specialized microtitre plate assays, where each well of the microtitre plate contains a different set of conditions and tests a different phenotype. Cellular respiration is monitored colorimetrically by the reduction of a tetrazolium dye. One clone, SMG 9, was found to be positive for utilization/transport of L-carnitine (a well-characterized osmoprotectant) in the …

Mitochondrial Dna Variation In North Dakota Residents Of European Ancestry, Katelyn Kjelland

Undergraduate Theses and Senior Projects

Globally, many groups have been subject to studies of genetic variation and structure. However, studies of this sort rarely engage populations in the United States and are often limited to analysis of continental supergroups (European, African American, Hispanic, Native American) that cluster several ancestral origins of diverse genetic and cultural pasts. The aim of this study is to examine the degree of mtDNA variation in the residents of European ancestry living in North Dakota. This state, located in north-central United States, has been relatively recently settled by European migrants of distinct origins who originally formed isolated ethnic enclaves.

Analysis of …

Science Fiction And The Myth Of Trajectory Evolution, Jocelyn D. Pickreign

The Macalester Review

Stephen Jay Gould first proposed the idea of “iconographies of progress.” Today, one of the most prominent forms of progress iconography is the science fiction story. Science fiction as a genre frequently portrays evolution as a linear trajectory of increasing complexity, and in doing so, furthers a worldview that is not unlike the pre-Darwin understanding of human beings as both the center and the pinnacle of the natural world.

Machine Learning And Genome Annotation: A Match Meant To Be?, Kevin Y. Yip, Chao Cheng, Mark Gerstein

Dartmouth Scholarship

By its very nature, genomics produces large, high-dimensional datasets that are well suited to analysis by machine learning approaches. Here, we explain some key aspects of machine learning that make it useful for genome annotation, with illustrative examples from ENCODE.

Chapter 11: Genome-Wide Association Studies, William S. Bush, Jason H. Moore

Dartmouth Scholarship

Genome-wide association studies (GWAS) have evolved over the last ten years into a powerful tool for investigating the genetic architecture of human disease. In this work, we review the key concepts underlying GWAS, including the architecture of common diseases, the structure of common human genetic variation, technologies for capturing genetic information, study designs, and the statistical methods used for data analysis. We also look forward to the future beyond GWAS.

The Human Gut Microbiome: Ecology And Recent Evolutionary Changes, Jens Walter, Ruth Ley

Department of Food Science and Technology: Faculty Publications

The human gastrointestinal tract is divided into sections, allowing digestion and nutrient absorption in the proximal region to be separate from the vast microbial populations in the large intestine, thereby reducing conflict between host and microbes. In the distinct habitats of the gut, environmental filtering and competitive exclusion between microbes are the driving factors shaping microbial diversity, and stochastic factors during colonization history and in situ evolution are likely to introduce intersubject variability. Adaptive strategies of microbes with different niches are genomically encoded: Specialists have smaller genomes than generalists, and microbes with environmental reservoirs have large accessory genomes. A shift …

Molecular Evolution Of Genes Underlying Phenotypic Differences Between Humans And Chimpanzees, Santhoshi Bandla

Legacy Theses & Dissertations (2009 - 2024)

Chimpanzees (Pan troglodytes) and bonobos (P. paniscus) are often used as models to study the genetic and morphological changes on the lineage leading to the modern humans (Homo sapiens). Results of this dissertation suggest that, in comparison to other hominoids, chimpanzees and bonobos are more derived in their relative testes sizes and promiscuous mating systems. Phylogenetic analysis of genes that might underlie increased testes size revealed that, in addition to being a sex-determining gene, SRY displays Pan-specific amino acid replacements that make it a compelling candidate as a testes-size determining gene. Strikingly, SRY and another candidate gene, DMRT3, display patterns …

Characterization Of The Yeast Ionome: A Genome-Wide Analysis Of Nutrient Mineral And Trace Element Homeostasis In Saccharomyces Cerevisiae, David J. Eide, Suzanne Clark, T . Murlidharan Nair, Mathias Gehl, Michael Gribskov, Mary Lou Guerinot, Jeffrey Harper

Dartmouth Scholarship

Nutrient minerals are essential yet potentially toxic, and homeostatic mechanisms are required to regulate their intracellular levels. We describe here a genome-wide screen for genes involved in the homeostasis of minerals in Saccharomyces cerevisiae. Using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), we assayed 4,385 mutant strains for the accumulation of 13 elements (calcium, cobalt, copper, iron, potassium, magnesium, manganese, nickel, phosphorus, selenium, sodium, sulfur, and zinc). We refer to the resulting accumulation profile as the yeast 'ionome'.

A Critical Role For Kalirin In Ngf Signaling Through Trka, Kausik Chakrabarti, Rong Lin, Noraisha I. Schiller, Yanping Wang, David Koubi, Ying-Xin Fan, Brian B. Rudkin, Gibbes R. Johnson, Martin R. Schiller

Life Sciences Faculty Research

Kalirin is a multidomain guanine nucleotide exchange factor (GEF) that activates Rho proteins, inducing cytoskeletal rearrangement in neurons. Although much is known about the effects of Kalirin on Rho GTPases and neuronal morphology, little is known about the association of Kalirin with the receptor/signaling systems that affect neuronal morphology. Our experiments demonstrate that Kalirin binds to and colocalizes with the TrkA neurotrophin receptor in neurons. In PC12 cells, inhibition of Kalirin expression using antisense RNA decreased nerve growth factor (NGF)-induced TrkA autophosphorylation and process extension. Kalirin overexpression potentiated neurotrophin-stimulated TrkA autophosphorylation and neurite outgrowth in PC12 cells at a low …

Chemical Genomics In Yeast, Charles Brenner

Dartmouth Scholarship

Four recent 'chemical genomic' studies, using genome-scale collections of yeast gene deletions, have presented complementary approaches to identifying gene-drug and pathway-drug interactions.Many drugs have unknown, controversial or multiple mechanisms of action. Four recent 'chemical genomic' studies, using genome-scale collections of yeast gene deletions that were either arrayed or barcoded, have presented complementary approaches to identifying gene-drug and pathway-drug interactions.

A Study Of The Effects Of Consanguinity At The Genomic Level In Two Pakistani Bradaris, Sheena Sullivan

Theses : Honours

The purpose of the project was to assess the effects of inbreeding on the genetic constitution of two Pakistani bradaris (literally defined as brotherhoods). Both bradaris contain children born to consanguineous (first cousin) and nonconsanguineous marriages. DNA samples have been supplied by Dr Subaib Ahmed of the Armed Forces Institute of Pathology in Rawalpindi, for a total of 91 individuals. The specific allele frequencies, and levels of homozygosity of each bradari, were determined using twenty fluorescence-labelled microsatellite markers for chromosomes 13 and 15. Amplification of the DNA was performed using the polymerase chain reaction (PCR). The PCR products were separated …

Localisation And Detection Of A Polymorphism In The Human Skeletal Beta-Tropomyosin Gene (Tpm2), Clive C.J. Hunt

Theses : Honours

Tropomyosin is one of the components of the thin filaments of muscle, binding to actin, and, together with troponin, regulating contraction in a calcium-dependent manner (Cho et al.,1990). There are at least four distinct tropomyosin genes in vertebrates and each may encode at least six different isoforms of tropomyosin by alternate splicing (Novy et al, 1993; MacLeod et al., 1988). The alpha-tropomyosin gene TPM1 has recently been localised to 15q22 (Eyre et al, 1994) and has been shown to be mutated in some cases of familial hypertrophic cardiomyopathy (Thierfelder et al., 1994). The alpha-tropomyosin gene TPM3 has been recently localised …

Legal Aspects Of Human Genetics, Roger B. Dworkin, Gilbert S. Omenn

Articles by Maurer Faculty

No abstract provided.