Genetics and Genomics Commons^™

Centers For Mendelian Genomics: A Decade Of Facilitating Gene Discovery, Samantha M Baxter, Jennifer E Posey, Nicole J Lake, Nara Sobreira, Jessica X Chong, Steven Buyske, Elizabeth E Blue, Lisa H Chadwick, Zeynep H Coban-Akdemir, Kimberly F Doheny, Colleen P Davis, Monkol Lek, Christopher Wellington, Shalini N Jhangiani, Mark Gerstein, Richard A Gibbs, Richard P Lifton, Daniel G Macarthur, Tara C Matise, James R Lupski, David Valle, Michael J Bamshad, Ada Hamosh, Shrikant Mane, Deborah A Nickerson, Heidi L Rehm, Anne O'Donnell-Luria

Faculty, Staff and Student Publications

PURPOSE: Mendelian disease genomic research has undergone a massive transformation over the past decade. With increasing availability of exome and genome sequencing, the role of Mendelian research has expanded beyond data collection, sequencing, and analysis to worldwide data sharing and collaboration.

METHODS: Over the past 10 years, the National Institutes of Health-supported Centers for Mendelian Genomics (CMGs) have played a major role in this research and clinical evolution.

RESULTS: We highlight the cumulative gene discoveries facilitated by the program, biomedical research leveraged by the approach, and the larger impact on the research community. Beyond generating a list of gene-phenotype relationships …

The Large And Small Of It: The Microbiome And Metagenomics, Austin Hopkins, Elaina Gollmar, Jessica Fernandez, Shawn Wolf, Austin Hilverding, Andrew M. Roecker

Pharmacy and Wellness Review

Metagenomics, the analysis of the microbial genome, permits scientists to understand the influences of external sources including diet, metabolism and antibiotics on the human microbiome. Research has revealed the possibility of a core symbiosis between humans and bacteria. The main role of the human microbiome is to aid in digestion, but identified ancillary roles include immunologic homeostasis and infection prevention. Quantifying the composition and variability of the microbiome will help lead to future treatments or preventive strategies against unhealthy change. A variety of methods may be used to define the microbiome, and 16S amplicon sequencing is primarily utilized today. Probiotics …

Standards Recommendations For The Earth Biogenome Project, Mara K. Lawniczak, Richard Durbin, Paul Flicek, Kerstin Lindblad-Toh, Xiaofeng Wei, John M. Archibald, William J. Baker, Katherine Belov, Mark L. Blaxter, Tomas Marques-Bonet, Anna K. Childers, Jonathan A. Coddington, Keith A. Crandall, Andrew J. Crawford, Robert P. Davey, Federica Di Palma, Qi Fang, Wilfried Haerty, Neil Hall, Katherine J. Hoff, Kerstin Howe, Erich D. Jarvis, Warren E. Johnson, Rebecca N. Johnson, Paul J. Kersey, Xin Liu, Jose V. Lopez, Eugene W. Myers, Olga Vinnere Pettersson, Adam M. Phillippy, Monica F. Poelchau, Kim D. Pruitt, Arang Rhie, Juan Carlos Castilla-Rubio, Sunil Kumar Sahu, Nicholas A. Salmon, Pamela S. Soltis, David Swarbreck, Françoise Thibaud-Nissen, Sibo Wang, Jill L. Wegrzyn, Guojie Zhang, He Zhang, Harris A. Lewin, Stephen Richards

Biology Faculty Articles

A global international initiative, such as the Earth BioGenome Project (EBP), requires both agreement and coordination on standards to ensure that the collective effort generates rapid progress toward its goals. To this end, the EBP initiated five technical standards committees comprising volunteer members from the global genomics scientific community: Sample Collection and Processing, Sequencing and Assembly, Annotation, Analysis, and IT and Informatics. The current versions of the resulting standards documents are available on the EBP website, with the recognition that opportunities, technologies, and challenges may improve or change in the future, requiring flexibility for the EBP to meet its goals. …

Chromomap: An R Package For Interactive Visualization Of Multi-Omics Data And Annotation Of Chromosomes, Lakshay Anand, Carlos M. Rodriguez Lopez

Horticulture Faculty Publications

BACKGROUND: The recent advancements in high-throughput sequencing have resulted in the availability of annotated genomes, as well as of multi-omics data for many living organisms. This has increased the need for graphic tools that allow the concurrent visualization of genomes and feature-associated multi-omics data on single publication-ready plots.

RESULTS: We present chromoMap, an R package, developed for the construction of interactive visualizations of chromosomes/chromosomal regions, mapping of any chromosomal feature with known coordinates (i.e., protein coding genes, transposable elements, non-coding RNAs, microsatellites, etc.), and chromosomal regional characteristics (i.e. genomic feature density, gene expression, DNA methylation, chromatin modifications, etc.) of organisms …

Single Cell Lineage Tracing Reveals Mechanisms Of Tumor Initiation And Chemoresistance In Small Cell Lung Cancer, Hannah Wollenzien

Dissertations and Theses

Small Cell Lung Cancer (SCLC) is a devastating disease characterized by a very low two-year survival rate and almost universal acquisition of chemoresistance. Nearly all patients have tumors driven by functional inactivation of the tumor suppressors Rb and p53, but despite the uniform origins of this tumor, not all patients are genetically or phenotypically identical. SCLC can be subtyped into four unique molecular subtypes, determined by the expression of ASCL1, NEUROD1, POU2F3, or YAP1. These subtypes are plastic, and subtype switching after chemotherapy has been documented. Without the understanding of how tumor heterogeneity arises, we cannot solve the challenge of …

Genomic Degeneration And Reduction In The Fish Pathogen Mycobacterium Shottsi, David T. Gauthier, Janis H. Doss, M. Lagatta, T. Gupta, R.K. Karls, F. D. Quinn

Biological Sciences Faculty Publications

Mycobacterium shottsii is a dysgonic, nonpigmented mycobacterium originally isolated from diseased striped bass (Morone saxatilis) in the Chesapeake Bay, USA. Genomic analysis reveals that M. shottsii is a Mycobacterium ulcerans/Mycobacterium marinum clade (MuMC) member, but unlike the superficially similar M. pseudoshottsii, also isolated from striped bass, it is not an M. ulcerans ecovar, instead belonging to a transitional group of strains basal to proposed “Aronson” and “M” lineages. Although phylogenetically distinct from the human pathogen M. ulcerans, the M. shottsii genome shows parallel but nonhomologous genomic degeneration, including massive accumulation of pseudogenes accompanied by proliferation of …

Applying Conservation Genomic Techniques To Guide Management Of The Reticulated Flatwoods Salamander (Ambystoma Bishopi), Miranda Gaupp

College of Graduate Studies: Theses & Dissertations

The Reticulated flatwoods salamander (Ambystoma bishopi) is a federally endangered amphibian endemic to the longleaf-pine ecosystem of the southeastern U.S. This study used analyses of single-nucleotide polymorphism (SNP) data, collected from 2,255 unique individuals across 5 breeding seasons, spread across the known extant range of A. bishopi, to characterize the genetic diversity and demographics of populations, genetic relationships among populations, and patterns and spatial extents of gene flow, and to evaluate potential effects of management on A. bishopi’s resiliency. Population structure was strongly hierarchical, with individual breeding ponds (n = 38) acting as semi-connected subpopulations …

Population Genomics Of Redbreast Sunfish (Lepomis Auritus): Exploring Gene Flow And Local Adaptation In A Widely Distributed Freshwater Fish, Garret J. Strickland

College of Graduate Studies: Theses & Dissertations

Little information is available concerning the distribution of genetic diversity in non-salmonid, non-imperiled, freshwater fish. In order to fill in this knowledge gap, I conducted a population genomics survey in Redbreast Sunfish (Lepomis auritus; RBS), a widespread, generalist species distributed along the Atlantic slope rivers of eastern North America. I sampled four basins (ACF, Savannah, Roanoke, and James) at eight sites each with a factorial experimental design. Sites were distributed among coastal plain, Piedmont, or mountain ecoregions in order to capture the greatest range of environmental states experienced by RBS, with the intention of finding evidence for local adaptation to …

Factors Impacting Genomic Testing Rates Among Epithelial Ovarian Cancer Patients Across A Large Community-Based Healthcare System, Nicole M. Kretzer, Christopher J. Darus, Nancy Biery, Roshanthi Weerasinghe, Grace Li, Ann Vita, Shwetha Pindikuri, Amy S. Parrish, Charles W Drescher, Fernanda B. Musa

All Podium Presentations

Background: Epithelial ovarian cancer (EOC) accounts for the highest mortality of all gynecological cancers. NCCN guidelines recommend germline and somatic testing for all women with invasive EOC. Despite this recommendation, there is a large diversity in the types of testing patients receive even within a single healthcare system. Reported data of genetic testing for epithelial ovarian cancer (EOC) patients is largely based on patients treated at academic medical centers or patients who participate in clinical trials.

Purpose: This study sought to determine the rates of germline and somatic testing for epithelial ovarian cancer patients and identify factors that impact testing …

Patterns Of Genomic Testing For Epithelial Ovarian Cancer Across A Large Community-Based Health Care Network- A Real World Experience, Nicole M. Kretzer, Fernanda B. Musa, Christopher Darus, Nancy Biery, Roshanthi Weerasinghe, Grace Li, Ann Vita, Shwetha Pindikuri, Amy S. Parrish, Charles W Drescher

All Podium Presentations

Background: NCCN guidelines recommend germline and somatic tumor testing for all women with invasive epithelial ovarian cancer (EOC). Despite this recommendation, testing rates remain low and an optimal strategy to achieve the recommended testing has not been defined.

Purpose: We elected to review the patterns of germline and somatic tumor testing for patients with EOC across a large health care network to identify barriers to testing.

Methods: Clinical, pathologic, demographic and genomic testing (GT) information including involvement of a genetic counselor, specific test(s) ordered, test vendor, test turn-around time, and test results were obtained from the diverse dataset within the …

Quantifying Contributions Of Climate, Geography, And Gene Flow To Divergence: A Case Study For Three North American Pines, Constance E. Bolte

Theses and Dissertations

Long-lived species of trees, especially conifers, often display weak patterns of reproductive isolation, but clear patterns of local adaptation and phenotypic divergence. Discovering the evolutionary history of these patterns is paramount to a generalized understanding of speciation and the processes that confer population persistence versus those that compromise adaptive potential under rapidly changing environments. Forest trees have long generation times and low migratory potential making them especially vulnerable to population fragmentation and reductions of genetic diversity due to insufficient tracking of niche optima and adaptational lags. Within clades of the genus Pinus, evolutionary histories appear to be riddled with hybridization …

Examination Of Common And Rare Variant Genetic Architecture Of Psychiatric Disorders, Mohammad Ahangari

Theses and Dissertations

Psychiatric disorders are often heterogenous in their manifestation and genome-wide association studies have identified many common risk variants involved in their polygenic architectures with varying degrees of pleiotropy. In recent years, large-scale biobanks have also begun sequencing the genome of their participants to elucidate the role of rare risk variation in the genetic architecture of complex phenotypes, including psychiatric traits. This dissertation sought to better understand the role of both common and rare risk variation in the genetic architecture of psychiatric disorders with a particular focus on schizophrenia and alcohol problems. In the first three analyses, we focused on characterizing …

Genomics Of Postprandial Lipidomics In The Genetics Of Lipid-Lowering Drugs And Diet Network Study, Marguerite R. Irvin, May E. Montasser, Tobias Kind, Sili Fan, Dinesh K. Barupal, Amit Patki, Rikki M. Tanner, Nicole D. Armstrong, Kathleen A. Ryan, Steven A. Claas, Jeffrey R. O’Connell, Hemant K. Tiwari, Donna K. Arnett

Epidemiology and Environmental Health Faculty Publications

Postprandial lipemia (PPL) is an important risk factor for cardiovascular disease. Inter-individual variation in the dietary response to a meal is known to be influenced by genetic factors, yet genes that dictate variation in postprandial lipids are not completely characterized. Genetic studies of the plasma lipidome can help to better understand postprandial metabolism by isolating lipid molecular species which are more closely related to the genome. We measured the plasma lipidome at fasting and 6 h after a standardized high-fat meal in 668 participants from the Genetics of Lipid-Lowering Drugs and Diet Network study (GOLDN) using ultra-performance liquid chromatography coupled …

Foe To Friend: Parallel Domestication Of Ophiocordyceps From Fungal Parasite To Beneficial Symbiont In Cicadas, Jason Vailionis, Eric Rl Gordon, Chris Simon

University Scholar Projects

Nutritional symbioses are integral to the survival and diversity of many insects. The majority of herbivorous insects in the order Hemiptera possess stable, inherited symbionts that produce essential amino acids and vitamins. However, instability has been observed in cicadas, with one bacterial symbiont, Hodgkinia cicadicola, being repeatedly replaced by a new fungal symbiont, Ophiocordyceps. The fungal symbionts are thought to be derived from parasitic Ophiocordyceps species, but little is known about these parasitic ancestors or how the transition from parasite to mutualist occurs. We used a combination of targeted amplified genes and metagenomic sequencing to investigate the evolution …

The Role Of Interspecies Recombination In The Evolution Of Antibiotic-Resistant Pneumococci, Joshua C. D'Aeth, Mark Pg Van Der Linden, Lesley Mcgee, Herminia De Lencastre, Paul Turner, Jae-Hoon Song, Stephanie W. Lo, Rebecca A. Gladstone, Gps Consortium, Sadia Shakoor

Department of Pathology and Laboratory Medicine

Multidrug-resistant Streptococcus pneumoniae emerge through the modification of core genome loci by interspecies homologous recombinations, and acquisition of gene cassettes. Both occurred in the otherwise contrasting histories of the antibiotic-resistant S. pneumoniae lineages PMEN3 and PMEN9. A single PMEN3 clade spread globally, evading vaccine-induced immunity through frequent serotype switching, whereas locally circulating PMEN9 clades independently gained resistance. Both lineages repeatedly integrated Tn916-type and Tn1207.1-type elements, conferring tetracycline and macrolide resistance, respectively, through homologous recombination importing sequences originating in other species. A species-wide dataset found over 100 instances of such interspecific acquisitions of resistance cassettes and flanking …

Impact Of Intratumor Heterogeneity And The Tumor Microenvironment In Shaping Tumor Evolution And Response To Therapy, Akash Mitra

Dissertations and Theses (Open Access)

Intratumor heterogeneity (ITH) is a crucial challenge in cancer treatment. The genotypic and phenotypic heterogeneity underlying diverse cancer types leads to subclonal variation, which may result in mixed or failed response to therapy. The heterogeneity at the tumor level, along with the tumor microenvironment (TME), often shapes tumor evolution and ultimately clinical outcome. Given that modern treatment paradigms increasingly expose patients with metastatic disease to multiple treatment modalities through the course of their disease, there exists a need to characterize robust and predictive biomarkers of response to therapy. In order to accurately characterize tumor evolution, we need to account for …

Development Of In-Silico Pipelines For Identification And Characterization Of Biomarker Panels And Therapeutic Interventions In Gastro-Intestinal (Gi) Cancers, Pranita Atri

Theses & Dissertations

Gastro-intestinal (GI) malignancies, including gastric, colorectal, and pancreatic cancers, have maintained their high overall mortality due to a lack of prognostic and diagnostic biomarkers and potential therapeutic modalities. While efforts have been made to improve both early detection and therapeutic interventions in these cancers, failure of conventional approaches have proven to be a big challenge, and alternate approaches are needed. Computational biology approaches owing to lesser time and more per target success rate offer a unique solution here. The current study explored the use of computational biology techniques to study the various aspects relating to GI malignancies. First, we sought …

Genomics, Exometabolomics, And Metabolic Probing Reveal Conserved Proteolytic Metabolism Of Thermoflexus Hugenholtzii And Three Candidate Species From China And Japan, Scott C. Thomas, Devon Payne, Kevin O. Tamadonfar, Cale O. Seymour, Jian Yu Jiao, Senthil K. Murugapiran, Dengxun Lai, Rebecca Lau, Benjamin P. Bowen, Leslie P. Silva, Katherine B. Louie, Marcel Huntemann, Alicia Clum, Alex Spunde, Manoj Pillay, Krishnaveni Palaniappan, Neha Varghese, Natalia Mikhailova, I. Min Chen, Dimitrios Stamatis, T. B.K. Reddy, Ronan O’Malley, Chris Daum, Nicole Shapiro, Natalia Ivanova, Nikos C. Kyrpides, Tanja Woyke, Emiley Eloe-Fadrosh, Trinity L. Hamilton, Paul Dijkstra, Brian P. Hedlund

Life Sciences Faculty Research

Thermoflexus hugenholtzii JAD2 , the only cultured representative of the Chloroflexota order Thermoflexales, is abundant in Great Boiling Spring (GBS), NV, United States, and close relatives inhabit geothermal systems globally. However, no defined medium exists for T. hugenholtzii JAD2 and no single carbon source is known to support its growth, leaving key knowledge gaps in its metabolism and nutritional needs. Here, we report comparative genomic analysis of the draft genome of T. hugenholtzii JAD2 and eight closely related metagenome-assembled genomes (MAGs) from geothermal sites in China, Japan, and the United States, representing “Candidatus Thermoflexus japonica,” “Candidatus Thermoflexus tengchongensis,” and “Candidatus …

Involvement Of The Ino80 Chromatin Remodeling Complex In Cell Division And Genomic Stability, Ethan Chen

Biomedical Engineering Undergraduate Honors Theses

Cell division is a vital biological process for growth and development in both single and multi-cellular organisms—whereby the cell must duplicate its organelles and genome in entirety and appropriately distribute the copied contents to the daughter cells. Cells undergo a cycle of two distinct phases: interphase and mitosis. During interphase, the cell replicates its genomic DNA (in the form of chromosomes) located within the nucleus. DNA replication is carried out in a euchromatin state, where the chromosome structure is loose and easily accessible by DNA polymerase and other replication enzymes. Upon the completion of replication, chromatin is condensed into highly …

Regenerative Rehabilitation And Genomics: Implications For Occupational Therapy, John V. Rider

The Open Journal of Occupational Therapy

The completion of the human genome project has paved the way for health care practitioners to use genetic and environmental information to tailor medical treatment. This innovative approach to health care is rapidly evolving, and occupational therapists need to be aware of the impact it will have on future practice. Regenerative rehabilitation is a product of knowledge and techniques from the fields of rehabilitation and regenerative medicine with the common goal to restore function. Occupational therapists have the potential to play a significant role in regenerative rehabilitation research and implementation. The purpose of this article is to (a) increase understanding …

Neoadjuvant Anti-Ox40 (Medi6469) Therapy In Patients With Head And Neck Squamous Cell Carcinoma Activates And Expands Antigen-Specific Tumor-Infiltrating T Cells., Rebekka Duhen, Carmen Ballesteros-Merino, Alexandra K Frye, Eric Tran, Venkatesh Rajamanickam, Shu-Ching Chang, Yoshinobu Koguchi, Carlo Bifulco, Brady Bernard, Rom Leidner, Brendan Curti, Bernard A Fox, Walter Urba, Richard Bryan Bell, Andrew D Weinberg

Articles, Abstracts, and Reports

Despite the success of checkpoint blockade in some cancer patients, there is an unmet need to improve outcomes. Targeting alternative pathways, such as costimulatory molecules (e.g. OX40, GITR, and 4-1BB), can enhance T cell immunity in tumor-bearing hosts. Here we describe the results from a phase Ib clinical trial (NCT02274155) in which 17 patients with locally advanced head and neck squamous cell carcinoma (HNSCC) received a murine anti-human OX40 agonist antibody (MEDI6469) prior to definitive surgical resection. The primary endpoint was to determine safety and feasibility of the anti-OX40 neoadjuvant treatment. The secondary objective was to assess the effect of …

Physical Mapping Of The Anopheles (Nyssorhynchus) Darlingi Genomic Scaffolds, Míriam Silva Rafael, Leticia Cegatti Bridi, Igor V. Sharakhov, Osvaldo Marinotti, Maria V. Sharakhova, Vladimir A. Timoshevskiy, Giselle Moura Guimarães-Marques, Valéria Silva Santos, Carlos Gustavo Nunes Da Silva, Spartaco Astolfi-Filho, Wanderli Pedro Tadei

Biology Faculty Publications

The genome assembly of Anopheles darlingi consists of 2221 scaffolds (N50 = 115,072 bp) and has a size spanning 136.94 Mbp. This assembly represents one of the smallest genomes among Anopheles species. Anopheles darlingi genomic DNA fragments of ~37 Kb were cloned, end-sequenced, and used as probes for fluorescence in situ hybridization (FISH) with salivary gland polytene chromosomes. In total, we mapped nine DNA probes to scaffolds and autosomal arms. Comparative analysis of the An. darlingi scaffolds with homologous sequences of the Anopheles albimanus and Anopheles gambiae genomes identified chromosomal rearrangements among these species. Our results confirmed that physical mapping …

The Dfam Community Resource Of Transposable Element Families, Sequence Models, And Genome Annotations., Jessica Storer, Robert Hubley, Jeb Rosen, Travis J Wheeler, Arian F Smit

Articles, Abstracts, and Reports

Dfam is an open access database of repetitive DNA families, sequence models, and genome annotations. The 3.0-3.3 releases of Dfam ( https://dfam.org ) represent an evolution from a proof-of-principle collection of transposable element families in model organisms into a community resource for a broad range of species, and for both curated and uncurated datasets. In addition, releases since Dfam 3.0 provide auxiliary consensus sequence models, transposable element protein alignments, and a formalized classification system to support the growing diversity of organisms represented in the resource. The latest release includes 266,740 new de novo generated transposable element families from 336 species …

Integrated Genetic And Metabolic Landscapes Predict Vulnerabilities Of Temozolomide Resistant Glioblastoma Cells., Selva Rupa Christinal Immanuel, Avinash D Ghanate, Dharmeshkumar S Parmar, Ritu Yadav, Riya Uthup, Venkateswarlu Panchagnula, Anu Raghunathan

Articles, Abstracts, and Reports

Metabolic reprogramming and its molecular underpinnings are critical to unravel the duality of cancer cell function and chemo-resistance. Here, we use a constraints-based integrated approach to delineate the interplay between metabolism and epigenetics, hardwired in the genome, to shape temozolomide (TMZ) resistance. Differential metabolism was identified in response to TMZ at varying concentrations in both the resistant neurospheroidal (NSP) and the susceptible (U87MG) glioblastoma cell-lines. The genetic basis of this metabolic adaptation was characterized by whole exome sequencing that identified mutations in signaling pathway regulators of growth and energy metabolism. Remarkably, our integrated approach identified rewiring in glycolysis, TCA cycle, …

Prognostic Gene Expression Signatures Of Breast Cancer Are Lacking A Sensible Biological Meaning., Kalifa Manjang, Shailesh Tripathi, Olli Yli-Harja, Matthias Dehmer, Galina Glazko, Frank Emmert-Streib

Articles, Abstracts, and Reports

The identification of prognostic biomarkers for predicting cancer progression is an important problem for two reasons. First, such biomarkers find practical application in a clinical context for the treatment of patients. Second, interrogation of the biomarkers themselves is assumed to lead to novel insights of disease mechanisms and the underlying molecular processes that cause the pathological behavior. For breast cancer, many signatures based on gene expression values have been reported to be associated with overall survival. Consequently, such signatures have been used for suggesting biological explanations of breast cancer and drug mechanisms. In this paper, we demonstrate for a large …

Consensus Guidelines For Advancing Coral Holobiont Genome And Specimen Voucher Deposition, Christian R. Voolstra, Kate M. Quigley, Sarah W. Davies, John Everett Parkinson, Raquel S. Peixoto, Manuel Aranda, Andrew C. Baker, Adam R. Barno, Daniel J. Barshis, Francesca Benzoni, Victor Bonito, David G. Bourne, Carol Buitrago-López, Tom C.L. Bridge, Cheong Xin Chan, David J. Combosch, Jamie Craggs, Jörg C. Frommlet, Santiago Herrera, Andrea M. Quattrini, Till Röthig, James D. Reimer, Esther Rubio-Portillo, David J. Suggett, Helena Villela, Maren Ziegler, Michael Sweet

Biological Sciences Faculty Publications

Coral research is being ushered into the genomic era. To fully capitalize on the potential discoveries from this genomic revolution, the rapidly increasing number of high-quality genomes requires effective pairing with rigorous taxonomic characterizations of specimens and the contextualization of their ecological relevance. However, to date there is no formal framework that genomicists, taxonomists, and coral scientists can collectively use to systematically acquire and link these data. Spurred by the recently announced “Coral symbiosis sensitivity to environmental change hub” under the “Aquatic Symbiosis Genomics Project” - a collaboration between the Wellcome Sanger Institute and the Gordon and Betty Moore Foundation …

Comparative Conservation Genomics Of A Suite Of Imperiled Freshwater Mussels, Scott C. Meyer

College of Graduate Studies: Theses & Dissertations

Maintenance of genetic diversity is a critical component to the management and recovery of imperiled species. By ensuring that a species’ genetic diversity is maintained, issues like inbreeding depression and loss of local adaptation can be prevented. However, the genetic diversity of many species are not well-characterized, and the factors that influence a species’ genetic diversity are often not well understood. In the case of imperiled unionid freshwater mussels, it is important to conduct conservation genetic assessments to aid in their management and preserve genetic diversity. This is the first study to conduct a comparative conservation genomic assessment for eight …

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 …

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 …

Genomic Adaptations And Evolutionary History Of The Extinct Scimitar-Toothed Cat, Homotherium Latidens, Ross Barnett, Michael V. Westbury, Marcela Sandoval-Velasco, Filipe Garrett Vieira, Sungwon Jeon, Grant Zazula, Michael D. Martin, Simon Y.W. Ho, Niklas Mather, Shyam Gopalakrishnan, Jazmín Ramos-Madrigal, Marc De Manuel, M. Lisandra Zepeda-Mendoza, Agostinho Antunes, Aldo Carmona Baez, Binia De Cahsan, Greger Larson, Stephen J. O'Brien, Eduardo Eizirik, Warren E. Johnson, Klaus Peter Koepfli, Andreas Wilting, Jörns Fickel, Love Dalén, Eline D. Lorenzen, Tomas Marques-Bonet, Anders J. Hansen, Guojie Zhang, Jong Bhak

Biology Faculty Articles

Homotherium was a genus of large-bodied scimitar-toothed cats, morphologically distinct from any extant felid species, that went extinct at the end of the Pleistocene [1–4]. They possessed large, saber-form serrated canine teeth, powerful forelimbs, a sloping back, and an enlarged optic bulb, all of which were key characteristics for predation on Pleistocene megafauna [5]. Previous mitochondrial DNA phylogenies suggested that it was a highly divergent sister lineage to all extant cat species [6–8]. However, mitochondrial phylogenies can be misled by hybridization [9], incomplete lineage sorting (ILS), or sex-biased dispersal patterns [10], which might be especially relevant for Homotherium since widespread …