Genetics and Genomics Commons^™

Weighted-Samgsr: Combining Significance Analysis Of Microarray-Gene Set Reduction Algorithm With Pathway Topology-Based Weights To Select Relevant Genes, Suyan Tian, Howard H. Chang, Chi Wang

Biostatistics Faculty Publications

Background: It has been demonstrated that a pathway-based feature selection method that incorporates biological information within pathways during the process of feature selection usually outperforms a gene-based feature selection algorithm in terms of predictive accuracy and stability. Significance analysis of microarray-gene set reduction algorithm (SAMGSR), an extension to a gene set analysis method with further reduction of the selected pathways to their respective core subsets, can be regarded as a pathway-based feature selection method.

Methods: In SAMGSR, whether a gene is selected is mainly determined by its expression difference between the phenotypes, and partially by the number of pathways to …

Parallel Mutations Result In A Wide Range Of Cooperation And Community Consequences In A Two-Species Bacterial Consortium, Sarah Douglas, Lon Chubiz, William Harcombe, F. Ytreberg, Christopher Marx

Biology Department Faculty Works

Multi-species microbial communities play a critical role in human health, industry, and waste remediation. Recently, the evolution of synthetic consortia in the laboratory has enabled adaptation to be addressed in the context of interacting species. Using an engineered bacterial consortium, we repeatedly evolved cooperative genotypes and examined both the predictability of evolution and the phenotypes that determine community dynamics. Eight Salmonella enterica serovar Typhimurium strains evolved methionine excretion sufficient to support growth of an Escherichia coli methionine auxotroph, from whom they required excreted growth substrates. Non-synonymous mutations in metA, encoding homoserine trans-succinylase (HTS), were detected in each evolved S. enterica …

Review Of "A Primer Of Human Genetics" By G. Gibson, John B. Jenkins

Biology Faculty Works

No abstract provided.

Population Dynamics And Genetic Differentiation Of The Threatened Freshwater Mussel Species Fusconaia Askewi, Fusconaia Lananensis, And Pleurobema Riddellii, Edith D. Plants-Paris

Biology Theses

North America has the most diverse freshwater mussel fauna in the world with approximately 300 species; unfortunately, extinction rates for freshwater mussels rivals the rates of many other groups of organisms. Population-level natural life history data is essential in the management of species of conservation concern, yet basic information about freshwater mussel life-history and demographic traits are unknown for many species. To further complicate matters, taxonomic uncertainty exists among some members of the group. The work detailed herein had two goals: to gain further understanding of the taxonomic relationship between Fusconaia lananensis and F. askewi by sequencing genes that had …

Global Intron Retention Mediated Gene Regulation During Cd4+ T Cell Activation., Ting Ni, Wenjing Yang, Miao Han, Yubo Zhang, Ting Shen, Hongbo Nie, Zhihui Zhou, Yalei Dai, Yanqin Yang, Poching Liu, Kairong Cui, Zhouhao Zeng, Yi Tian, Bin Zhou, Gang Wei, Keji Zhao, Weiqun Peng, Jun Zhu

Genomics and Precision Medicine Faculty Publications

T cell activation is a well-established model for studying cellular responses to exogenous stimulation. Using strand-specific RNA-seq, we observed that intron retention is prevalent in polyadenylated transcripts in resting CD4(+) T cells and is significantly reduced upon T cell activation. Several lines of evidence suggest that intron-retained transcripts are less stable than fully spliced transcripts. Strikingly, the decrease in intron retention (IR) levels correlate with the increase in steady-state mRNA levels. Further, the majority of the genes upregulated in activated T cells are accompanied by a significant reduction in IR. Of these 1583 genes, 185 genes are predominantly regulated at …

Developmental Functions Of Mir156-Regulated Squamosa Promoter Binding Protein-Like (Spl) Genes In Arabidopsis Thaliana, Mingli Xu, Tieqiang Hu, Jianfei Zhao, Mee-Yeon Park, Keith W. Earley, Gang Wu, Li Yang, R. Scott Poethig

Faculty Publications

Correct developmental timing is essential for plant fitness and reproductive success. Two important transitions in shoot development—the juvenile-to-adult vegetative transition and the vegetative-to-reproductive transition—are mediated by a group of genes targeted by miR156, SQUAMOSA PROMOTER BINDING PROTEIN (SBP) genes. To determine the developmental functions of these genes in Arabidopsis thaliana, we characterized their expression patterns, and their gain-of-function and loss-of-function phenotypes. Our results reveal that SBP-LIKE (SPL) genes in Arabidopsis can be divided into three functionally distinct groups: 1) SPL2, SPL9, SPL10, SPL11, SPL13 and SPL15 contribute to both the juvenile-to-adult vegetative transition …

Optimization Of A Genomic Editing System Using Crispr/Cas9-Induced Site-Specific Gene Integration, Jillian L. Mccool Ms., Nick Hum, Gabriela G. Loots

STAR Program Research Presentations

The CRISPR-Cas system is an adaptive immune system found in bacteria which helps protect against the invasion of other microorganisms. This system induces double stranded breaks at precise genomic loci (1) in which repairs are initiated and insertions of a target are completed in the process. This mechanism can be used in eukaryotic cells in combination with sgRNAs (1) as a tool for genome editing. By using this CRISPR-Cas system, in addition to the “safe harbor locus,” ROSAβ26, the incorporation of a target gene into a site that is not susceptible to gene silencing effects can be achieved through few …

The Role Of Mfd In Stationary-Phase Oxidative Damage Repair In Bacillus Subtilis, Katelyn E. Porter

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the 1950’s it has been shown that bacterial cells accumulate mutations even in non- dividing conditions, but how this type of mutation occurs is still highly debated. In Bacillus subtilis, Mfd, a precursor of the nucleotide excision repair (NER) system, mediates the formation of mutations in stationary-phase or non-replicating cells. In growing cells, Mfd recruits repair when RNA polymerase is stalled during transcription; it then recruits proteins from NER to repair damage. Here, we examine the hypothesis that Mfd mediates the formation of mutations by interacting with cellular components that repair reactive oxygen species (ROS), a natural byproduct of …

Polyandry In The Absence Of Fitness Benefits In A Species With Female-Biased Sexual Size Dimorphism, Marie Claire Chelini, Eileen A. Hebets

Eileen Hebets Publications

Most studies exploring the evolution of female mating systems focus on species in which females are either monandric (mate with a single male) or highly polyandric (mate with multiple males), but less is understood about variation in mating decisions within a species. How and why do females of a single species decide whether or not to copulate with additional mates? In this study we attempt to answer this question in the highly dimorphic crab spider, Mecaphesa celer, whose females may be either monandric or polyandric. We tested three hypotheses: (1) a female’s decision to remate is based on sequential mate …

Sex Chromosome-Wide Transcriptional Suppression And Compensatory Cis-Regulatory Evolution Mediate Gene Expression In The Drosophila Male Germline, Emily L. Landeen, Christina A. Muirhead, Lori Wright, Colin D. Meiklejohn, Daven C. Presgraves

School of Biological Sciences: Faculty Publications

The evolution of heteromorphic sex chromosomes has repeatedly resulted in the evolution of sex chromosome-specific forms of regulation, including sex chromosome dosage compensation in the soma and meiotic sex chromosome inactivation in the germline. In the male germline of Drosophila melanogaster, a novel but poorly understood form of sex chromosome-specific transcriptional regulation occurs that is distinct from canonical sex chromosome dosage compensation or meiotic inactivation. Previous work shows that expression of reporter genes driven by testis-specific promoters is considerably lower—approximately 3-fold or more—for transgenes inserted into X chromosome versus autosome locations. Here we characterize this transcriptional suppression of X-linked …

Machine Learning Meta-Analysis Of Large Metagenomic Datasets: Tools And Biological Insight, Edoardo Pasolli, Duy Tin Truong, Faizan Malik, Levi Waldron, Nicola Segata

Publications and Research

Shotgun metagenomic analysis of the human associated microbiome provides a rich set of microbial features for prediction and biomarker discovery in the context of human diseases and health conditions. However, the use of such high-resolution microbial features presents new challenges, and validated computational tools for learning tasks are lacking. Moreover, classification rules have scarcely been validated in independent studies, posing questions about the generality and generalization of disease-predictive models across cohorts. In this paper, we comprehensively assess approaches to metagenomics-based prediction tasks and for quantitative assessment of the strength of potential microbiome-phenotype associations. We develop a computational framework for prediction …

Cloning, Characteristics, And Functional Analysis Of Rabbit Nadph Oxidase 5, Feng Chen, Caiyong Yin, Christiana Dimitropoulou, David J.R. Fulton

Bioelectrics Publications

Background: Nox5 was the last member of the Nox enzyme family to be identified. Functionally distinct from the other Nox isoforms, our understanding of its physiological significance has been hampered by the absence of Nox5 in mouse and rat genomes. Nox5 is present in the genomes of other species such as the rabbit that have broad utility as models of cardiovascular disease. However, the mRNA sequence, characteristics, and functional analysis of rabbit Nox5 has not been fully defined and were the goals of the current study.

Methods: Rabbit Nox5 was amplified from rabbit tissue, cloned, and sequenced. COS-7 cells were …

The Maintenance Of Phenotypic Divergence Through Sexual Selection: An Experimental Study In Barn Swallows Hirundo Rustica, Rebecca Safran, Yoni Vortman, Brittany R. Jenkins, Joanna K. Hubbard, Matt Wilkins, Rachel J. Bradley, Arnon Lotem

School of Biological Sciences: Faculty Publications

Previous studies have shown that sexual signals can rapidly diverge among closely related species. However, we lack experimental studies to demonstrate that differences in trait-associated reproductive performance maintain sexual trait differences between closely related populations, in support for a role of sexual selection in speciation. Populations of Northern Hemisphere distributed barn swallows Hirundo rustica are closely related, yet differ in two plumage-based traits: ventral color and length of the outermost tail feathers (streamers). Here we provide experimental evidence that manipulations of these traits result in different reproductive consequences in two subspecies of barn swallow: (H. r. erythrogaster in North …

Cellular And Molecular Features Of Developmentally Programmed Genome Rearrangement In A Vertebrate (Sea Lamprey: Petromyzon Marinus), Vladimir A. Timoshevskiy, Joseph R. Herdy, Melissa C. Keinath, Jeramiah J. Smith

Biology Faculty Publications

The sea lamprey (Petromyzon marinus) represents one of the few vertebrate species known to undergo large-scale programmatic elimination of genomic DNA over the course of its normal development. Programmed genome rearrangements (PGRs) result in the reproducible loss of ~20% of the genome from somatic cell lineages during early embryogenesis. Studies of PGR hold the potential to provide novel insights related to the maintenance of genome stability during the cell cycle and coordination between mechanisms responsible for the accurate distribution of chromosomes into daughter cells, yet little is known regarding the mechanistic basis or cellular context of PGR in …

Alcohol Discrimination And Preferences In Two Species Of Nectar-Feeding Primate, Samuel R. Gochman, Michael B. Brown, Nathaniel J. Dominy

Dartmouth Scholarship

Recent reports suggest that dietary ethanol, or alcohol, is a supplemental source of calories for some primates. For example, slow lorises (Nycticebus coucang) consume fermented nectars with a mean alcohol concentration of 0.6% (range: 0.0–3.8%). A similar behaviour is hypothesized for aye-ayes (Daubentonia madagascariensis) based on a single point mutation (A294V) in the gene that encodes alcohol dehydrogenase class IV (ADH4), the first enzyme to catabolize alcohol during digestion. The mutation increases catalytic efficiency 40-fold and may confer a selective advantage to aye-ayes that consume the nectar of Ravenala madagascariensis. It is uncertain, however, whether alcohol exists in this nectar …

Loss Of Cell Adhesion Increases Tumorigenic Potential Of Polarity Deficient Scribble Mutant Cells, Indrayani Waghmare, Madhuri Kango-Singh

Biology Faculty Publications

Epithelial polarity genes are important for maintaining tissue architecture, and regulating growth. The Drosophila neoplastic tumor suppressor gene scribble (scrib) belongs to the basolateral polarity complex. Loss of scrib results in disruption of its growth regulatory functions, and downregulation or mislocalization of Scrib is correlated to tumor growth. Somatic scribble mutant cells (scrib-) surrounded by wild-type cells undergo apoptosis, which can be prevented by introduction of secondary mutations that provide a growth advantage. Using genetic tools in Drosophila, we analyzed the phenotypic effects of loss of scrib in different growth promoting backgrounds. We investigated if a central …

Investigating The Origin And Functions Of A Novel Small Rna In Escherichia Coli, Fenil Rashmin Kacharia

Dissertations and Theses

Non-coding small RNAs (sRNAs) regulate various cellular processes in bacteria. They bind to a chaperone protein Hfq for stability and regulate gene expression by base-pairing with target mRNAs. Although the importance of sRNAs in bacteria has been well established, the mode of origination of novel sRNA genes is still elusive, mainly because the rapid rate of evolution of sRNAs obscures their original sources. To overcome this impediment, we identified a recently formed sRNA (EcsR2) in E. coli, and show that it evolved from a degraded bacteriophage gene. Our analyses also revealed that young sRNAs such as EcsR2 are expressed …

Effects Of Mutating The Mrub_1345 Gene Found In Meiothermus Ruber, Brandon M. Wills, Lori R. Scott

Celebration of Learning

Meiothermus ruber is a unique, red-pigmented, thermophilic bacterium that preferentially grows in high-temperature environments ranging from 35-70°C. Due to the lack of studies performed on this organism, there is quite a bit of information missing in regard to the genes found within this organism’s genome and their function. This study focuses in on the Mrub_1345 gene in M. ruber, which has been suggested to be orthologous to the proC gene found of E. coli proline biosynthesis pathway. To test if these genes are orthologs, we performed the complementation assay on wild-type proC. Next, we performed site-directed mutagenesis on amino acids …

The Role Of Daf-19 In Non-Ciliated Neurons: How Is Neural Development Regulated By Different Daf-19 Isoforms?, Zabdiel Ek Vazquez

Lawrence University Honors Projects

A degenerative disease-like phenotype, specifically reduction in synaptic protein levels in adult worms, is correlated with loss-of-function of the only RFX transcription factor gene, daf-19, in C. elegans. This gene encodes four known transcription factor isoforms, two of which are correlated with particular functions. The DAF-19C isoform activates genes responsible for cilia development, while DAF-19M is needed for cilia specification in males. A comparison of the transcriptome of daf-19 null and isogenic wild type adult worms suggests both positive and negative regulation of gene expression is correlated with the presence of DAF-19 proteins. We have assessed DAF-19 regulation …

Genome-Wide Differentiation In Closely Related Populations: The Roles Of Selection And Geographic Isolation, Rebecca Safran, Elizabeth Scordato, Matt Wilkins, Joanna K. Hubbard, B. R. Jenkins, Tomáš Albrecht, Samuel Flaxman, H. Karaardiç, Yoni Vortman, Arnon Lotem, Patrik Nosil, P. Pap, Sheng-Feng Shen, S.-F. Chan, T. L. Parchman, Nolan C. Kane

School of Biological Sciences: Faculty Publications

Population divergence in geographic isolation is due to a combination of factors. Natural and sexual selection may be important in shaping patterns of population differentiation, a pattern referred to as “isolation by adaptation” (IBA). IBA can be complementary to the well-known pattern of “isolation by distance” (IBD), in which the divergence of closely related populations (via any evolutionary process) is associated with geographic isolation. The barn swallow Hirundo rustica complex comprises six closely related subspecies, where divergent sexual selection is associated with phenotypic differentiation among allopatric populations. To investigate the relative contributions of selection and geographic distance to genome-wide differentiation, …

Review Of "The Least Likely Man: Marshall Nirenberg And The Discovery Of The Genetic Code" By F. H. Portugal, John B. Jenkins

Biology Faculty Works

No abstract provided.

Investigating The Effects Of 17Α-Ethynylestradiol On Mitochondrial Genome Stability, Alicia M. Chivers

Dissertations and Theses

Environmental toxicants are ubiquitous throughout the environment as a result of human activity. Among these toxicants, environmental estrogens are a category of particular concern due to their environmental prevalence and potency in altering reproductive traits. While many studies have addressed the detrimental effects of environmental estrogens on both aquatic and terrestrial organisms, few have analyzed the potential for these compounds to alter mitochondrial function. Mitochondria are the primary energy-generating system for all eukaryotic life, supporting all aspects of development, metabolism, and growth. Each cell within the body contains many mitochondria which in turn contain multiple copies of their own DNA …

Hiv Vaccines: Progress, Limitations And A Crispr/Cas9 Vaccine, Omar A. Garcia Martinez

Biology: Student Scholarship & Creative Works

ABSTRACT: The HIV-1 pandemic continues to thrive due to ineffective HIV-1 vaccines. Historically, the world’s most infectious diseases, such as polio and smallpox, have been eradicated or have come close to eradication due to the advent of effective vaccines. Highly active antiretroviral therapy is able to delay the onset of AIDS but can neither rid the body of HIV-1 proviral DNA nor prevent further transmission. A prophylactic vaccine that prevents the various mechanisms HIV-1 has to evade and attack our immune system is needed to end the HIV-1 pandemic. Recent advances in engineered nuclease systems, like the CRISPR/Cas9 system, have …

Phylogenetic Analysis Of Human Cytomegalovirus Pus27 And Pus28: Ascertaining An Independent Or Linked Evolutionary History, Jessica A. Scarborough

Undergraduate Honors Theses

Human cytomegalovirus (HCMV) is a widespread pathogen that is particularly skilled at evading immune detection and defense mechanisms, largely due to extensive co-evolution with its host’s immune system. One aspect of this co-evolution involves the acquisition of four virally encoded GPCR chemokine receptor homologs, products of the US27, US28, UL33 and UL78 genes. G protein-coupled receptors (GPCR) are the largest family of cell surface proteins, found in organisms from yeast to humans. In this research, phylogenetic analysis was used to investigate the origins of the US27 and US28 genes, which are adjacent in the viral genome. The results indicate that …

Life In The Underworld: Anchialine Cave Biology In The Era Of Speleogenomics, Jorge L. Pérez-Moreno, Thomas M. Iliffe, Heather D. Bracken-Grissom

International Journal of Speleology

Anchialine caves contain haline bodies of water with underground connections to the ocean and limited exposure to open air. Despite being found on islands and peninsular coastlines around the world, the isolation of anchialine systems has facilitated the evolution of high levels of endemism among their inhabitants. The unique characteristics of anchialine caves and of their predominantly crustacean biodiversity nominate them as particularly interesting study subjects for evolutionary biology. However, there is presently a distinct scarcity of modern molecular methods being employed in the study of anchialine cave ecosystems. The use of current and emerging molecular techniques, e.g., next-generation sequencing …

Successful Enrichment And Recovery Of Whole Mitochondrial Genomes From Ancient Human Dental Calculus, Andrew T. Ozga, Maria A. Nieves-Colon, Tanvi P. Honap, Krithivasan Sankaranarayanan, Courtney A. Hofman, George R. Milner, Cecil M. Lewis Jr., Anne C. Stone, Christina Warinner

Biology Faculty Articles

Objectives

Archaeological dental calculus is a rich source of host‐associated biomolecules. Importantly, however, dental calculus is more accurately described as a calcified microbial biofilm than a host tissue. As such, concerns regarding destructive analysis of human remains may not apply as strongly to dental calculus, opening the possibility of obtaining human health and ancestry information from dental calculus in cases where destructive analysis of conventional skeletal remains is not permitted. Here we investigate the preservation of human mitochondrial DNA (mtDNA) in archaeological dental calculus and its potential for full mitochondrial genome (mitogenome) reconstruction in maternal lineage ancestry analysis.

Materials and …

A Novel Variant In Cmah Is Associated With Blood Type Ab In Ragdoll Cats, Barbara Gandolfi, Robert Grahn, Nicholas Gustafson, Daniela Proverbio, Eva Spada, Badri Adhikari, Janling Cheng, Gordon Andrews, Leslie Lyons, Chris Helps

Computer Science Faculty Works

The enzyme cytidine monophospho-N-acetylneuraminic acid hydroxylase is associated with the production of sialic acids on cat red blood cells. The cat has one major blood group with three serotypes; the most common blood type A being dominant to type B. A third rare blood type is known as AB and has an unclear mode of inheritance. Cat blood type antigens are defined, with N-glycolylneuraminic acid being associated with type A and N-acetylneuraminic acid with type B. Blood type AB is serologically characterized by agglutination using typing reagents directed against both A and B epitopes. While a genetic characterization of blood …

Embryonic And Post-Embryonic Hoxa13 Expression In The Four-Toed Salamander, Hemidactylium Scutatum., Breanna R. Lee

Senior Honors Projects, 2010-2019

The process of somitogenesis occurs during embryological development and results in the definition of persisting axial segments. The four toed salamander, Hemidactylium scutatum, exhibits post-embryonic segmentation while most other vertebrates stop segmentation at the end of embryological development. HoxA13, a transcription factor expressed along the developing anteroposterior axis, plays a role in specifying caudal segmental identity, cell ingression into the pre-somitic mesoderm (PSM), and PSM truncation. HoxA13’s responsibilities in influencing embryological development make it an interesting candidate for involvement in post-embryonic segment addition mechanisms. This study explores the role of HoxA13 in tail segmentation in H. scutatum embryonic, larval, …

Reverse Genetic Screening Of Innexin Gap Junction Proteins In Drosophila Neurons, Shannon P. Fox

Senior Honors Projects, 2010-2019

The reflexive response and perception of pain (nociception) is an evolutionarily conserved process in animals. Pain can be a major health concern and current treatments often prove insufficient, especially in regards to chronic pain. Greater understanding of the molecular processes underlying pain sensation could lead to new and more effective treatments. The aim of this study is to investigate the molecular mechanisms of cold nociception in Drosophila melanogaster. A specific subset of peripheral sensory neurons (Class III dendritic arborization (da) neurons), are implicated in Drosophila larvae’s response to noxious cold.

Previous literature has associated a family of gap junction protein, …

Mrub_2874 Is Homologous To B3386 And Mrub_1349 Is Homologous To B2914, But Mrub_1349 Is Not Homologous To B4090, Samantha Murad, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

ABSTRACT. This project is part of the Meiothermus ruber genome analysis project, which uses the bioinformatics tools associated with the Guiding Education through Novel Investigation – Annotation Collaboration Toolkit (GENI-ACT) to predict gene function. We investigated the biological function of the genes Mrub_2874 and Mrub_1349. We predict that Mrub_2874 encodes the enzyme ribulose-5-phosphate 3-epimerase (DNA coordinates 2912530..2913204 on the reverse strand), which is the first step of the pentose phosphate pathway (KEGG map number 00030). It catalyzes the conversion of D-ribulose 5-phosphate to D-xylulose 5-phosphate. The E. coli K12 MG1655 ortholog is predicted to be b3386, which has the gene …