Genetics Commons^™

Deletion Mutant Library For Investigation Of Functional Outputs Of Cyclic Diguanylate Metabolism In Pseudomonas Aeruginosa Pa14, Dae-Gon Ha, Megan E. Richman, George A. O'Toole

Dartmouth Scholarship

We constructed a library of in-frame deletion mutants targeting each gene in Pseudomonas aeruginosa PA14 predicted to participate in cyclic di-GMP (c-di-GMP) metabolism (biosynthesis or degradation) to provide a toolkit to assist investigators studying c-di-GMP-mediated regulation by this microbe. We present phenotypic assessments of each mutant, including biofilm formation, exopolysaccharide (EPS) production, swimming motility, swarming motility, and twitch motility, as a means to initially characterize these mutants and to demonstrate the potential utility of this library.

Investigating A Role For The Ccaat/Enhancer-Binding Protein Δ In The Developing Zebrafish, Alisha Jennifer Beirl

Dissertations and Theses

The CCAAT/enhancer-binding protein delta (C/EBPδ) is a highly conserved transcription factor capable of regulating numerous cell fate processes, such as cell growth, differentiation, proliferation and apoptosis. C/EBPδ is inducible during cellular stress responses, including inflammation and responses to growth factor deprivation or thermal stress. C/EBPδ is stress-inducible in a diversity of fishes, including the zebrafish Danio rerio; however, little is known about its role in fish development. Here I show that overexpression of C/EBPδ leads to severe developmental defects, including reduced body length, edema, liver malformation and retinal abnormalities. The proportion of individuals that display developmental abnormalities is significantly …

Is Sickle Cell Trait As Benign As Is Usually Assumed?, Carroll Nicole Flansburg

USF Tampa Graduate Theses and Dissertations

Abstract

Introduction Sickle cell trait carriers may experience sickling events, which can cause severe health problems. Some sickle cell haplotypes contain genetic modifiers that are associated with increased levels of fetal hemoglobin, which is resistant to sickling. The aim of this study is to determine if sickle cell trait individuals who do not carry these modifiers are more likely to experience sickling episodes than those who do carry the modifiers.

Methods: Participants were eligible for inclusion in this study if they were male, 18 years of age or older, a sickle cell trait carrier, and had previously played any level …

Student Identity Considerations And Implications Associated With Socioscientific Issues Instruction, Mitchel James Ruzek

USF Tampa Graduate Theses and Dissertations

The purpose of this investigation was to explore how aspects of identity, perceived levels of controversy, and the strength of a student's attachment to their controversial identity relate to conceptual understanding and knowledge acquisition during socioscientific issues (SSI) based instruction in a biology classroom. The knowledge gained from this study will have the capacity to enhance our understanding of the role that attachment to identity plays during SSI negotiation. Additionally, insight was gained into the role played by aspects of identity in conceptual understanding of scientifically controversial topics during SSI based instruction.

This study contributed to the existing knowledge base …

Did Pre-Clovis People Inhabit The Paisley Caves (And Why Does It Matter)?, Stuart J. Fiedel

Human Biology Open Access Pre-Prints

The date and processes of initial human colonization of the Americas are crucial issues for the understanding of human biological and cultural development. For example, Soares et al. (2009) cited the American archaeological record to validate their proposed revision of the human mitochondrial molecular clock. Their suggested mutation rate puts the date of rapid expansion of Native American clades at around 13,500–15,000 cal BP. Similarly, Poznik et al. (2013) have used the “high-confidence archaeological dating” of the initial peopling of the Americas to calibrate the rates of both Y-chromosome and mtDNA mutation and thereby to reconcile the ages of the …

Comparing Partial Least Square Approaches In Gene-Or Region-Based Association Study For Multiple Quantitative Phenotypes, Zhongshang Yuan, Xiaoshuai Zhang, Fangyu Li, Jinghua Zhao, Fuzhong Xue

Human Biology Open Access Pre-Prints

On thinking quantitatively of complex diseases, there are at least three statistical strategies for association study: single SNP on single trait, gene-or region (with multiple SNPs) on single trait and on multiple traits. The third of which is the most general in dissecting the genetic mechanism underlying complex diseases underpinning multiple quantitative traits. Gene-or region association methods based on partial least square (PLS) approaches have been shown to have apparent power advantage. However, few attempts are developed for multiple quantitative phenotypes or traits underlying a condition or disease, and the performance of various PLS approaches used in association study for …

Genetic Origins Of Lactase Persistence And The Spread Of Pastoralism In Africa, Michael Campbell

Department of Biology Faculty Publications

In humans, the ability to digest lactose, the sugar in milk, declines after weaning because of decreasing levels of the enzyme lactase-phlorizin hydrolase, encoded by LCT. However, some individuals maintain high enzyme amounts and are able to digest lactose into adulthood (i.e., they have the lactase-persistence [LP] trait). It is thought that selection has played a major role in maintaining this genetically determined phenotypic trait in different human populations that practice pastoralism. To identify variants associated with the LP trait and to study its evolutionary history in Africa, we sequenced MCM6 introns 9 and 13 and ∼2 kb of the …

Chip-Seq And Rna-Seq Reveal An Amrz-Mediated Mechanism For Cyclic Di-Gmp Synthesis And Biofilm Development By Pseudomonas Aeruginosa, Christopher J. Jones, David Newsom, Benjamin Kelly, Yasuhiko Irie, Laura K. Jennings, Binjie Xu, Dominique H. Limoli, Joe J. Harrison, Matthew R. Parsek, Peter White, Daniel J. Wozniak

Biology Faculty Publications

The transcription factor AmrZ regulates genes important for P. aeruginosa virulence, including type IV pili, extracellular polysaccharides, and the flagellum; however, the global effect of AmrZ on gene expression remains unknown, and therefore, AmrZ may directly regulate many additional genes that are crucial for infection. Compared to the wild type strain, a ΔamrZ mutant exhibits a rugose colony phenotype, which is commonly observed in variants that accumulate the intracellular second messenger cyclic diguanylate (c-di-GMP). Cyclic di-GMP is produced by diguanylate cyclases (DGC) and degraded by phosphodiesterases (PDE). We hypothesized that AmrZ limits the intracellular accumulation of c-di-GMP through transcriptional repression …

Quantitative Field Testing Heterodera Glycines From Metagenomic Dna Samples Isolated Directly From Soil Under Agronomic Production., Yan Li, Gary W. Lawrence, Shien Lu, Clarissa Balbalian, Vincent P. Klink

CALS Publications

A quantitative PCR procedure targeting the Heterodera glycines ortholog of the Caenorhabditis elegans uncoordinated-78 gene was developed. The procedure estimated the quantity of H. glycines from metagenomic DNA samples isolated directly from field soil under agronomic production. The estimation of H. glycines quantity was determined in soil samples having other soil dwelling plant parasitic nematodes including Hoplolaimus, predatory nematodes including Mononchus, free-living nematodes and biomass. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from field soil.

Gene And Protein Sequence Optimization For High-Level Production Of Fully Active And Aglycosylated Lysostaphin In Pichia Pastoris, Hongliang Zhao, Kristina Blazanovic, Yoonjoo Choi, Chris Bailey-Kellogg, Karl E. Griswold

Dartmouth Scholarship

Lysostaphin represents a promising therapeutic agent for the treatment of staphylococcal infections, in particular those of methicillin-resistant Staphylococcus aureus (MRSA). However, conventional expression systems for the enzyme suffer from various limitations, and there remains a need for an efficient and cost-effective production process to facilitate clinical translation and the development of nonmedical applications. While Pichia pastoris is widely used for high-level production of recombinant proteins, there are two major barriers to the production of lysostaphin in this industrially relevant host: lack of expression from the wild-type lysostaphin gene and aberrant glycosylation of the wild-type protein sequence. The first barrier can …

Direct-To-Consumer Genetic Testing In The College Classroom: Knowledge, Attitudes, And Concerns Of Introductory Biology Students, Nicanor Austriaco

Biology Faculty Publications

Pioneered by companies like 23andMe.com, deCODEme.com, and Navigenics.com, direct-to-consumer genetic testing refers to genetic tests that are marketed directly to consumers via television, print media, or the Internet. This kind of testing provides access to a customer’s genetic information without necessarily involving either a medical health care professional or a genetic counselor in the process. In recent years, a course offered to medical and graduate students at Stanford University has included an option for students to undergo personal genotyping, raising the possibility that direct-to-consumer genetic testing could also be incorporated into undergraduate biology courses to enhance student learning. In this …

Deletion Of Aif1 But Not Of Yca1/Mca1 Protects Saccharomyces Cerevisiae And Candida Albicans Cells From Caspofungin-Induced Programmed Cell Death, Nicanor Austriaco, Christopher Chin, Faith Donaghey, Kathrine Helming, Morgan Mccarthy, Stephen Rogers

Biology Faculty Publications

Caspofungin was the first member of a new class of antifungals called echinocandins to be approved by a drug regulatory authority. Like the other echinocandins, caspofungin blocks the synthesis of β(1,3)-D-glucan of the fungal cell wall by inhibiting the enzyme, β(1,3)-D-glucan synthase. Loss of β(1,3)-D-glucan leads to osmotic instability and cell death. However, the precise mechanism of cell death associated with the cytotoxicity of caspofungin was unclear. We now provide evidence that Saccharomyces cerevisiae cells cultured in media containing caspofungin manifest the classical hallmarks of programmed cell death (PCD) in yeast, including the generation of reactive oxygen species (ROS), the …

Phylogeny And Population Genetics Of The Endangered Dwarf Bear-Poppy, Arctomecon Humilis Coville (Papaveraceae) Using Microsatellite Markers, Joshua Simpson

Dissertations, Theses, and Capstone Projects

The genus Arctomecon (Papaveraceae) is comprised of three narrowly endemic rare species that are largely restricted to gypsum soils of the eastern Mojave Desert. The small, remaining populations of these species have become increasingly isolated by urban development and habitat fragmentation. Arctomecon humilis is federally listed as endangered due to its limited distribution within a ~15 km radius of an actively expanding city. Organizations involved with land management and conservation have called for greater insight into the genetic variation and population structure of the remaining subpopulations as they make important decisions regarding where to focus their efforts and resources.

The …

Trip/Nopo E3 Ubiquitin Ligase Promotes Ubiquitylation Of Dna Polymerase Η, Heather A. Wallace, Julie A. Merkle, Michael C. Yu, Taloa G. Berg, Ethan Lee, Giovanni Bosco, Laura A. Lee

Dartmouth Scholarship

We previously identified a Drosophila maternal effect-lethal mutant named ‘no poles’ (nopo). Embryos from nopo females undergo mitotic arrest with barrel-shaped, acentrosomal spindles during the rapid cycles of syncytial embryogenesis because of activation of a Chk2-mediated DNA checkpoint. NOPO is the Drosophila homolog of human TNF receptor associated factor (TRAF)-interacting protein (TRIP), which has been implicated in TNF signaling. NOPO and TRIP contain RING domains closely resembling those of known E3 ubiquitin ligases. We herein sought to elucidate the mechanism by which TRIP/NOPO promotes genomic stability by performing a yeast two-hybrid screen to identify potential substrates/interactors. We identified members of …

Measuring Radiation Exposure In Human Blood Using Gene Expression, Krystal Naranjo, Melissa Bentley, Harsha Konery, Matthew Coleman

STAR Program Research Presentations

Mammalian cells are known to express genes that are associated with repairing damaged DNA. The transcript CDKN1A is one of several cell cycle regulator genes expressed in response to cell damage by ionizing radiation (IR). In this study, male and female lymphocytes; previously exposed ex vivo to IR, were used to demonstrate linear gene expression responses that may vary between genders. We used qRT-PCR to generate response curves for CDKN1A. No differences were identified for the endogenous control gene GAPDH. CDKN1A expression demonstrated average fold changes well above three fold for three of the four healthy patient donors at 24 …

Finding Fault?: Exploring Legal Duties To Return Incidental Findings In Genomic Research, Elizabeth R. Pike, Karen H. Rothenberg, Benjamin E. Berkman

Faculty Scholarship

The use of whole genome sequencing in biomedical research is expected to produce dramatic advances in human health. The increasing use of this powerful, data-rich new technology in research, however, will inevitably give rise to incidental findings (IFs), findings with individual health or reproductive significance that are beyond the aims of the particular research, and the related questions of whether and to what extent researchers have an ethical obligation to return IFs. Many have concluded that researchers have an ethical obligation to return some findings in some circumstances, but have provided vague or context-dependent approaches to determining which IFs must …

Relationships Between The Weedy (Amaranthaceae) And The Grain Amaranths [Abstract], Kiel D. Kielinski, Felix Jimenez, Eric N. Jellen, Peter J. Maughan, Scott M. Smith, Donald B. Pratt

Faculty Publications

No abstract provided.

Complete Genome Sequence Of Anabaena Variabilis Atcc 29413, Teresa Thiel, Brenda Pratte, Jinshun Zhong, Lynne Goodwin, Alex Copeland, Susan Lucas, Cliff Han, Sam Pitluck, Miriam Land, Nikos Kyrpides, Tanja Woyke

Biology Department Faculty Works

Anabaena variabilis ATCC 29413 is a filamentous, heterocyst-forming cyanobacterium that has served as a model organism, with an extensive literature extending over 40 years. The strain has three distinct nitrogenases that function under different environmental conditions and is capable of photoautotrophic growth in the light and true heterotrophic growth in the dark using fructose as both carbon and energy source. While this strain was first isolated in 1964 in Mississippi and named Anabaena flos-aquae MSU A-37, it clusters phylogenetically with cyanobacteria of the genus Nostoc. The strain is a moderate thermophile, growing well at approximately 40° C. Here we provide …

Set-Based Tests For Genetic Association In Longitudinal Studies, Zihuai He, Min Zhang, Seunggeun Lee, Jennifer A. Smith, Xiuqing Guo, Walter Palmas, Sharon L.R. Kardia, Ana V. Diez Roux, Bhramar Mukherjee

The University of Michigan Department of Biostatistics Working Paper Series

Genetic association studies with longitudinal markers of chronic diseases (e.g., blood pressure, body mass index) provide a valuable opportunity to explore how genetic variants affect traits over time by utilizing the full trajectory of longitudinal outcomes. Since these traits are likely influenced by the joint effect of multiple variants in a gene, a joint analysis of these variants considering linkage disequilibrium (LD) may help to explain additional phenotypic variation. In this article, we propose a longitudinal genetic random field model (LGRF), to test the association between a phenotype measured repeatedly during the course of an observational study and a set …

Frequency-Dependent Mate Selection In The Guppy (Poeciliidae: Poecilia Reticulata), Andre Porter, Jack Frankel

Department of Biology Faculty Publications

Heterogeneity within a population enhances its long-term survival. A fundamental method of maintaining population heterogeneity is the retention of rare or uncommon phenotypes by selective mating strategies. Employing two color morphs, red tuxedo and red, of the guppy (Poecilia reticulata, Poeciliidae), this study was designed to investigate whether P. reticulata females would preferentially seek out heterogeneous groupings of males exhibiting two color morphs. Adult female guppies were exposed simultaneously to two groups of males (n=10); one comprised of only the tuxedo color morph (n=5) and the other of both color morphs (n=5). For the latter group, the ratio of males …