Biology Commons^™

Effects Of Excitation Pressure On Variegation And Global Gene Expression In Arabidopsis Thaliana, Rainer Bode

Electronic Thesis and Dissertation Repository

I assessed the effects of photosystem II excitation pressure on chloroplast biogenesis and leaf sectoring in the Arabidopsis thaliana variegated mutants im, spotty, var1, var2, chs5 and atd2. The plants were grown under varying degrees of excitation pressure induced by growth at increasing irradiance at different temperatures and the extent of variegation was quantified throughout the plant’s development. I found that the degree of variegation was positively correlated with excitation pressure, regardless of whether high light or low temperature was used to induce increased excitation pressure in all the mutants tested. This was irrespective of …

Genetic Sex Conditions And Redefining Sex, Jayce O'Shields

Student Scholarship

Western culture has a tendency to value binaries and discreet categories that separate its social structure and provide a sense of order and organization. The value placed on binaries and categories may be advantageous in some aspects, but when it starts to infringe upon the legal and medical rights of individuals not easily placed in either binary category, it can become less advantageous.

A baby is usually classified as either male or female shortly after birth, and all future legal, social, and economic actions and rights of that individual are more or less decided according to this classification. A problem …

Determining Parentage And The Effects Of Relatedness On Play Partner Preference In Belding's Ground Squirrels, Jessica Weidenbach

Master's Theses

I investigated 1) multiple paternity in Belding’s ground squirrels (Urocitellus beldingi) and 2) social partner preferences in juvenile U. beldingi. Prior work with blood allozymes demonstrated multiple paternity in U. beldingi litters. I evaluated paternity using microsatellite DNA analysis, which is more accurate than examining blood allozymes. My results indicate that multiple paternity in U. beldingi is more extensive than previously shown, occurring in about 90% of litters with more than one juvenile, and averaging 2.95 fathers in multiply sired litters. I also evaluated the hypothesis that play and other social behavior promotes bonding among juvenile female …

Single Nucleotide Polymorphisms Linked To Essential Hypertension In Kasigau, Kenya, Julia Carol Freeman

Masters Theses & Specialist Projects

Hypertension, or high blood pressure (BP), is an ever-growing epidemic in the developing world. Understanding the genetics behind essential hypertension (EH), or hypertension with no known cause, is especially important. In this study, three single nucleotide polymorphisms (SNPs) known to be linked to an increase in susceptibility to EH were quantified from a cohort of Kenyans living in the Kasigau region. The SNPs are located in three genes that are part of the renin angiotensin system, the primary regulatory pathway in humans controlling BP. They include: AGT (rs699), AGTR1 (rs5186), and HSD11β2 (rs5479). Overall, by using a fluorescent-based RT-PCR technique, …

Population Demographics And Genetic Structure Of Black Bears In Coastal Louisiana, Jesse Charles Troxler

Masters Theses

The range and abundance of the Louisiana black bear (Ursus americanus luteolus) were greatly diminished during the 20th century. This subspecies was reduced to 3 small, isolated subpopulations in Louisiana as bottomland hardwood habitat was converted to agriculture. These bears were listed as threatened by the U.S. Fish and Wildlife Service in 1992 and a recovery plan was published in 1995. Recovery requires estimates of population parameters to evaluate current population status and future viability. I conducted a mark-recapture study from 2010 to 2012 to estimate demographic parameters of the coastal population of Louisiana black bears. Because inbreeding …

The Roles Of Phenotypic Plasticity And Genotypic Specialization In High Altitude Adaptation, Danielle M. Tufts

School of Biological Sciences: Dissertations, Theses, and Student Research

In vertebrates living at high altitude, arterial hypoxemia may be ameliorated by reversible changes in the oxygen-carrying capacity of the blood (regulated by erythropoiesis) and/or changes in blood–oxygen affinity (regulated by allosteric effectors of hemoglobin function). These hematological traits often differ between taxa that are native to different elevational zones, but it is often unknown whether the observed physiological differences reflect fixed, genetically based differences or environmentally induced acclimatization responses (phenotypic plasticity). Here, we report measurements of hematological traits related to blood–O₂ transport in populations of deer mice (Peromyscus maniculatus) that are native to high- and low-altitude …

Novel Neuroprotective Function Of Apical-Basal Polarity Genecrumbs In Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration, Andrew Steffensmeier, Meghana Tare, Oorvashi Roy Puli, Rohan Modi, Jaison Nainaparampil, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD, OMIM: 104300), a progressive neurodegenerative disorder with no cure to date, is caused by the generation of amyloid-beta-42 (Aβ42) aggregates that trigger neuronal cell death by unknown mechanism(s). We have developed a transgenic Drosophilaeye model where misexpression of human Aβ42 results in AD-like neuropathology in the neural retina. We have identified an apical-basal polarity gene crumbs (crb) as a genetic modifier of Aβ42-mediated-neuropathology. Misexpression of Aβ42 caused upregulation of Crb expression, whereas downregulation of Crb either by RNAi or null allele approach rescued the Aβ42-mediated-neurodegeneration. Co-expression of full length Crb with Aβ42 increased severity of Aβ42-mediated-neurodegeneration, …

Homeotic Gene Teashirt (Tsh) Has A Neuroprotective Function In Amyloid-Beta 42 Mediated Neurodegeneration, Michael T. Moran, Meghana Tare, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Background: Alzheimer's disease (AD) is a debilitating age related progressive neurodegenerative disorder characterized by the loss of cognition, and eventual death of the affected individual. One of the major causes of AD is the accumulation of Amyloid-beta 42 (Aβ42) polypeptides formed by the improper cleavage of amyloid precursor protein (APP) in the brain. These plaques disrupt normal cellular processes through oxidative stress and aberrant signaling resulting in the loss of synaptic activity and death of the neurons. However, the detailed genetic mechanism(s) responsible for this neurodegeneration still remain elusive.

Methodology/Principal Findings: We have generated a transgenic Drosophila eye model where …

Genetic Character Of Cyb5 Gene Among Different Pig Breeds.Pdf, Ying Bai, Jibin Zhang, Meiying Fang

Jibin Zhang

Identification Of Set1 Target Genes, William Beyer, Scott D. Briggs

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Set1 complex, a histone methyltransferase complex found in S. cerevisiae (budding yeast), is the only histone methyltransferase responsible for catalyzing methylation of histone H3 at Lysine 4. It possesses homologues in other species, humans included. While yeast only have the Set1 complex, the human homologues of the yeast Set1 complex include mixed-lineage leukemia family (MLL1-4), Set1 A, Set1 B, among others. MLL1-4 has been shown to play a role in transcription, cell type specification, and the development of leukemia. One application of characterizing the role of a protein is that the information gained can provide insight into the function …

Welcome To The Journal Of Evolution And Health, Aaron Blaisdell, Paul Jaminet, David C. Pendergrass

Aaron P Blaisdell

Welcome to the first issue of the Journal of Evolution and Health! The Journal of Evolution and Health is the peer-reviewed, open-access journal of the Ancestral Health Society, a community of scientists, healthcare professionals, and laypersons who collaborate to understand health challenges from an evolutionary perspective.

Fast Quantitative Real-Time Pcr-Based Screening For Common Chromosomal Aneuploidies In Mouse Embryonic Stem Cells, Charlotte D'Hulst, Irena Parvanova, Delia Tomoiaga, Maria L. Sapar, Paul Feinstein

Publications and Research

Chromosomal integrity has been known for many years to affect the ability of mouse embryonic stem cells (mESCs) to contribute to the germline of chimeric mice. Abnormal chromosomes are generally detected by standard cytogenetic karyotyping. However, this method is expensive, time consuming, and often omitted prior to blastocyst injection, consequently reducing the frequency of mESC-derived offspring. Here, we show a fast, accurate, and inexpensive screen for identifying the two most common aneuploidies (Trisomy 8 and loss of chromosome Y) in genetically manipulated mESCs using quantitative real-time PCR (qPCR). Screening against these two aneuploidies significantly increases the fraction of normal mESC …

Acclimatization Of The Tropical Reef Coral Acropora Millepora To Hyperthermal Stress, Anthony John Bellantuono

FIU Electronic Theses and Dissertations

The demise of reef-building corals potentially lies on the horizon, given ongoing climate change amid other anthropogenic environmental stressors. If corals cannot acclimatize or adapt to changing conditions, dramatic declines in the extent and health of the living reefs are expected within the next half century. The primary and proximal global threat to corals is climate change. Reef-building corals are dependent upon a nutritional symbiosis with photosynthetic dinoflagellates belonging to the group Symbiodinium. The symbiosis between the cnidarian host and algal partner is a stress-sensitive relationship; temperatures just 1°C above normal thermal maxima can result in the breakdown of …

Evolution Of Hybrid Incompatibilities In Gene Regulatory Networks, Alexander Y. Tulchinsky

Open Access Dissertations

Under the Dobzhansky-Muller model, postzygotic isolation results from incompatibility between interacting genes. Evidence points to regulatory networks as a rich source of incompatibilities that impact hybrid fitness. Pleiotropy is a natural feature of regulatory networks because regulatory elements generally have multiple targets. Both pleiotropy and hybrid incompatibility arise due to genetic interactions; therefore we can expect an intimate association between them. In the following chapters, I investigate the relationship between pleiotropy and hybrid incompatibility in the context of regulatory networks.

In chapter one, I extend a general network-based study of hybrid incompatibility by incorporating a sequence-based thermodynamic model of transcriptional …

Signatures Of Rapid Evolution In Urban And Rural Transcriptomes Of White-Footed Mice (Peromyscus Leucopus) In The New York Metropolitan Area, Stephen Edward Harris, Jason Munshi-South, Craig Oberfell, Rachel O'Neill

Publications and Research

Urbanization is a major cause of ecological degradation around the world, and human settlement in large cities is accelerating. New York City (NYC) is one of the oldest and most urbanized cities in North America, but still maintains 20% vegetation cover and substantial populations of some native wildlife. The white-footed mouse, Peromyscus leucopus, is a common resident of NYC’s forest fragments and an emerging model system for examining the evolutionary consequences of urbanization. In this study, we developed transcriptomic resources for urban P. leucopus to examine evolutionary changes in protein-coding regions for an exemplar “urban adapter.” We used Roche 454 …

Characterization Of Staphylococcus Aureus Lipase, Vithooshan Vijayakumaran

Electronic Thesis and Dissertation Repository

USA300, a strain of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA), has become prevalent in the community. Colonization of human skin requires mechanisms that allow this bacterium to overcome the innate immune defenses on the skin, including secretion of antimicrobial lipids. Antimicrobial lipids inhibit S. aureus growth and induce the staphylococcal proteolytic cascade, producing aureolysin (Aur) which processes the lipase glycerol ester hydrolase (Geh). Nearly all S. aureus strains secrete Geh, yet little information exists concerning its function. Using purified Aur and Geh we confirm that aureolysin processes proGeh to Geh. We then confirmed that geh was required for lipase activity …

Role Of Branched-Chain Amino Acid Transporters In Staphylococcus Aureus Virulence, Sameha Omer

Electronic Thesis and Dissertation Repository

Branched-chain amino acids (BCAAs) act as effector molecules that signal a global transcriptional regulator, CodY, to regulate virulence factors in nutrient depleted environments. Staphylococcus aureus contains three putative BCAA transporters (BrnQ1, BrnQ2, BrnQ3) whose role in BCAA uptake is unknown. We hypothesize that BrnQ transporters are involved in BCAA uptake and contribute to virulence in S. aureus by modulating CodY activity. Results from radioactive uptake assays indicate that BrnQ1 is the predominant BrnQ transporter of isoleucine, valine and leucine. Meanwhile, BrnQ2 is more specific for isoleucine. Furthermore, only the lack of BrnQ1 hinders growth of S. aureus in chemically-defined media …

Genome-Wide Analyses Of Shavenbaby Target Genes Reveals Distinct Features Of Enhancer Organization, Delphine Menoret, Marc Santolini, Isabelle Fernandes, Rebecca Spokony, Jennifer Zanet, Ignacio Gonzalez, Yvan Latapie, Pierre Ferrer, Hervé Rouault, Kevin P. White, Philippe Besse, Vincent Hakim, Stein Aerts, Francois Payre, Serge Plaza

Publications and Research

Background: Developmental programs are implemented by regulatory interactions between Transcription Factors (TFs) and their target genes, which remain poorly understood. While recent studies have focused on regulatory cascades of TFs that govern early development, little is known about how the ultimate effectors of cell differentiation are selected and controlled. We addressed this question during late Drosophila embryogenesis, when the finely tuned expression of the TF Ovo/Shavenbaby (Svb) triggers the morphological differentiation of epidermal trichomes.

Results: We defined a sizeable set of genes downstream of Svb and used in vivo assays to delineate 14 enhancers driving their specific expression in trichome …

Dysfunctional Gene Regulation Of The Meiotic Program In An Interspecific Yeast Hybrid, Devjanee Swain Lenz

Arts & Sciences Electronic Theses and Dissertations

Speciation, the evolutionary process by which species arise, is a fundamental biological concept. One of the major goals of evolutionary genetics is to understand the genetic basis of reproductive isolation (RI), a collection of barriers that prevents two species from forming viable or fertile hybrids. Given the lack of viable or fertile hybrid progeny, identifying genes that impact RI as well as their functions has been difficult. Thus we lack a view of the total genetic contribution to RI. Recently the budding yeast Saccharomyces has served as an evolutionary model, as abundant sequence, expression, and phenotypic data exist for the …

Type 1 Diabetes And The Male Reproductive Axis, Erica Schoeller

Arts & Sciences Electronic Theses and Dissertations

Glucose regulation is important in both spermatogenesis as well as mature sperm function. The impact of diabetes on sperm function is becoming increasingly clear, though much work is still needed to elucidate the mechanism by which diabetes impairs spermatogenesis. Diabetes causes disruptions in the hypothalamic pituitary gonadal (HPG) axis, the regulatory system that controls reproduction. The HPG axis functions by secreting GnRH pulses from the hypothalamus, which bind to receptors on the pituitary and cause secretion of follicle stimulating hormone and luteinizing hormone, which then bind to receptors in the testes and facilitate spermatogenesis. Type 1 diabetes can severely impact …

A Study On The Regulation Of Amino Acids And Glucose Sensing Pathways In Saccharomyces Cerevisiae, Mengying Chiang

University of New Orleans Theses and Dissertations

Nutrient availability regulates eukaryotic cell growth. This study focuses on two signaling pathways, involved in sensing amino acids and carbon sources, which allow cells to respond appropriately to their presence. The first part of this study shows that Ssy1, a plasma membrane localized sensor in the Ssy1-Ptr3-Ssy5 (SPS) amino acid sensing pathway, can detect 19 common L-amino acids with different potencies and affinities based on the physiochemical structure of amino acids. Substituents around alpha carbon are critical for amino acid sensing by Ssy1. Furthermore, a high concentration of cysteine is toxic to cells. Inactivation of SPS signaling confers resistance to …

Identifying Molecular Markers Associated With Salt And Boron Tolerance In Poplar Trees, Darshanpreet Gill, Nathan Follen, Davis W. Cheng, Kyan Salehi, Gary Banuelos, James P. Prince

STAR Program Research Presentations

Standard irrigation practices promote salt and boron accumulation in soils on the Westside of Central California. The build-up of these inorganic salts leads to the degradation of arable land and reduction of crop production. Different clones of poplar trees have been shown to grow in salt- and boron-contaminated soils, and in doing so, gradually remove significant amounts of these inorganic salts from the soil. In an effort to identify molecular markers linked with salt and boron tolerance in poplars, 31 PCR primer pairs have been designed based on candidate genes identified from the literature, and an additional 31 PCR primer …

Defining The Requirements For Early Gene Expression In Bacteriophage Hk639, Amanda L. Seaton

Masters Theses & Specialist Projects

Lambdoid phages suppress transcription termination to fully express their genes. Antitermination of early gene expression in most lambdoid phages is mediated by an interaction between the N protein and a number of host-encoded factors. Bacteriophage HK022 does not rely on a protein for antitermination. To promote full expression of early phage genes, the transcripts of the HK022 put sites interact directly with RNA polymerase to convert it to a termination resistant form. Bacteriophage HK639 also uses RNA-mediated antitermination. However, it only possesses a single put-like element in its left operon. Because most lambdoid phages, including HK022, have antiterminator elements in …

The Importance Of Epigenetic Phenomena In Regulating Activity Of The Genetic Material, Sin Chan

Senior Honors Projects

Genetics has taught us that genes are represented as discrete sequences within a larger DNA molecule found embedded within the chromosomes of a living cell. Collectively these chromosomes and their associated genes carry all of the instructions for life. Until recently, the prevailing thought has been that genes are destiny in the life of an individual since the genes carry the information that determines the general traits and characteristics associated with that individual. The relatively recent understanding of mechanisms that underlie epigenetic phenomena has led to a rethinking of this concept. Epigenetics describes cellular mechanisms that explain how two individuals …

Development Of Tools To Assess The Effects Of Lunasin On Normal Development And Tumor Progression In Drosophila Melanogaster, Gillian E. Jones

Masters Theses & Specialist Projects

Soy contains many bioactive molecules known to elicit anti-cancer effects. One such peptide, Lunasin, has been shown to selectively act on newly transformed cells while having no cytotoxic effect on non-tumorigenic or established cancer cell lines. In this study we attempt to understand the developmental effects of Lunasin overexpression in vivo and create reagents that will help us understand Lunasin’s anti tumorigenic effects in an intact organism. cDNA encoding lunasin and EGFP-lunasin were cloned into pUAST and microinjected into Drosophila embryos. Tissue-specific overexpression of EGFP-Lun in the resulting transgenic lines was accomplished by crossing transgenics to various GAL4 driver lines. …

Prkca: Identification Of A Novel Downstream Target Of Wt1, Devin Jones

Dissertations & Theses (Open Access)

Wilms tumor is a childhood tumor of the kidney arising from the undifferentiated metanephric mesenchyme. Tumorigenesis is attributed to a number of genetic and epigenetic alterations. In 20% of Wilms tumors, Wilms tumor gene 1 (WT1) undergoes inactivating homozygous mutations causing loss of function of the zinc finger transcription factor it encodes. It is hypothesized that mutations in WT1 result in dysregulation of downstream target genes, leading to aberrant kidney development and/or Wilms tumor. These downstream target genes are largely unknown, and identification is important for further understanding Wilms tumor development. Heatmap data of human Wilms tumor protein …

Trends In Borrelia Spp. Prevalence In Ixodes Spp. Ticks From The Southeastern Coastal United States, Lauren Paul Maestas

Masters Theses

The Lyme borreliosis (LB) cycle, involving Ixodes scapularis and Borrelia burgdorferi sensu stricto (Bbss), is well documented in the northeastern US, where LB is becoming increasingly prevalent. In coastal North Carolina, I. affinis has been shown to have a higher incidence of Bbss than I. scapularis. My objectives were, to assess changes in prevalence of Bbss in Ixodes spp. along a transect from Virginia to Florida, and to assess the value of dogs and mesomammals as sentinels for spread of Borrelia burgdorferi sensu lato.

Ixodes spp. were collected at sites from 37.4^o N to 30.0^{o …}

Recurrent Modification Of A Conserved Cis-Regulatory Element Underlies Fruit Fly Pigmentation Diversity, William A. Rogers, Joseph R. Salomone, David J. Tacy, Eric M. Camino, Kristen A. Davis, Mark Rebeiz, Thomas M. Williams

Biology Faculty Publications

The development of morphological traits occurs through the collective action of networks of genes connected at the level of gene expression. As any node in a network may be a target of evolutionary change, the recurrent targeting of the same node would indicate that the path of evolution is biased for the relevant trait and network. Although examples of parallel evolution have implicated recurrent modification of the same gene and cis-regulatory element (CRE), little is known about the mutational and molecular paths of parallel CRE evolution. InDrosophila melanogaster fruit flies, the Bric-à-brac (Bab) transcription factors control the development …

Array-Based Genomic Diversity Measures Portray Mus Musculus Phylogenetic And Genealogical Relationships, And Detect Genetic Variation Among C57bl/6j Mice And Between Tissues Of The Same Mouse, Susan T. Eitutis

Electronic Thesis and Dissertation Repository

Mouse models lack affordable genomic technologies slowing the identification of candidate variants contributing to complex phenotypes. The Mouse Diversity Genotyping Array (MDGA) is a low cost, high-resolution platform permitting genomic diversity assessment. Using a validated list of >500,000 single nucleotide polymorphisms (SNPs), we applied the first comprehensive analysis of SNP differences to detect genetic distance across 362 Mus musculus samples. Genetic distance measured between distantly and closely related mice correlates with known phylogeny and genealogy. Variation detected between C57BL/6J mice is consistent with previous reports of variants within this strain. Putative genetic variation detected between and within tissues indicates somatic …

The Rate And Effects Of Spontaneous Mutation On Fitness Traits In The Social Amoeba, Dictyostelium Discoideum, David W. Hall, Sara Fox, Jennie J. Kuzdzal-Fick, Joan E. Strassmann, David C. Queller

Biology Faculty Publications & Presentations

We performed a mutation accumulation (MA) experiment in the social amoeba Dictyostelium discoideum to estimate the rate and distribution of effects of spontaneous mutations affecting eight putative fitness traits. We found that the per-generation mutation rate for most fitness components is 0.0019 mutations per haploid genome per generation or larger. This rate is an order of magnitude higher than estimates for fitness components in the unicellular eukaryote Saccharomyces cerevisiae, even though the base-pair substitution rate is two orders of magnitude lower. The high rate of fitness-altering mutations observed in this species may be partially explained by a large mutational target …