Genetics Commons^™

Diversity And Distribution Of Diatom Endosymbionts In Amphistegina Spp. (Foraminifera) Based On Molecular And Morphological Techniques, Kwasi H. Barnes

USF Tampa Graduate Theses and Dissertations

Diatoms associated with foraminifers of the genus Amphistegina were assessed using a combination of morphological and molecular techniques. These included: 1) microscopic identification of diatoms cultured from the host, 2) sequencing of portions of the small subunit of the ribosomal RNA gene (18S) and the large subunit of the ribulose-1,5-bisphosphate carboxylase/oxygenase [i.e., RubisCO] gene (rbcL) from DNA extracted directly from the Amphistegina hosts and also from diatoms cultured from these hosts, and 3) denaturing gradient gel electrophoresis (DGGE) profiles of rbcL and internal transcribed spacer 1 (ITS1) PCR amplicons from DNA extracted directly from …

Genetic Moderators Of Cognitive Decline In The Health And Retirement Study, Shannon K. Runge

USF Tampa Graduate Theses and Dissertations

The current dissertation used a gene x environment (G x E) approach to examine the independent and interactive effects of specific genetic variants and participation in physical and cognitive/social activities (PA and CSA) on cognitive performance in 4,764 participants of the Health and Retirement Study. Using three-wave data, three sets of multi-level growth models were conducted to examine baseline, longitudinal, and interactive effects of genotype (i.e., ApoE, COMT, and BDNF) and CSA/PA on performance across five cognitive measures: immediate, delayed and total word recall, and serial 7s and backwards counting.

At baseline, the ApoE ε4 allele predicted …

Nonreplicative Dna Helicases Involved In Maintaining Genome Stability, Salahuddin Syed

USF Tampa Graduate Theses and Dissertations

Double-strand breaks and stalled forks arise when the replication machinery encounters damage from exogenous sources like DNA damaging agents or ionizing radiation, and require specific DNA helicases to resolve these structures. Sgs1 of Saccharomyces cerevisiae is a member of the RecQ family of DNA helicases and has a role in DNA repair and recombination. The RecQ family includes human genes BLM, WRN, RECQL4, RECQL1, and RECQL5. Mutations in BLM, WRN, and RECQL4 result in genetic disorders characterized by developmental abnormalities and a predisposition to cancer. All RecQ helicases have common features including a …

Population Genetics And Epigenetics Of Two Salt Marsh Plant Species Along An Environmental Gradient, Christy M. Foust

USF Tampa Graduate Theses and Dissertations

Phenotypic plasticity is the ability of a given genotype to exhibit different phenotypes in response to environmental variables, which can impact population level processes. Plasticity of ecologically-relevant traits is important to an organism’s environmental response; however, the underlying mechanisms of plasticity are largely unknown. Ecological epigenetics may offer mechanisms (e.g. DNA methylation) underlying phenotypic plasticity. Epigenetics can be defined as the underlying molecular mechanisms that allow one genotype to exhibit different phenotypes. Differential DNA methylation is one epigenetic mechanism that has been correlated with a number of ecologically-relevant traits; including, differential herbivory in Viola cazorlensis, spinescence in Ilex aquifolium …

Functional Analysis Of The Ovarian Cancer Susceptibility Locus At 9p22.2 Reveals A Transcription Regulatory Network Mediated By Bnc2 In Ovarian Cells, Melissa Buckley

USF Tampa Graduate Theses and Dissertations

GWAS have identified several chromosomal loci associated with ovarian cancer risk. However, the mechanism underlying these associations remains elusive. We identify candidate functional Single Nucleotide Polymorphisms (SNPs) at the 9p22.2 ovarian cancer susceptibility locus, several of which map to transcriptional regulatory elements active in ovarian cells identified by FAIRE-seq (Formaldehyde assisted isolation of regulatory elements followed by sequencing) and ChIP-seq (Chromatin Immunoprecipitation followed by sequencing) in relevant cell types. Reporter and electrophoretic mobility shift assays (EMSA) determined the extent to which candidate SNPs had allele specific effects. Chromosome conformation capture (3C) reveals a physical association between Basonuclin 2 (BNC2) and …

Cloning And Characterization Of Il-1Β, Il-8, Il-10, And Tnfα From Golden Tilefish (Lopholatilus Chamaeleonticeps) And Red Snapper (Lutjanus Campechanus), Kristina L. Deak

USF Tampa Graduate Theses and Dissertations

Cytokines are pleiotropic and redundant signaling molecules that govern the inflammatory response and immunity, a critical ecological parameter for organism success and population growth. Produced at the site of injury or pathogen intrusion by a variety of cell types, cytokines mediate cell-signaling in either an autocrine or paracrine manner. The type and magnitude of the cytokine milieu produced subsequently dictates the strength and form of immune response. As the most diverse vertebrate group, with a high sensitivity to contaminants, fish represent an important foci for the evaluation of immune system evolution, function, and alteration upon toxicant exposure. While many cytokines …

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 …

Functional And Mutational Analysis Of Human Recq-Like Dna Helicases In Saccharomyces Cerevisiae, Hamed Mirzaei-Souderjani

USF Tampa Graduate Theses and Dissertations

RecQ-like proteins are a family of DNA helicases that are evolutionary conserved from prokaryotes to eukaryotes. A large amount of experimental evidence suggests these proteins have a major role in the maintenance of genome stability. In humans five RecQ like helicase have been identified (RecQL1, BLM, WRN, RecQL4, and RecQL5), three of which are associated with rare genetic disorders with sever chromosomal and developmental abnormalities, and an elevated predisposition to cancer. Among the disease associated RecQ-like helicases, BLM and WRN have been subject to extensive research, while our collective knowledge about the function of RecQL4 is still very limited. Similarly, …

Sirt1 Regulation Of The Heat Shock Response In An Hsf1-Dependent Manner And The Impact Of Caloric Restriction, Rachel Rene Raynes

USF Tampa Graduate Theses and Dissertations

The heat shock response (HSR) is the cell's molecular reaction to protein damaging stress and is critical in the management of denatured proteins. Activation of HSF1, the master transcriptional regulator of the HSR, results in the induction of molecular chaperones called heat shock proteins (HSPs). Transcription of hsp genes is promoted by the hyperphosphorylation of HSF1, while the attenuation of the HSR is regulated by a dual mechanism involving negative feedback inhibition from HSPs and acetylation at a critical lysine residue within the DNA binding domain of HSF1, which results in a loss of affinity for DNA. SIRT1 is a …

The Role Of Epigenetics In Evolution: The Extended Synthesis, Aaron W. Schrey, Christina L. Richards, Victoria Meller, Vincent Sollars, Douglas M. Ruden

Integrative Biology Faculty and Staff Publications

No abstract provided.

Epigenetic Variation May Compensate For Decreased Genetic Variation With Introductions: A Case Study Using House Sparrows (Passer Domesticus) On Two Continents, Aaron W. Schrey, Courtney A. C. Coon, Michael T. Grispo, Mohammed Awad, Titus Imboma, Earl D. Mccoy, Henry R. Mushinsky, Christina L. Richards, Lynn B. Martin

Integrative Biology Faculty and Staff Publications

Epigenetic mechanisms impact several phenotypic traits and may be important for ecology and evolution. The introduced house sparrow (Passer domesticus) exhibits extensive phenotypic variation among and within populations. We screened methylation in populations from Kenya and Florida to determine if methylation varied among populations, varied with introduction history (Kenyan invasion < 50 years old, Florida invasion ~150 years old), and could potentially compensate for decrease genetic variation with introductions. While recent literature has speculated on the importance of epigenetic effects for biological invasions, this is the first such study among wild vertebrates. Methylation was more frequent in Nairobi, and outlier loci suggest that populations may be differentiated. Methylation diversity was similar between populations, in spite of known lower genetic diversity in Nairobi, which suggests that epigenetic variation may compensate for decreased genetic diversity as a source of phenotypic variation during introduction. Our results suggest that methylation differences may be common among house sparrows, but research is needed to discern whether methylation impacts phenotypic variation.

Comparative Developmental Transcriptomics Of Echinoderms, Roy Vaughn

USF Tampa Graduate Theses and Dissertations

The gastrula stage represents the point in development at which the three primary germ layers diverge. At this point the gene regulatory networks that specify the germ layers are established and the genes that define the differentiated states of the tissues have begun to be activated. These networks have been well characterized in sea urchins, but not in other echinoderms. Embryos of the brittle star Ophiocoma wendtii share a number of developmental features with sea urchin embryos, including the ingression of mesenchyme cells that give rise to an embryonic skeleton. Notable differences are that no micromeres are formed during cleavage …

Population Genetics Of Amphiuma Means And Siren Lacertina In Central Florida, Anna C. Deyle

USF Tampa Graduate Theses and Dissertations

Population structure can be defined as a difference in the frequencies of alleles among populations, and it is often caused by barriers to dispersal. I used mitochondrial DNA sequences to examine the population structure of two large, aquatic salamanders, Amphiuma means (the Two-Toed Amphiuma) and Siren lacertina (the Greater Siren), at two spatial scales in peninsular Florida. Both species appear to have similar life histories, including poor dry land dispersal capabilities, and I hypothesized that they would exhibit significant population structure at both broad and fine scales. Wetland loss and landscape fragmentation are certain to have caused decreases in abundance …

From Dna To Protein: A Study Of Genomic Instability Candidate Genes During Zebrafish Development, Kristine Griffett

USF Tampa Graduate Theses and Dissertations

The zebrafish, Danio rerio, is a type of freshwater minnow often used to model human diseases including cancer, anxiety and aging diseases. The overall biology of zebrafish is strikingly similar to that of humans, allowing these fish to be used for drug discovery and toxicology studies for preclinical trials. In this study, zebrafish embryos were used to identify and characterize several candidate genes within two known regions of genomic instability on chromosome 18 and chromosome 4. This fish that were used in this study had been previously classified as genomic instability (gin) mutants due to increased incidence of somatic mutation …