Genetics Commons^™

Temperature And Polyunsaturated Fatty Acid’S Effect On Daphnia Magna Reproduction, Mark Albright

Electronic Theses and Dissertations

Organisms adapt to their environments by adjusting their biochemistry and physiology; such adaptation is limited by resource availability and physiological constraints. The freshwater crustacean Daphnia magna inhabits a wide range of environments and must survive and reproduce within a range of temperatures. One limit to low-temperature adaptation is thought to be the availability of unsaturated fatty acids necessary to maintain proper fluidity of cellular membranes. D. magna maintained at 10 ºC on a diet poor in unsaturated fatty acids have been observed to produce clutches that fail to develop. However, this has not been observed on a diet rich in …

This Is Just A Phase : The Impact Of Population Structure On Haplotype Phasing And Linkage Disequilibrium Measures At Functional Genetic Sites., Roxanne Kaaren Leiter

Electronic Theses and Dissertations

The block-like structure of the human genome has been the subject of many scientific papers and is of practical significance in large-scale genome-wide association studies. How stringent haplotype block boundaries are within and between populations has been the subject of ongoing debate within human population genetics. This thesis will contribute to the description of universal and population-specific haplotype blocks at functional sites, namely across the IL-10 gene family (including IL-10, IL-19, IL-20 and IL-24), which is involved in a number of immune system processes, and MAPKAP-K2, an adjacent and functionally significant kinase gene. Beyond the description of blocks across these …

The Dlk1-Meg3 Locus In Malignant Cells Of Proposed Primordial Germ Cell Origins., Zachariah Payne Sellers

Electronic Theses and Dissertations

Primordial germ cells (PGCs) are hypothesized to deposit hematopoietic stem cells (HSCs) along their migration route through the embryo during the early stages of embryogenesis. PGCs also undergo global chromatin remodeling, including the erasure and reestablishment of genomic imprints, during this migration. While PGCs do not spontaneously form teratomas, their malignant development into germ cell tumors (GCTs) in vivo is often accompanied by the retention of hypomethylation at the IGF2-H19 imprinting control differentially methylated region (DMR). Previous studies in bimaternal embryos determined that proper genomic imprinting at two paternally imprinted loci was necessary for their growth and development: Igf2-H19 and …

Using Rna Seq To Define Genes And Pathways Affecting Salmonella Vaccine Response In Beef Cattle, Sara Awrahman

Electronic Theses and Dissertations

A Salmonella siderophore receptor and porin (SRP) proteins vaccine is an intervention strategy to control Salmonella burden in cattle. The vaccine works by stimulating immunity to produce antibodies against bacterial SRPs as siderophore molecules play a major role in transporting iron to bacteria. Blocking iron uptake system by antibodies causes death of bacterial cells. The vaccine can also be useful to protect humans against salmonellosis, which causes high rates of illness and death annually, by reducing shedding of Salmonella in the feces of cattle. Though other researchers have evaluated efficacy and immune response of this Salmonella SRP vaccine, genes …

Examination Of The Relevance Of Pi3k And Pten Pathway In Ustilago Maydis., Nathaniel Edward Dalton

Electronic Theses and Dissertations

Ustilago maydis is a fungal pathogen that is an obligate parasite on Zea mays (Corn) in order to undergo and complete its sexual life cycle. The cells grow as a haploid form until they meet a compatible partner and undergo a dimorphic switch from a budding yeast-like cell type to a filamentous dikaryon. Infection of the host plant is characterized by leaf chlorosis, anthocyanin content, and formation of large galls that develop on the stem, leaves, cobs, and flowers. Many signaling cascades such as MAPK and PKA are involved in the regulation of the infection lifecycle. The Phosphatidylinosotiol 3 Kinase/ …

Congenic And Functional Analysis Of Rat Mammary Cancer Susceptibility., Saasha Le

Electronic Theses and Dissertations

Breast cancer is a complex disease affected by genetic, epigenetic and environmental factors. The genetic architecture of breast cancer comprises of high to low penetrance alleles. Although low penetrance alleles associate with a small change in an individual’s risk to breast cancer, the total number of variants present and the high population frequency attributes to a much greater population based impact compared to rare high penetrance alleles. Animal models have been used to study these low penetrance modifier alleles in breast cancer. Different rat strains vary in their susceptibility to 7,12- dimethybenzanthracene (DMBA) induced mammary carcinogenesis, with the Wistar- Furth …

Insights Into The Introduction Histories And Population Genetic Dynamics Of The Nile Monitor (Varanus Niloticus) And Argentine Black And White Tegu (Salvator Merianae) In Florida., Jared Price Wood

Electronic Theses and Dissertations

This dissertation examines the population genetic dynamics of two Florida invasives: the Nile monitor (Varanus niloticus) and Argentine black and white tegu (Salvator merianae). I also provide insights into the introduction histories of both species. This study was developed as part of a collaborative effort with the Florida Wildlife Commission to expand our knowledge of these highly detrimental, invasive lizards. All research activities involving animals and animal tissues were approved by the University of Louisville’s Institutional Animal Care and Use Committee (IACUC Proposal #: 12024). I start with a brief introduction into what makes invasive species …

Atmospheric Nitrogen Assimilation In Ustilago Maydis., Michael Cooper

Electronic Theses and Dissertations

Nitrogen is an essential nutrient for all living creatures. Ammonium is one of the most efficiently used and thus preferred, sources of nitrogen. As with other dimorphic fungi, yeast-like cells of Ustilago maydis, a fungal pathogen of maize, switches to filamentous growth when starved for nitrogen/ammonium. U. maydis carries two genes, ump1 and ump2, encoding ammonium transporters that facilitate both uptake of ammonium and the filamentous response to its absence. While no obvious phenotype is observed when ump1 is deleted, cells without ump2 are unable to filament in response to low ammonium, although they can still grow. Surprisingly, …

Isolation And Characterization Of A Full Length Retrotransposon: Cr1, Cassandra Michelle Weason

Electronic Theses and Dissertations

Transposable elements (TE) have been found in all genomes and have clearly had a major impact on genomic evolution. The described research takes advantage of an abundant transposable element present in the genomes of Anseriformes, called Chicken Repeat 1 (CR1). Previous studies in Anseriformes suggest that CR1 is presently active in recent evolutionary time (St. John, 2004). A fully functional CR1 element itself is approximately 4.5kb long (Kajikawa, 1997), where almost all inserts are truncated at the 5' end. Because of this, it has been a challenge to isolate a full length, active element. In this study, two CR1 sequences …

Novel Functions For Neuronal Rna Processing Bodies In The Control Of Axon Terminal Growth In Drosophila Melanogaster, Sarala Joshi Pradhan

Electronic Theses and Dissertations

In this thesis we first characterized neuronal functions for HPat/Pat1, a core component of RNA processing bodies or "P bodies". We show that hpat mutants exhibit a strong synaptic hyperplasia at the developing and acutely stimulated Drosophila larval neuromuscular junctions (NMJs). The synaptic defects observed in hpat mutants are associated with rearrangement of the axonal microtubule cytoskeleton suggesting that HPat negatively regulates presynaptic microtubule-based growth during NMJ development. Interestingly, we also found that both pre-and postsynaptic HPat expression controlled rapid axon terminal growth in response to acute spaced synaptic stimulation. We also demonstrate that HPat interacts genetically with the catalytic …

Pomc Is Expressed In Pancreatic Alpha Cells, Samia M.M Farrara

Electronic Theses and Dissertations

Pancreatic alpha cells secrete glucagon to increase blood glucose during hypoglycemia. Currently, the mechanisms that initiate glucagon secretion are not well understood. This study investigates the expression of pro-opiomelanocortin (POMC), a potent regulator of glucagon secretion, in alpha cells.

Insulin tolerance tests in mice lacking the POMC gene showed a correlation between alpha MSH, and glucagon secretion from alpha cells (Hochgeschwender et al. 2003). Results from a previous study showed that the POMC product, melanocortin á-MSH, acts through a melanocortin receptor 4 (MC4R) at the surface of the alpha cells to trigger the release of glucagon [Angleson, unpublished data, Lumsden …

Characterization Of Cis-Regulatory Elements Controlling Repo Transcription In Drosophila Melanogaster, Robert Johnson

Electronic Theses and Dissertations

The glial cells missing (gcm) gene has been identified as a "master regulator" of glial cell fate in the fruit fly Drosophila . However, the gcm gene is also expressed in and required for the development of larval macrophages and tendon cells, and lamina neurons in the adult CNS. Thus, the Gcm protein activates the transcription of different sets of genes in different developmental contexts. How the Gcm protein regulates these different outcomes is not known. My long-term goal is to identify proteins that collaborate with Gcm to promote the transcriptional activation of Gcm target genes specifically in glial cells, …

A Family-Based Association Study Of Conduct Disorder., Xueqiu Jian

Electronic Theses and Dissertations

Conduct disorder (CD) is a psychiatric syndrome in childhood and adolescence that is one of the most common childhood disorders with continuously increasing prevalence but uncertain pathogenesis. We performed a genome-wide, family-based association study of CD using P2BAT/FBAT software. The data is gathered from Collaborative Study on the Genetics of Alcoholism (COGA) and International Multi-Center ADHD Genetics Project (IMAGE).

Using COGA data, we identified 20 markers which showed suggestive associations (p<10^-3) with CD. Nine of them are located in known genes. Two genes, ADAM10 and CAMK2A, which had been reported associated with Alzheimer's disease (AD), bipolar disorder, …

Gene Expression And Phenotype Response Of Drosophila Melanogaster To Selection., Kenneth W. Mcdonald

Electronic Theses and Dissertations

The evolution of phenotypic plasticity is currently a topic of paramount interest in a diverse field of sub-disciplines. Salience is placed by all fields in describing the interaction of selection and phenotypic plasticity and the consequence of this interaction more broadly on evolution. Lacking in the discussion is substantial empirical description of genotype/phenotype interactions that by definition constitute the plastic response to novel and stressful environments. Here, I present empirical observations that bring the interaction of genotype and phenotype into focus. Drosophila melanogaster populations subjected to selection for tolerance to low food or high alcohol conditions each exhibited an enhancement …

A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan

Electronic Theses and Dissertations

A temperature-sensitive mutant of Escherichia coli affected in the alpha subunit of RNA polymerase has been investigated. Gene mapping and complementation experiments placed the mutation to temperature-sensitivity within the alpha operon at 72 min on the bacterial chromosome. The rate of RNA synthesis in vivo and the accumulation of ribosomal RNA were significantly reduced in the mutant at 44$\sp\circ$C. The thermostability at 44$\sp\circ$C of the purified holoenzyme from mutant cells was about 20% of that of the normal enzyme. Assays with T7 DNA as a template showed that the fraction of active enzyme competent for transcription was reduced as a …

Variants And Polymorphisms Of Three Repetitive Dna Families In The Human Genome, Robert M. Roudabush

Electronic Theses and Dissertations

A novel 0.6 kb LINE family in human DNA, designated L2Hs, has been described (Musich and Dykes 1986). Studies employing clone N6.4, containing three 0.6 kb segments of this family, indicate that these sequences are interspersed and moderately repetitive. Two additional variant sequences of the L2Hs family, N6.1 and N6.3, have been identified. Restriction mapping of each cloned segment indicates similarities among N6.4, N6.3 and N6.1. When the cloned DNAs were cleaved with restriction enzymes and subjected to cross-hybridization, each cloned insert produced a pattern indicating that the sequences contained in N6.1 and N6.3 are represented in at least one …