Molecular Biology Commons^™

Global And Specific Controls Of Protein Synthesis In Hibernators, Peipei Pan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mammalian hibernation is a highly dynamic physiological process that is composed of a series of torpor bouts, wherein hibernators oscillate between periods of torpor and interbout arousal. Although normally vital to homeostasis, many energetically consumptive processes such as translation or protein synthesis are virtually ceased during hibernation. Earlier studies indicated that protein synthesis had fallen to almost negligible levels. Cap-dependent initiation of translation is well regulated by eukaryotic translation initiation factor 4E (eIF4E) and its binding partner eIF4E-binding protein 1 (4E-BP1) when hibernators cycle in and out the torpor state. Herein, I investigated well-characterized regulatory mechanisms of global and specific …

Mitochondrial Dna Analysis By Denaturing High-Performance Liquid Chromatography For The Characterization And Separation Of Mixtures In Forensic Samples, Richard Kristinsson

Electronic Theses and Dissertations

A mixture of different mtDNA molecules in a single sample is a significant obstacle to the successful use of standard methods of mtDNA analysis (i.e., dideoxy dye-terminator sequencing). Forensic analysts often encounter either naturally occurring mixtures (e.g., heteroplasmy) or situational mixtures typically arising from a combination of body fluids from separate individuals. The ability to accurately resolve and interpret these types of samples in a timely and cost efficient manner would substantially increase the power of mtDNA analysis and potentially provide valuable investigative information by allowing its use in cases where the current approach is limited or fails. Therefore, this …

Investigating The Roles Of Ndj1 And Tid1 In Crossover Assurance In Saccharomyces Cerevisiae, Rianna Knowles

Master's Theses

Meiosis is the specialized process of cell division utilized during gametogenesis in all sexually reproducing eukaryotes, which consists of one round of DNA replication followed by two rounds of chromosome segregation and results in four haploid cells. Crossovers between homologous chromosomes promote proper alignment and segregation of chromosomes during meiosis.

Crossover interference is a genetic phenomenon in which crossovers are non-randomly placed along chromosomes. Crossover assurance ensures that every homologous chromosome pair obtains at least one crossover during Prophase I. Crossovers physically connect homologous pairs, allowing spindle fibers to attach and separate homologs properly. However, some organisms have shown an …

Downregulation Of Pax2 Suppresses Ovarian Cancer Cell Growth, Huijuan Song

Dissertations & Theses (Open Access)

PAX2 is one of nine PAX genes regulating tissue development and cellular differentiation in embryos. PAX2 promotes cell proliferation, oncogenic transformation, cell-lineage specification, migration, and survival. Unattenuated PAX2 has been found in several cancer types. We therefore sought to elucidate the role of PAX2 in ovarian carcinomas. We found that PAX2 was expressed in low-grade serous, clear cell, endometrioid and mucinous cell ovarian carcinomas, which are relatively chemoresistant compared to high grade serous ovarian carcinomas. Four ovarian cancer cell lines, RMUGL (mucinous), TOV21G (clear cell), MDAH-2774 (endometrioid) and IGROV1 (endometrioid), which express high-levels of PAX2, were used to study the …

The Role And Mechanism Of The Homeobox Gene Dlx4 In Transforming Growth Factor-B Resistance In Cancer, Bon Q. Trinh

Dissertations & Theses (Open Access)

Transforming growth factor-b (TGF-b) is a cytokine that plays essential roles in regulating embryonic development and tissue homeostasis. In normal cells, TGF-b exerts an anti-proliferative effect. TGF-b inhibits cell growth by controlling a cytostatic program that includes activation of the cyclin-dependent kinase inhibitors p15^Ink4B and p21^WAF1/Cip1 and repression of c-myc. In contrast to normal cells, many tumors are resistant to the anti-proliferative effect of TGF-b. In several types of tumors, particularly those of gastrointestinal origin, resistance to the anti-proliferative effect of TGF-b has been attributed to TGF-b receptor or Smad mutations. However, these mutations are absent from many …

Expression And Regulation Of Human Cytochrome P450 4f Isoforms In Tissue Samples And Under Tnf-Alpha Challenges, Jordan C. Bell

Dissertations & Theses (Open Access)

CYP4F (Cytochrome P4504F) enzymes metabolize endogenous molecules including leukotrienes, prostaglandins and arachidonic acid. The involvement of these endogenous compounds in inflammation has led to the hypothesis that changes in the inflamed tissue environment may affect the expression of CYP4Fs during the pro-inflammatory state, which in turn may modulate inflammatory conditions during the anti-inflammatory state. We demonstrated that inflamed tissues have different levels of CYP4F isoform expression profiles in a number of human samples when compared to the average population. The CYP4F isoform expression levels change with the degree of inflammation present in tissue. Further investigation in cell culture studies revealed …

Regulation Of Set1-Mediated Methylation Of Dam1, John A. Latham

Dissertations & Theses (Open Access)

Eukaryotic genomes exist within a dynamic structure named chromatin in which DNA is wrapped around an octamer of histones forming the nucleosome. Histones are modified by a range of posttranslational modifications including methylation, phosphorylation, and ubiquitination, which are integral to a range of DNA-templated processes including transcriptional regulation. A hallmark for transcriptional activity is methylation of histone H3 on lysine (K) 4 within active gene promoters. In S. cerevisiae, H3K4 methylation is mediated by Set1 within the COMPASS complex. Methylation requires prior ubiquitination of histone H2BK123 by the E2-E3 ligases Rad6 and Bre1, as well as the Paf1 transcriptional …

Molecular Evolution And Historical Biogeography Of New World Birds, Brian T. Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Deciphering the patterns of how biodiversity has evolved across time and space has remained a fundamental objective for biologists for the last 200 years. Researchers are faced with the challenge of interpreting the complexity of evolutionary patterns that have been generated over the deep history of the Earth. The advancement of DNA sequencing technology has yielded a new and powerful genetic toolkit that has allowed biologists to address novel evolutionary questions. For my dissertation research, I used molecular genetics and a statistical framework to study the evolution and historical biogeography of birds distributed in North and South America. My dissertation …

Cooperative And Antagonistic Roles For Heterochromatin Proteins In Transcriptional Regulation Of The Drosophila Sex Determination Masterswitch Gene, Hui Li

University of Kentucky Doctoral Dissertations

HOAP was originally identified as a component of an ORC-containing multi-protein complex of Heterochromatin Protein 1 (HP1) from early Drosophila embryos. HOAP immunostaining showed prominent association of it with telomeres, and mutants for HOAP (cav¹) showed it functions along with HP1 in forming a telomere capping complex that prevents telomeric fusions.

Weaker HOAP immunostaining is also observed in regions of pericentric heterochromatin and euchromatin. To examine the role of HOAP at these non-telomeric sites, we applied Affymetric Drosophila Genome Arrays to undertake a microarray expression profiling study of genes that are mis-expressed in cav¹ mutant larvae. The …

Circadian And Homeostatic Regulation Of Sleep In Cast/Eij And C57bl/6j Mice, Peng Jiang

University of Kentucky Doctoral Dissertations

Sleep is essential for mammals and possibly for all animals. Advancing our knowledge of sleep regulation is crucial for the development of interventions in sleep-related health and social problems. With this aim, this study utilizes laboratory mice to explore sleep regulatory mechanisms at behavioral, molecular, and genetic levels.

Sleep is regulated by the interaction of circadian and homeostatic processes. The circadian clock facilitates sleep to occur at a favorable time of the day. Normal mice, such as the C57BL/6J (B6) strain, sleep mostly during the day and initiate activities at dark onset. Here, I show mice of the CAST/EiJ (CAST) …

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 …

Rox1 Function In Dosage Compensation: Structural / Functional Analysis Of A Non-Coding Rna, Ying Kong

Wayne State University Dissertations

roX1 is a long non-coding RNA involved in the chromosome-wide gene regulation that occurs during dosage compensation in Drosophila. Dosage compensation in Drosophila melanogaster occurs by a global two-fold increase of transcription from the single male X chromosome. This essential process compensates for X chromosome monosomy. The male-specific lethal (MSL) complex, containing five proteins, localizes to the male X chromosome and alters chromatin to modify gene expression. roX1 and roX2 RNAs are redundant components of MSL complex that are required for its exclusive X-localization. Recent studies in our lab have revealed a second role of roX RNAs in heterochromatic gene …

The Role Of Trm9 In Stress Responses, Ashish Ravindra Patil

Legacy Theses & Dissertations (2009 - 2024)

Cells need to respond appropriately to environmental changes in order to maintain homeostasis. The cellular response to an environmental stress is regulated at transcriptional, translational and post translational levels. The tRNA, which acts as an adaptor molecule between the mRNA and the protein, plays an important role in the translational regulation of cellular responses to stress and is one of the most heavily modified biomolecules. In Saccharomyces cerevisiae , the wobble uracil of the tRNA(3'-UCU-5') Arg, tRNA(3'-UUC-5') Glu and certain other specific tRNAs are modified to 5-methoxycarbonylmethyluridine (mcm5U) and 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) residues by the tRNA methyltransferase 9 (Trm9). Modifications at …