Cellular and Molecular Physiology Commons^™

Molecular Mechanisms Of Dna Replication Initiation In Hpvs With Genetic Variations Leading To Cellular Carcinogenesis, Gulden Yilmaz

Graduate School of Biomedical Sciences Theses and Dissertations

Human papillomaviruses are a vast family of double-stranded DNA viruses containing non-carcinogenic and carcinogenic types, whose crucial differences remain unknown, except for the difference in the frequency of DNA replication. The human papillomavirus (HPV) E2 protein regulates the initiation of viral DNA replication and transcription. Its recognition and binding to four 12 bp palindromic sequences in the viral origin is essential for its function. Little is known about the DNA binding mechanism of the E2 protein found in HPV types that have low risk for oncogenicity (low-risk) as well as the roles of various elements of the individual binding sites. …

Chaperoning Ef Hands That Shape Calcium Response: Ncald, Hpca And S100b, Jingyi Zhang

Graduate School of Biomedical Sciences Theses and Dissertations

All organisms have an internal clock with a defined period between repetitions of activities. The period for circadian clock in human is 24.5 hours, while in mouse and rat, it is 23.5 hours. However, all organisms are forced to be in synchronization with their environment. A major environmental force that resets the internal clock to 24 hours is light. This phenomenon is defined as “light entrainment” or “phase-setting”. It is unclear how this entrainment process occurs. Studies from this laboratory indicate a role for two neuronal calcium sensor proteins: Neurocalcin  (NCALD) and S100B. For these two genes, mRNA as …

Patterns Of Morphological And Molecular Evolution In The Antillean Tree Bat, Ardops Nichollsi (Chiroptera: Phyllostomidae), Roxanne J. Larsen, Peter A. Larsen, Caleb D. Phillips, Hugh H. Genoways, Gary G. Kwiecinski, Scott C. Pedersen, Carleton J. Phillips, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Species endemic to oceanic islands offer unique insights into the mechanisms underlying evolution and have served as model systems for decades. Often these species show phenotypic variation that is correlated with the ecosystems in which they occur and such correlations may be a product of genetic drift, natural selection, and/or environmental factors. We explore the morphologic and genetic variation within Ardops nichollsi, a species of phyllostomid bat endemic to the Lesser Antillean islands. Ardops nichollsi is an ideal taxon to investigate the tempo of evolution in Chiroptera, as it: is a recently derived genus in the family Phyllostomidae; contains …

The Thioredoxin Trx-1 Regulates The Major Oxidative Stress Response Transcription Factor, Skn-1, In Caenorhabditis Elegans, Katie C. Mccallum

Dissertations and Theses (Open Access)

The ability to respond to hostile environmental conditions is critical for the survival of an organism. Oxidative stress is an adverse state in which reactive oxygen species (ROS) accumulate to a harmful level and, if left unresolved, can lead to cellular dysfunction and organismal disease. Sophisticated detoxification systems, characterized by a battery of enzymatic antioxidants, are utilized to neutralize ROS thereby reducing stress. However, ROS are also purposefully produced by designated cellular enzymes to facilitate the signaling and regulation of critical physiological processes. Therefore, both the production and neutralization of ROS must be tightly controlled. Indeed, the expression of detoxification …

Hippocalcin Response To Calcium: Do Conserved Tryptophans – W30 Or W103 – Matter?, Sunkesula K. Sagar

Graduate School of Biomedical Sciences Theses and Dissertations

Changes in intracellular calcium levels play a very important role in cell signaling, in turn, affecting neuronal functions such as memory, learning and cell death. A class of proteins called Neuronal Calcium Sensor (NCS) proteins serves to modulate the functioning of the neuronal cells in response to changes in calcium levels, and prevent neuronal apoptosis. Structurally, all NCS proteins have 4 calcium-binding EF hand motifs, although EF1 does not bind to calcium in many members. All NCS proteins have an acyl modification at the N- terminus – where a myristoyl group is added post-translationally. Hippocalcin (HPCA) is an NCS protein, …

The Proteomic Response In The Crustacean Molting Gland Of Land Crab Gecarcinus Lateralis In Response To Artificially Induced Molting Throughout Its Molting Cycle., Andrea Reider, Talia B. Head, Lars Tomanek, Donald L. Mykles

STAR Program Research Presentations

Molting in crustaceans is a highly complex physiological process involving negative regulation by two paired endocrine glands, the X-organ/sinus gland complex (XO/SG) and the Y-organ (YO). The XO/SG complex is responsible for making molt-inhibiting hormone (MIH) which negatively regulates synthesis of molting hormones (ecdysteroids) by the YO. Eyestalk ablation (ESA) removes the source of MIH and provides an experimental means to manipulate and induce molting, although the physiological effects of ESA on the YO have not been fully characterized. Analysis of gene expression in the XOs and YOs has lead to the development of a proposed molecular signaling pathway which …

Med13p Prevents Stress-Independent Mitochondrial Hyperfragmentation And Aberrant Apoptosis Activation In Saccharomyces Cerevisiae By Controlling Cyclin C Nuclear Localization, Svetlana Khakhina

Graduate School of Biomedical Sciences Theses and Dissertations

During aging, and as a result of environmental changes, cells are exposed to elevated levels of reactive oxygen species (ROS). High ROS levels induce lipid oxidation, protein aggregation, mitochondrial hyperfragmentation, DNA damage and programmed cell death (PCD), also called apoptosis. PCD is a highly regulated process and its misregulation has been linked to neurodegenerative diseases and cancer development.

Our hypothesis is that cyclin C plays a role in the initiation of apoptosis. During normal conditions, cyclin C represses the transcription of stress response genes (SRG). In response to stress, cyclin C translocates to the cytoplasm where it facilitates mitochondrial hyperfragmentation …

Small Interfering Rna-Mediated Translation Repression Alters Ribosome Sensitivity To Inhibition By Cycloheximide In Chlamydomonas Reinhardtii, Xinrong Ma

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

RNA interference (RNAi) is an evolutionarily conserved gene silencing mechanism in eukaryotes, with regulatory roles in a variety of biological processes, including cell cycle, cell differentiation, physiological and metabolic pathways, and stress responses. RNAi can function by transcriptional silencing, mRNA target cleavage, translation repression and/or DNA elimination. In this study, we used the unicellular green alga Chlamydomonas reinhardtii as a model system to study RNAi-mediated translation repression. We demonstrated that small RNAs (sRNAs) generated from exogenously introduced inverted repeat transgenes, with perfect complementarity to the 3’UTR of a target transcript, can inhibit protein synthesis, without or with only minimal mRNA …

Mutations In Dmrt3 Affect Locomotion In Horses And Spinal Circuit Function In Mice, Lisa S. Andersson, Martin Larhammar, Fatima Memic, Hanna Wootz, Doreen Schwochow, Carl-Johan Rubin, Kalicharan Patra, Thorvaldur Arnason, Lisbeth Wellbring, Göran Hjälm, Freyja Imsland, Jessica Lynn Petersen, Molly E. Mccue, James R. Mickelson, Gus Cothran, Nadav Ahituv, Lars Roepstorff, Sofia Mikko, Anna Vallstedt, Gabriella Lindgren, Leif Andersson, Klas Kullander

Department of Animal Science: Faculty Publications

Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement. These networks produce left–right alternation of limbs as well as coordinated activation of flexor and extensor muscles. Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favorable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is expressed in the dI6 subdivision of spinal cord neurons, takes …

Characterization Of 24 Microsatellite Loci In Delta Smelt, Hypomesus Transpacificus, And Their Cross-Species Amplification In Two Other Smelt Species Of The Osmeridae Family, Kathleen M. Fisch, Jessica Lynn Petersen, Melinda R. Baerwald, John K. Pedroia, Bernie May

Department of Animal Science: Faculty Publications

We characterized 24 polymorphic tetranucleotide microsatellite loci for delta smelt (Hypomesus transpacificus) endemic to the San Francisco Bay Estuary, California, USA. Screening of samples (n = 30) yielded two to 26 alleles per locus with observed levels of heterozygosity ranging from 0.17 to 1.0. Only one locus deviated from Hardy–Weinberg equilibrium, suggesting these individuals originate from a single panmictic population. Linkage disequilibrium was found in two pairs of loci after excluding the locus out of Hardy–Weinberg equilibrium. Twenty-two primer pairs cross-amplified in wakasagi smelt (Hypomesus nipponensis), and 15 primer pairs cross-amplified in longfin smelt ( …

Characterization Of 35 Microsatellite Loci In The Pacific Lion-Paw Scallop (Nodipecten Subnodosus) And Their Cross-Species Amplification In Four Other Scallops Of The Pectinidae Family, Ana M. Ibarra, Jessica Lynn Petersen, Thomas R. Famula, Bernie May

Department of Animal Science: Faculty Publications

Four microsatellite-enriched DNA libraries yielded 35 microsatellite loci from 100 primer pairs designed for Pacific lion-paw scallop, Nodipecten subnodosus. The number of alleles ranged from four to 28. Three of the 35 loci were not in Hardy–Weinberg equilibrium and linkage disequilibrium was found for one pair of loci. These microsatellites will be used to analyze the population structure of the species in Mexico’s Baja Peninsula to propose management strategies for scallop aquaculture development. Twenty-six primer pairs cross-amplified in Nodipecten nodosus, whereas none (Argopecten ventricosus) or few cross-amplified in the Argopecten species.

The Role Of Brn-3.2 In Retinal Ganglion Cell Differentiation, Jerin Marie Wright

Loma Linda University Electronic Theses, Dissertations & Projects

Within the retina, the POU domain of transcription factors brn-3.0, brn-3.1, and brn-3.2 are present only in retinal ganglion cells. These genes are believed to be involved in establishing neural cell lineages in mammals. In this study brn-3.2 was examined by comparing the number of ganglion cells present during postnatal development in normal mice (+/+), in mice homozygous (-/-) for the brn-3.2 gene, and in adult mice with a heterozygous gene deletion (+/-) for brn-3.2. Optic nerve cross sections were imaged by electron microscopy, and axon profiles counted systematically by hand. These counts were then related to the nerve cross …

Characterization Of Hsd::Mudx128 Operon Fusion Mutant Of Escherichia Coli K-12, Marjorie Ann T. Reyno

Loma Linda University Electronic Theses, Dissertations & Projects

The study of the regulation of gene expression in complex genes can be facilitated by the use of operon fusions which place a well characterized lacZ gene under the control of a promoter of interest. An hsd::MudX128 operon fusion mutant of E. coli K-12 isolated by Prakash (1986) was observed to have a high β-galactosidase activity (1000 units), ten to twenty times higher than other hsd::MudX mutants. This β-galactosidase activity was suppressed to a very low level (25 units) by the introduction of an F’ plasmid, F'101, which carries the 98 min to 2 min region of the …