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Phospholipase D- And Phosphatidic Acid-Mediated Signaling In Plant Response To Abscisic Acid And Reactive Oxygen Species, Liang Guo Dec 2013

Phospholipase D- And Phosphatidic Acid-Mediated Signaling In Plant Response To Abscisic Acid And Reactive Oxygen Species, Liang Guo

Dissertations

The Arabidopsis genome has 12 phospholipase D (PLD) genes that are classified into six types, PLDα, PLDβ, PLDγ, PLDδ, PLDε, and PLDζ, based on sequence similarities, domain structures, and biochemical properties. Phosphatidic acids (PA) produced by PLDs have been identified as important lipid signaling molecules in cell growth, development, and stress responses. This study was undertaken to determine the role of PLD and PA in plant response to abscisic acid (ABA) and reactive oxygen species (ROS). The lipid mediator PA was found to interact with sphingosine kinases (SPHKs) in Arabidopsis. Two unique SPHK cDNAs were cloned and expressed. Both SPHKs ...


The Evolution Of Floral Symmetry Across The Plant Order Lamiales, Jinshun Zhong Dec 2013

The Evolution Of Floral Symmetry Across The Plant Order Lamiales, Jinshun Zhong

Dissertations

Bilaterally symmetrical corollas have evolved independently numerous times from radially symmetrical ancestors and are thought to represent adaptation to specific pollinators. However, evolutionary losses of bilateral symmetry have occurred sporadically in different lineages. CYC2-like and RAD-like are genes needed for the normal development of bilateral symmetry in snapdragon corollas. However, exactly how changes in the floral symmetry patterning genes correlate with the origin and loss of floral bilateral remains poorly known. To address this question, a densely sampled phylogeny of CYC2-like genes across the order Lamiales was inferred and calibrated. The expression patterns of these genes in early diverging and ...


Elucidating The Factors That Modulate The Distribution Of Avian Haemosporida Parasites Across A Community Of Hosts, Matthew Christopher Ikaika Medeiros Dec 2013

Elucidating The Factors That Modulate The Distribution Of Avian Haemosporida Parasites Across A Community Of Hosts, Matthew Christopher Ikaika Medeiros

Dissertations

Parasites are heterogeneously distributed across host species, host populations, and host individuals within populations. A primary aim of infectious disease ecology seeks to uncover the factors that drive this heterogeneity. At a fundamental level, host infection is determined by exposure and susceptibility to a pathogen. My dissertation explores how evolutionary and ecological forces associated with these fundamental determinates of infection shape variation in parasite host breadth and host infection status. Here, I focus on a community of vector-borne avian Haemosporida parasites among suburban birds of Chicago, IL. These parasites exhibit strong variation in their distribution among available hosts, and provide ...


Exploring The Local And Regional Effects Of Plant Diversity On Plant Herbivore Interactions, Diego Salazar Dec 2013

Exploring The Local And Regional Effects Of Plant Diversity On Plant Herbivore Interactions, Diego Salazar

Dissertations

The study of biological diversity and its effects on ecosystem functioning and species interactions has always been a fundamental part of biology. The accelerating loss of species in conjunction with an increasing change in the natural environment has underlined the importance of the role that biodiversity has on the evolutionary and ecological dynamics of natural systems. In this dissertation I explore the effect of local and regional patterns of plant diversity in plant-herbivore interactions. Furthermore, this work goes beyond the classical concepts of taxonomical diversity and investigates the role of phylogenetic and chemical diversity on plant-herbivore interactions. In chapter one ...


Connecting The Dots: Understanding Migration In The Context Of Other Periods Of The Annual Cycle, Kristina Lee Paxton Dec 2013

Connecting The Dots: Understanding Migration In The Context Of Other Periods Of The Annual Cycle, Kristina Lee Paxton

Dissertations

Migration is a fundamental characteristic of the life history of many organisms. Large-scale seasonal movements expose migratory species to an array of differing environmental conditions such that the ecology, behavior, and life history strategies of migratory species must balance selection pressures associated with each phase of the annual cycle. Therefore, scientists increasingly realize that to understand the ecology of a migratory species in any one phase of the annual cycle requires an understanding of how other phases may interact with and influence the period of interest. That said, following individuals throughout the year poses a serious challenge.

The focus of ...


Middle Mississippi River Islands: Historical Distribution, Restoration Planning, And Biological Importance, Teresa Cecilia Allen Nov 2013

Middle Mississippi River Islands: Historical Distribution, Restoration Planning, And Biological Importance, Teresa Cecilia Allen

Dissertations

The Middle Mississippi River’s (MMR’s) hydrology and sedimentation patterns have been altered. These activities contribute to loss of backwaters, islands, secondary channels, and reduced biodiversity. The Fish and Wildlife Service included reasonable and prudent alternatives (RPAs) in its Biological Opinion for the Operation and Maintenance of the Nine-Foot Channel Navigation Project. These RPAs mandate dike notching and island building to increase habitat diversity. My first goal was to examine changes in the number and relative location of islands from 1797 to 2003. I found that the total number of islands increased, the number of central islands decreased, and ...


Colonization History And Origin Of The Galapagos Flycatcher (Myiarchus Magnirostris) And Its Parasites, Eloisa Helena Reis Sari Aug 2013

Colonization History And Origin Of The Galapagos Flycatcher (Myiarchus Magnirostris) And Its Parasites, Eloisa Helena Reis Sari

Dissertations

The Galápagos flycatcher (Myiarchus magnirostris) is an endemic species to the Galápagos Islands, Ecuador, and is among the least studied Galápagos terrestrial birds. In this work I unveiled the origin and colonization history of the Galápagos flycatcher, and also the origin of the parasites that are currently found in/on this bird species. To determine the origin of the Galápagos flycatcher, I rebuilt the phylogeny of the Myiarchus genus using cytb and ND2, and applied a Bayesian approach to estimate its colonization time. I discovered that the closest living relative of the Galápagos flycatcher is Myiarchus tyrannulus (Brown-crested flycatcher) from ...


Role Of Msa In Immune Evasion, Persistence, And Protease Regulation In The Human Pathogenic Strains Of Staphylococcus Aureus, Maria Deepa Basco Aug 2013

Role Of Msa In Immune Evasion, Persistence, And Protease Regulation In The Human Pathogenic Strains Of Staphylococcus Aureus, Maria Deepa Basco

Dissertations

Opportunistic pathogens like Staphylococcus aureus on entering the host can stay colonized at the foci of infection or evade the immune system to disseminate to other sites. In this study we investigated the regulatory influence of the modulator of sarA (msa) on immune evasion and host persistence, employing the hospital-acquired strain S. aureus UAMS-1 and community-acquired strain S. aureus USA300 LAC. In the murine sepsis model, mutation of the msa gene in LAC showed no change in dissemination of infection; however, in UAMS-1 a decrease in microbial load was observed in the lungs. Differential regulation by the msa gene was ...


Population Demographics And Genetics Of Spix's Disk-Winged Bat: Insights Regarding Survival, Mate Choice, Gene Flow And Effective Population Size, Michael Buchalski Aug 2013

Population Demographics And Genetics Of Spix's Disk-Winged Bat: Insights Regarding Survival, Mate Choice, Gene Flow And Effective Population Size, Michael Buchalski

Dissertations

Simultaneous study of the demographics and genetics of populations are relatively rare within the literature, despite insights their combined use offers regarding the life history, ecology, and evolution of species. Here I take a comprehensive approach, using capture-recapture data, polymorphic microsatellite markers, and various modeling techniques to examine the demographics and genetics of multiple local populations of Spix’s disk-winged bat (Thyroptera tricolor) in southwestern Costa Rica. T. tricolor is a highly gregarious, neotropical bat species known to form kin-based social groups with high retention of offspring of both sexes. The implications of this highly unusual social structure for survival ...


Science Fair: Is It Worth The Work? A Qualitative Study On Deaf Students' Perceptions And Experiences Regarding Science Fair In Primary And Secondary School, Vivian Lee Smith Aug 2013

Science Fair: Is It Worth The Work? A Qualitative Study On Deaf Students' Perceptions And Experiences Regarding Science Fair In Primary And Secondary School, Vivian Lee Smith

Dissertations

Science fairs have a long history in American education. They play an important role for establishing inquiry-based experiences in a science classroom. Students may be more motivated to learn science content when they are allowed to choose their own science fair topics. The purpose of this study was to examine Deaf college students’ perceptions and experiences regarding science fair participation during primary and/or secondary school and determine the influence of science fair involvement on the development of language skills, writing skills, and higher order thinking skills as well as its impact on choice of a STEM major.

This study ...


The Characterization Of Algae Grown On Nutrient Removal Systems And Evaluation Of Potential Uses For The Resulting Biomass, Kristin Hampel Aug 2013

The Characterization Of Algae Grown On Nutrient Removal Systems And Evaluation Of Potential Uses For The Resulting Biomass, Kristin Hampel

Dissertations

Eutrophication resulting from excess nutrient loads is a major environmental issue that affects surface water quality and causes surplus primary production, thereby reducing dissolved oxygen concentrations. A method for managing nutrients in surface waters involves absorption of excess nutrients by deliberately cultivating benthic algal turf biomass, then harvesting it for a variety of uses, including biofuels, soil amendments, or feed supplements, thus coupling nutrient removal to additional economic drivers.

The goals of this work are to (1) evaluate the composition of algal biomass grown to remove surface water nutrients, (2) compare biomass grown at different geographic locations and in dissimilar ...


Interrelationships Between Testosterone, Aggression, And Parental Care Of A Temperate-Zone, Resident Songbird, The Northern Cardinal (Cardinalis Cardinalis), Margaret Susan Devries May 2013

Interrelationships Between Testosterone, Aggression, And Parental Care Of A Temperate-Zone, Resident Songbird, The Northern Cardinal (Cardinalis Cardinalis), Margaret Susan Devries

Dissertations

Interrelationships among testosterone (T), aggression, and parental care have received much investigative attention. Within birds, many studies have focused on examining such relationships using species characterized by relatively brief periods of territoriality and breeding. Few have investigated links between circulating T and reproductive behavior in birds that are year-round territorial residents and have lengthy breeding seasons, such as the Northern Cardinal (Cardinalis cardinalis). The following six chapters report and discuss findings from this dissertation’s examination of aspects of T production and potential interconnections with circulating T, aggression, and parental care in male and female cardinals. This work suggests that ...


Community Metrics And Trophic Dynamics In Tidal Creeks In An Anthropogenically Fragmented, Coastal Landscape, Michael Robert Lowe May 2013

Community Metrics And Trophic Dynamics In Tidal Creeks In An Anthropogenically Fragmented, Coastal Landscape, Michael Robert Lowe

Dissertations

Salt marsh landscapes are among the most anthropogenically altered ecosystems in the world. Urbanization (i.e., accumulation of impervious cover and man made structrues) of the coastal landscape can disrupt the delivery of numerous ecosystem services. Among the many services provided by salt marsh habitats, they serves as the primary habitats for distinct macroinfauna (i.e., benthic and epibenthic macrofauna) and nekton (i.e., fish and decapod crustaceans) assemblages. In this dissertation, I used a number of metrics to test the overarching hypothesis that coastal urbanization has negative consequences for salt marsh faunal assemblages. Chapter I uses a landscape ecology ...


A Bird In The Binoculars: Understanding Birdwatchers' Potential To Contribute To Sustainable Development And Biological Conservation, Sheri Lynn Glowinski May 2013

A Bird In The Binoculars: Understanding Birdwatchers' Potential To Contribute To Sustainable Development And Biological Conservation, Sheri Lynn Glowinski

Dissertations

The three studies comprising this research drew from local economic development and environmental sociology to understand aspects of human dynamics that influence the conservation of birds. Using survey data collected from birdwatchers visiting coastal Alabama, the first study examined the local economic impact of birdwatching tourism and the factors that participants deemed important with respect to their recreation. Birdwatchers spent $103,305 during the four month study period. The total annual economic impact of this recreation on the area was estimated at $937,470, producing a multiplier of 1.48 and the equivalent of 20.3 full time jobs. Infrastructural ...


Phytoplankton Community Distribution And Light Absorption Properties In The Northern Gulf Of Mexico, Sumit Chakraborty May 2013

Phytoplankton Community Distribution And Light Absorption Properties In The Northern Gulf Of Mexico, Sumit Chakraborty

Dissertations

The theme of this dissertation was to understand the spatio-temporal dynamics of the phytoplankton community, its light absorption properties, and its relationship to underlying physicochemical processes. Understanding these phenomena will benefit efforts to predict pathways of carbon transformation in the ocean, to estimate primary productivity (PP) and to characterize distributions of phytoplankton communities using ocean color remote sensing.

This research entailed four different studies, which address different objectives. The first two studies dealt with phytoplankton community composition and its relationship to environmental variables. A chemotaxonomic approach was used, which was successful in revealing distinct phytoplankton assemblages in distinct water mass ...


Evaluation Of Human Fecal Pollution In Mississippi Coastal And Creek Waters Using Library Independent Markers, Christopher John Flood May 2013

Evaluation Of Human Fecal Pollution In Mississippi Coastal And Creek Waters Using Library Independent Markers, Christopher John Flood

Dissertations

The objective of this study was to determine whether statistically valid correlations could be elucidated between standard indicator bacteria (enterococci and fecal coliforms) from coastal creek and marine samples and the presence of four library independent molecular markers that are human or sewage specific. Eight hundred and nineteen samples were collected between August 2007 and July 2010 to determine enterococcal and fecal coliform counts and the presence of genetic markers for sewage indicator organisms Methanobrevibacter smithii, human specific Bacteroides sp., Bacteroides thetaiotaomicron, and Fecalibacterium sp. During the course of this study environmental parameters were measured and statistically analyzed to determine ...


Habitat Characterization, Habitat Use And Associated Growth Of Juvenile Spotted Seatrout (Cynoscion Nebulosus) In A Mississippi Bay System: Implications For Stock Enhancement Practices, Joseph Read Hendon May 2013

Habitat Characterization, Habitat Use And Associated Growth Of Juvenile Spotted Seatrout (Cynoscion Nebulosus) In A Mississippi Bay System: Implications For Stock Enhancement Practices, Joseph Read Hendon

Dissertations

The spotted seatrout (Cynoscion nebulosus) is the most targeted recreational fishery species in Mississippi coastal waters. Consequently, the Seatrout Population Enhancement Cooperative stock enhancement program was initiated to investigate methods for supplementing this heavily exploited population. Given ecological data needs for both wild and hatchery-reared (HR) juveniles of the species, habitat mapping, directed sampling and a caging study were conducted. Submerged aquatic vegetation (SAV), oyster shell and non-vegetated substrates were mapped at water depths < 2 m in Point aux Chenes Bay, Mississippi, using a sidescan sonar, which provided more accurate estimations of habitat coverage, particularly for SAV, compared to point-based sampling. Applying habitat strata delineated from sidescan mapping, late-juvenile spotted seatrout [125 - 275 mm total length (TL)] were sampled in SAV, marsh-edge and non-vegetated habitats as part of a seasonal gill net survey conducted in 2011 and 2012. Spotted seatrout ranging from 138 to 485 mm TL were collected using a smallmesh gill net, and 65% of collected individuals fell within the targeted late-juvenile size range. Overall mean catch-per-unit-effort of C. nebulosus did not differ for abundance or biomass between years, but both metrics were significantly higher in SAV habitats. Employing cage enclosures that excluded predators ...


Investigating The Function Of The Mold Specific Gene M46, In The Pathogenic Dimorphic Fungus Histoplasma Capsulatum, Davida Lashaundra Crossley May 2013

Investigating The Function Of The Mold Specific Gene M46, In The Pathogenic Dimorphic Fungus Histoplasma Capsulatum, Davida Lashaundra Crossley

Dissertations

Histoplasma capsulatum (Hc) is a dimorphic fungus that is the etiologic agent for the respiratory infection histoplasmosis. The fungus is found in the environment in contaminated soils of birds and bat excreta as a multi-cellular saprophytic mold. Once the soil is disturbed, spores are released and are inhaled into the lungs. In the lungs, the fungus converts to uni-cellular parasitic yeast (Maresca & Kobayashi, 1989). The conversion from mold to yeast is a requirement for pathogenesis. Previously, several mold specific genes have been isolated by our laboratory from a subtracted cDNA library. One such gene, is M46. M46 is a single ...


Characterization Of Whole Pine Tree Substrates For Adventitious Rooting Of Cuttings And Initial Growth Of Seedlings, Anthony Lynn Witcher May 2013

Characterization Of Whole Pine Tree Substrates For Adventitious Rooting Of Cuttings And Initial Growth Of Seedlings, Anthony Lynn Witcher

Dissertations

Processed whole pine (Pinus taeda L.) trees have been extensively evaluated to supplement peatmoss and pine bark usage in container substrates for greenhouse and nursery crop production. The suitability of whole pine tree (WPT) substrates for crop propagation has not been investigated. Demonstrating the versatility of WPT substrates is essential to expanding their commercial availability and use.

The objective of this work was to evaluate WPT substrates for stem cutting and seed propagation of ornamental crops, and to identify factors affecting root development. Stem cutting and seedling root development was evaluated in WPT and traditional (peatmoss and pine bark) substrates ...


The Effectiveness Of Internet And Instant Messaging Approaches In Promoting Intention To Breastfeed, Brigett Landry Scott May 2013

The Effectiveness Of Internet And Instant Messaging Approaches In Promoting Intention To Breastfeed, Brigett Landry Scott

Dissertations

Breastfeeding rates for the southern portion of the United States are low compared to the rest of the country. This study sought to determine the effectiveness of electronic delivery of breastfeeding education compared to written education in regards to intention to breastfeed in a convenience sample of pregnant women in coastal Louisiana and Mississippi. The final sample included 147 women randomized into one of three groups to complete the six week education intervention study. Questionnaires measuring demographics, Need for Cognition Scale (NFC), the Iowa Infant Feeding Attitude Scale (IIFAS), and the IFI Feeding Intentions Assessment were utilized. MANCOVA was used ...


Investigations Toward Tunability Of Mechanical, Thermal, And Impact Properties Of Thiol-Ene Networks For Novel High Energy Absorbing Materials, Olivia Devon Mcnair May 2013

Investigations Toward Tunability Of Mechanical, Thermal, And Impact Properties Of Thiol-Ene Networks For Novel High Energy Absorbing Materials, Olivia Devon Mcnair

Dissertations

The UV polymerization of thiols with electron rich alkenes is a highly resourceful reaction that has been utilized by scientists within various disciplines to produce an even more versatile display of applications. This dissertation focuses on a newer application, thiol-ene network (TEN) materials for energy absorption devices. TEN networks display a host of positive polymer properties such as low stress, high optical clarity and uniformity, but they also suffer from unfavorable mechanical properties such as low toughness and elongation at break. The poor mechanical properties demonstrated by TENs prohibit them as choice materials for applications requiring thicker material forms, including ...


Accessing Learning In The Adult Zebrafish With A Novel Associative Learning Task, David Joseph Jouandot Ii May 2013

Accessing Learning In The Adult Zebrafish With A Novel Associative Learning Task, David Joseph Jouandot Ii

Dissertations

The zebrafish (Danio rerio) is accepted in the developmental and genomic communities as a model organism. However, the capacity for the zebrafish as a behavioral model has yet to be fully acknowledged. The research presented provides evidence validating the novel task, aids in gaining a better understanding of the learning processes, and identifies individual differences. The novel associative learning task differs from any present well established behavioral model and lends itself to future development. The task provides the zebrafish community with a high output behavioral task which is readily replicated and allows one researcher to test between eight and ten ...


Tactile Behavior In A Group Of Captive Rough-Toothed Dolphins As A Function Of Opportunities To Play With Objects, Kelly Ann Caffery May 2013

Tactile Behavior In A Group Of Captive Rough-Toothed Dolphins As A Function Of Opportunities To Play With Objects, Kelly Ann Caffery

Dissertations

Cetaceans live in complex physical and social environments that are frequently changing. In contrast, the captive environment for marine mammals is often lacking in stimulation. As a result, enrichment is often used to increase species-typical behaviors and enhance the well-being of the animals. The purpose of this study was to compare the effects of enrichment objects on the social behavior of a group of seven captive rough-toothed dolphins (Steno bredanensis). Observations of this species in the wild suggest it may have a particular affinity for tactile and object play behaviors. Therefore, these behavior categories were a primary focus during this ...


Effects Of Food Dispersion On Dominance Related Behaviors In Garnett's Bushbaby (Otolemur Garnettii)?, Kyle Daniel Edens May 2013

Effects Of Food Dispersion On Dominance Related Behaviors In Garnett's Bushbaby (Otolemur Garnettii)?, Kyle Daniel Edens

Dissertations

Socio-ecological theorists tie primate social structure diversity to variations in habitats within which primate species reside. This premise permits laboratory researchers to investigate specific factors that influence or relate to social structure formation and maintenance. The focus of the current investigation was three fold. We first aimed to determine the relationships between traditional and non-traditional behavioral measures of dominance, then evidence for dominance hierarchy formation was examined, and various hypotheses were tested to discern if adjustments in the foraging context altered social behaviors in Garnett’s bushbaby (Otolemur garnettii). It was determined that animals likely to displace conspecifics were more ...


Diversification And Coexistence In The Madagascar Olive (Noronhia, Oleaceae), Cynthia Hong-Wa Apr 2013

Diversification And Coexistence In The Madagascar Olive (Noronhia, Oleaceae), Cynthia Hong-Wa

Dissertations

The long-isolated island of Madagascar provides a suitable setting for studying species diversification, with most groups of organisms there both radiating and showing a high level of endemism. Noronhia is one of these groups and represents the most successful radiation of the olive family (Oleaceae) in Madagascar, with ca. 80 species. In this study, using plastid and nuclear DNA sequences obtained from a comprehensive sampling both within Noronhia and the family, I show that Noronhia, together with Indian Ocean species of Chionanthus, form a monophyletic clade sister to African Chionanthus. The diversification of Noronhia followed a likely Cenozoic dispersal from ...


Exercise Alters Glial Cell Line-Derived Neurotrophic Factor (Gdnf) Protein Content In The Spinal Cord, Monica Janine Mccullough Apr 2013

Exercise Alters Glial Cell Line-Derived Neurotrophic Factor (Gdnf) Protein Content In The Spinal Cord, Monica Janine Mccullough

Dissertations

Neurotrophic factors may play a role in exercise-induced neuroprotective effects; however, it is not known if exercise mediates changes in glial cell line-derived neurotrophic factor (GDNF) protein levels in the spinal cord. The aim of the studies described herein was to determine if exercise alters GDNF protein expression in the lumbar spinal cord of healthy and diseased animals. The lumbar spinal cord was analyzed from adult rats aged 6-, 12-, 18- and 24-months, and from transgenic amyotrophic lateral sclerosis (ALS) mice and wild-type mice aged 3 months. Animals had undergone either forced wheel running, voluntary wheel running or swimming for ...


Defining A Role For Inducible Heat Shock Protein 70 (Hsp70i) In Mediating Autoimmune Vitiligo, Jeffrey Alan Mosenson Jan 2013

Defining A Role For Inducible Heat Shock Protein 70 (Hsp70i) In Mediating Autoimmune Vitiligo, Jeffrey Alan Mosenson

Dissertations

Vitiligo is an autoimmune disease characterized by destruction of melanocytes, leaving 0.5% of the population with progressive depigmentation. Current treatments offer limited efficacy. Observations that heat shock proteins (HSPs) can serve as adjuvants in antitumor vaccines first suggested to us a link between HSPs and stress-induced vitiligo. Such proteins are marvelously well conserved throughout evolution, which has placed them in the spotlight for helping to understand the intriguing relationship between infection and immunity. Intracellularly, inducible heat shock protein 70 (HSP70i) is upregulated by stress and helps protect cells from undergoing apoptosis. In times of stress, melanocytes will secrete antigen ...


Targeting The Notch-1/Igf-1r/Akt Axis In At Orthotopic Model Of Advanced Non-Small Cell Lung Cancer, Shuang Liang Jan 2013

Targeting The Notch-1/Igf-1r/Akt Axis In At Orthotopic Model Of Advanced Non-Small Cell Lung Cancer, Shuang Liang

Dissertations

Lung cancer is the leading cause of cancer death in the U.S. and worldwide. The most frequent type of lung cancer is non-small cell lung cancer (NSCLC). NSCLC is mostly diagnosed at advanced stages (stage IIIB 18% of cases, stage IV 40% of cases) due to the lack of effective early detection methods. Thus, the discovery of alternative therapeutic strategies is of extreme importance.

Others and we have previously found that Notch signaling plays a crucial role in NSCLC. Our preliminary results indicate that Notch-1 provides necessary survival signals to NSCLC cells by positively regulating IGF-1R to activate the ...


Novel Role Of Erbb-2 In Inhibition Of Jagged-1-Mediated Trans-Activation Of Notch In Breast Cancer, Kinnari Pandya Jan 2013

Novel Role Of Erbb-2 In Inhibition Of Jagged-1-Mediated Trans-Activation Of Notch In Breast Cancer, Kinnari Pandya

Dissertations

The ErbB-2 gene is amplified and the resulting protein product overexpressed in 15-30% of breast tumors, and associated with aggressive behavior and poor overall survival. Currently, there are two FDA approved therapies targeting ErbB-2 for the treatment of ErbB-2 positive breast cancer: trastuzumab, a humanized monoclonal antibody is directed against the extracellular domain of ErbB-2 and lapatinib, a dual EGFR/ErbB-2 tyrosine kinase inhibitor. Unfortunately, anti-ErbB-2 therapy resistance remains a major problem in metastatic breast cancer. Our data suggested that gene amplification or overexpression of ErbB-2 inhibits Notch-1 transcriptional activity and trastuzumab or lapatinib increased

Notch-1 transcriptional activity. Furthermore, Notch-1 ...


Understanding The Posttranslational Regulation Of The Response Regulator Rcsb And Acetyl Phosphate As An Acetyl Group Donor In E. Coli, Linda Hu Jan 2013

Understanding The Posttranslational Regulation Of The Response Regulator Rcsb And Acetyl Phosphate As An Acetyl Group Donor In E. Coli, Linda Hu

Dissertations

The observation that Nepsilon-lysine acetylation occurs on a hundreds of proteins in bacteria is a recent discovery. To study the mechanisms that regulate acetylation and to determine if acetylation affects physiology, I studied the Escherichia coli response regulator and transcription factor RcsB, which was reported to be acetylated in vitro. To monitor RcsB activity, I measured transcription from the rprA promoter, which requires RcsB. I confirmed that RcsB is activated by phosphorylation through the Rcs phosphorelay and acetyl phosphate and showed that acetyl phosphate could phosphorylate RcsB. However, a mutant that accumulates acetyl phosphate (ackA) exhibited reduced rprA transcription instead ...