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Paratransgenic Control Of Pierce's Disease, Arinder Arora
Paratransgenic Control Of Pierce's Disease, Arinder Arora
Biology ETDs
Pierce's Disease (PD) is a deadly grapevine disease, which is caused by a Gram negative bacterium, Xylella fastidiosa and transmitted by leafhoppers commonly known as sharpshooters, including the glassy-winged sharpshooter (GWSS, Homalodisca vitripennis). We developed paratransgenic control of PD using a commensal bacterium Pantoea agglomerans E325. The GWSSs acquired enhanced green fluorescent (EGFP)-expressing P. agglomerans from an artificial feeding system and the bacteria persisted within the insect foregut for two weeks. P. agglomerans was selected as the paratransgenic control agent based on its persistence within the sharpshooter foregut, a niche also inhabited by X. fastidiosa. P. agglomerans lines secreting two …
Transcriptional Regulation Of Muscle Development In Drosophila Melanogaster, Tonya Brunetti
Transcriptional Regulation Of Muscle Development In Drosophila Melanogaster, Tonya Brunetti
Biology ETDs
The transcriptional regulation of muscle development involves several complex processes that must work together in order to form functional, syncytial muscle cells. However, when transcription is mis-regulated, muscle development is often times negatively affected and can lead to muscle diseases such as muscular dystrophy and cardiac myopathies. In order to gain more insight into how transcription is regulated, I use Drosophila melanogaster as a model for understanding muscle development. In chapter one, I use a traditional genetic screen to phenotypically and molecularly identify two Hox co-factors, extradenticle and homothorax, that have the ability to change muscle identity. Additionally, in chapter …
A Life History Of The Roundnose Minnow, Dionda Episcopa, In The Middle Pecos River Valley, New Mexico., Michael A. Farrington
A Life History Of The Roundnose Minnow, Dionda Episcopa, In The Middle Pecos River Valley, New Mexico., Michael A. Farrington
Biology ETDs
Life history aspects of Roundnose Minnows, Dionda episcopa, were examined for specimens collected between 2011 and 2013 in El Rito Creek, near Santa Rosa New Mexico. A recent study examining DNA suggested that, instead of supporting a widespread population of the Roundnose Minnow, New Mexico is actually home to two evolutionarily distinct Roundnose Minnow populations. This focus of this study is on the life history attributes of what may become a newly described species of Dionda. Modal class progression analysis (Bhattacharya method) documented four distinct age classes of Roundnose Minnows within El Rito Creek. Sex ratios deviated from the expected …
Gene Duplications During Experimental Evolution Of Caenorhabditis Elegans : Duplication Rates And Evolutionary Responses, James Charles Farslow
Gene Duplications During Experimental Evolution Of Caenorhabditis Elegans : Duplication Rates And Evolutionary Responses, James Charles Farslow
Biology ETDs
Copy-number variants (CNVs) are a ubiquitous form of genetic variation. How often this form of variation arises and its adaptive significance are active areas of contemporary research. This work presents evidence regarding both of these subjects. First, it demonstrates that gene duplications occur at a frequency two orders of magnitude greater than point mutations. Specifically, the gene duplication rate is estimated to be 1.2 x 10-7/gene/generation, compared to a point mutation rate on the order of ~10-9/site/ generation. Second, it was found that populations in a low state of fitness due to mutation accumulation could recover some or all of …
The Impact Of Temperature, Ph And Environmental Heterogeneity On Prokaryotic Diversity In Yellowstone National Park Thermal Springs, Xiaoben Jiang
The Impact Of Temperature, Ph And Environmental Heterogeneity On Prokaryotic Diversity In Yellowstone National Park Thermal Springs, Xiaoben Jiang
Biology ETDs
Yellowstone National Park (YNP) is one of the largest and most diverse hydrothermal areas on Earth. Extensive culture-independent studies in YNP thermal springs have shown dramatic taxonomic and metabolic diversity in microbial communities. We conducted a survey of bacterial communities along temperature gradients in three alkaline springs with similar geochemistries at the local scale. With these data, we investigated the influence of environmental variables on bacterial community diversity and assemblages along a broad temperature range using high throughput 454 pyrosequencing. Previous studies have suggested that pH is the driver of microbial diversity in thermal springs among geographical regions or at …
Quantifying Temperature Sensitivity Of Soil Respiration Across A Range Of Semi-Arid Biomes, Michelle Nuanez
Quantifying Temperature Sensitivity Of Soil Respiration Across A Range Of Semi-Arid Biomes, Michelle Nuanez
Biology ETDs
Soils in semi-arid regions store approximately 10% of earths soil organic carbon, the substrate which microbes oxidize, resulting in the largest source of carbon to the atmosphere from terrestrial ecosystems. Semi-arid regions are expected to experience increased temperatures and altered precipitation regimes over the next 100 years, altering soil temperature and water, the two predominant drivers in soil respiration processes. In this study we quantify the temperature sensitivity of soil respiration in five semi-arid biomes ranging from desert grassland to ponderosa pine forest along an elevational/climate gradient in central New Mexico. We measured statistically similar temperature sensitivities in 4 of …
Effects Of Stream Edges On Algal Biomass In The Middle Rio Grande, Steven Daniel Scholle
Effects Of Stream Edges On Algal Biomass In The Middle Rio Grande, Steven Daniel Scholle
Biology ETDs
In river systems, there are many factors that impede or facilitate algal standing stock and therefore impact primary production in these environments. I am particularly interested in the influence of edges in riverine systems and how these geomorphic features affect the available surface area for algal production. This study investigates the middle Rio Grande system near Albuquerque, New Mexico, USA. The middle Rio Grande is a turbid, partially braided lotic ecosystem. Although edge characteristics can vary widely, especially between errosional and depositional banks, I hypothesize that edges become important zones of primary production, due in part to decreased water depth, …
Disturbance Events In Arid Ecosystems : Comparisons Of Enzyme Activity Profiles Across Multiple Soil Microbial Communities, Daniel Warnock
Disturbance Events In Arid Ecosystems : Comparisons Of Enzyme Activity Profiles Across Multiple Soil Microbial Communities, Daniel Warnock
Biology ETDs
Arid ecosystems are home to approximately 35% of earth's human population, and approximately 40% of earth's terrestrial carbon. These systems are especially prone to releasing the stored carbon when under global climate change (GCC) related pressures. My goal for these studies was to expand on our already growing knowledge base of how the soil microbial communities in disturbed arid ecosystems undergo shifts in functional patterns, as they respond to a rapidly changing environment. In chapter two, I examined the overall functional activity levels and functional behaviors exhibited by both pinon and juniper supported RAM communities in the context of widespread, …
Flight Muscle Progenitor Populations In Drosophila Melanogaster, Elizabeth Clarke
Flight Muscle Progenitor Populations In Drosophila Melanogaster, Elizabeth Clarke
Biology ETDs
We use the Drosophila system to define how genes control muscle development and function. Many of the genes in the fruit fly, Drosophila melanogaster, are conserved with higher animals, and so our results can be important in understanding mechanisms of vertebrate muscle development and disease. Study of the flight muscle progenitor populations in Drosophila gives clearer understanding of the genetic regulatory networks that lead to the development of flight muscle. The direct flight muscles (DFMs) and indirect flight muscles (IFMs) arise from the myoblast population of the notal region of the Drosophila wing imaginal disc. Within the myoblast population, there …
Macroecology And Sociobiology Of Humans And Other Mammals, Joseph Robert Burger
Macroecology And Sociobiology Of Humans And Other Mammals, Joseph Robert Burger
Biology ETDs
Despite being the most studied species on the planet, ecologists typically do not study humans the same way we study other organisms. My Ph.D. thesis contributes to scientific development in two ways: i) synthesizing our understand of the inter and intraspecific variation in social behavior in an understudied rodent lineage, the caviomorphs, providing a comparative context to understand social evolution in general, and 2) developing a macroecological approach to understand the metabolic trajectory of the human species. Through comparative analysis, chapter 2 synthesizes the available information on the diversity of sociality in the caviomorph rodents, both within and across species. …
Foliar Respiration And Carbon Dynamics Of Mature Piñon And Juniper Trees In Response To Experimental Drought And Heat, Adam Collins
Foliar Respiration And Carbon Dynamics Of Mature Piñon And Juniper Trees In Response To Experimental Drought And Heat, Adam Collins
Biology ETDs
Plant respiration (R) is generally well-coupled with temperature and in the absence of thermal acclimation, respiration is expected to increase as climate change brings higher temperatures. Increased drought is also predicted for future climate, which could drive respiration higher if the carbon (C) cost to maintain tissues (Rm) or grow increases, or lower if substrate or other factors become limiting. We examined the effects of temperature and drought on R as well as photosynthesis, growth, and carbohydrate storage of mature individuals of two co-dominant tree species. Three mature, in-situ piñon (Pinus edulis) and juniper (Juniperus monosperma) trees were assigned to …
Diversity Of Understudied Archaeal And Bacterial Populations Of Yellowstone National Park: From Genes To Genomes, Daniel Colman
Diversity Of Understudied Archaeal And Bacterial Populations Of Yellowstone National Park: From Genes To Genomes, Daniel Colman
Biology ETDs
Yellowstone National Park (YNP) thermal springs have been a crucial resource for the discovery and characterization of microbial biodiversity. The use of cultivation-independent methods has documented many new phyla of uncultured Archaea and Bacteria within thermal springs. Here, I describe the phylogenetic diversity and distribution of Archaea within the YNP thermal spring ecosystem and the phylogenetic and physiologic characterization of novel, uncultured hyperthermophilic bacterial lineages from metagenomic data. In chapter two, I evaluated the efficacy of commonly used, 'universal' archaeal-specific 16S rRNA gene PCR primers in detecting archaeal phylogenetic diversity. In chapter three, using the PCR primers that would provide …
Schistosomes Of Nepal, Ramesh Devkota
Schistosomes Of Nepal, Ramesh Devkota
Biology ETDs
Globally, digenetic trematodes called schistosomes (Family Schistosomatidae) have enormous public and veterinary health significance because they cause debilitating and chronic infections collectively called schistosomiasis. Schistosomes have a life cycle featuring a bird or mammal definitive host in which adult worms are found, and freshwater snail intermediate hosts in which larval stages are found and free-swimming cercariae are produced which infect the definitive host. Although schistosomes are known to be common in tropical and subtropical Asia, their presence in Nepal, a small south Asian country situated between India and China, was almost completely unknown at the beginning of this study. Consequently, …
Drying Events In The Rio Grande: Effects On Hydrology, Riparian Vegetation, And Arthropod Communities, Kimberly Fike
Drying Events In The Rio Grande: Effects On Hydrology, Riparian Vegetation, And Arthropod Communities, Kimberly Fike
Biology ETDs
1. Anthropogenic-induced river intermittency is an increasing global concern with far-reaching ecological consequences. Cessation of flow outside of a rivers natural regime can have cascading effects on aquatic and terrestrial community composition and structure. Water abstraction during summer months often leaves the Rio Grande below Isleta Diversion Dam dry. This research investigates differences in hydrology, riparian vegetation, and arthropod communities within the Rio Grande floodplain, known locally as the 'bosque,' between perennial and intermittent reaches of the river. 2. Despite the high degree of interannual variability, a spatio-temporal analysis of stream discharge revealed a trend of declining flow in both …
Constraints On Distributions And Diversity Of Birds And Mammals Over Variable Environments, Trevor S. Fristoe
Constraints On Distributions And Diversity Of Birds And Mammals Over Variable Environments, Trevor S. Fristoe
Biology ETDs
The distributions of species are determined by intrinsic factors such as physiological tolerances as well as extrinsic factors of the environment such as the availability of resources. While physiological tolerances generally change over evolutionary time scales, changes in environmental productivity due to processes such as succession or seasonal progression often occur over ecological times. I address both physiology and resource availability as drivers of the distributions and diversity of endothermic birds and mammals using a macroecological approach and a metabolic perspective. Migratory birds, altering communities over seasonal cycles, provide a unique opportunity to investigate the drivers of distributions and diversity …
Evolution Of Young Gene Duplicates In The Caenorhabditis Briggsae Genome, Lucille Packard
Evolution Of Young Gene Duplicates In The Caenorhabditis Briggsae Genome, Lucille Packard
Biology ETDs
Gene duplication plays a significant role in the evolution of novel function. Investigations concerning the genomic features of young gene duplicates can enhance our understanding of the nature of gene duplicates at inception and their fates over evolutionary time. Previous analysis of young gene duplicates in Caenorhabditis elegans has revealed genomic features of evolutionarily young gene duplicates with respect to structure, span, location and orientation of paralogous genes. The analysis of young gene duplicate pairs in Caenorhabditis briggsae provides insight into the characteristics of gene duplication in another member of the genus Caenorhabditis. The identification of 376 evolutionarily young gene …
Conservation Genetics At The Interface Of Theory And Application, Tyler J. Pilger
Conservation Genetics At The Interface Of Theory And Application, Tyler J. Pilger
Biology ETDs
Understanding the ecological mechanisms responsible for patterns of spatial genetic structure and diversity is a central issue to evolutionary ecology and biodiversity conservation. The Anthropocene has seen a mass extinction only previously observed through geological records, and freshwater fishes of North America have not been spared owing to large-scale modification of freshwater habitats and introduction of nonnative species. Concomitant with reduced numbers of species is a rapid reduction in genetic diversity within species; this diversity that is required for species to adapt to rapidly changing environments of human dominated landscapes. However, understanding why species exhibit different patterns of spatial genetic …
The Effects Of Ecology And Evolution On Avian Flight Morphology, Natalie Wright
The Effects Of Ecology And Evolution On Avian Flight Morphology, Natalie Wright
Biology ETDs
The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight-genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production, or maneuverability that impinges on the physical genome? I measured genome sizes, wing dimensions, and heart, flight muscle, and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, I found that genome size was negatively …
Into The Tropics: A Quantitative Study Of Mammals In The Great American Biotic Interchange, Winifred Whiteman-Jennings
Into The Tropics: A Quantitative Study Of Mammals In The Great American Biotic Interchange, Winifred Whiteman-Jennings
Biology ETDs
For almost 100 million years, North and South America were isolated from each other. This long period of geologic separation led to the evolution of strikingly different mammalian faunas: marsupials were prevalent in South America, while ecosystems in North America were composed of placental mammals. Roughly 3 Mya, a land bridge formed between the two continents leading to an accelerated exchange of mammalian fauna. The Great American Biotic Interchange (or GABI, as this has come to be called,) led to the successful colonization of many North American species, but few South American species. The highly asymmetrical nature of the faunal …
Pre-Industrial Melanism: The Origin, Maintenance, And Genetic Basis Of An Urban Melanic Morph Of The Vermilion Flycatcher., Carl Jonathan Schmitt
Pre-Industrial Melanism: The Origin, Maintenance, And Genetic Basis Of An Urban Melanic Morph Of The Vermilion Flycatcher., Carl Jonathan Schmitt
Biology ETDs
Industrial melanism is a celebrated evolutionary phenomenon because it demonstrates the efficacy of natural selection in response to anthropogenic environmental change. We investigated a potential instance of industrial melanism in a vertebrate, the vermilion flycatcher (Pyrocephalus rubinus). The species is strikingly bright red throughout its broad range, but a sooty brown morph is abundant in the heavily polluted city of Lima, Peru. We found that plumage morph is perfectly predicted by a single nucleotide polymorphism in the MC1R gene. We quantified genotype and allele frequencies in seven neighborhoods of Lima. Within neighborhoods, there were fewer heterozygotes than expected, and surveys …
Comparative Study Of Genomic Features Of Evolutionarily Young Gene Duplicates, Lijing Bu
Comparative Study Of Genomic Features Of Evolutionarily Young Gene Duplicates, Lijing Bu
Biology ETDs
Gene duplication is considered a major contributor to genome evolution and functional diversity. Differences in genomic features (such as structural resemblance, transcriptional orientation, and genomic location) between members of a gene duplicate pair may indicate the possible duplication mechanisms, as well as the evolutionary fates the paralogs may experience. In addition to these genomic features, molecular genetic features, such as differences in codon usage and expression levels may provide further insight into functional changes between paralogs. In this dissertation, multiple genomic analyses were conducted in order to evaluate the differences in genomic and genetic properties between duplicate copies in order …
The Gene Blistered Selectively Controls Muscle Type Differentiation In Drosophila Melanogaster, Ashley A. Deaguero
The Gene Blistered Selectively Controls Muscle Type Differentiation In Drosophila Melanogaster, Ashley A. Deaguero
Biology ETDs
The muscle fiber is a structural unit of skeletal muscle in many organisms. Muscle fiber composition has been implicated in maintaining muscle longevity and controlling systemic energy homeostasis, however not much is known about how different types of muscle fibers are specified. The fruit fly Drosophila melanogaster provides a useful model to study specification and differentiation of different types of muscle fiber. In this study, the functional properties of the transcription factor blistered (bs) were explored. The gene bs is evolutionarily conserved and has a mammalian homologue, Serum Response Factor (SRF). When bs is genetically down-regulated in all muscles, only …
How Ants Turn Information Into Food, Tatiana Flanagan
How Ants Turn Information Into Food, Tatiana Flanagan
Biology ETDs
Animals constantly process information from their environment. In social organisms, information exchange among individuals allows for behaviors to be finely tuned to local environmental cues. Such is the case of foraging in ants, where sharing information about the distribution of resources can drive adaptive behaviors to exploit those resources. In a first study, we quantified how clustering of experimental seed baits significantly increased foraging rates of seed harvester ants. That study found that species with larger colonies were no better than species with smaller colonies at collecting clumped seeds. In a second study, we integrated computer simulations, information science and …
Unraveling The Mysteries Of Plant Mating Systems In Raphanus Sativus, Lindsey C. Kaufman
Unraveling The Mysteries Of Plant Mating Systems In Raphanus Sativus, Lindsey C. Kaufman
Biology ETDs
Plant mating systems include a variety of mechanisms that result in non-random success of self- and outcross pollen, pollen from different compatible mates, and pollen from the same or different species. Although some of these mechanisms have received considerable attention (i.e., Charlesworth et al. 2005; Pannell and LaBouche 2013), most previous study has been of only one of these mechanisms at a time. Further in the field, a plant might simultaneously receive pollen of several types; thus, it is likely that multiple mechanisms of sorting among pollen operate simultaneously. If these mechanisms interact in ways that alter sorting among mates, …
Too Wet For Frogs, Too Dry For Lizards: Role Of Changing Precipitation On Tropical Frogs And Arid Lizards, Mason J. Ryan
Too Wet For Frogs, Too Dry For Lizards: Role Of Changing Precipitation On Tropical Frogs And Arid Lizards, Mason J. Ryan
Biology ETDs
During the course of the Anthropocene, humans have modified the landscape and atmosphere resulting in increased global temperatures and intensification of the hydrologic cycle over the last 100 years. Amphibians and reptiles are especially vulnerable to climate change because of their ectothermic physiology and sensitivity to changes in water availability. The role of moisture or precipitation in ectotherm responses to climate change has not been well studied, but moisture plays a vital role in all aspects of the lives of lizards and frogs. It is exceedingly difficult to study the ecological effects of changing precipitation patterns due the stochastic nature …
The Indirect Effects Of Climate Variability On The Reproductive Dynamics And Productivity Of An Avian Predator In The Arid Southwest, Corrie C. Borgman
The Indirect Effects Of Climate Variability On The Reproductive Dynamics And Productivity Of An Avian Predator In The Arid Southwest, Corrie C. Borgman
Biology ETDs
The deserts of the Southwestern United States are experiencing rapid warming and climate models predict declining winter precipitation. The combined effects of higher air temperatures and drought are a reduction in productivity, which may importantly impact reproduction in consumers. Here, we investigate the effects of warming and drought on the reproductive timing and output in loggerhead shrikes (Lanius ludovicianus) in central New Mexico from 2007 to 2012. We found increases in air temperature of 3°C during the breeding season (March—July) and highly variable winter and annual precipitation. With increasing spring temperatures, shrikes advanced nesting phenology by 20 days over 6 …
Negative Effects Of Rapid Warming And Drought On Reproductive Dynamics And Population Size Of An Avian Predator In The Arid Southwest, Kirsten Cruz-Mcdonnell
Negative Effects Of Rapid Warming And Drought On Reproductive Dynamics And Population Size Of An Avian Predator In The Arid Southwest, Kirsten Cruz-Mcdonnell
Biology ETDs
Avian communities of arid ecosystems may be particularly vulnerable to global climate change due to the magnitude of model projected change for desert regions and the inherent challenges for species of resource limited ecosystems. How arid zone birds will be affected by rapid increases in air temperature and increased drought frequency and severity is poorly understood. To date, avian responses to climate change have primarily been studied in northern temperate regions in relatively mesic habitats. We studied the effects of increasing air temperature and aridity on a Burrowing Owl (Athene cunicularia) population in the southwestern USA from 1998-2013. Over 16 …
Root Associated Microbes: The Mediators Between Plants And Soil, Sarah Dean
Root Associated Microbes: The Mediators Between Plants And Soil, Sarah Dean
Biology ETDs
Globally, increasing human populations have either caused or accelerated several types of environmental change. Symbiotic microbes have powerful effects on plant fitness, yet little study has been done on how microbial-plant relationships are affected by environmental changes. In two different ecosystems I explore how either nitrogen (N) pollution or drought can alter root associated microbe (RAM)-plant relationships using Next Generation Sequencing. In moist-meadow alpine tundra at Niwot Ridge, CO, I examine the relative contribution of host identity, N enrichment, and plant neighborhood on RAM diversity and community composition in two co-dominant plant species; Geum rossii and Deschampsia cespitosa. In New …
Multi-Scale Models Of Ovarian Cancer, Kimberly Rene Kanigel Winner
Multi-Scale Models Of Ovarian Cancer, Kimberly Rene Kanigel Winner
Biology ETDs
In ovarian cancer, disease and treatment can be examined across multiple spatial scales including molecules, cells, intra-tumor vasculature, and body-scale dynamics of circulating drugs. Survival of primary tumor cells and their development into disseminated tumors is related to adhesion between the cells, attachment, and invasion. Growth of new tumors depends on the delivery of nutrients, which depends on the tumor diameter and the tumors vasculature. Drug delivery also depends on tumor diameter and vasculature, and molecular- and gross-scale drug processes. A cellular Potts simulation integrated data at these multiple scales to model microscopic residual disease during relapse after a primary …
A Novel Family Of Major Histocompatibility Complex Class I Genes In Marsupials And Monotremes, Katina Krasnec
A Novel Family Of Major Histocompatibility Complex Class I Genes In Marsupials And Monotremes, Katina Krasnec
Biology ETDs
The Major Histocompatibility Complex (MHC) class I family of genes encode for molecules that have well-conserved structures, but have evolved to perform a diverse functions. The availability of an opossum genome from the grey, short-tailed opossum, Monodelphis domestica, has allowed for analysis of MHC class I genes in a marsupial. Traditional methods for gene discovery uncovered 13 MHC class I genes in the opossum. Utilization of a novel method to search for MHC domain structures discovered a family of 17 novel MHC class I genes. These genes, named ModoUT1-17, were located in a cluster on chromosome 1, unlinked to the …