Biology Commons^™

Acceleration Of The Panin Development In Mice Expressing Oncogenic K-Ras Due To A High Fat Diet, Bincy Philip

Dissertations and Theses (Open Access)

Obesity is postulated to be one of the major risk factors for pancreatic cancer, and recently it was indicated that an elevated body mass index (BMI correlates strongly with a decrease in patient survival. Despite the evident relationship, the molecular mechanisms involved are unclear. Oncogenic mutation of K-Ras is found early and is universal in pancreatic cancer. Extensive evidence indicates oncogenic K-Ras is not entirely active and it requires a triggering event to surpass the activity of Ras beyond the threshold necessary for a Ras-inflammation feed-forward loop. We hypothesize that high fat intake induces a persistent low level inflammatory response …

Investigating The Roles Of The P63 Isoforms In The Microrna Biogenesis Pathway, Deepavali Chakravarti

Dissertations and Theses (Open Access)

MicroRNAs play roles in various biological processes like development, tumorigenesis, metastasis and pluripotency. My thesis work has demonstrated roles for p63, a p53 family member, in the upstream regulation of microRNA biogenesis. The p63 gene has a complex gene structure and has multiple isoforms. The TAp63 isoforms contain an acidic transcription activation domain. The ΔNp63 isoforms, lack the TA domain, but have a proline rich region critical for gene transactivation. To understand the functions of these isoforms, the Flores lab generated TAp63 and ΔNp63 conditional knock out mice. Using these mice and tissues and cells from these mice we have …

Preservation Effects On Common Macroinvertebrates Of The Intermountain West, Megan Paxton

Undergraduate Honors Capstone Projects

Dry mass/wet mass ratios are essential for estimating energy flow through ecosystems, determining energy budgets, and studying energy allocation in organisms. Preserving specimens by freezing or storing them in ethanol has known effects on the wet mass measurements. These storage methods are used regardless of their effects - altering the wet mass and thereby changing the mass ratio for the organism. We evaluated the effects of ethanol storage and freezing on six different taxa from the Interrnountain West: Hesperoperla, lsoperla, Rhithrogena, Drunella, Arctopsyche, and Rhyacophila. All the taxa studied except Hesperoperla and Rhyacophila showed a significant loss in …

Using Student-Produced Time-Lapse Plant Movies To Communicate Concepts In Plant Biology, Marcia Harrison-Pitaniello Phd

Biological Sciences Faculty Research

Why do students think plants are “boring”? One factor may be that they do not see plant movement in real (i.e., their) time. This attitude may negatively impact their understanding of plant biology. Time-lapse movies of plants allow students to see the sophistication of movements involved in both organ development and orientation.

The objective of this project was to develop simple methods to capture image sequences for lab analysis and for converting to movies. The technology for making time-lapse movies is now easily attainable and fairly inexpensive, allowing its use for skill levels from grade school through college undergraduates. In …

Protein Interactions In Mrna Methylation Complexes, Yazan Ali Alqara

Senior Honors Theses

Experiments were performed to test sequence and structural specific interactions of proteins with a conserved RNA modification enzyme, which is known as Ime4 in yeast and Mettl3 in mammals. Ime4 methylates N6-adenosine bases on mRNA molecules. The goal of this project is to gain direct insights into how novel proteins interact with Ime4 to form the methyltranferase (MTase) complex and to identify proteins that are essential for Ime4 activity. It has been recognized that there are two proteins that interact within the Ime4 complex, which are known as Mum2 (a cytoplasmic protein essential for meiotic DNA replication within yeast) and …

The Cultural Manifestations Of Anorexia Nervosa, Aaron Volk

Tredway Library Prize for First-Year Research

No abstract provided.

Antifreeze Proteins In The Primary Urine Of Larvae Of The Beetle Dendroides Canadensis, Philip K. Nickell, Sandra Sass, Dawn Verleye, Edward M. Blumenthal, John G. Duman

Biological Sciences Faculty Research and Publications

To avoid freezing while overwintering beneath the bark of fallen trees, Dendroides canadensis (Coleoptera: Pyrochroidae) larvae produce a family of antifreeze proteins (DAFPs) that are transcribed in specific tissues and have specific compartmental fates. DAFPs and associated thermal hysteresis activity (THA) have been shown previously in hemolymph and midgut fluid, but the presence of DAFPs has not been explored in primary urine, a potentially important site that can contain endogenous ice-nucleating compounds that could induce freezing. A maximum mean THA of 2.65±0.33°C was observed in primary urine of winter-collected D. canadensis larvae. THA in primary urine increased significantly through autumn, …

Roles Of Predicted Glycosyltransferases In The Biosynthesis Of The Rhizobium Etli Ce3 O Antigen, Kristylea J. Ojeda, Laurie Simonds, K. Dale Noel

Biological Sciences Faculty Research and Publications

The Rhizobium etli CE3 O antigen is a fixed-length heteropolymer. The genetic regions required for its synthesis have been identified, and the nucleotide sequences are known. The structure of the O antigen has been determined, but the roles of specific genes in synthesizing this structure are relatively unclear. Within the known O-antigen genetic clusters of this strain, nine open reading frames (ORFs) were found to contain a conserved glycosyltransferase domain. Each ORF was mutated, and the resulting mutant lipopolysaccharide (LPS) was analyzed. Tricine SDS-PAGE revealed stepwise truncations of the O antigen that were consistent with differences in mutant LPS sugar …

Inhibition Of Diuretic Stimulation Of An Insect Secretory Epithelium By A Cgmp-Dependent Protein Kinase, Kristen A. Ruka, Anna P. Miller, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

The rate of urine secretion by insect Malpighian tubules (MTs) is regulated by multiple diuretic and antidiuretic hormones, often working either synergistically or antagonistically. In the Drosophila melanogaster MT, only diuretic factors have been reported. Two such agents are the biogenic amine tyramine (TA) and the peptide drosokinin (DK), both of which act on the stellate cells of the tubule to increase transepithelial chloride conductance. In the current study, TA and DK signaling was quantified by microelectrode recording of the transepithelial potential in isolated Drosophila MTs. Treatment of tubules with cGMP caused a significant reduction in the depolarizing responses to …

Predicted Effects Of Climate Change On The Distribution Of The Invasive Grass Dichanthium Annulatum, Cynthia Isabel Garcia

Theses and Dissertations - UTB/UTPA

Kleberg bluestem (Dichanthium annulatum) is an invasive grass species native to Africa but now found in southern United States, Mexico, and other tropical and subtropical countries throughout the world. Using the modeling software MaxEnt, climatic variables from WorldClim, the Intergovernmental Panel on Climate Change (IPCC) scenario A1B, and two General Circulatory Models: the Canadian model (Canadian Centre for Climate Modelling and Analysis or CCCMA), and the Australian model (Commonwealth Scientific and Industrial Research Organisation or CSIRO), several models were developed to determine the possible implications of climatic change on the suitable habitat for D. annulatum, in the year 2050. Models …

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 …

Amphetamine Elicits Opposing Actions On Readily Releasable And Reserve Pools For Dopamine, Dan P. Covey, Steven A. Juliano, Paul A. Garris

Faculty Publications – Biological Sciences

Amphetamine, a highly addictive drug with therapeutic efficacy, exerts paradoxical effects on the fundamental communication modes employed by dopamine neurons in modulating behavior. While amphetamine elevates tonic dopamine signaling by depleting vesicular stores and driving non-exocytotic release through reverse transport, this psychostimulant also activates phasic dopamine signaling by up-regulating vesicular dopamine release. We hypothesized that these seemingly incongruent effects arise from amphetamine depleting the reserve pool and enhancing the readily releasable pool. This novel hypothesis was tested using in vivo voltammetry and stimulus trains of varying duration to access different vesicular stores. We show that amphetamine actions are stimulus dependent …

Dispersal Ecology Of Desert Mosses Along Gradients Of Elevation, Wildfire Disturbance And Local Niche, Robert Joseph Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the variation in plant communities can be explained by the dispersal of individuals across landscapes, an ecological process that contributes to clinal variation, post-disturbance recovery and habitat occupancy. The role of dispersal is of particular concern for Mojave Desert plant communities that may not be able to tolerate recent departures from historical fire regimes. The aim of this thesis was to infer how dispersal is reflected by patterns of diversity in disturbed and undisturbed bryophyte communities in the Spring Mountains of southern Nevada. Chapter 2 presents an examination of sub-surface bryophyte communities (propagule "soil-banks") along a 1400 m …

Differences In Population Structure Estimated Within Maternally- And Paternally-Inherited Forms Of Mitochondria In Lampsilis Siliquoidea (Bivalvia: Unionidae), Robert A. Krebs, W. Calvin Borden, Na'tasha M. Evans, F. Paul Doerder

Biological, Geological, and Environmental Faculty Publications

Mussels in several orders possess two separate mitochondrial lineages: a standard female-inherited form and one inherited only through males. This system of doubly uniparental inheritance (DUI) for mitochondrial genes provides an opportunity to compare the population structure of gene-lineages passed either mother-to-daughter or father-to-son. In the present study, we contrast variation in the male and female haplotype lineages of the American freshwater mussel species, Lampsilis siliquoidea (sometimes called Lampsilis radiata luteola), throughout the Lake Erie, Ohio River, and upper Mississippi River watersheds, and contrast variation with the sequences obtained for the related species/subspecies Lampsilis radiata radiata from Maine. The …

Kinematic Analysis Of Axial Rotations And The Effects Of Stress Selection On Takeoff Flight Performance, Michael L. Brewer

UNLV Theses, Dissertations, Professional Papers, and Capstones

The importance of flying insects cannot be understated; without them as pollinators, the great diversity of flowing plants could not have occurred. Flight requires a suite of highly derived morphological and physiological characteristics that may limit the evolutionary responses of other life history traits.

To investigate the complexities of maneuvering flight, I used high-speed videography to analyze wing and body motions in the HoverflySyritta pipiens(Order: Diptera) during horizontal turns called saccades. I characterized the saccades by calculating the instantaneous rotational velocities throughout the saccade, maximum rotational velocity, and the mean rotational velocity. I then compared the shape of the rotational …

Effects Of Environmental Variables On The Reproduction Of Quagga Mussels (Dreissena Rostriformis Bugensis) In Lake Mead, Nv/Az, Richard Steven Ianniello

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2007, quagga mussels (Dreissena rostriformis bugensis) were found in Lake Mead and have spread downstream on the Colorado River and to other lakes and reservoirs in the Southwestern United States. The quagga mussel's extremely quick colonization of Lake Mead and annual veliger abundance trends provide evidence that the quagga mussels in the Southwest have different reproductive behavior than in previous habitats. This study is one of the first to specifically examine quagga mussel reproduction in the Southwest and examines how quagga mussel reproduction varies at sites known to have different temperatures and other environmental variables resulting from the input …

The Effects Of Starvation Selection On Drosophila Melanogaster Life History And Development, Lauren A. Reynolds

UNLV Theses, Dissertations, Professional Papers, and Capstones

In nature, animals may endure periods of famine to complete their life cycles. Starvation stress will increase in populations as climates around the world change. To predict how populations may respond to such a stress, laboratory experimentation becomes essential. The evolutionary process of adaptation, its innovations and their trade-offs, can be studied in populations experiencing starvation stress. For this purpose outbred populations ofDrosophila melanogasterwere selected for starvation resistance in the laboratory.

After 60+ generations of starvation selection the starvation-selected flies have gone from surviving 2-3 days without food to 12-14 days without food. How this amazing feat of resistance is …

Evaluation Of Different Methods For Detection And Enumeration Of Indicator Organisms In Water Bodies Of Northern New Jersey, Alexandra Peri

Theses, Dissertations and Culminating Projects

Bodies of water, particularly those used for drinking or recreation, are monitored for many different types of pollution. One type that causes especial concern is fecal contamination from humans and other mammals. Bodies of water affected by fecal contamination may harbor bacteria and viruses that can threaten human health. Identifying the source of such microbes is the first step towards eliminating the contamination, and making the body of water usable again. Fecal pollution is typically identified through the detection of indicator organisms, which are present in feces in large numbers. Examples of such organisms include total coliforms, and subsets of …

Exploring Signals Of Historical Demography In Boreal Mammals Through Integration Of Statistical Conservation Phylogenetics, Taxonomy, And Comparative Phylogeography, Jason L. Malaney

Biology ETDs

Understanding how diversity is partitioned across the landscape can provide perspectives related to the environmental processes that have influenced the evolutionary history of organisms. This main idea, often termed phylogeography, serves as the backdrop to my research where I explore three broad concepts including historical biogeography, cryptic diversity and ecology, and conservation phylogenetics. I address various questions in each of these concepts by using a set of mammals that are associated with montane and mesic environments of North America. More specifically, I focus on the jumping mice (Zapodidae) to test hypotheses that scale to the broader community. This approach allows …

Regulation Of Hydraulic Function And Consequences For Drought-Related Mortality In Mature Woody Plants, Jennifer A. Plaut

Biology ETDs

Precipitation and temperature patterns are expected to shift over at least the next century due to anthropogenic climate change. Effects of these shifts may be felt most acutely in arid and semi-arid regions where water is already the most limiting resource. Vegetation mortality due to drought is a likely outcome of predicted future climate, with consequences for ecosystem structure and function and feedbacks on regional and global climate. Yet, mechanisms and interactions of key plant drought responses and the end-point of mortality remain poorly understood. In this dissertation I examine the roles of xylem cavitation resistance and stomatal control of …

Life History And Morphometric Variation Of Gambusia Nobilis At Bitter Lake National Wildlife Refuge, Alyssa Renee Hopkins

Biology ETDs

The Pecos Gambusia, Gambusia nobilis, is an endangered, live bearing fish inhabiting sinkholes in a restricted range of the Pecos River Watershed in New Mexico and Texas. The sink holes at Bitter Lake National Wildlife Refuge (BLNWR), Roswell, NM create isolated habitats with varying ecological conditions (habitat size, community composition, dissolved oxygen, salinity and pH). This ecological variation imposes unique selective pressures that may shape differences in life history characteristics and morphology between populations. The goals of this research were to characterize seasonal and population variation in 1) life history characteristics, 2) embryo development patterns, 3) morphology and 4) explore …

A Holarctic Perspective On Mammalian Evolution: The Evolutionary And Biogeographic History Of Red-Backed Voles And Their Close Relatives (Rodentia: Arvicolinae), Brooks A. Kohli

Biology ETDs

The influence of Quaternary environmental changes on demography and geographic distribution is paramount to understanding how contemporary genetic diversity is partitioned in high-latitude species. This history of change in northern ecosystems sets the stage for forecasting how species inhabiting tundra and boreal forest will respond to the ongoing shift in climate. Utilizing broad geographic and taxonomic sampling, a multilocus species tree approach, ecological niche models, and population genetic techniques, I investigate the evolutionary and biogeographic history of a Holarctic mammal, the northern red-backed vole (Clethrionomys rutilus) and the systematics of the tribe it belongs to, Clethrionomyini. This tribe of forest …

Molecular Control Of Muscle Patterning, Development And Stability In Drosophila, Elisa Mignon Labeau Dimenna

Biology ETDs

Muscle is a highly conserved and specialized tissue in animals. Failure of proper muscle patterning, maintenance and stability in animals can have variety of consequences for the individual. Mutations in loci that control muscle can result in death during embyogenesis, dysmorphism, and/or reduced lifespan after progressive muscle degeneration (Emery 2002, Mathews and Moore 2003, Amato and Griggs 2011). Muscle defects, such as these, have origins ranging from improper transcriptional control to direct sequence disruptions in proteins that play a wide variety of roles in the cell (Emery 2002, Mathews and Moore 2003, Amato and Griggs 2011). Thus, out of this …

Habitat Preference Of Western Diamond-Backed Rattlesnakes (Crotalus Atrox) At Bosque Del Apache National Wildlife Refuge, New Mexico: An Analysis At Multiple Scales, Theresa Lorraine Mcinnes

Biology ETDs

Bosque del Apache National Wildlife Refuge is located in central New Mexico in the Chihuahuan desert. Approximately 25% of the refuge spans the Rio Grande floodplain and consists of managed riparian and agriculture areas. The upland areas are dominated by creosote bush (Larrea tridentata), honey mesquite (Prosopis sp.), and four-wing saltbush (Atriplex canescens). Western diamond-backed rattlesnakes (Crotalus atrox) are habitat generalists of dry lowland areas and commonly use dry washes, Larrea and Prosopis desert, rocky slopes, scrub/grassland, man-made structures, and less commonly hydric habitats. A high diversity of vegetation types span the refuge and hydric and upland habitats are often …

Mitochondrial Genome Evolution In Pupillid Land Snails, Jason D. Marquardt

Biology ETDs

Pupillid land snails (Family Pupillidae) are small (< 6mm) snails with a broad geographic distribution and often found in very high density in their habitat. The sequencing of the mitochondrial genome (mt genome) of three pupillid taxa has been undertaken to understand their genome evolution more fully. The Gastrocopta cristata mitochondrial genome is 14,060 bp in length and contains 13 protein coding genes, 2 rRNA genes and 22 tRNA genes. The Pupilla muscorum, and Vertigo pusilla genomes contain all of the same genes but are of differing total sizes, 14,149 bp and 14,078 bp respectively. The AT content of the three genomes is similar at ~71% A+T which is comparable to their closest sequenced relatives. There are no major gene rearrangements among the mt genomes of the three pupillids, but the positions of many tRNA genes differ from those of Albinaria caerulea. There is a genomic sequence region of high concentration of thymine on the leading strand of the mt genome that is shared among all three genomes as well as their relatives.

Systematics Of Longhorned Beetles (Insecta: Coleoptera: Cerambycidae), Eugenio Hernán Nearns

Biology ETDs

The longhorned wood boring beetles (Insecta: Coleoptera: Cerambycidae) are a diverse and economically important group of insects. With an estimated 4,000 genera and more than 35,000 described species, the Cerambycidae comprise one of the largest beetle families. Cerambycid beetles are found on all continents except Antarctica, from sea level to montane sites as high as 4000 m. Cerambycids are among the most serious wood boring pest species globally, affecting many agricultural crops, ornamental trees, and lumber products, causing millions of dollars in damage each year. Despite their economic importance and biological diversity, relatively little is known of cerambycid beetle ecology, …

An Environmental History Of The Bear River Range, 1860-1910, Bradley Paul Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The study of environmental history suggests that nature and culture change all the time, but that the rate and scale of such change can vary enormously. During the late 19th and early 20th centuries, Anglo settlement in the American West transformed landscapes and ecologies, creating new and complex environmental problems. This transformation was particularly impressive in Cache Valley, Utah's Bear River Range. From 1860 to 1910, Mormon settlers overused or misused the Bear River Range's lumber, grazing forage, wild game, and water resources and introduced invasive plant and animal species throughout the area.

By the turn of the 20th century, …

Evaluating Eriogonum Corymbosum Tolerance To Frequent Irrigation And Evaluating Its Significant Morphological Variations For Potential Cultivars, Graham C. Hunter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Eriogonum corymbosum (Lacy Buckwheat) is an attractive subshrub species native to low rainfall areas of the Colorado Plateau and suitable for low water landscapes in the Intermountain West (IMW). Low water use landscapes can contribute to water conservation in arid climates; developing a palette of plants that are both attractive and drought tolerant can promote the acceptance of low water use landscapes as an alternative to the traditional bluegrass landscapes of the IMW. In 2007 a strip plot design containing four repetitions with four randomly assigned plants each of Eriogonum corymbosum, Eriogonum thompsoniae, and the control species Cornus …

Kisspeptins - Expression, Purification, And Biological Assays, Mathew Puthayathu Kurian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Kisspeptins are hormones involved in the onset of puberty in adolescents and maintenance of reproductive function in adults. Defects in kisspeptin signaling are associated with many reproductive disorders. Kisspeptins were originally discovered as metastasis suppressors and have been found to suppress the metastasis of certain cancers. Unfortunately, many aspects of kisspeptin action at a cellular level remain unknown. Kisspeptins, therefore, are attractive candidates for large-scale production for use as research and therapeutic reagents. We developed a simple and cost effective method to express and purify kisspeptins in large quantities. We also tested the biological activity of kisspeptins on cells expressing …

Reproductive Biology And Impacts Of Energy Development On Physaria Congesta And Physaria Obcordata (Brassicaceae), Two Rare And Threatened Plants In The Piceance Basin, Colorado, Sarah Lynn Clark

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Oil and gas development has increased profoundly over the last 20 years in the United States. A large underground deposit of natural gas has been found in the Piceance Basin, which is located in the northwestern part of the state of Colorado. This deposit occurs in an area inhabited by two rare mustard species commonly named the Dudley Bluffs bladderpod and the Dudley Bluffs twinpod. These two plant species are also listed as threatened by the US Fish and Wildlife Service. Concerns about gas development effects on these rare plants have motivated research that quantifies these potential impacts. Through funding …