Digital Commons Network^™

The Impact And Shortfall Of Conservation On The Status Of The World's Vertebrates , M Hoffmann, C Hilton-Taylor, A Angulo, Monica Bohm Phd, Shm Bbutchart, K E. Carpenter, J Chanson, B Collen, N A. Cox, Neil Cumberlidge

Journal Articles

No abstract provided.

From Energy Gradient And Natural Selection To Biodiversity And Stability Of Ecosystems, Bo Deng

Department of Mathematics: Faculty Publications

The purpose of this paper is to incorporate well-established ecological principles into a foodweb model consisting of four trophic levels --- abiotic resources, plants, herbivores, and carnivores. The underlining principles include Kimura's neutral theory of genetic evolution, Liebig's Law of the Minimum for plant growth, Holling's functionals for herbivore foraging and carnivore predation, the One-Life Rule for all organisms, and Lotka-Volterra's model for intraand interspecific competitions. Numerical simulations of the model led to the following statistical findings: (a) particular foodwebs can give contradicting observations on biodiversity and productivity, in particular, all known functional forms -- - positive, negative, sigmoidal, and …

The Fungal Connection: Characterizing The Ectomycorrhizal Community And Belowground Response To Restoration Treatments In Northern Mississippi., Ashley Jane Craig

Electronic Theses and Dissertations

Ectomycorrhizal (ECM) fungi are symbionts on the roots of woody plant species throughout the world. These fungi provide plants with nutrients and are important drivers of ecosystem processes. ECM fungi vary in their effect on host plants and host-specificity, making them important considerations in restoration projects seeking to restore target tree species. Restoration strategies such as burning and thinning may have strong impacts on ECM fungi, and given the that ECM are important in structuring aboveground communities and maintaining certain dominant plant taxa, knowledge of ECM fungal response is needed to ensure restoration efforts succeed. Using molecular methods, this research …

The Effects Of Ecological Restoration On Soil Microbial Enzyme Activities And Leaf Litter Decomposition, Anthony Jason Rietl

Electronic Theses and Dissertations

This study examined the immediate effects of ecological restoration on soil enzyme activities and decomposition. The activities of five enzymes: phosphatase, ?-glucosidase, ?-N-acetylglucosadminidase (NAGase), phenol oxidase, and lignin-peroxidase were measured in both soils and on decomposing Quercus falcata leaf litter in unburned, burned, and burned and thinned plots in a mesic forest in northern Mississippi. Rates of decomposition were also assessed for Q. falcata leaf litter at each plot. The restoration treatments decreased phosphatase activity in relation to an increase in soil organic matter after the fire, and increased NAGase activity in relation to a decrease in leaf litter after …

Apparent Competition With An Invasive Plant Hastens The Extinction Of An Endangered Lupine, Emily M. Dangremond, Eleanor A. Pardini, Tiffany M. Knight

Biology Faculty Research

Invasive plants may compete with native plants by increasing the pressure of native consumers, a mechanism known as "apparent competition." Apparent competition can be as strong as or stronger than direct competition, but the role of apparent competition has rarely been examined in biological invasions. We used four years of demographic data and seed-removal experiments to determine if introduced grasses caused elevated levels of seed consumption on native plant species in a coastal dune system in California, USA. We show that the endangered, coastal dune plant Lupinus tidestromii experiences high levels of pre-dispersal seed consumption by the native rodent Peromyscus …

The Wnt/Β-Catenin Pathway Regulates Growth And Maintenance Of Colonospheres, Shailender S. Kanwar, Yingjie Yu, Jyoti Nautiyal, Bhaumik B. Patel, Adhip Pn Majumdar

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Recent evidence suggests that epithelial cancers, including colorectal cancer are driven by a small sub-population of self-renewing, multi-potent cells termed cancer stem cells (CSCs) which are thought to be responsible for recurrence of cancer. One of the characteristics of CSCs is their ability to form floating spheroids under anchorage-independent conditions in a serum-free defined media. The current investigation was undertaken to examine the role of Wnt/β-catenin pathway in regulating the growth and maintenance of colonospheres. Human colon cancer cells HCT-116 (p53 wild type; K-ras mutant), HCT-116 (p53 null; K-ras mutant) and HT-29 (p53 mutant) were used.

Results

Colonospheres …

The Drosophila Homolog Of The Mammalian Imprint Regulator, Ctcf, Maintains The Maternal Genomic Imprint In Drosophila Melanogaster, William A. Macdonald, Debashish Menon, Nicholas J. Bartlett, G Elizabeth Sperry, Vanya Rasheva, Victoria Meller, Vett K. Lloyd

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

CTCF is a versatile zinc finger DNA-binding protein that functions as a highly conserved epigenetic transcriptional regulator. CTCF is known to act as a chromosomal insulator, bind promoter regions, and facilitate long-range chromatin interactions. In mammals, CTCF is active in the regulatory regions of some genes that exhibit genomic imprinting, acting as insulator on only one parental allele to facilitate parent-specific expression. In Drosophila, CTCF acts as a chromatin insulator and is thought to be actively involved in the global organization of the genome.

Results

To determine whether CTCF regulates imprinting in Drosophila, we generated CTCF mutant alleles …

Loss Of The Sin3 Transcriptional Corepressor Results In Aberrant Mitochondrial Function, Valerie L. Barnes, Bethany S. Strunk, Icksoo Lee, Maik Hüttemann, Lori A. Pile

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

SIN3 is a transcriptional repressor protein known to regulate many genes, including a number of those that encode mitochondrial components.

Results

By monitoring RNA levels, we find that loss of SIN3 inDrosophilacultured cells results in up-regulation of not only nuclear encoded mitochondrial genes, but also those encoded by the mitochondrial genome. The up-regulation of gene expression is accompanied by a perturbation in ATP levels in SIN3-deficient cells, suggesting that the changes in mitochondrial gene expression result in altered mitochondrial activity. In support of the hypothesis that SIN3 is necessary for normal mitochondrial function, yeastsin3null mutants exhibit very poor …

How Our Health Depends On Biodiversity, Eric Chivian M.D., Aaron Bernstein M.D., M.P.H.

Ecosystem Disruption & Climate Change

The eminent Harvard biology Professor Edward O.Wilson once said about ants, “We need them to survive, but they don’t need us at all.” The same, in fact, could be said about countless other insects, bacteria, fungi, plankton, plants, and other organisms. This fundamental truth, however, is largely lost to many of us. Rather, we humans often act as if we are totally independent of Nature, as if our driving thousands of other species to extinction and disrupting the life-giving services they provide will have no effect on us whatsoever.

This summary, using concrete examples from our award-winning Oxford University Press …

Cellular And Molecular Dissection Of Pluripotent Adult Somatic Stem Cells In Planarians, Norito Shibata, Labib Rouhana, Kiyokazu Agata

Biological Sciences Faculty Publications

Freshwater planarians, Plathelminthes, have been an intriguing model animal of regeneration studies for more than 100 years. Their robust regenerative ability is one of asexual reproductive capacity, in which complete animals develop from tiny body fragments within a week. Pluripotent adult somatic stem cells, called neoblasts, assure this regenerative ability. Neoblasts give rise to not only all types of somatic cells, but also germline cells. During the last decade, several experimental techniques for the analysis of planarian neoblasts at the molecular level, such as in situ hybridization, RNAi and fluorescence activated cell sorting, have been established. Moreover, information about genes …

Diel Fish Habitat Selection In A Tributary Stream, Andria K. Salas, Eric B. Snyder

Peer Reviewed Publications

This study investigated the location and diel habitat preferences (at 100 m reach scale) of fish in a small tributary stream in late spring, early summer. During the day, coho (Oncorhynchus kisutch) preferred areas with more cover (deeper, greater extent of undercut banks) vs. night when LWD was preferred (Pearson correlation and step-wise MLR). Chinook (O. tshawytscha) exhibited an opposite pattern, preferring LWD during the day vs. higher velocity at night. This suggests these two potadromous species may be partitioning resources. Pooling coho, chinook and rainbow trout (O. mykiss) indicated reaches with more LWD …

Characterization Of Lim Kinase And Activity In Early Amphibian Embryos, Stephanie Seegert

Senior Honors Theses and Projects

EphA4 is a cellular receptor that functions in mediating tissue interactions in embryonic development. The downstream effectors of EphA4 are mainly unknown, although previous research has indicated that the enzyme p160ROCK is one of the downstream mediators in the pathway. LIM kinase is an enzyme that is activated by p160ROCK. We have hypothesized that LIM kinase acts downstream of p160ROCK in the signaling pathway. Our results showed that LIM kinase is present and activated during development when EphA4 is active in the embryo, which is consistent with a role for LIM kinase in EphA4 signaling. Further testing is necessary to …

Analysis Of Eurycea Hybrid Zone In Eastern Missouri, Bonnie Jean Beasley

Masters Theses

"Evolutionary mechanisms are often difficult to observe in action because evolution generally works slowly over time. Hybrid zones provide a unique opportunity to observe many evolutionary processes, such as reinforcement, because of the rapid changes that tend to occur in these zones. Salamanders provide an ideal model for examining the rapid changes in populations that result from hybridization because many closely-related species lack reproductive barriers. In Missouri, a well-documented hybridization zone exists among the two subspecies Eurycea longicauda longicauda (long-tailed salamander) and E. L. melanopleura (dark-sided salamander). These salamanders inhabit caves, limestone creek beds, and abandoned mine shafts. A closely …

Microbial Community Characterization And Pathogen Analysis Within Constructed Wetlands Of Varying Scale Designed For Contaminant Removal, Michael R. Mitzel

Theses and Dissertations (Comprehensive)

Constructed wetlands (CWs) are complex treatment environments, requiring an integrative research approach to improve our understanding of them. The goal of this thesis was to establish an understanding of the functional and structural characteristics of microbial communities within bench-, field- and industrial-scale environmental treatment systems. The impact of pathogenic and/or antibiotic contaminants on these communities based on their functional and structural profiles using community-level physiological profiling (CLPP) and denaturing-gradient gel electrophoresis (DGGE), respectively, was investigated. Under normal operation, bench-, field- and industrial-scale treatment systems were able to produce similarly behaving structural and functional profiles. Increased retention time was consistently associated …

Interaction Between The Biotin Carboxyl Carrier Domain And The Biotin Carboxylase Domain In Pyruvate Carboxylase From Rhizobium Etli, Adam D. Lietzan, Ann L. Menefee, Tonya N. Zeczycki, Sudhanshu Kumar, Paul V. Attwood, John C. Wallace, W. Wallace Cleland, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Pyruvate carboxylase (PC) catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in mammalian tissues. To effect catalysis, the tethered biotin of PC must gain access to active sites in both the biotin carboxylase domain and the carboxyl transferase domain. Previous studies have demonstrated that a mutation of threonine 882 to alanine in PC from Rhizobium etli renders the carboxyl transferase domain inactive and favors the positioning of biotin in the biotin carboxylase domain. We report the 2.4 Å resolution X-ray crystal structure of the Rhizobium etli PC T882A mutant which reveals the first high-resolution description of …

Inhibitors Of Pyruvate Carboxylase, Tonya N. Zeczycki, Martin St. Maurice, Paul V. Attwood

Biological Sciences Faculty Research and Publications

This review aims to discuss the varied types of inhibitors of biotin-dependent carboxylases, with an emphasis on the inhibitors of pyruvate carboxylase. Some of these inhibitors are physiologically relevant, in that they provide ways of regulating the cellular activities of the enzymes e.g. aspartate and prohibitin inhibition of pyruvate carboxylase. Most of the inhibitors that will be discussed have been used to probe various aspects of the structure and function of these enzymes. They target particular parts of the structure e.g. avidin – biotin, FTP – ATP binding site, oxamate – pyruvate binding site, phosphonoacetate – binding site of the …

A Review Of Sex Determining Mechanisms In Geckos (Gekkota: Squamata), Tony Gamble

Biological Sciences Faculty Research and Publications

Geckos are a species-rich clade of reptiles possessing diverse sex determining mechanisms. Some species possess genetic sex determination, with both male and female heterogamety, while other species have temperature-dependent sex determination. I compiled information from the literature on the taxonomic distribution of these sex determining mechanisms in geckos. Using phylogenetic data from the literature, I reconstructed the minimum number of transitions among these sex determining mechanisms with parsimony-based ancestral state reconstruction. While only a small number of gecko species have been characterized, numerous changes among sex determining mechanisms were inferred. This diversity, coupled with the high frequency of transitions, makes …

Small-Mammal Seed Predation Limits The Recruitment And Abundance Of Two Perennial Grassland Forbs, Mary Bricker, Dean Pearson, John L. Maron

Biological Sciences Faculty Publications

Although post-dispersal seed predators are common and often reduce seed density, their influence on plant population abundance remains unclear. On the one hand, increasing evidence suggests that many plant populations are seed limited, implying that seed predators could reduce plant abundance. On the other hand, it is generally uncertain whether the magnitude of seed limitation imposed by granivores is strong enough to overcome density-dependent processes that could compensate for seed loss at later stages. We examined the impact of seed predation by small mammals, primarily deer mice (Peromyscus maniculatus), on seedling recruitment and subsequent plant establishment of two …

Building A Mechanistic Understanding Of Predation With Gps-Based Movement Data, Evelyn Merrill, Ha˚Kan Sand, Barbara Zimmermann, Heather Mcphee, Nathan Webb, Mark Hebblewhite, Peter Wabakken, Jacqueline L. Frair

Biological Sciences Faculty Publications

Quantifying kill rates and sources of variation in kill rates remains an important challenge in linking predators to their prey. We address current approaches to using global positioning system (GPS)-based movement data for quantifying key predation components of large carnivores. We review approaches to identify kill sites from GPS movement data as a means to estimate kill rates and address advantages of using GPS-based data over past approaches. Despite considerable progress, modelling the probability that a cluster of GPS points is a kill site is no substitute for field visits, but can guide our field efforts. Once kill sites are …

Species Composition And Spatiotemporal Pattern Of The Seed Bank And Vegetation In Native And Degraded Florida Rosemary Scrub, Jennifer J. Navarra

Electronic Theses and Dissertations

The soil seed bank plays a dynamic role in the regeneration of plant communities after natural and anthropogenic disturbance. In this thesis, I addressed how disturbances influence the vegetation and seed bank of Florida rosemary scrub. In Chapter One I evaluated changes in species composition and spatiotemporal pattern of the vegetation and seed bank along a gradient of disturbance. During the summers and winters of 2007-2009 percent ground cover and seed bank species composition were assessed among replicates of three vegetation types subjected to minimal, moderate, and extreme anthropogenic disturbance (native rosemary scrub, degraded scrub, and agriculturally improved pasture, respectively). …

Characterizing The Vertical Structure And Structural Diversity Of Florida Oak Scrub Vegetation Using Discrete-Return Lidar, James J. Angelo

Electronic Theses and Dissertations

Vertical structure, the top-to-bottom arrangement of aboveground vegetation, is an important component of forest and shrubland ecosystems. For many decades, ecologists have used foliage height profiles and other measures of vertical structure to identify discrete stages in post-disturbance succession and to quantify the heterogeneity of vegetation. Such studies have, however, required resource-intensive field surveys and have been limited to relatively small spatial extents (e.g.,

Using Landscape Genetics To Assess Population Connectivity In A Habitat Generalist, Tyler Duncan Hether

Electronic Theses and Dissertations

Understanding the nature of genetic variation in natural populations is an underlying theme of population genetics. In recent years population genetics has benefited from the incorporation of landscape and environmental data into pre-existing models of isolation by distance (IBD) to elucidate features influencing spatial genetic variation. Many of these landscape genetics studies have focused on populations separated by discrete barriers (e.g., mountain ridges) or species with specific habitat requirements (i.e., habitat specialists). One difficulty in using a landscape genetics approach for taxa with less stringent habitat requirements (i.e., generalists) is the lack of obvious barriers to gene flow and preference …

Biogeography And Diversification In The Neotropics: Testing Macroevolutionary Hypotheses Using Molecular Phylogenetic Data, Juan Manuel Daza Rojas

Electronic Theses and Dissertations

Lineage diversification in the Neotropics is an interesting topic in evolutionary biology and one of the least understood. The complexity of the region precludes generalizations regarding the historical and evolutionary processes responsible for the observed high diversity. Here, I use molecular data to infer evolutionary relationships and test hypotheses of current taxonomy, species boundaries, speciation and biogeographic history in several lineages of Neotropical snakes. I comprehensively sampled a widely distributed Neotropical colubrid snake and Middle American pitvipers and combined my data with published sequences. Within the colubrid genus Leptodeira, mitochondrial and nuclear markers revealed a phylogeograhic structure that disagrees with …

Clonality And Genetic Diversity In Polygonella Myriophylla, A Lake Wales Ridge Endemic Plant, Genevieve Metzger

Electronic Theses and Dissertations

Although capable of sexual reproduction, many plants also rely heavily on clonal reproduction. The formation of multiple, physiologically-independent units with the same genotype has important implications for spatial genetic structure and genetic diversity in these plants. The endangered scrub-dwelling perennial, Polygonella myriophylla is known to reproduce both sexually and clonally but no study to date has been able to investigate the spatial genetic patterns that occur in this species. I use microsatellite markers to investigate questions about clonal structure and genetic diversity in five populations of P. myriophylla and address some of the implications of my findings for conservation of …

Dynamic Genomes Of Eukaryotes And The Maintenance Of Genomic Integrity, Laura Wegener Parfrey, Laura A. Katz

Biological Sciences: Faculty Publications

Many biologists assume that eukaryotic genomes are transmitted stably between generations with only minor variations. Yet, this presumed constancy is at odds with data indicating that eukaryotic genomes are dynamic, varying extensively in content among many different lineages. Thus, rather than being constant, genomes vary considerably within individuals during their lifetimes.

Gender Dimorphism In The Exercise-Naïve Murine Skeletal Muscle Proteome, Lauren Ann Metskas, Mohini Kulp, Stylianos P. Scordilis

Biological Sciences: Faculty Publications

Skeletal muscle is a plastic tissue with known gender dimorphism, especially at the metabolic level. A proteomic comparison of male and female murine biceps brachii was undertaken, resolving an average of 600 protein spots of MW 15-150 kDa and pI 5-8. Twenty-six unique full-length proteins spanning 11 KOG groups demonstrated statistically significant (p< 0.05) abundance differences between genders; the majority of these proteins have metabolic functions. Identified glycolytic enzymes demonstrated decreased abundance in females, while abundance differences in identified oxidative phosphorylation enzymes were specific to the proteins rather than to the functional group as a whole. Certain cytoskeletal and stress proteins showed specific expression differences, and all three phosphorylation states of creatine kinase showed significant decreased abundance in females. Expression differences were significant but many were subtle (≤ 2-fold), and known hormonally-regulated proteins were not identified. We conclude that while gender dimorphism is present in non-exercised murine skeletal muscle, the proteome comparison of male and female biceps brachii in exercise-naive mice indicates subtle differences rather than a large or obviously hormonal dimorphism.

Trapping Mammals In A Cautious World: The Effect Of Disinfectants On Trap Success, James Wilson, K. E. Mabry

Biology Faculty Publications

Disinfecting traps that have captured small mammals is one recommendation for preventing occurrence of hantavirus infection; however, the potential effects of disinfection on small mammal trappability have not been investigated thoroughly. We conducted an experiment to compare the effects of 2 disinfectants (Lysol® and household bleach) on the trappability of 4 small mammal species (Peromyscus maniculatus, Neotamias spp., and Spermophilus lateralis). We established triplicate trap grids in 2 forest types (red fir and mixed conifer), each consisting of a 6 × 6 array of Sherman live-traps placed at 10-m intervals. Traps were given 1 of 3 treatments: control (water), Lysol, …

Alternative Splicing And Polyadenylation Contribute To The Generation Of Herg1 C-Terminal Isoforms, Qiuming Gong, Matthew R. Stump, A. Russell Dunn, Vivianne Deng, Zhengfeng Zhou

Faculty Publications - Department of Biological & Molecular Science

The human ether-a-go-go-related gene 1 (hERG1) encodes the pore-forming subunit of the rapidly activating delayed rectifier potassium channel. Several hERG1 isoforms with different N- and C-terminal ends have been identified. The hERG1a, hERG1b, and hERG1-3.1 isoforms contain the full-length C terminus, whereas the hERG1_USOisoforms, hERG1a_USO and hERG1b_USO, lack most of the C-terminal domain and contain a unique C-terminal end. The mechanisms underlying the generation of hERG1_USOisoforms are not understood. We show that hERG1 isoforms with different C-terminal ends are generated by alternative splicing and polyadenylation of hERG1 pre-mRNA. We identified an …

Direct And Indirect Effects Of Climate Change On Amphibian Populations, Andrew R. Blaustein, Susan C. Walls, Betsy A. Bancroft, Joshua J. Lawler, Catherine L. Searle, Stephanie S. Gervasi

Biology Faculty Scholarship

As part of an overall decline in biodiversity, populations of many organisms are declining and species are being lost at unprecedented rates around the world. This includes many populations and species of amphibians. Although numerous factors are affecting amphibian populations, we show potential direct and indirect effects of climate change on amphibians at the individual, population and community level. Shifts in amphibian ranges are predicted. Changes in climate may affect survival, growth, reproduction and dispersal capabilities. Moreover, climate change can alter amphibian habitats including vegetation, soil, and hydrology. Climate change can influence food availability, predator-prey relationships and competitive interactions which …

Webs In Vitro And In Vivo: Spiders Alter Their Orb-Web Spinning Behavior In The Laboratory, Andrew Sensenig, Ingi Agnarsson, Taylor M. Gondek, Todd A. Blackledge

Biology Faculty Research

Many studies of the elegant architectures of orb webs are conducted in controlled laboratory environments that remove environmental variability. The degree to which spider behavior in these circumstances resembles that of spiders in the wild is largely unknown. We compared web architecture and silk investment of furrowed orb weavers Larinioides corium's (Clerck 1757) building webs in laboratory cages and spinning webs on fences in the field and found significant differences. The volume of major ampullate silk in radii was 53% lower in cage webs, primarily because the silk was 50% thinner, but also because spiders tended to spin 14% fewer …