Life Sciences Commons^™

Mechanisms For Regulation Of Plant Kinesins, Anindya Ganguly, Ram Dixit

Biology Faculty Publications & Presentations

Throughout the eukaryotic world, kinesins serve as molecular motors for the directional transport of cellular cargo along microtubule tracks. Plants contain a large number of kinesins that have conserved as well as specialized functions. These functions depend on mechanisms that regulate when, where and what kinesins transport. In this review, we highlight recent studies that have revealed conserved modes of regulation between plant kinesins and their non-photosynthetic counterparts. These findings lay the groundwork for understanding how plant kinesins are differentially engaged in various cellular processes that underlie plant growth and development.

A Seasonal, Density-Dependent Model For The Management Of An Invasive Weed, Esther Shyu, Eleanor A. Pardini, Tiffany M. Knight, Hal Caswell

Biology Faculty Publications & Presentations

The population effects of harvest depend on complex interactions between density dependence, seasonality, stage structure, and management timing. Here we present a periodic nonlinear matrix population model that incorporates seasonal density dependence with stage-selective and seasonally selective harvest. To this model, we apply newly developed perturbation analyses to determine how population densities respond to changes in harvest and demographic parameters. We use the model to examine the effects of popular control strategies and demographic perturbations on the invasive weed garlic mustard (Alliaria petiolata). We find that seasonality is a major factor in harvest outcomes, because population dynamics may …

Conservation In The Context Of Climate Change: Practical Guidelines For Land Protection At Local Scales, Kevin Ruddock, Peter V. August, Christopher Damon, Charles Labash, Pamela Rubinoff, Donald Robadue Jr.

Natural Resources Science Faculty Publications

Climate change will affect the composition of plant and animal communities in many habitats and geographic settings. This presents a dilemma for conservation programs – will the portfolio of protected lands we now have achieve a goal of conserving biodiversity in the future when the ecological communities occurring within them change? Climate change will significantly alter many plant communities, but the geophysical underpinnings of these landscapes, such as landform, elevation, soil, and geological properties, will largely remain the same. Studies show that extant landscapes with a diversity of geophysical characteristics support diverse plant and animal communities. Therefore, geophysically diverse landscapes …

Real-Time Qpcr Assay Development For Detection Of Bacillus Thuringiensis And Serratia Marcescens Dna And The Influence Of Complex Microbial Community Dna On Assay Sensitivity, Jonathan Segal

FIU Electronic Theses and Dissertations

Real-time quantitative polymerase chain reaction (real-time qPCR) assays are an effective technique to detect biological warfare agents and surrogate organisms. In my study, primers were designed to detect chromosomal DNA of biological warfare agent surrogates B. thuringiensis and S. marcescens (representing B. anthracis and Y. pestis, respectively) via real-time qPCR. Species-level specificity of the primers was demonstrated through comparisons with a bacterial strain panel and corroborated by qPCR data. Additionally, the primer efficacy was tested when template DNA was spiked into metagenomic DNA extracted from clinical lung microbiome samples. The results showed that while detection of B. thuringiensis or …

Acquisition Of An Electrochemical System Instrument For The Development Of Sensors, Elmer-Rico E. Mojico

Cornerstone 1 Reports : Expansion and Enhancements of the Thinkfinity Platform

No abstract provided.

Lifelines Fall 2013, Southern Adventist University

Lifelines - Biology Department Newsletter

The Fall 2013 issue of Lifelines features articles on toxins found in nature, student missions in Tanzania, an alumni spotlight, undergraduate research, and updates on department happenings.

Mscs-Like Mechanosensitive Channels In Plants And Microbes, Margaret E. Wilson, Grigory Maksaev, Elizabeth S. Haswell

Biology Faculty Publications & Presentations

The challenge of osmotic stress is something all living organisms must face as a result of environmental dynamics. Over the past three decades, innovative research and cooperation across disciplines have irrefutably established that cells utilize mechanically gated ion channels to release osmolytes and prevent cell lysis during hypoosmotic stress. Early electrophysiological analysis of the inner membrane of Escherichia coli identified the presence of three distinct mechanosensitive activities. The subsequent discoveries of the genes responsible for two of these activities, the mechanosensitive channels of large (MscL) and small (MscS) conductance, led to the identification of two diverse families of mechanosensitive channels. …

A Force Of Nature: Molecular Mechanisms Of Mechanoperception In Plants, Gabriele B. Monshausen, Elizabeth S. Haswell

Biology Faculty Publications & Presentations

The ability to sense and respond to a wide variety of mechanical stimuli-gravity, touch, osmotic pressure, or the resistance of the cell wall-is a critical feature of every plant cell, whether or not it is specialized for mechanotransduction. Mechanoperceptive events are an essential part of plant life, required for normal growth and development at the cell, tissue, and whole-plant level and for the proper response to an array of biotic and abiotic stresses. One current challenge for plant mechanobiologists is to link these physiological responses to specific mechanoreceptors and signal transduction pathways. Here, we describe recent progress in the identification …

The Rate And Effects Of Spontaneous Mutation On Fitness Traits In The Social Amoeba, Dictyostelium Discoideum, David W. Hall, Sara Fox, Jennie J. Kuzdzal-Fick, Joan E. Strassmann, David C. Queller

Biology Faculty Publications & Presentations

We performed a mutation accumulation (MA) experiment in the social amoeba Dictyostelium discoideum to estimate the rate and distribution of effects of spontaneous mutations affecting eight putative fitness traits. We found that the per-generation mutation rate for most fitness components is 0.0019 mutations per haploid genome per generation or larger. This rate is an order of magnitude higher than estimates for fitness components in the unicellular eukaryote Saccharomyces cerevisiae, even though the base-pair substitution rate is two orders of magnitude lower. The high rate of fitness-altering mutations observed in this species may be partially explained by a large mutational target …

Lysophosphatidic Acid Stimulates Lymphangiogenesis In Human Lymphatic Endothelial Cells, John Macbeth, Donna Nofziger-Plank

Featured Research

Lymphangiogenesis is the process by which new lymphatic vessels sprout and grow from existing vessels whether under developmental, immunological, or cancerous conditions. Proper lymphatic vessel formation is important in working alongside normal angiogenesis in order to help regulate the body’s tissue fluid as well as aid in immunosurveillance. Various factors regulate lymphangiogenesis such as members of the vascular endothelial growth factor family (VEGF). Another factor that has recently been identified to play a role in lymphangiogenesis is the bio-active phospholipid lysophosphatidic acid (LPA) however the molecular mechanism by which LPA regulates lymphangiogenesis has not been well characterized. In this study, …

The Survivin And Ciap1 Anti-Apoptotic Proteins Are Differentially Downregulated In Response To Endoplasmic Reticulum Stress, Vicki Mercado, Jay L. Brewster

Featured Research

The endoplasmic reticulum (ER) is an organelle tasked with synthesis and transport of 50% of new cellular proteins. Dysfunction within this organelle creates signals for repair, adaptation, and in severe cases, cellular apoptosis. Multiple human diseases have been associated with ER dysfunction, and the activation of apoptosis in important populations of cells. Inhibitor of Apoptosis (IAP) proteins are cytosolic proteins that play an anti-apoptotic role in the cytosol. The relationship between endoplasmic reticulum (ER) stress and the expression/stability of IAPs is not well characterized. The objective of this study was to characterize the affect of ER stress on the expression/stability …

Evaluating Itpr-Dependence Of Apoptotic Signaling From The Endoplasmic Reticulum, Agustin Vargas, Jay L. Brewster

Featured Research

Stress within the endoplasmic reticulum (ER) can be induced by misfolded proteins accumulating in the lumen of this organelle. Signaling of ER stress to other parts of the cell results in altered gene expression, physiological adaptation, and with sustained stress, apoptosis (cell suicide). ER stress is often studied with highly toxic compounds that create severe ER stress rapidly, and a condition that is likely not physiologically relevant within an organism. In this study, we examine the apoptotic signaling induced by moderate ER stress, and in particular the inositol 1,4,5-trisphosphate receptor (ITPR). The ITPR regulates Ca2+ release from the ER lumen, …

Carbon Black And Titanium Dioxide Nanoparticles Differentially Activate Oxidative Stress And Apoptosis In A549 Human Alveolar Epithelial Cells, Sarah Alvarado, Brianna Manes, Jay L. Brewster

Featured Research

Recent studies have demonstrated that variation between particulate matter compositions have universally adverse effects on cells and living tissues. Carbon black and titanium dioxide are two such particulates that we are continuously exposed to, yet there is limited research to examine the potential deleterious effects on living tissue. The objective of this study is to characterize the effect of carbon black (CB) and titanium dioxide (TiO2) particulates on A549 human alveolar epithelial lung cells. CB and TiO2 powders were dispersed throughout a solution of water and bovine serum albumin by high-powered sonication. The effects of these particulates on A549 cells …

Immunomodulatory Activity Of Sambucus Mexicana And Trichostema Lanatum On Lps Stimulated Raw 264.7 Macrophage Cells, Victoria Hester, P. Matthew Joyner

Featured Research

Chumash medicinal plants Sambucus mexicana (Mexican elderberry) and Trichostema lanatum (woolly blue curls) were tested for immunomodulatory activity. Anti-inflammatory effects were determined by treating LPS induced RAW 264.7 macrophage cells with plant extracts and measuring the levels of cytokines: tumor necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10). We hypothesized that both plants would exert immunomodulatory activity by reducing the pro-inflammatory production of TNF-alpha or by promoting M2 polarization with a concurrent increase in IL-10 production. At concentration 0.01 mg/mL woolly blue curls and Mexican elderberry demonstrated anti-inflammatory activity by reducing the concentration of TNF-alpha in vitro, while levels of …

The Regulatory Effect Of Semaphorin 7a On Proliferation And Migration In Human Umbilical Vein Endothelial Cells, Steven R. Flemming, Donna Nofziger-Plank

Featured Research

Semaphorin 7A (SEMA 7A), a factor originally identified as regulating axon growth, has recently been implicated as a pro-angiogenic factor. The molecular mechanisms for this ability to stimulate angiogenesis have not been identified. This study examines if SEMA 7A can have a direct effect on vascular endothelial cells or whether it indirectly induces angiogenesis through stimulation and recruitment of macrophages as has been suggested. Using a human umbilical vein endothelial cells (HUVECs), the ability of SEMA 7A to affect proliferation and migration was examined. HUVECs were exposed to SEMA 7A directly or to conditioned media collected from macrophages exposed to …

Effect Of Shear Stress On Ecnos Expression And Dilation In Soleus Feed Arteries, Blanca Perez, Jay L. Brewster, Jeffrey Jasperse

Featured Research

Shear stress causes artery dilation and increased expression of endothelial cell nitric oxide synthase (ecNOS) in coronary and placental arteries. We sought to determine the importance of shear stress in maintaining normal dilation and normal levels of ecNOS in rat soleus feed arteries (SFA). SFA were isolated from male Sprague-Dawley rats and cannulated for in vitro microscopy (Fig. 6). SFA were exposed to no shear stress, low shear stress, or high shear stress conditions for 4 hours. After 4 hours, endothelium-dependent dilation (acetylcholine: ACh) and endothelium-independent dilation (sodium nitroprusside: SNP) were tested. Arteries were then uncannulated, mRNA was isolated, and …

An Ethnobotanical Approach To Finding Antimicrobial Compounds In Wooly Blue Curls (Trichostema Lanatum) Using A Kirby-Bauer Disc Diffusion Assay, Matthew C. Fleming, P. Matthew Joyner

Featured Research

Plants can be an important source of creativity and production of new drugs. In this study, extracts of wooly blue curls (Trichostema lanatum) were made using DMSO and tested for antimicrobial activity on a panel of bacteria commonly found in separate ecological niches. Wooly blue curls (WBC) was chosen due to its being recorded as a strong disinfectant by the Chumash people. It was found that WBC does exhibit antimicrobial activity against gram positive bacteria and not against gram negative bacteria. However, gram negative bacteria with reduced drug efflux function became susceptible to the WBC extract.

Role Of Nucleation In Cortical Microtubule Array Organization: Variations On A Theme, Erica A. Fishel, Ram Dixit

Biology Faculty Publications & Presentations

The interphase cortical microtubules (CMTs) of plant cells form strikingly ordered arrays in the absence of a dedicated microtubule-organizing center. Considerable research effort has focused on activities such as bundling and severing that occur after CMT nucleation and are thought to be important for generating and maintaining ordered arrays. In this review, we focus on how nucleation affects CMT array organization. The bulk of CMTs are initiated from γ-tubulin-containing nucleation complexes localized to the lateral walls of pre-existing CMTs. These CMTs grow either at an acute angle or parallel to the pre-existing CMT. Although the impact of microtubule-dependent nucleation is …

The Effect Of Shear Stress, Potassium, And Adenosine On Α-1 Adrenergic Vasoconstriction Of Rat Soleus Feed Arteries, Tanner J. Heckle, Jeffrey Jasperse

Featured Research

During exercise, blood flow increases to the working skeletal muscle primarily because of dilation of the arteries and arterioles feeding the muscle. Sympathetic nerve activity also increases during exercise, augmenting the release of the neurotransmitter norepinephrine (NE) at the arterial wall and into the blood. NE acts to constrict blood vessels; however, arteries and arterioles within contracting skeletal muscle dilate despite the increased NE present. This has led to the concept of functional sympatholysis (4), the idea that a chemical released from contracting skeletal muscle interferes with NE signaling. NE acts by binding to adrenergic (alpha and beta) receptors, and …

Plant Cytoskeleton: Della Connects Gibberellins To Microtubules, Ram Dixit

Biology Faculty Publications & Presentations

A new study reveals that DELLA proteins directly interact with the prefoldin complex, thus regulating tubulin subunit availability in a gibberellin-dependent manner. This finding provides a mechanistic link between the growth-promoting plant hormone gibberellin and cortical microtubule organization.

Recent Characterizations Of Mscs And Its Homologs Provide Insight Into The Basis Of Ion Selectivity In Mechanosensitive Channels, Grigory Maksaev, Elizabeth S. Haswell

Biology Faculty Publications & Presentations

The bacterial mechanosensitive channel MscS provides an excellent model system for the study of mechanosensitivity and for investigations into the cellular response to hypoosmotic shock. Numerous studies have elucidated the structure, function and gating mechanism of Escherichia coli MscS, providing a wealth of information for the comparative analysis of MscS family members in bacteria, archaea, fungi and plants. We recently reported the electrophysiological characterization of MscS-Like (MSL)10, a MscS homolog from the model flowering plant Arabidopsis thaliana. Here we summarize our results and briefly compare MSL10 to previously described members of the MscS family. Finally, we comment on how …

Bromus Tectorum Litter Alters Photosynthetic Characteristics Of Biological Soil Crusts From A Semiarid Shrubland, Marcelo D. Serpe, Eric Roberts, David J. Eldridge, Roger Rosentreter

Biology Faculty Publications and Presentations

Invasion by the exotic annual grass Bromus tectorum has increased the cover and connectivity of fine litter in the sagebrush steppes of western North America. This litter tends to cover biological soil crusts, which could affect their metabolism and growth. To investigate this possible phenomenon, biological soil crusts dominated by either the moss Bryum argenteum or the lichen Diploschistes muscorum were covered with B.tectorum litter (litter treatment) or left uncovered (control treatment) and exposed to natural field conditions. After periods of five and ten months, we removed the litter and compared the photosynthetic performance of biological soil crusts …

Diagnosis And Prevention Of Metabolic Diseases In Drosophila Melanogaster, Claire Marie Coogan

Collection of Engaged Learning

No abstract provided.

Using The Pace Eportfolio To Assess Core Values, Beth Klingner, Linda Anstendig, Sarah Burns-Feyl

Cornerstone 3 Reports : Interdisciplinary Informatics

No abstract provided.

Locating The Modifier Of Segregation Distorter In Drosophila Melanogaster, Samuel Craven

Honors Program Projects

The Drosophila melanogaster meiotic drive system Segregation Distorter (SD) has been a topic of great interest over the past decades due to its implications for fertility issues in fruit flies and other species as well. Several genes have been associated with this system; however, little research has focused on a particular one of these genes—the Modifier of SD. The location of this modifier gene is still unknown, so multiple deleted segments of DNA that compose a suspect area along the 2nd chromosome were tested here to see if some level of distortion is established in the absence of these segments. …

Plant-Pollinator Interactions Over 120 Years: Loss Of Species, Co-Occurrence, And Function, Laura A. Burkle, John C. Marlin, Tiffany M. Knight

Biology Faculty Publications & Presentations

Using historic data sets, we quantified the degree to which global change over 120 years disrupted plant-pollinator interactions in a temperate forest understory community in Illinois, USA. We found degradation of interaction network structure and function and extirpation of 50% of bee species. Network changes can be attributed to shifts in forb and bee phenologies resulting in temporal mismatches, nonrandom species extinctions, and loss of spatial co-occurrences between extant species in modified landscapes. Quantity and quality of pollination services have declined through time. The historic network showed flexibility in response to disturbance; however, our data suggest that networks will be …

S-Adenosyl-L-Methionine Protects The Probiotic Yest, Saccharomyces Boulardii, From Acid-Induced Cell Death, Nicanor Austriaco, Vincent Cascio, Daniel Gittings, Kristen Merloni, David Laprade

Biology Faculty Publications

Background

Saccharomyces boulardii is a probiotic yeast routinely used to prevent and to treat gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. However, only 1-3% of the yeast administered orally is recovered alive in the feces suggesting that this yeast is unable to survive the acidic environment of the gastrointestinal tract.

Results

We provide evidence that suggests that S. boulardii undergoes programmed cell death (PCD) in acidic environments, which is accompanied by the generation of reactive oxygen species and the appearance of caspase-like activity. To better understand the mechanism of cell death at the molecular level, we …

Dictyostelium Development Shows A Novel Pattern Of Evolutionary Conservation, Xiangjun Tian, Joan E. Strassmann, David C. Queller

Biology Faculty Publications & Presentations

von Baer's law states that early stages of animal development are the most conserved. More recent evidence supports a modified "hourglass" pattern in which an early but somewhat later stage is most conserved. Both patterns have been explained by the relative complexity of either temporal or spatial interactions; the greatest conservation and lowest evolvability occur at the time of the most complex interactions, because these cause larger effects that are harder for selection to alter. This general kind of explanation might apply universally across independent multicellular systems, as supported by the recent finding of the hourglass pattern in plants. We …

You’Ll Find No Answers Here, Joseph M. Morelli

Masters Theses 1911 - February 2014

One Studio Art graduate student's slog through the disciplines of art and science; noting the similarities, overlaps, and differences, and becoming utterly flummoxed in the process. It's about coming to terms with not knowing a whole lot about anything, really, but pressing on regardless.

Comparison Of Th1 Cytokines And T Cell Markers Gene Expressions Between Virulent And An Attenuated Eiav Vaccine Strain, Talia R. Henkle

Lewis Honors College Capstone Collection

The equine infectious anemia virus (EIAV) is closely related to HIV and has been used as a model to identify protective mechanisms against lentivirus infection. In horses, EIA infection progresses for about a year before infected horses manage to control virus replication. This naturally-gained protection is absolutely dependent on active immune responses as evidenced by the fact that immunosuppressive drugs can induce the recurrence of disease. As the resolution of initial viremia correlates with the appearance of virus specific cytotoxic T lymphocytes (CTL), we believe that cellular immune responses play a key role in controlling EIAV in the horse. In …