Biology Commons^™

A Simple Assay To Screen Antimicrobial Compounds Potentiating The Activity Of Current Antibiotics, Junaid Iqbal, Ruqaiyyah Siddiqui, Shahana Urooj Kazmi, Naveed Ahmed Khan

Department of Biological & Biomedical Sciences

Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by …

Association Of Body Iron Status With The Risk Of Premature Acute Myocardial Infarction In A Pakistani Population, Mohammadl Perwaiz Iqbal, Naseema Mehbooi Ali, Asal Khan Tareen, Mohsin Yakub, Saleeml Perwaizl Iqbal, Khalida Iqbal, Ghulam Haider

Department of Biological & Biomedical Sciences

Background

Coronary artery disease is very common in Pakistani population. Some of the studies carried out on Western populations have shown a relationship between body iron status as determined by the ratio of concentrations of serum soluble transferrin receptor (sTfR) to ferritin and the risk of acute myocardial infarction (AMI). In order to investigate whether increased body iron status has any relationship with the risk of premature AMI in Pakistani population, a case-control study was carried out.

Methodology/Principal findings

In this case-control study, 203 consecutive AMI patients [146 males and 57 females; age range 18–45 years] admitted to the National …

Sexual Dimorphisms In Habitat-Specific Morphology And Behavior In The Green Anole Lizard, A K. Dill, T J. Sanger, Andrew C. Battles, Michele A. Johnson

Biology Faculty Research

Species that occur in variable environments often exhibit morphological and behavioral traits that are specific to local habitats. Because the ability to move effectively is closely associated with structural habitat, locomotor traits may be particularly sensitive to fine-scale habitat differences. Anolis lizards provide an excellent opportunity to study the relationship between locomotion and natural perch use in the field, as laboratory studies have demonstrated that lizards that use broader perches develop longer limbs and have higher sprint speeds. We examined Anolis carolinensis (the green anole) in three habitats in close proximity. Our goals were to determine whether habitat-specific differences in …

Use Of Image Cytometry For Quantification Of Pathogenic Fungi In Association With Host Cells, Charlotte A. Berkes, Leo Li-Ying Chan, Alisha Wilkinson, Benjamin Paradis

Biology Faculty Publications

Studies of the cellular pathogenesis mechanisms of pathogenic yeasts such as Candida albicans, Histoplasma capsulatum, and Cryptococcus neoformans commonly employ infection of mammalian hosts or host cells (i.e. macrophages) followed by yeast quantification using colony forming unit analysis or flow cytometry. While colony forming unit enumeration has been the most commonly used method in the field, this technique has disadvantages and limitations, including slow growth of some fungal species on solid media and low and/or variable plating efficiencies, which is of particular concern when comparing growth of wild-type and mutant strains. Flow cytometry can provide rapid quantitative information regarding yeast …

Surprisingly Little Population Genetic Structure In A Fungus-Associated Beetle Despite Its Exploitation Of Multiple Hosts, Corlett W. Wood , '08, H. M. Donald, Vincent A. Formica, E. D. Brodie Iii

Biology Faculty Works

In heterogeneous environments, landscape features directly affect the structure of genetic variation among populations by functioning as barriers to gene flow. Resource-associated population genetic structure, in which populations that use different resources (e.g., host plants) are genetically distinct, is a well-studied example of how environmental heterogeneity structures populations. However, the pattern that emerges in a given landscape should depend on its particular combination of resources. If resources constitute barriers to gene flow, population differentiation should be lowest in homogeneous landscapes, and highest where resources exist in equal proportions. In this study, we tested whether host community diversity affects population genetic …

Ontogeny Of Venom Use And Venom Composition In The Western Widow Spider Latrodectus Hesperus, David Roger Nelsen

Loma Linda University Electronic Theses, Dissertations & Projects

I investigated the behavioral ecology of venom and venom use by the western widow spider (Latrodectus hesperus), emphasizing the role of ontogeny. In an introductory paper, I reviewed existing definitions of venom and poison, and refined these by adding a third category of toxic biological secretions: toxungen. These three can be distinguished by mode of toxin delivery and presence of a wound. In the first of four empirical studies, I investigated venom use by adult females in the context of threat assessment. A single brief poke at the lowest threat level elicited primarily avoidance responses ("move" and "retract"), repeated prodding …

The Evolutionary Histories Of Clinical And Environmental Shv Β-Lactamases Are Intertwined, Robert L. Dorit, Christopher M. Roy, Sandra M. Robinson, Margaret A. Riley

Biological Sciences: Faculty Publications

The rise of antibiotic-resistant pathogens focuses our attention on the source of antibiotic resistance genes, on the existence of these genes in environments exposed to little or no antibiotics, and on the relationship between resistance genes found in the clinic and those encountered in non-clinical settings. Here, we address the evolutionary history of a class of resistance genes, the SHV β-lactamases. We focus on bla SHV genes isolated both from clinical and non-clinical sources and show that clinically important resistance determinants arise repeatedly from within a diverse pool of bla SHV genes present in the environment. While our results argue …

Linezolid Exerts Greater Bacterial Clearance But No Modification Of Host Lung Gene Expression Profiling: A Mouse Mrsa Pneumonia Model, Jiwang Chen, Gang Feng, Yang Song, Juliane B. Wardenburg, Simon Lin, Ichiro Inoshima, Michael Otto, Richard G. Wunderink

Faculty Publications – Biological Sciences

Background: Linezolid (LZD) is beneficial to patients with MRSA pneumonia, but whether and how LZD influences global host lung immune responses at the mRNA level during MRSA-mediated pneumonia is still unknown. Methods: A lethal mouse model of MRSA pneumonia mediated by USA300 was employed to study the influence of LZD on survival, while the sublethal mouse model was used to examine the effect of LZD on bacterial clearance and lung gene expression during MRSA pneumonia. LZD (100mg/kg/day, IP) was given to C57Bl6 mice for three days. On Day 1 and Day 3 post infection, bronchoalveolar lavage fluid (BALF) protein concentration …

Isolation Of Primary Cilia By Shear Force, Kimberly A. P. Mitchell

Faculty Publications and Presentations

The cell’s primary cilium is both a mechanical and chemical sensor involved in many signaling pathways. In order to ascertain protein enrichment in the primary cilium or study sub-ciliary localization of various proteins, it is advantageous to remove the primary cilium from the cell body. The protocol described here gives detailed instructions on purifying primary cilia by separating them from the cell body using shear force. This simple technique avoids using harsh purification conditions that may affect signaling proteins in the cilium or cause the ciliary membrane to disintegrate. In addition, as the cell body remains mostly intact, contamination of …

Plant Cytoskeleton: Della Connects Gibberellins To Microtubules, Ram Dixit

Biology Faculty Research

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.

Targeting Heterochromatin Formation To Transposable Elements In Drosophila: Potential Roles Of The Pirna System, Monica F. Sentmanat, Sh Wang, Sarah C.R. Elgin

Biology Faculty Research

Successful heterochromatin formation is critical for genome stability in eukaryotes, both to maintain structures needed for mitosis and meiosis and to silence potentially harmful transposable elements. Conversely, inappropriate heterochromatin assembly can lead to inappropriate silencing and other deleterious effects. Hence targeting heterochromatin assembly to appropriate regions of the genome is of utmost importance. Here we focus on heterochromatin assembly in Drosophila melanogaster, the model organism in which variegation, or cell-to-cell variable gene expression resulting from heterochromatin formation, was first described. In particular, we review the potential role of transposable elements as genetic determinants of the chromatin state and examine how …

Use Of A Specific Alpha7 Nicotinic Acetylcholine Receptor Agonist Can Prevent Loss Of Retinal Ganglion Cells In An In Vivo Rat Glaucoma Model, David Mata

Masters Theses

Acetylcholine (ACh) has been shown to have a neuroprotective effect against glutamate-induced excitotoxicity in cultured retinal ganglion cells (RGCs) through activation of α7 nicotinic ACh receptors (nAChRs). In this study, the neuroprotective effects of the α7 nAChR agonist, PNU-282987, were investigated using an in vivo model of glaucoma in adult Long Evans rats. Hypertonic saline injections were used to induce a glaucoma model. After one month, retinas were removed, flat mounted, fixed and labeled with an antibody against Thy 1.1 to label RGCs and fluorescently tagged for visualization. Eye drop application of PNU-282987 resulted in neuroprotection against RGC loss in …

Pheromone Exposure Influences Preoptic Arginine Vasotocin Gene Expression And Inhibits Social Approach Behavior In Response To Rivals But Not Potential Mates, Lisa A. Mangiamele, Alex D.T. Keeney, Erin N. D'Agostino, Richmond R. Thompson

Biological Sciences: Faculty Publications

The nonapeptides arginine vasotocin (AVT) and vasopressin mediate a variety of social behaviors in vertebrates. However, the effects of these peptides on behavior can vary considerably both between and within species. AVT, in particular, stimulates aggressive and courtship responses typical of dominant males in several species, although it can also inhibit social interactions in some cases. Such differential effects may depend upon AVT influences within brain circuits that differ among species or between males that adopt alternative reproductive phenotypes and/or upon the differential activation of those circuits in different social contexts. However, to date, very little is known about how …

Rna Interference-Mediated Depletion Of N-Ethylmaleimide Sensitive Fusion Protein And Synaptosomal Associated Protein Of 25 Kda Results In The Inhibition Of Blood Feeding Of The Gulf Coast Tick, Amblyomma Maculatum, Rebecca Browning, Shahid Karim

Faculty Publications

The signalling pathways in tick salivary glands that control ‘sialo‐secretome’ secretion at the tick−host interface remain elusive; however, this complex process is essential for successful feeding and manipulation of the host haemostatic response. Exocytosis of the sialo‐secretome in the salivary glands requires a core of soluble N‐ethylmaleimide‐sensitive fusion (NSF) attachment proteins (SNAPs) and receptor proteins (SNAREs). SNAREs have been identified as the key components in regulating the sialo‐secretome in the salivary gland cells. In this study, we utilized RNA interference to investigate the functional role of two Amblyomma maculatum SNARE complex proteins, AmNSF and AmSNAP‐25, in the tick salivary glands …

Testing Subspecies Limits In Monardella Villosa, Taylor Mclaughlin Crow

Master's Theses

Several subspecies of Monardella villosa (California Coyote Mint) have been distinguished on the basis of leaf thickness, shape, and trichome characteristics, yet many intermediates are known. We investigated morphological differences in natural populations of two subspecies (M. v. subsp. villosa and M. v. subsp. franciscana) in the Scott Creek watershed, north of Davenport, in Santa Cruz County, CA. Monardella villosa subsp. franciscana grows in coastal scrub in gulches and ocean terraces whereas subsp. villosa grows at more protected inland sites. Morphological difference between subspecies may be adaptations to these different habitats. I grew plants in a common garden at Cal …

Discovery And Characterization Of A Tanapoxvirus Encoded Human Neuregulin Mimetic, David Jeng

Dissertations

Studies on large dsDNA viruses such as poxviruses have been helpful in identifying a number of viral and cellular growth factors that contribute to our broad understanding of virus-host interaction. Orthopoxviruses and leporipoxviruses are among the most studied viruses in this aspect. However, tanapoxvirus (TPV) a member of the genus Yatapoxvirus, still remains largely unexplored, as the only known hosts for this virus are humans and monkeys. Here, we describe the initial characterization of an EGF-like growth factor mimicking human neuregulin from TPV, expressed by the TPV-15L gene. Assays using a baculovirus expressed and tagged TPV-15L protein demonstrated the ability …

Allelopathy As An Emergent, Exploitable Public Good In The Bloom-Forming Microalga Prymnesium Parvum, William W. Driscoll, Noelle J. Espinosa, Omar T. Eldakar, Jeremiah D. Hackett

Biology Faculty Articles

Many microbes cooperatively secrete extracellular products that favorably modify their environment. Consistent with social evolution theory, structured habitats play a role in maintaining these traits in microbial model systems, by localizing the benefits and separating strains that invest in these products from ‘cheater’ strains that benefit without paying the cost. It is thus surprising that many unicellular, well-mixed microalgal populations invest in extracellular toxins that confer ecological benefits upon the entire population, for example, by eliminating nutrient competitors (allelopathy). Here we test the hypotheses that microalgal exotoxins are (1) exploitable public goods that benefit all cells, regardless of investment, or …

Global Dynamics Of A Water-Borne Disease Model With Multiple Transmission Pathways, Prasanta K. Mondal, T. K. Kar

Applications and Applied Mathematics: An International Journal (AAM)

We propose and analyze a water born disease model introducing water-to-person and person-toperson transmission and saturated incidence. The disease-free equilibrium and the existence criterion of endemic equilibrium are investigated. Trans critical bifurcation at the disease-free equilibrium is obtained when the basic reproductive number is one. The local stability of both the equilibria is shown and a Lyapunov functional approach is also applied to explore the global stability of the system around the equilibria. We display the effects of pathogen contaminated water and infection through contact on the system dynamics in the absence of person-to-person contact as well as in the …

The Correlation Between Veldt Grass (Ehrharta Calycina) And Reproductive Condition Of The Lompoc Kangaroo Rat (Dipodomys Heermanni Arenae), Jacqueline Mae Bates

Biological Sciences

The invasive species, Veldt grass (Ehrharta calycina), has come to dominate coastal dune shrub vegetation along the Central Coast of California. Along with creating many land management obstacles, this grass has become dominant in the open habitat of Lompoc Kangaroo Rats (Dipodomys heermanni arenae). It is hypothesized that, due to a lack of suitable kangaroo rat habitat, during the breeding season months of March and April, there will be significantly fewer reproductively active females in areas of relatively high Veldt grass cover as opposed to relatively low Veldt grass cover. This study used data from a …

Making A Difference In Majuro, Ashleigh Jardine

Lake Union Herald

No abstract provided.

Associations Between Alcohol Consumption And Fasting Blood Glucose In Young Adults, Julie Ann Lucca

Master's Theses

Current research shows moderate alcohol consumption is associated with decreased risk of diabetes and excessive consumption or binge drinking can cause insulin resistance and diabetes. In 2010, diabetes was the seventh leading cause of death in the United Statesand was responsible for significant health complications: blindness, kidney failure, and limb amputations, and is a large national economic burden. Fasting blood glucose (FBG) is a tool used to help diagnose diabetes. Abnormally high FBG, ≥100 mg/dl, is indicative of diabetes and pre-diabetes. Few studies have observed diabetic prevalence among young adults or college students. Studying young adults can help provide added …

Root Kinematics In Relation To Temperature And Genome Size In Wild And Domesticated Zea., Avery B. Cromwell

Master's Theses

We studied root kinematics in relation to temperature and genome size variation in teosinte (Zea mays subspecies parviglumis) and corn (Zea mays subspecies mays). Corn had significantly faster radicle growth than teosinte when grown at a constant temperature. Both species exhibited variation in seed size and for each species larger seeds had faster root growth. Genome size was not significantly correlated with faster radicle growth rates across multiple land races of corn. To examine temperature dependent growth in corn and teosinte, a germinated seedling was grown at multiple temperatures. Growth rates at these temperatures were used …

Mouse Embryonic Stem Cells Are Deficient In Type I Interferon Expression In Response To Viral Infections And Double-Stranded Rna, Ruoxing Wang, Jundi Wang, Amber M. Paul, Dhiraj Acharya, Fengwei Bai, Faqing Huang, Yan-Lin Guo

Faculty Publications

Embryonic stem cells (ESCs) are considered to be a promising cell source for regenerative medicine because of their unlimited capacity for self-renewal and differentiation. However, little is known about the innate immunity in ESCs and ESC-derived cells. We investigated the responses of mESCs to three types of live viruses; La Crosse virus (LACV), West Nile virus (WNV), and Sendai virus (SeV). Our results demonstrated mESCs were susceptible to viral infection, but they were unable to express type I interferons (IFNα and IFNβ,IFNα/β which differ from fibroblasts (10T1/2 cells) that robustly express IFNα/β upon viral infections. The failure of mESCs to …

Deer Impact And Plant Resistance Traits, Xueyang Fan

Theses

White-tail deer (Odocoileus virginianus), a generalist herbivore, are widely considered to influence ecological communities, ecosystems and human wellbeing by foraging preferentially on certain plant species. Previous research has shown that high deer density can change the relative abundance of tree species in forest communities. Furthermore, some evidence shows that resistance traits of plants can influence plant photosynthetic ability which is an important factor in an ecosystem. The purpose of this experiment is to test whether plant resistance traits can change within species when they are exposed to high levels of deer herbivores. The experiment, established in 1979, enclosed …

Propagation Of Homalodisca Coagulata Virus-01 Via Homalodisca Vitripennis Cell Culture, Anna Biesbrock

Biology Theses

The glassy-winged sharpshooter (Homalodisca vitripennis) is a highly vagile and polyphagous insect, which feeds on more than 100 plant species throughout the southwestern United States. Sharpshooters are the predominant vector of Xylella fastidiosa (Xf), a xylem-limited bacterium that is the causal agent of Pierce's disease (PD) of grapevine. Infected H. vitripennis transmit the bacterium while feeding. The rise of PD has been economically damaging for agriculture and H. vitripennis have become a target for disease control. A dicistrovirus identified as Homalodisca coagulata virus-01 (HoCV-01) has been associated with an increase in mortality rates within infected H. vitripennis populations. A host …

Bactericera Cockerelli: Range Expansion, Candidatus Liberibacter Solanacaerum Detection, And Microbial Community Analysis, Alex Arp

Biology Theses

The potato psyllid (Bactericera cockerelli) is an emerging pest of solanacious crops. Traditionally their range expanded from Guatemala north through the central United States and into southern California. Recent expansions have led to potato psyllids residing as far south as Nicaragua and as for north as Washington State. Potato psyllids were also accidentally imported into New Zealand. These expansions are alarming because potato psyllids transmit Candidatus Liberibacter solanacaerum (Lso), the bacteria associated with Zebra Chip disease in potato, which results in millions of dollars in damages annually. In this study, potato psyllid and Zebra Chip range expansion into Central America …

Stromal Tumor Microenvironment In Chronic Lymphocytic Leukemia: Regulation Of Leukemic Progression, Ashima Shukla, Nagendra K. Chaturvedi, Adam K. Ahrens, Christine E. Cutucache, Amit K. Mittal, Philip Bierman, Dennis D. Weisenburger, Runqing Lu, Shantaram S. Joshi

Biology Faculty Publications

Chronic Lymphocytic Leukemia (CLL), the most prevalent adult leukemia in western countries, which is highly heterogeneous with a very variable clinical outcome. Emerging evidence indicates that the stromal tumor microenvironment (STME) and stromal associated genes (SAG) play important roles in the pathogenesis and progression of CLL. However, the precise mechanisms by which STME and SAG are involved in this process remain unknown. In an attempt to explore the role of STME in this process, we examined the expression levels of stromal associated genes using gene expression profiling (GEP) of CLL cells from lymph nodes (LN) (n=15), bone marrow (BM) (n=18), …

The Effects Of Habitat Use On The Round Goby, Neogobius Melanostomus, In The Lower Fox River And Lake Michigan., Matthew E. Larsen

Lawrence University Honors Projects

The invasive round goby was introduced to Lake Michigan in 1998 (DeStasio, 2012). Since the species was introduced they have increased their range to include tributaries of the Lake Michigan watershed; such as the Lower Fox River. The presence of the round goby in the Lower Fox River was first documented in the Lower Fox River in 2006 (Kornis, 2008). We compared the size and age differences between round goby populations at these habitats to see if there was a variance between the two habitats. Round goby from Lake Michigan were statistically longer and heavier than those from the Lower …

Investigating Potential Target Genes Of The Rfx Transcription Factor Daf-19 In Caenorhabditis Elegans, He Zhang

Lawrence University Honors Projects

Neurodegenerative diseases, such as Alzheimer’s disease, are characterized by an age-related decrease in the synaptic activity of the patient’s brain. Previous research suggested that a RFX transcription factor DAF-19 in the nematode Caenorhabditis elegans (C. elegans) may be involved in the maintenance of synaptic protein levels. Particularly, worms that were DAF-19A/B defective showed reduced synaptic activities when compared to their age-matched controls.

This study investigated the role of DAF-19A/B isoforms in the C. elegans nervous system. Three genes, F46G11.3, F57B10.9, and F58E2.3 were selected as potential downstream targets of DAF-19A/B based on their potential neuronal expression. …

Behavioral And Neurogenomic Transcriptome Changes In Wild-Derived Zebrafish With Fluoxetine Treatment, Ryan Y. Wong, Sarah E. Oxendine, John Godwin

Biology Faculty Publications

Background: Male and female vertebrates typically differ in a range of characteristics, from morphology to physiology to behavior, which are influenced by factors such as the social environment and the internal hormonal and genetic milieu. However, sex differences in gene expression profiles in the brains of vertebrates are only beginning to be understood. Fishes provide a unique complement to studies of sex differences in mammals and birds given that fish show extreme plasticity and lability of sexually dimorphic characters and behaviors during development and even adulthood. Hence, teleost models can give additional insight into sexual differentiation. The goal of …