Organisms Commons^™

Phylogenomics Of Reichenowia Parasitica, An Alphaproteobacterial Endosymbiont Of The Freshwater Leech Placobdella Parasitica, Sebastian Kvist, Apurva Narechania, Alejandro Oceguera-Figueroa, Bella Fuks, Mark E. Siddall

Publications and Research

Although several commensal alphaproteobacteria form close relationships with plant hosts where they aid in (e.g.,) nitrogen fixation and nodulation, only a few inhabit animal hosts. Among these, Reichenowia picta, R. ornata and R. parasitica, are currently the only known mutualistic, alphaproteobacterial endosymbionts to inhabit leeches. These bacteria are harbored in the epithelial cells of the mycetomal structures of their freshwater leech hosts, Placobdella spp., and these structures have no other obvious function than housing bacterial symbionts. However, the function of the bacterial symbionts has remained unclear. Here, we focused both on exploring the genomic makeup of R. parasitica and on …

Cluster K Mycobacteriophages: Insights Into The Evolutionary Origins Of Mycobacteriophage Tm4, Welkin H. Pope, Christina M. Ferreira, Deborah Jacobs-Sera, Robert C. Benjamin

University Faculty Publications and Creative Works

Five newly isolated mycobacteriophages -Angelica, CrimD, Adephagia, Anaya, and Pixie - have similar genomic architectures to mycobacteriophage TM4, a previously characterized phage that is widely used in mycobacterial genetics. The nucleotide sequence similarities warrant grouping these into Cluster K, with subdivision into three subclusters: K1, K2, and K3. Although the overall genome architectures of these phages are similar, TM4 appears to have lost at least two segments of its genome, a central region containing the integration apparatus, and a segment at the right end. This suggests that TM4 is a recent derivative of a temperate parent, resolving a long-standing conundrum …

African Elephants Change Gaits When Walking Downhill, Robert H.I. Dale, Robert Warren, Brock Ward, Eric Noble

Scholarship and Professional Work - LAS

Abstract from the International Elephant and Rhino Conservation and Research Symposium, Rotterdam, NL, October 10-14, 2011.

Action Spectrum For Photoentrainment Of The Circadian Clock In Wild-Type Chlamydomonas Reinhardtii, Jennifer Forbes=Stovall

Masters Theses & Specialist Projects

The circadian clock is an endogenous timer that oscillates with a period of approximately 24 hours and is reset upon environmental time cues such as the daily light/ dark or temperature cycles. Chlamydomonas reinhardtii is an ideal model organism for research on the circadian clock, because it shows several well-characterized behaviors that exhibit a circadian rhythm. Its circadian rhythm of phototaxis (swimming toward light) has been automated. Former action spectrum studies using the circadian phototaxis rhythm as an indicator surprisingly found that pulses of blue light were not effective in resetting the circadian clock of dark-adapted cells. This may have …

Multistate Mark-Recapture Analysis Reveals No Effect Of Blood Sampling On Survival And Recapture Of Eastern Kingbirds (Tyrannus Tyrannus), Lucas J. Redmond, Michael T. Murphy

Biology Faculty Publications and Presentations

The experimentally supported and prevailing opinion is that blood sampling has few to no long-term effects on survival of birds when conducted properly, and blood sampling has become a vital addition to the toolbox of many ornithologists. However, many of the studies that concluded that blood sampling had negligible effects on birds used approaches that did not account for temporary emigration and probability of capture. To date, the only study to have done so found that blood sampling had a strong negative effect on survival. We conducted a mark–recapture analysis of 8 years of banding and bleeding data on Eastern …

Antivirulence Potential Of Tr-700 And Clindamycin On Clinical Isolates Of Staphylococcus Aureus Producing Phenol-Soluble Modulins, Jason Yamaki, Timothy Synold, Annie Wong-Beringer

Pharmacy Faculty Articles and Research

Staphylococcus aureus strains (n = 50) causing complicated skin and skin structure infections produced various levels of phenol-soluble modulin alpha-type (PSMα) peptides; some produced more than twice that produced by the control strain (LAC USA300). TR-700 (oxazolidinone) and clindamycin strongly inhibited PSM production at one-half the MIC but exhibited weak to modest induction at one-fourth and one-eighth the MICs, primarily in low producers. Adequate dosing of these agents is emphasized to minimize the potential for paradoxical induction of virulence.

Metacaspase Gene Function In The Mushroom Fungus Schizophyllum Commune, Matthew P. Hanley

Honors Theses

The overall goal of this project was to investigate the biological role of a putative metacaspase gene present in the mushroom fungus Schizophyllum commune. For this study, we have utilized a strain of S. commune that is unable to integrate DNA via the non-homologous end joining pathway. This forces transforming DNA to integrate homologously, as is required for the purposes of gene knockout. The gene Scp1 encodes a likely member of the metacaspase protein family, which are suspected to have activity similar to caspases, the latter crucial to programmed cell death. A knockout construct containing a non-functional version of Scp1 …

Intermediate Filaments Regulate Tissue Size And Stiffness In The Murine Lens, Douglas S. Fudge, John V. Mccuaig, Shannon Van Stralen, John F. Hess, Huan Wang, Richard T. Mathias, Paul G. Fitzgerald

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

PURPOSE. To define the contributions of the beaded filament (BF), a lens-specific intermediate filament (IF), to lens morphology and biomechanics.

METHODS. Wild-type and congenic CP49 knockout (KO) mice were compared by using electrophysiological, biomechanical, and morphometric approaches, to determine changes that occurred because of the absence of this cytoskeletal structure.

RESULTS. Electrophysiological assessment established that the fiber cells lacking the lens-specific IFs were indistinguishable from wild-type fiber cells. The CP49 KO mice exhibited lower stiffness, and an unexpected higher resilience than the wildtype lenses. The absence of these filaments resulted in lenses that were smaller, and exhibited a higher ratio …

Spiroplasma Eriocheiris Sp. Nov., Associated With Mortality In The Chinese Mitten Crab, Eriocheir Sinensis, Wen Wang, Wei Gu, Gail E. Gasparich, Keran Bi, Jiangtao Ou, Qingguo Meng, Tingming Liang, Qi Feng, Jianqiong Zhang, Ying Zhang

Gail Gasparich

Giant Viruses, James L. Van Etten

James Van Etten Publications

The common view of viruses, mostly true, is of tiny burglars that sneak into cells, grab the biosynthetic controls and compel the cell to make huge numbers of progeny that break out of the cell and keep the replication cycle going. Viruses are supposed to be diminutive even compared to cells that are just a micrometer (1,000 nanometers) in diameter. They are supposed to travel light, making do with just a few well-adapted genes.

In 1992, a new microorganism was isolated from a power-plant cooling tower in Bradford, England, where Timothy Robotham, a microbiologist at Leeds Public Health Laboratory, was …

Minimal Art: Or Why Small Viral K+ Channels Are Good Tools For Understanding Basic Structure And Function Relations, Gerhard Thiel, Dirk Baumeister, Indra Schroeder, Stefan M. Kast, James L. Van Etten, Anna Moroni

James Van Etten Publications

Some algal viruses contain genes that encode proteins with the hallmarks of K+ channels. One feature of these proteins is that they are less than 100 amino acids in size, which make them truly minimal for a K+ channel protein. That is, they consist of only the pore module present in more complex K+ channels. The combination of miniature size and the functional robustness of the viral K+ channels make them ideal model systems for studying how K+ channels work. Here we summarize recent structure/function correlates from these channels, which provide insight into functional properties such as gating, pharmacology and …

Functional Hak/Kup/Kt-Like Potassium Transporter Encoded By Chlorella Viruses, Timo Greiner, José Ramos, Maria C. Alvarez, James Gurnon, Ming Kang, James L. Van Etten, Anna Moroni, Gerhard Thiel

James Van Etten Publications

Chlorella viruses are a source of interesting membrane transport proteins. Here we examine a putative K+ transporter encoded by virus FR483 and related chlorella viruses. The protein shares sequence and structural features with HAK/KUP/KT-like K+ transporters from plants, bacteria and fungi. Yeast complementation assays and Rb+ uptake experiments show that the viral protein, termed HAKCV (high-affinity K+ transporter of chlorella virus), is functional, with transport characteristics that are similar to those of known K+ transporters. Expression studies revealed that the protein is expressed as an early gene during viral replication, and proteomics data indicate that it is not packaged in …

Sars, Richard N. Bradley

Richard N Bradley

Description: Viral infection of the human respiratory tract.

Causes: Infection by SARS-associated coronavirus.

Risk Factors: Direct, close contact with someone who is infected.

Symptoms: Fever over 38° C, headache, body aches, dry cough, an overall feeling of discomfort, and pneumonia.

Diagnosis: Laboratory tests of blood, nasal secretions or faeces.

Treatments: Experimental use of antiviral treatments. No approved treatments are available yet.

Pathogenesis: Humans lack immunity to SARS-CoV and severe symptoms develop quickly.

Prevention: Good hygiene practices such as frequent hand washing and covering one’s mouth with a tissue when sneezing.

Epidemiology: Slightly over 8,000 cases occurred worldwide between November 2002 …

Alzheimer's Disease Association With Chlamydia Pneumoniae, Andrew Short

PCOM Biomedical Studies Student Scholarship

Exogenous bacteria, such as Chlamydia pneumoniae, may be a cause of inflammation that contributes to the progression of Alzheimer's disease (AD). Inflammation has been previously established as a contributor to AD progression. Balin et al. first reported C. pneumoniae in the brains of post-mortem late onset AD patients. PCR analysis showed that 17/19 AD patients were positive for the organism in areas of the brain with typical AD-related neuropathology while 18/19 control patients were PCR-negative. Gerard et al. determined, using real-time PCR, that C. pneumoniae-infected cells colocalize with both neuritic senile plaques and neurofibrillary tangles, the defining pathologies of AD. …

Significant Inhibition Of Corneal Scarring In Vivo With Tissue-Selective, Targeted Aav5 Decorin Gene Therapy, Rajiv R. Mohan, Ashish Tandon, Ajay Sharma, John W. Cowden, Jonathan C. K. Tovey

Pharmacy Faculty Articles and Research

PURPOSE. This study tested a hypothesis that tissue-selective targeted decorin gene therapy delivered to the stroma with adeno-associated virus serotype 5 (AAV5) inhibits corneal fibrosis in vivo without significant side effects.

METHODS. An in vivo rabbit model of corneal fibrosis was used. Targeted decorin gene therapy was delivered to the rabbit cornea by a single topical application of AAV5 (100 L; 6.5 1012 g/mL) onto the bare stroma for 2 minutes. The levels of corneal fibrosis were determined with stereomicroscopy, slit lamp biomicroscopy, -smooth muscle actin ( SMA), fibronectin, and F-actin immunocytochemistry, and/or immunoblotting. CD11b, F4/80 immunocytochemistry, and TUNEL assay …

Targeted Decorin Gene Therapy Delivered With Adeno-Associated Virus Effectively Retards Corneal Neovascularization In Vivo, Rajiv R. Mohan, Jonathan C. K. Tovey, Ajay Sharma, Gregory S. Schultz, John W. Cowden, Ashish Tandon

Pharmacy Faculty Articles and Research

Decorin, small leucine-rich proteoglycan, has been shown to modulate angiogenesis in nonocular tissues. This study tested a hypothesis that tissue-selective targeted decorin gene therapy delivered to the rabbit stroma with adeno-associated virus serotype 5 (AAV5) impedes corneal neovascularization (CNV) in vivo without significant side effects. An established rabbit CNV model was used. Targeted decorin gene therapy in the rabbit stroma was delivered with a single topical AAV5 titer (100 μl; 5x10^12 vg/ml) application onto the stroma for two minutes after removing corneal epithelium. The levels of CNV were examined with stereomicroscopy, H&E staining, lectin, collagen type IV, CD31 immunocytochemistry and …

Polyethylenimine-Conjugated Gold Nanoparticles: Gene Transfer Potential And Low Toxicity In The Cornea, Ajay Sharma, Ashish Tandon, Jonathan C. K. Tovey, Rangan Gupta, J. David Robertson, Jennifer A. Fortune, Alexander M. Klibanov, John W. Cowden, Frank G. Rieger, Rajiv R. Mohan

Pharmacy Faculty Articles and Research

This study examined the gene transfer efficiency and toxicity of 2-kDa polyethylenimine conjugated to gold nanoparticles (PEI2-GNP) in the human cornea in vitro and rabbit cornea in vivo. PEI2-GNP with nitrogen-to-phosphorus (N/P) ratios of up to 180 exhibited significant transgene delivery in the human cornea without altering the viability or phenotype of these cells. Similarly, PEI2-GNP applied to corneal tissues collected after 12 h, 72 h, or 7 days exhibited appreciable gold uptake throughout the rabbit stroma with gradual clearance of GNP over time. Transmission electron microscopy detected GNP in the keratocytes and the extracellular matrix of the rabbit corneas. …

Efficacious And Safe Tissue-Selective Controlled Gene Therapy Approaches For The Cornea, Rajiv R. Mohan, Sunilima Sinha, Ashish Tandon, Rangan Gupta, Jonathan C. K. Tovey, Ajay Sharma

Pharmacy Faculty Articles and Research

Untargeted and uncontrolled gene delivery is a major cause of gene therapy failure. This study aimed to define efficient and safe tissue-selective targeted gene therapy approaches for delivering genes into keratocytes of the cornea in vivo using a normal or diseased rabbit model. New Zealand White rabbits, adeno-associated virus serotype 5 (AAV5), and a minimally invasive hair-dryer based vector-delivery technique were used. Fifty microliters of AAV5 titer (6.561012 vg/ml) expressing green fluorescent protein gene (GFP) was topically applied onto normal or diseased (fibrotic or neovascularized) rabbit corneas for 2-minutes with a custom vector-delivery technique. Corneal fibrosis and neovascularization in rabbit …