Biology Commons^™

The Effect Of Ph On Synaptic Transmission At The Neuromuscular Junction In Drosophila Melanogaster, Catherine Elizabeth Stanley

Theses and Dissertations--Biology

Synaptic transmission is the main avenue of neuronal communication and can be affected by a multitude of factors, both intracellularly and extracellularly. The effects of pH changes on synaptic transmission have been studied for many years across many different models. Intracellular acidification at the presynaptic terminal is known to occur with increased neuronal activity and can also occur in pathological conditions. The effects of these pH alterations are therefore an important area of study. Here, intracellular acidification using either propionic acid or the ammonium chloride pre-pulse technique was examined for the effects on both spontaneous and evoked synaptic transmission at …

From Organisms To Ecosystems: Impacts Of Limb Loss And Regeneration On Crayfish Behavior, Luc Arnaud Dunoyer

Theses and Dissertations--Biology

The ability of some organisms to regenerate tissues and organs has fascinated naturalists since antiquity, dating back to the earliest accounts of scientific inquiry with Aristotle in Ancient Greece. Then, Darwin’s theory invigorated some scientists’ dream of stimulating (or reactivating) regenerative capacities in human beings by showing that we are related to highly regenerative organisms. More recently, a renewed interest in discovering the molecular and genetic basis for organ and tissue regeneration has led biologists to focus more specifically on a restrictive set of model organisms.

Although the process of limb regeneration is different between invertebrate and vertebrate organisms, it …

From Genes To Species: Ecological Speciation With Gene Flow In Neodiprion Pinetum And N. Lecontei, Emily E. Bendall

Theses and Dissertations--Biology

My dissertation focuses on how differences accumulate across the genome during ecological speciation with geneflow. To do this I used two species of Neodiprionpine sawflies, which are plant-feeding hymenopterans with high host specificity. I used experimental crosses to measure both intrinsic and extrinsic postzygotic isolation and to understand the contribution of specific traits to reproductive isolation. Despite substantial genetic divergence and haploid males in which all recessive incompatibilities should be expressed, I found surprisingly little evidence of intrinsic postzygotic isolation. Recombination in hybrid males may reconstitute viable genotypes and counteract the effects of haploidy in males. Nevertheless, hybrids have …

Elucidating The Role Of Light-Induced Circadian Disruption On Atherosclerosis In Apolipoproteine-Deficient Mice, Jeffrey Chalfant

Theses and Dissertations--Biology

Circadian rhythms are approximately 24-hour oscillations of nearly every biological process in the body. The circadian system coordinates these rhythms of physiology and behavior with environmental cycles such as the light-dark cycle. Shift workers, who experience irregular exposure to the light-dark cycle, have chronically disrupted circadian rhythms and increased risk of developing cardiovascular disease, but the mechanisms are unknown. Our studies investigated the effects of light-induced circadian disruption on atherosclerosis in ApolipoproteinE-deficient (ApoE^-/-) mice. We found that male ApoE^-/- mice housed in constant light for 12 weeks, which results in severe disruption of circadian rhythms …

Vertical‑Surface Navigation In The Neotropical Whip Spider Paraphrynus Laevifrons (Arachnida: Amblypygi), Patrick Casto, Daniel D. Wiegmann, Vincent J. Coppola, Daniele Nardi, Eileen A. Hebets, Verner P. Bingman

Eileen Hebets Publications

Studies on whip spider navigation have focused on their ability to locate goal locations in the horizontal plane (e.g., when moving along the ground). However, many species of tropical whip spiders reside and move along surfaces in the vertical plane (e.g., trees). Under controlled laboratory conditions, the current study investigated the ability of the tropical whip spider, Paraphrynus laevifrons, to return to a home shelter on a vertical surface in the presence of numerous, similar, and competing refuge sites, as well as the distribution of navigational errors in the vertical, horizontal, and diagonal plane. We also assessed the relative …

Ectomycorrhizal Fungi Drive Positive Phylogenetic Plant–Soil Feedbacks In A Regionally Dominant Tropical Plant Family, R. Max Segnitz, Sabrina E. Russo, Stuart J. Davies, Kabir G. Peay

School of Biological Sciences: Faculty Publications

While work in temperate forests suggests that there are consistent differences in plant–soil feedback (PSF) between plants with arbuscular and ectomycorrhizal associations, it is unclear whether these differences exist in tropical rainforests. We tested the effects of mycorrhizal type, phylogenetic relationships to overstory species, and soil fertility on the growth of tree seedlings in a tropical Bornean rainforest with a high diversity of both ectomycorrhizal and arbuscular mycorrhizal trees. We found that ectomycorrhizal tree seedlings had higher growth in soils conditioned by close relatives and that this was associated with higher mycorrhizal colonization. By contrast, arbuscular mycorrhizal tree seedlings generally …

The Globin Gene Family In Arthropods: Evolution And Functional Diversity, Andreas Prothmann, Federico G. Hoffmann, Juan C. Opazo, Peter Herbener, Jay F. Storz, Thorsten Burmester, Thomas Hankeln

School of Biological Sciences: Faculty Publications

Globins are small heme-proteins that reversibly bind oxygen. Their most prominent roles in vertebrates are the transport and storage of O2 for oxidative energy metabolism, but recent research has suggested alternative, non-respiratory globin functions. In the species-rich and ecologically highly diverse taxon of arthropods, the coppercontaining hemocyanin is considered the main respiratory protein. However, recent studies have suggested the presence of globin genes and their proteins in arthropod taxa, including model species like Drosophila. To systematically assess the taxonomic distribution, evolution and diversity of globins in arthropods, we systematically searched transcriptome and genome sequence data and found a conserved, widespread …

Outcome Markers Of Art-Treated Hiv+ Patients With Early Stage Kaposi’S Sarcoma, Owen Ngalamika, For Yue Tso, Salum Lidenge, Sody Munsaka, Danielle Shea, Charles Wood, John West

School of Biological Sciences: Faculty Publications

HIV-associated/epidemic Kaposi’s sarcoma (EpKS) is an AIDS-defining angio-proliferative malignancy. It can be treated with antiretroviral therapy (ART) alone or with ART plus cytotoxic chemotherapy. ART-treated EpKS can either respond or worsen upon treatment. This study aimed at identifying immunological markers of ART-treatment response. We compared responders (those with clinical EpKS tumor regression) versus poor responders (those with progressive or non-responsive EpKS). We measured plasma cytokine and chemokine levels using cytometric bead assays. Kaposi’s sarcoma herpesvirus (KSHV) neutralizing antibody (nAb) responses were also quantified to test associations with treatment outcome. Interleukin (IL)-5 levels were significantly elevated in responders versus poorresponders at …

Innovative Teaching Knowledge Stays With Users, A. Kelly Lane, Jacob D. Mcalpin, Brittnee Earl, Stephanie Feola, Jennifer E. Lewis, Karl Mertens, Susan E. Shadle, John Svoretz, John P. Ziker, Brian A. Couch, Luanna B. Prevost, Marilyne Stains

School of Biological Sciences: Faculty Publications

Programs seeking to transform undergraduate science, technology, engineering, and mathematics courses often strive for participating faculty to share their knowledge of innovative teaching practices with other faculty in their home departments. Here, we provide interview, survey, and social network analyses revealing that faculty who use innovative teaching practices preferentially talk to each other, suggesting that greater steps are needed for information about innovative practices to reach faculty more broadly.

Production Of Isoprene By Methane - Producing Archaea, Nicole Roswitha Buan Murphy, Karrie A. Weber, Jared T. Aldridge, Robert Carr

School of Biological Sciences: Faculty Publications

Plasmid vectors and use of plasmid vectors in methods for producing methane and isoprene using Archaea are disclosed . Particularly, plasmid vectors that express isoprene synthase ( ispS ) are prepared and inserted into methanogens, such as Methanosarcina acetivorans, to allow for co - production of methane and isoprene. In one embodiment , the methods of the present disclosure can be used for wastewater management.

Trade-Offs Between Morphology And Thermal Niches Mediate Adaptation In Response To Competing Selective Pressures, Stella F. Uiterwaal, Ian T. Lagerstrom, Thomas M. Luhring, Miranda E. Salsbery, John P. Delong

School of Biological Sciences: Faculty Publications

Abstract

The effects of climate change—such as increased temperature variability and novel predators—rarely happen in isolation, but it is unclear how organisms cope with multiple stressors simultaneously. To explore this, we grew replicate Paramecium caudatum populations in either constant or variable temperatures and exposed half to predation. We then fit thermal performance curves (TPCs) of intrinsic growth rate (r_max) for each replicate population (N = 12) across seven temperatures (10°C–38°C). TPCs of P. caudatum exposed to both temperature variability and predation responded only to one or the other (but not both), resulting in unpredictable outcomes. These changes in …

Engineered Clostridium Botulinum Toxin Adapted To Deliver Molecules Into Selected Cells, Benjamin J. Pavlik, Paul H. Blum, Kevin Van Cott

School of Biological Sciences: Faculty Publications

An engineered payload-delivery system includes a target cell binding unit, covalently bound to a pore forming unit, and a payload portion adapted with a region capable of non-covalently binding to the pore forming unit. The pore forming unit is derived from a particular sub-serotype of Clostridium toxin, while the payload region is derived from a different sub-serotype of Clostridium toxin. The disclosed chimeric protein-based composition is capable of specifically delivering payload to neural cells.

Longer Ubiquinone Side Chains Contribute To Enhanced Farnesol Resistance In Yeasts, Ruvini U. Pathirana, Cory Boone, Kenneth Nickerson

School of Biological Sciences: Faculty Publications

Ubiquinones (UQ) are intrinsic lipid components of many membranes. Besides their role in electron-transfer reactions there is evidence for them acting as free radical scavengers, yet their other roles in biological systems have received little study. The dimorphic fungal pathogen Candida albicans secretes farnesol as both a virulence factor and a quorum-sensing molecule. Thus, we were intrigued by the presence of UQ9 isoprenologue in farnesol-producing Candida species while other members of this genera harbor UQ7 as their major electron carrier. We examined the effect of UQ side chain length in Saccharomyces cerevisiae and C. albicans with a view towards identifying …

Effects Of Lethal Bronzing Disease, Palm Height, And Temperature On Abundance And Monitoring Of Haplaxius Crudus, De-Fen Mou, Chih-Chung Lee, Philip G. Hahn, Noemi Soto, Alessandra R. Humphries, Ericka E. Helmick, Brian W. Bahder

School of Biological Sciences: Faculty Publications

Insect vector feeding preference and behavior play important roles in pathogen transmission, especially for pathogens that solely rely on insect vector transmission. This study aims to examine the effects of the 16SrIV-D phytoplasma, the causal agent of lethal bronzing (LB) disease of palms, on associated auchenorrhynchan insects. The numbers of auchenorrhynchans collected during weekly surveys during a yearlong study using yellow sticky traps were analyzed. The cumulative number of H. crudus was 4.5 times greater on phytoplasma-infected relative to non-infected palms. Other auchenorrhynchans showed no difference between phytoplasma-infected and non-infected palms or were greater on non-infected rather than on infected …

Towards Understanding Factors Influencing The Benefit Of Diversity In Predator Communities For Prey Suppression, Amanda N. Laubmeir, Richard Rebarber, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

It is generally assumed that high biodiversity is key to sustaining critical ecosystem services, including prey suppression by natural predator guilds. Prey suppression is driven by complex interactions between members of predator and prey communities, as well as their shared environment. Because of this, empirical studies have found both positive and negative effects of high predator diversity on prey suppression. However, we lack an understanding of when these different prey suppression outcomes will occur. In this work, we use a mechanistic, trait-based model to unravel how intraguild interactions, species body mass, predator foraging area, and ambient temperature can combine to …

Benefits Of A College Stem Faculty Development Initiative: Instructors Report Increased And Sustained Implementation Of Research-Based Instructional Strategies, Mary F. Durham, Oriana R. Aragón, Meghan E. Bathgate, Aiyanan Bobrownicki, Andrew J. Cavanagh, Xinnian Chen, William M. Trochim, Jonathan K. Waterhouse, Maek J. Graham, Brian A. Couch

School of Biological Sciences: Faculty Publications

The Summer Institutes on Scientific Teaching (SI) is a faculty development workshop in which science, technology, engineering, and mathematics (STEM) instructors, particularly from biology, are trained in the Scientific Teaching (ST) pedagogy. While participants have generally reported positive experiences, we aimed to assess how the SI affected participants’ teaching practices. Building on a previously developed taxonomy of ST practices, we surveyed SI participants from the 2004–2014 SI classes regarding specific ST practices. Participants’ self-reported use and implementation of ST practices increased immediately after SI attendance as well as over a longer time frame, suggesting that implementation persisted and even increased …

How Demographic Processes Shape Animal Social Networks, Daizaburo Shizuka, Allison E. Johnson

School of Biological Sciences: Faculty Publications

Invited review

Demographic processes play a key role in shaping the patterns of social relations among individuals in a population. Social network analysis is a powerful quantitative tool for assessing the social structure formed by associations between individuals. However, demographic processes are rarely accounted for in such analyses. Here, we summarize how the structure of animal social networks is shaped by the joint effects of social behavior and turnover of individuals and suggest how a deeper understanding of these processes can open new, exciting avenues for research. Death or dispersal can have the direct effect of removing an individual and …

Evolutionary Origin And Genetic Diversity Of Ring‐Necked Pheasants In The Upper Midwest United States, Hernán Vázquez-Miranda, Magdalena Jean Olson, Robert M. Zink

School of Biological Sciences: Faculty Publications

We compared mitochondrial cytochrome b sequences of ring‐necked pheasants (Phasianus colchicus) from Midwestern United States (SD and NE, USA) to a molecular phylogeographic hypothesis of pheasants in the native Eurasian range to understand which subspecies are represented by wild and captive released birds. We found that these birds represent 2 Eurasian lineages, which we refer to generally as northern Eurasian (Colchicus group) and eastern China (Torquatus group). These mitochondrial DNA lineages occur in different frequencies in the wild, with the latter being 3 times more common. This suggests that 1) the eastern China lineage is either …

A Role For Triglyceride Lipase Brummer In The Regulation Of Sex Differences In Drosophila Fat Storage And Breakdown, Lianna W. Wat, Chien Chao, Rachael Bartlett, Justin L. Buchanan, Jason W. Millington, Hui Ju Chih, Zahid S. Chowdhury, Puja Biswas, Vivian Huang, Leah J. Shin, Lin Chuan Wang, Marie-Pierre L. Gauthier, Maria C. Barone, Kristi L. Montooth, Michael A. Welte, Elizabeth J. Rideout

School of Biological Sciences: Faculty Publications

Triglycerides are the major form of stored fat in all animals. One important determinant of whole-body fat storage is whether an animal is male or female. Here, we use Drosophila, an established model for studies on triglyceride metabolism, to gain insight into the genes and physiological mechanisms that contribute to sex differences in fat storage. Our analysis of triglyceride storage and breakdown in both sexes identified a role for triglyceride lipase brummer (bmm) in the regulation of sex differences in triglyceride homeostasis. Normally, male flies have higher levels of bmm mRNA both under normal culture conditions and …

Trade-Offs Between Morphology And Thermal Niches Mediate Adaptation In Response To Competing Selective Pressures, Stella F. Uiterwaal, Ian T. Lagerstrom, Thomas M. Luhring, Miranda E. Salsbery, John P. Delong

School of Biological Sciences: Faculty Publications

The effects of climate change—such as increased temperature variability and novel predators—rarely happen in isolation, but it is unclear how organisms cope with mul- tiple stressors simultaneously. To explore this, we grew replicate Paramecium caudatum populations in either constant or variable temperatures and exposed half to predation. We then fit thermal performance curves (TPCs) of intrinsic growth rate (r_max) for each replicate population (N = 12) across seven temperatures (10°C–38°C). TPCs of P. caudatum exposed to both temperature variability and predation re- sponded only to one or the other (but not both), resulting in unpredictable outcomes. …

Radiomics-Based Outcome Prediction For Pancreatic Cancer Following Stereotactic Body Radiotherapy, Elsa Parr, Qian Du, Chi Zhang, Chi Lin, Ahsan Kamal, Josiah Mcalister, Xiaoying Liang, Kyle Bavitz, Gerard Rux, Michael Hollingsworth, Michael Baine, Dandan Zheng

School of Biological Sciences: Faculty Publications

(1) Background: Radiomics use high-throughput mining of medical imaging data to extract unique information and predict tumor behavior. Currently available clinical prediction models poorly predict treatment outcomes in pancreatic adenocarcinoma. Therefore, we used radiomic features of primary pancreatic tumors to develop outcome prediction models and compared them to traditional clinical models. (2) Methods: We extracted and analyzed radiomic data from pre-radiation contrast-enhanced CTs of 74 pancreatic cancer patients undergoing stereotactic body radiotherapy. A panel of over 800 radiomic features was screened to create overall survival and local-regional recurrence prediction models, which were compared to clinical prediction models and models combining …

Extreme Offspring Ornamentation In American Coots Is Favored By Selection Within Families, Not Benefits To Conspecific Brood Parasites, Bruce E. Lyon, Daizaburo Shizuka

School of Biological Sciences: Faculty Publications

Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within …

Mitochondrial Localization Of Dictyostelium Discoideum Dutpase Mediated By Its N‑Terminus, Catherine P. Chia, Noriko Inoguchi, Kyle C. Varon, Bradley M. Barholomai, Hideaki Moriyama

School of Biological Sciences: Faculty Publications

Objective: The nuclear and mitochondrial genomes of Dictyostelium discoideum, a unicellular eukaryote, have relatively high A+T-contents of 77.5% and 72.65%, respectively. To begin to investigate how the pyrimidine biosynthetic pathway fulfills the demand for dTTP, we determined the catalytic properties and structure of the key enzyme deoxyuridine triphosphate nucleotidohydrolase (dUTPase) that hydrolyzes dUTP to dUMP, the precursor of dTTP. Results: The annotated genome of D. discoideum identifies a gene encoding a polypeptide containing the five conserved motifs of homotrimeric dUTPases. Recombinant proteins, comprised of either full-length or core polypeptides with all conserved motifs but lacking residues 1-37 of the …

Conserving Spawning Stocks Through Harvest Slot Limits And No-Take Protected Areas, Gaya Gnanalingam, Holly Gaff, Mark J. Butler Iv

Biological Sciences Faculty Publications

The key to the conservation of harvested species is the maintenance of reproductive success. Yet for many marine species large, old individuals are targeted despite their disproportionate contribution to reproduction. We hypothesized that a combination of no-take marine protected areas (MPAs) and harvest slot limits (maximum and minimum size limits) would result in the conservation of large spawning individuals under heavy harvest. We tested this approach under different harvest intensities with a 2-sex, stage-structured metapopulation model for the Caribbean spiny lobster (Panulirus argus). P. argus is intensively harvested in the Caribbean, and in many localities large, mature individuals no longer …

Factors Affecting The Microbiome Of Ixodes Scapularis And Amblyomma Americanum, R. Jory Brinkerhoff, Chris Clark, Kelly Ocasio, David T. Gauthier, Wayne L. Hynes

Biological Sciences Faculty Publications

The microbial community composition of disease vectors can impact pathogen establishment and transmission as well as on vector behavior and fitness. While data on vector microbiota are accumulating quickly, determinants of the variation in disease vector microbial communities are incompletely understood. We explored the microbiome of two human-biting tick species abundant in eastern North America (Amblyomma americanum and Ixodes scapularis) to identify the relative contribution of tick species, tick life stage, tick sex, environmental context and vertical transmission to the richness, diversity, and species composition of the tick microbiome. We sampled 89 adult and nymphal Ixodes scapularis (N …

Phenotypic Variation Of Partridge Pea (Chamaecrista Fasciculata) From Mississippi Persists In A Common Garden, Lisa E. Wallace, Mahboubeh Hosseinalizadeh-Nobarinezhad, Robert Coltharp

Biological Sciences Faculty Publications

Intraspecific phenotypic variation occurs for many different reasons and understanding its basis has applications in taxonomy, ecology, and evolution. Chamaecrista fasciculata (partridge pea) is a widely distributed species with much phenotypic variation and varied interactions with other species in communities where it grows. Botanists have often noted that phenotypic variation in some traits of this species increases from north to south in the eastern United States. In this study, we grew seeds collected from five Mississippi populations in a common greenhouse environment to determine if the observed variation in leaf and stem traits is maintained in this environment. Interpopulation variation …

Squids Use Multiple Escape Jet Patterns Throughout Ontogeny, Carly A. York, Ian K. Bartol, Paul S. Krueger, Joseph T. Thompson

Biological Sciences Faculty Publications

Throughout their lives, squids are both predators and prey for a multitude of animals, many of which are at the top of ocean food webs, making them an integral component of the trophic structure of marine ecosystems. The escape jet, which is produced by the rapid expulsion of water from the mantle cavity through a funnel, is central to a cephalopod's ability to avoid predation throughout its life. Although squid undergo morphological and behavioral changes and experience remarkably different Reynolds number regimes throughout their development, little is known about the dynamics and propulsive efficiency of escape jets throughout ontogeny. We …

Tick-Borne Flavivirus Inhibits Sphingomyelinase (Issmase), A Venomous Spider Ortholog To Increase Sphingomyelin Lipid Levels For Its Survival In Ixodes Scapularis Ticks, Pravesh Regmi, Supreet Khanal, Girish Neelakanta, Hameda Sultana

Biological Sciences Faculty Publications

Our previous study showed that cells from medically important arthropods, such as ticks, secrete extracellular vesicles (EVs) including exosomes that mediate transmission of flavivirus RNA and proteins to the human cells. Understanding the molecular determinants and mechanism(s) of arthropod-borne flavivirus transmission via exosome biogenesis is very important. In this current study, we showed that in the presence of tick-borne Langat Virus (LGTV; a member of tick-borne encephalitis virus complex), the expression of arthropod IsSMase, a sphingomyelinase D (SMase D) that catalyzes the hydrolytic cleavage of substrates like sphingomyelin (SM) lipids, was significantly reduced in both Ixodes scapularis ticks (in vivo) …

Discovery Of Exosomes From Tick Saliva And Salivary Glands Reveals Therapeutic Roles For Cxcl12 And Il-8 In Wound Healing At The Tick-Human Skin Interface, Wenshuo Zhou, Faizan Tahir, Joseph Che-Yen Wang, Michael Woodson, Michael B. Sherman, Shahid Karim, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Ticks secrete various anti-coagulatory, anti-vasoconstrictory, anti-inflammatory, and anti-platelet aggregation factors in their saliva at the bite site during feeding to evade host immunological surveillance and responses. For the first time, we report successful isolation of exosomes (small membrane-bound extracellular signaling vesicles) from saliva and salivary glands of partially fed or unfed ixodid ticks. Our data showed a novel role of these in vivo exosomes in the inhibition of wound healing via downregulation of C-X-C motif chemokine ligand 12 (CXCL12) and upregulation of interleukin-8 (IL-8). Cryo-electron microscopy (cryo-EM) analysis revealed that tick saliva and salivary glands are composed of heterogeneous populations …

Abiotic Conditions, Algal Biomass & Fish Growth Rates Affect Fish Mercury Concentrations In Two Subarctic Lakes, Ari Yamaguchi

Theses and Dissertations (Comprehensive)

Kakisa Lake and Tathlina Lake, located in the Dehcho Region of the Northwest Territories, support important fisheries for the local Ka’a’gee Tu First Nation (KTFN). Recently, Walleye (Sander vitreus) of typical catch size in Tathlina Lake were found to have mercury concentrations above Health Canada’s commercial sale guideline of 0.5 ppm. Wild foods with elevated mercury concentrations can pose health risks to the humans who consume them, depending on consumption amounts and vulnerability factors such as age and pregnancy. Because wild fish can accumulate relatively high mercury levels and subsistence fishing contributes greatly to food security in northern …