Poster Sessions - First Floor

First Floor #1

Elucidating the Processes by Which Nanoparticles Enter Cells
T.R. Garner1, W.S. Baldwin1,2, A.M. Rao3, and S.J. Klaine1,2

1Institute of Environmental Toxicology, and Departments of 2Biological Sciences, and 3Physics & Astronomy
Faculty Mentor: Dr. Stephen J. Klaine

ABSTRACT: While nanomaterials have been shown to cross cell membranes, little research has examined the processes by which this occurs. The goal of this project was to characterize how particle-protein complexes interact with membranes and enter A549 carcinomic alveolar cells. Particle uptake decreased as cells were exposed in media supplemented with increasing concentrations of fetal bovine serum, yet increased when supplemented with increasing concentrations of bovine serum albumin; suggesting albumin is integral in the transport of particles across membranes. Uptake further decreased when calcium was removed from the exposure media; suggesting calcium is involved as well. Future work will utilize a toxicity identification evaluation (TIE) approach, removing components from the exposure media, to determine factors and constituents critical to particle uptake. This research provides a fundamental foundation to accurately understand biological interactions with nanoparticles utilizing a rapid high throughput assay, and will facilitate future risk assessment endeavors.

First Floor #2

Empowering Clemson University Creative Inquiry Students through the Development of Cognitive Interview Training Modules for the Youth EFNEP Multi-state Evaluation Project
Joyce Senior, Andrea Aguilar, Kattia Blanco, Elizabeth Ramirez, Maciel Ugalde, Katherine Cason, Yenory Hernandez, and Brittney Linton
Department of Food, Nutrition & Packaging Sciences
Faculty Mentor: Katherine Cason

ABSTRACT: During the spring and fall semesters of 2012, Clemson University took the lead in the development and implementation of Cognitive Interviews Training Modules for the Youth Expanded Food Nutrition Education Program Multi-state Evaluation Project. The modules were created in response to the imperative need to upgrade the training information and research skills of nutrition undergraduate students who lacked the knowledge, practice and confidence to develop interviews with this population. The empowerment-based training was designed to enhance the quality of education in advanced research techniques, increase awareness of collaborative national research nutrition education projects and strengthen the self-competency and professional skills of undergraduates who require a higher level of expertise in nutrition research with young audiences. Undergraduate students from Creative Inquiry teams were the target audience for this project. The methodology consisted of three comprehensive modules covering the protocol of the highly specialized technique of cognitive interviewing. The first round of data collection was in the spring of 2012 and served as the pilot-testing. The second round of data collection was held in the fall 2012. Pre and post evaluations, student observations, and a focus group set to begin this spring semester will help assess the overall learning process and the development of skills and self-competency acquired by the students. The results of the pilot testing were used to improve, adapt and further standardize the training procedure, which increases the rigorousness, reliability and validity of the data obtained using this method. The Cognitive Interviews Training Modules will become a cutting-edge learning tool to be used by Youth EFNEP at the multi-state and national level in their projects involving qualitative research with children.

First Floor #3

Evaluation of Bacterial and Viral Toll-like Receptor Ligands Stimulation of Chicken Thrombocyte Inflammatory Responses
Farzana Ferdous and Tom Scott
Departments of Biological Sciences, and Animal & Veterinary Sciences
Faculty Mentor: Tom Scott

ABSTRACT: Chicken thrombocytes are nucleated blood cells homologous in function to enucleated platelets. Thrombocytes are known for their role in hemostasis. Researchers have found that thrombocytes play an integral role in innate immunity. Thrombocytes express several Toll-like receptors that detect the presence of bacterial or viral pathogens and signal the release of certain pro-inflammatory cytokines and mediators. Thrombocytes exhibit differential inflammatory responses between bacterial and viral pathogenic ligand stimulations. Among the bacterial and viral ligands examined, only Lipopolysaccharide (LPS) significantly increased expression of the IL-6 gene. Although gene expression of iNOS did not significantly increase due to ligand exposure, constitutive expression of iNOS was observed compared to GAPDH. In addition the releases of these products were also examined. Viral ligand stimulation led to significant increase of NO release. IL-6 was observed only in LPS stimulated thrombocyte supernatants. Future work involves a thorough understanding of thrombocytes in innate immunity.

First Floor #5

Expression of CD44, Ki67, and FOXO3a in Mesenchymal Stem-Like Triple Negative Breast Cancer Cell Lines
E. Vegter, T.R. Scott, and H. Dunn

Department of Animal & Veterinary Science
Faculty Mentor: Heather Walker Dunn

ABSTRACT: Triple negative breast cancer (TNBC) comprises 10-20% of all breast cancers, but is one of the most aggressive forms with poor prognosis. The description TNBC refers to the fact that it does not express the three known cell-surface hormone receptors E2, P4 and Her2/neu that are present in other types of breast cancer and are common targets for traditional cancer treatments. TNBC encompasses multiple subtypes that include many different cell lines, each with their own unique characteristics. The subtype mesenchymal stem-like include cell lines that typically are highly motile and metastasize. Expression of certain proteins in the cells such as CD44, Ki67 and FOXO3a may help in understanding this subtype. The purpose of this study is to evaluate in-vitro expression of Foxo3a in 2-D and 3-D cultures.

First Floor #6

Expression of MULT1 in TC-1 Cells
Robert Borucki, Ashlee Tietje, Graham Temples, and Yanzhang Wei

Department of Biological Sciences
Faculty Mentor: Yanzhang Wei

ABSTRACT: Cells expressing mouse UL16-binding protein-like transcript 1 (MULT1) bind and activate the NKG2D receptor of natural killer cells. This binding of the NKG2D receptor to the MULT1 domain will cause the MULT1 expressing cell to be targeted and destroyed by lysis from natural killer cells and other NKG2D expressing cells. The goal of this project was to successfully transfect TC-1 cells with a plasmid encoding the extracellular domain of MULT1 and select clones that stably express the secreted protein in order to enhance the killing activity of NK cells and other NKG2D expressing cells. The expression of MULT1 was tested using methods such as reverse transcriptase PCR and immunofluorescence. Based on our results we can speculate that the cell lines mentioned above were successfully transcribed with the plasmid containing the gene that codes for the MULT1 protein.

 

First Floor #7

Production of Spider Silk-Like Proteins in Transgenic Tobacco Nicotiana tabacum
Congyue Annie Peng, Allison Nelson, Charlene Gravgaard, Heather McCartney, and William R. Marcotte, Jr.
Department of Genetics & Biochemistry
Faculty Mentor: Dr. William R. Marcotte, Jr.

ABSTRACT: The high tensile strength and biocompatibility of spider dragline silk makes it desirable in many engineering and tissue regeneration applications. Here, we present feasible mass production of recombinant mini-spidroins from transgenic tobacco Nicotiana tabacum. The mini-spidroins contain native N and C-terminal flanking domains and an abbreviated number of consensus repeat domains. Two different promoters (pKM12 and pKLP36) were tested. A downstream self-cleavable intein and chitin binding domain were attached for protein purification. We confirmed gene insertion and RNA transcription by PCR and reverse-transcriptase PCR. Mini-spidroin production was detected by N- terminus specific antibodies. Purification of mini-spidroins was done through chitin binding and subsequent intein activation and self-cleavage. Pooled mini-spidroins were dialyzed and freeze-dried. Mini-spidroins formed viscous gelatin-like fluids which exhibited extending continuum property. Immuno-detection of this fluid showed various degree of polymerization of mini-spidroin monomers. Transition of this gelatin-like fluid into solid fibers will be examined in future studies.

First Floor #8

Factors That Influence the Bioavailability of Gold Nanoparticles to Aquatic Macrophytes

Brad Glenn and Stephen J. Klaine

Institute of Environmental Toxicology

Faculty Mentor: Stephen J. Klaine

 

ABSTRACT: Understanding the factors that control bioavailability of engineered nanoparticles to plants are crucial in understanding fate of nanomaterials in the environment. Plants make up the base of the food chain and interact closely with their surrounding environment. Due to the potential release of nanomaterials through municipal waste and terrestrial run off, factors that influence bioavailability of nanomaterials were investigated with regards to aquatic plants. Azolla caroliniana Willd., Egeria densa Orch., and Myriophyllum simulans Planch. were investigated using gold nanoparticles of three sizes, 4, 18 and 30 nm. Factors that influenced uptake included the presence of roots, dissolved organic carbon, as well as nanoparticle size. Results indicate 4-way interactions between factors suggesting nanoparticle bioavailability is a complex result of multiple parameters. Size and species dependent absorption was observed that was dependent on the presence of roots and dependent of nanoparticle size. The presence of dissolved organic carbon was found to stabilize both 4 and 18 nm gold nanoparticles in suspension and form a nanoparticle/organic matter complex that resulted in 1) a more stable complex that minimized aggregation, and 2) a decrease of nanoparticle absorption by the aquatic plants. The same effect was not observed with the 30 nm nanoparticle treatment. These results indicate that multiple factors, both biotic and abiotic, must be taken into account when investigating bioavailability of nanomaterials to aquatic plants.

 

First Floor #9

Equilibrium and Kinetic-based Toxicological Assessment of Cerium Oxide Nanoparticles in Soil Denitrifiers
Jessica T. Dahle and Yuji Arai
Institute of Environmental Toxicology
Faculty Mentor: Yuji Arai

ABSTRACT: This study was designed to gain an improved understanding of cerium biogeochemistry in the terrestrial environment; specifically; the impact of aqueous Ce(III) and nanoparticulate cerium(IV) oxide (NP Ce(IV)O2) on soil denitrifying microbial communities. Using cerium(III) sulfate and well characterized NP Ce(IV)O2, batch denitrification experiments were conducted to evaluate the toxicity of Ce(III) and NP Ce(IV)O2 as a function of: 1) speciation (Ce(III) vs. NP Ce(IV)), 2) concentration (50-500 ppm), and 3) NP particle size (10 and 50 nm) in Toccoa sandy loam. It was found that soluble Ce(III) was more toxic than Ce(IV)O2 NPs when an equal total concentration of Ce was exposed and that concentration-dependent toxicity occurred for both Ce(III) and the two Ce(IV) NPs. Particle size-dependent toxicity was also observed for the two nanoparticles; the small (10 nm) NPs exhibited much more devastating toxic effects to the denitrification process than the large (50 nm) NPs.

First Floor #10

Finding a mutant: A genetic approach to identifying the mutation causative of the Araucana rumpless phenotype
Nowlan Freese, Brianna Lam, Rooksana Noorai, Leigh Anne Clark, and Susan C. Chapman
Department of Biological Sciences
Faculty Mentor: Susan C. Chapman


ABSTRACT: The Araucana chicken is characterized by a rumpless phenotype, caused by the caudal-most vertebrae not forming. To identify genomic regions associated with the rumpless phenotype, we conducted a genome-wide association study using single nucleotide polymorphism (SNP) BeadChips. Genomic DNA was isolated from 60 Araucana from 6 separate flocks with rumpless, tailed, or partially tailed phenotypes. Case/control analysis with 41-rumpless and 12-tailed Araucana was conducted for 56,685 SNPs. The 10 most significant pgenome values were obtained for SNPs on chromosome 2. A haplotype block of 740Kb on chromosome 2 was identified in rumpless Araucana. To identify candidate mutations within the haplotype block, we conducted whole genome sequencing of six Araucana (3-homozygous rumpless, 2-heterozygous, 1-homozygous tailed). We identified 197 SNPs and 22 insertion/deletions unique to rumpless Araucana. We hypothesize that one of these mutations is causative of the Araucana rumpless phenotype. Additional sequencing to test for segregation of each mutation is ongoing.

First Floor #11

Freezing Effects on Bacterial Survival
Dong Han and Paul Dawson
Department of Food, Nutrition & Packaging Science
Faculty Mentor: Paul Dawson

ABSTRACT: When fresh food is stored at room temperature, microbes’ respiration and chemical action will consume food nutrition extremely and spoilage occurs. At low temperature microbial metabolism will be destroyed, the intracellular accumulation of toxic substances and other microbial peroxide can cause the death and inactivation of bacteria. Reducing storage temperature slows microbial growth, reproduction enzyme activity and then extends the shelf life of food. The poster uses some articles’ research to reveal the effects on some kinds of bacteria by freezing treatment.

First Floor #12

Functional Analyses of Insect and Virus Gap Junction Structural Proteins
D.K. Hasegawa and M.W. Turnbull
Department of Biological Sciences
Faculty Mentor: Matthew W. Turnbull

ABSTRACT: The gap junctions which occur throughout the tissues of most multicellular animals provide a route for intercellular communication, which is important for development and homeostasis. Additional functions of the structural proteins of gap junctions, such as adhesion and influencing of signaling pathways, are now being identified. Gap junctions in deuterostomes are formed by members of the Connexin and Pannexin protein families, which interact with, and are widely regulated by, cell signaling and structural components; Connexins and Pannexins affect signaling and structural components in turn, an additional mechanism for affecting cell physiology. Protostomes including insects lack Connexins, and their gap junctions are exclusively comprised by Pannexin homologues termed Innexins. The regulation and roles of Innexins, and as a result comparability to Pannexins and Connexins, are generally unclear. Our lab has addressed this by examining Innexins in the context of development and cellular immunity of model caterpillars and flies. Here, we summarize work on gene expression, protein localization, and implications of ectopic expression of both insect Innexins – including a previously undescribed paralogue – and Innexins expressed by insect viruses known as polydnaviruses. Our data clearly demonstrate both expected similarities between the Innexins, Connexins, and Pannexins, as well as potential dissimilarities.

First Floor #14

Habitat mediated raccoon response to an artificial increase in coyote activity
Cady Etheredge, Greg Yarrow, Patrick Gerard, and Jamie Dozier
School or Agricultural, Forest, & Environmental Sciences – Wildlife & Fisheries Biology
Faculty Mentor: Greg Yarrow

ABSTRACT: Most predator control programs treat species in isolation, never considering how competition between predators as predicted by the mesopredator release hypothesis (MRH) can result in indirect benefits to ground nesting prey. Understanding these dynamics will be especially important in the southeastern United States, where recent coyote (Canis latrans) invasions may provide systems with a new top predator capable of suppressing booming mesopredator populations. This project indirectly tests the MRH by examining the spatial avoidance of raccoons (Procyon lotor) to areas with artifically increased coyote activity. Radio collared raccoon home ranges were intensely mapped for one week before and after test plots were treated with coyote urine (impact) or walked but not treated (control). Trials were conducted inside both 50 and 95% fixed kernal contours to test for differential raccoon responses based on potentially habitat mediated tradeoffs between resource availability and predation risk. Habitat variables (habitat type, vegetation density, etc.) were measured at five randomly selected points within each plot as soon as possible after trials ended. The number of locations inside treated and control plots before and after impact is currently being compared for both contour types. If raccoons avoid areas with heavy coyote use, interspecific killing of raccoons by coyotes and associated indirect benefits to prey populations could be inferred. Raccoons avoiding treated areas inside the 95% contour but not in the 50% might indicate that the potential threat coyotes pose to raccoons is not greater than the benefits provided by key foraging or denning areas inside core areas.

First Floor #15

Identifying, Cloning and Characterizing Nodule Regulatory Mutants

Benjamin Flanigan, Andrew Puncheon, Ashley Crook, Tessema Kassaw, Elise Schnabel, and Julia Frugoli
Department of Genetics & Biochemistry
Faculty Mentor: Julia Frugoli

ABSTRACT: The formation of nitrogen-fixing nodules in legumes is controlled by a long-distance signaling system in which nodulating roots signal to shoot tissues to systemically suppress further nodulation. The lab identified and published on mutants in Medicago truncatula that lack the ability to regulate nodule number from the shoot (sunn and lss) or from the root (rdn1). For each, we characterized the mutation and cloned the gene, allowing us to build a model of how the plant regulates the number of nodules it forms. We focused on identifying more mutants that affect nodule regulation, or characterizing plant physiology in mutants already identified to refine our model. Here we present investigations into the distribution of auxin in wild type and mutant plants undergoing nodulation, the function of a nodulation gene (RDN) in a non-nodulating plant, and mapping of a new gene that suppresses the supernodulation phenotype of sunn mutants. This work is supported by the Calhoun Honors College, Creative Inquiry, and NSF# #IOS1146014.

First Floor #16

Impact of Cranberry Consumption on Bacterial Infections in the C. elegans model
Miranda Klees, Sujay Guha, Yuqing Dong, and Min Cao
Department of Biological Sciences
Faculty Mentor: Dr. Min Cao

ABSTRACT: Cranberry and its products have been widely consumed and are thought to improve human health through their anti-microbial, anti-virus, and anti-oxidation activities. We have reported that consumption of cranberry can promote healthy aging in the invertebrate model organism, Caenorhabditis elegans. Recently, we found that cranberry can protect C. elegans from infection by Vibrio cholerae, a Gram-negative bacterium that causes cholera. The concentration of cranberry we applied to this protection assay did not kill or inhibit the growth of V. cholera, indicating other mechanisms were involved. We hypothesized that cranberry treatment could affect Vibrio virulence gene expression, or boost C. elegans immunity, or affect both sides. To understand this cranberry-mediated protection, we currently focus on these goals: (1) To compare V. cholerae virulence gene expression +/- cranberry by real-time PCR. (2) To investigate C. elegans innate immunological response to cranberry by using different worm mutant strains in the Vibrio killing assays.

First Floor #17

Influence of Compost Particle Size on Pathogen Survival Under Greenhouse Condition
Junshu Diao and Xiuping Jiang

Department of Food, Nutrition & Packaging Science
Faculty Mentor: Xiuping Jiang

ABSTRACT: Purpose: This study was to investigate the survival of Escherichia coli O157:H7 and Salmonella typhimurium in compost with different particle sizes as affected by initial moisture content and seasonality under greenhouse condition. The mixture of avirulent S. typhimurium and E. coli O157:H7 were inoculated into the finished compost and were sieved into three particle size of >1000, 500-1000 and <500 μm. At selected intervals during 30 days of storage, compost samples were tested for pathogen population. For moisture contents of 20 and 30%, the average Salmonella reductions in compost with particle sizes of >1000, 500-1000 and <500 μm were 2.15, 2.27 and 2.47 log CFU g-1 within 5 days of storage in summer, respectively, as compared with 1.60, 2.03 and 2.26 log CFU g-1 in late fall, and 2.61, 3.33 and 3.67 log CFU g-1 for winter, respectively. E. coli O157: H7 reduction in compost with particle sizes followed the same trend as Salmonella.

First Floor #18

Interacting Partners of the SUNN Symbiotic Kinase
 Ashley Crook, Elise Schnabel, and Julia Frugoli
Department of Genetics & Biochemistry
Faculty Mentor: Julia Frugoli


ABSTRACT: Leucine rich repeat receptor-like kinases (LRR-RLKs) are the predominant means for cellular communication in plants. Our lab studies the control of nodule number, or autoregulation of nodulation (AON), exhibited by nodule-forming legume species involves a complex signaling pathway encompassing molecules that act in both the root and the shoot. The symbiotic regulatory LRR-RLK, SUNN, is expressed in the vasculature of the plant and provides shoot-derived control of nodulation. Because of its high homology to the LRR-RLK Arabidopsis CLAVATA1 which acts in a multiprotein complex to control meristem development, we postulate that SUNN may likewise act in a protein complex. Subcellular localization studies conducted using Agrobacterium-mediated tissue infiltration of Medicago truncatula and Nicotiana bethamiana indicate the SUNN kinase is localized to the plasma membrane. We are now attempting to identify primary protein-protein interactions using co-immunoprecipitation and fluorescent microscopy techniques and preliminary results will be presented. This work supported by NSF awards #IOS-0950700 and #IOS1146014.

First Floor #19

Interplay of mechanical and molecular signaling during chick columella condensation
Poulomi Ray and Susan C. Chapman

Department of Biological Sciences

Faculty Mentor: Susan C. Chapman

ABSTRACT: The physical mechanism of mesenchymal condensation during skeletal development is not well understood. Here, we show that dynamic cell shape changes are required for mesenchymal condensation during chick middle ear morphogenesis. The chick middle ear columella arises from two separate condensations; the cartilaginous extracolumella and an osseous columella. Our modeling results show that the extracolumella undergoes condensation earlier than the columella. The extracolumella condensation resembles the classical definition of condensation with tightly packed cells. Conversely, the columella condensation has a novel appearance with a loosely organized web-like network of cells, with elongated cell-to-cell connections. However, dynamic cytoskeletal reorganization is observed in both condensations over several days, indicating that cell shape changes are important. Using Cytochalasin D, an inhibitor of actin polymerization, we disrupted the ability of the mesenchyme cells to reorganize their cytoskeleton. Our results show that inhibition of cell shape changes disrupts mesenchymal condensation during chick middle ear morphogenesis.

First Floor #20

Investigating the role of ADP-forming acetyl-CoA synthetase in Entamoeba histolytica
Cheryl Howell, Kerry Smith, and Cheryl Ingram-Smith
Department of Genetics & Biochemistry
Faculty Mentor: Dr. Cheryl Ingram-Smith

ABSTRACT: Entamoeba histolytica, the protozoan parasite responsible for amoebic dysentery, is estimated to infect over 50 million people worldwide. This amitochondriate protist relies on glycolysis and alternative pathways to generate high-energy compounds. ADP-forming acetyl-CoA synthetase (ACD) catalyzes the conversion of acetyl-CoA to acetate to generate ATP via substrate level phosphorylation. ACD is believed to play a role in energy conservation in E. histolytica, and may also play a role in recycling of CoA.

Purified recombinant E. histolytica ACD (EhACD) displayed significant activity in both directions of the reaction. Both acetyl-CoA and propionyl-CoA can be utilized in the acetate-forming direction. These substrates are provided from glycolysis and amino acid degradation to supplement ATP formation. Acetate, propionate, and butyrate, all found at high levels in the human colon where E. histolytica resides, displayed activity in the acyl-CoA forming direction. Therefore, it is feasible that this enzyme catalyzes a reversible reaction in vivo.

 

First Floor #21

Histological Analysis of Ruminant Tissue and Organs
J. Major, S. Kennerly, J. Forbes, and H. Dunn

Department of Animal & Veterinary Science
Faculty Mentor: Heather Walker Dunn

ABSTRACT: This collection of images displays various histological samples of ruminant tissues and organs to be used in a photographic atlas for undergraduate studies. Paraffin embedded tissue sections were mounted to slides, stained with hematoxylin and eosin, and images were photographed in order to best display the cellular composition of each tissue of interest. Tissues include the vena cava, ileocecal junction, kidney, analrectal junction, bladder, ureter, abomasum, and adrenal gland. These histological samples allow us to analyze the physiologic processes of ruminant animals to better understand how they develop, function and become diseased.

First Floor #22

Local adaptation despite gene flow in the Hawaiian goby fish, Sicyopterus stimpsoni
Kristine Moody

Department of Biological Sciences
Faculty Mentor: Margaret Ptacek

ABSTRACT: High gene flow is a homogenizing force thought to predominate in marine systems as a result of long duration larval dispersal counteracting local divergence as a result of natural selection or genetic drift. If true, then how do local adaptation and speciation occur in the marine environment? The waterfall climbing fish of the Hawaiian Islands, Sicyopterus stimpsoni, alternates life history stages between marine and freshwater environments. High gene flow and low subpopulation differentiation (FST = 0 to 0.0027; p = 1 to 0.002) is facilitated by time spent during the marine larval phase (~ 6 months). However, subpopulations greatly differ from each other in morphology (MANOVA: Year, Island, Island*Year, Stream[Island]; p = < 0.0001) due to differences in stream topology (slope gradients). Therefore, natural selection may be overriding the effects of gene flow leading to local adaptation in subpopulations in S. stimpsoni.

 

First Floor #23

Long-term supplementation of Cranberry Extract improves the healthspan in C. elegans aged population
Ryan M. Kane, Luke T. Lampe, Elisabeth H. Peevy, Randall S. Watson, Sujay Guha, Min Cao, and Yuqing Dong
Department of Biological Sciences
Faculty Mentor: Yuqing Dong

ABSTRACT: Due to their beneficial properties to alleviate the symptoms of aging and stress, natural compounds/nutraceuticals have been studied extensively. In our lab we employ the aging model Caenorhabditis elegans to study the effects of numerous nutraceuticals. Findings from our lab have suggested that supplementation of cranberry extract (CBE) at an optimum concentration not only increase the lifespan, but also helps the worms survive under various stresses. Currently we want to test, how CBE supplementation would affect the different worm populations at different ages. We found that CBE supplementation lead profound lifespan extension in aged population. We also observed improved cognitive skills in aged worms. Next we wanted to see if CBE improved survival of certain mutants used to study age related pathologies. Our preliminary data suggests that CBE helps combat the progression of these age related pathologies. Currently we are trying to investigate the mechanisms involved in this protective effect.

First Floor #24

Mechanisms of ecological-genetic differentiation in a nascent crop-weed species interaction
Kimberly L. Kanapeckas1*, Amy L. Lawton-Rauh1, Nilda R. Burgos2, Albert J. Fischer3
Departments of 1Genetics & Biochemistry (Clemson Univ.), 2Crop, Soil, and Environmental Sciences (Univ. of Arkansas); 3Plant Sciences (Univ. of California-Davis)
Faculty Mentor: Amy L. Lawton-Rauh

ABSTRACT: Weedy rice is tillered, competitive, resists lodging, and shatters easily, traits promoting persistence with crop rice (Oryza sativa L.) and significantly reducing yield. Coalescent models estimate a divergence time of 24 generations between crop and weedy rice in California. Gene genealogies and haplotype relationships further support this very recent weedy rice origin independent from sampled global weed and crop Oryzas. This suggests a recent, independent origin of a new genotype through feralisation. We aim to identify mechanisms responsible for this transition to ferality to understand, how weeds evolve and compete in agroecosystems, domestication, and to address broader questions of adaptation. To identify partitions of phenotypic variance in weed and crop lineages, Principal Components Analysis was performed on combined quantitative and transformed qualitative traits to determine eigenvectors contributing most to group separation. Future work will employ a candidate gene approach to identify microevolutionary mechanisms driving feralisation in this unique ecosystem.

First Floor #25

Metabolic Interactions in the Functions of Plastids Isolated from Soybean Somatic Embyros
Salvatore A. Sparace1, Karen R. Clark1, Yan He1, Tammie E. Young1, Zhigang Li2, Hong Luo2 and Kathryn F. Kleppinger-Sparace1
Departments of 1Biological Sciences, and 2Genetics & Biochemistry
Faculty Mentor: S.A. Sparace

ABSTRACT: Soybean (Glycine max L.) somatic embryos and their plastids are being used to study developmental relationships and metabolic interactions in plastid function. Plastids isolated from exponentially growing embryos are actively engaged in de novo fatty acid biosynthesis. These plastids appear to function like heterotrophic plastids. ATP, coenzymeA and bicarbonate are essential. Acetate is preferred precursor at low (1 mM) concentrations. Pyruvate is preferred at higher concentrations. Isolated plastids can utilize glucose-6-phosphate as a precursor, indicating embryo plastids likely have a complete glycolytic pathway. Precursor radioactivity is recovered in palmitic and oleic acids. Embryos and plastids show high activity rates for key enzymes of nitrogen assimilation, and both zygotic and somatic embryos express homologs of GOGAT and GS, suggesting involvement in nitrogen assimilation. Addition of selected intermediates of glycolytic metabolism and nitrogen assimilation to plastids has various effects on FAB activity, indicating that these metabolic processes may interact with FAB.

First Floor #26

Microbial Growth on Glycerol and Methanol from Several Environments: An Examination of Diversity and EPS Production

Meghan Conlin, Matthew Floyd, Kathleen Robinson, and Joseph Wunderlich
Department of Biological Sciences
Faculty Mentor: Harry D. Kurtz, Jr.

ABSTRACT: Our current research is designed to isolate microbes capable of growth on methanol or glycerol from several environments. These are tested for their ability to produce extracellular polysaccharides (EPS) which we are characterizing using chemical assays and HPLC. Additionally, we are examining the diversity of these organisms in beach ecosystems in the presence and absence of Corexit 9500 components. Several bacterial strains were found to produce EPS when grown on glycerol and we are chemically characterizing them. We are finding that Corexit components have an effect on culturable microbial diversity when glycerol is supplied as a growth substrate. To better understand these effects, we are using molecular genetic techniques to quantify the number of taxonomic groups affected by these treatments. From this work, we expect to learn more about the role of EPS in natural ecosystems and develop a basic understanding of how oil dispersants affect complex microbial communities.

First Floor #27

Modeling Cuttlefish Chromotophore Excitation
Zachary Zboch and James Peterson

Department Biological Sciences
Faculty Mentor: James Peterson

ABSTRACT: A model of cuttlefish neuroanatomy is developed using Matlab. The focus is on the cuttlefish chromatophore system and the primary literature is used to find the neural modules that are connected dynamically to form the chromatophore excitation network. The neural modules and their interconnections are modeled as graphs of computational nodes connected by edges. The nodes are neurons and the edges are the synaptic connections. Our focus is on mapping visual cue inputs to desired output patterns that are displayed on the cuttlefish's skin using a variety of graph training algorithms implemented in Matlab. The graph models are built using a hierarchical or vector based system which allows us to easily find where a given module's neuron is located in full computational graph.

First Floor #28

MULT1E/mIL-12: A Novel Bi-Functional Fusion Protein for NK Cell Activation
Ashlee Tietje, Jinhua Li, Xianzhong Yu, and Yanzhang Wei
Department of Biological Sciences
Faculty Mentor: Yanzhang (Charlie) Wei

ABSTRACT: The novel bi-functional fusion gene joins the NKG2D ligand MULT1E with mIL-12. An expression vector was used to transfect mouse TC-1 lung carcinoma cells. NK cells cultured with clones expressing high or moderate levels of protein expressed significantly higher levels of IFN-γ than the regular TC-1 cells. Interestingly, the clone expressing a moderate amount of the protein induced a significantly higher level of IFN-γ production than the clone expressing a high amount or a clone expressing mIL-12 alone. Furthermore, this clone also showed a reduction in cell growth. When injected intravenously in C57BL/6 mice, clones expressing high and moderate levels of the protein grew slower than clones expressing either a low level or mIL-12 alone. All the clones grew significantly slower than the regular TC-1 cells in vivo. The data suggest that the MULT1E/mIL-12 bi-functional fusion protein is an effective activator of NK cells for cancer treatment.