2004 Undergraduate Research and Creative Achievements Forum (MU)
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Mizzou's annual Undergraduate Research and Creative Achievements Forum showcases student research and scholarly and creative achievements to the Mizzou community. Undergraduates from any major and all academic levels are eligible to present their work. Students presenting at the forum are eligible to compete for the Chancellor's Award for Excellence in Undergraduate Research and Creative Achievements.
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Item Going underground: Benefits of phototropism in Arabidopsis depend on the soil environment [abstract](University of Missouri--Columbia. Office of Undergraduate Research, 2004) Youngstrom, Sarah; University of Missouri-Columbia. Office of Undergraduate Research; Undergraduate Research and Creative Achievements Forum (2004 : University of Missouri--Columbia)Phototropins are blue-light photoreceptors that control shoot and root phototropism in Arabidopsis thaliana. We investigated whether the soil environment influences the benefit of phototropism. We hypothesized that root phototropism should improve survival and growth under dry soil conditions, but not under wet conditions. We used a greenhouse experiment to test whether phototropism under dim light benefits plants in drought conditions. Seed of two non-phototropic (phot 1, nph3) mutants and wildtype A. thaliana (Columbia ecotype) were planted into a range of soil moisture regimes created by altering the sand content in the soil and varying the watering schedule. The soil water content varied from 26%-65% (w/w) mainly due to the sand content. Seedling size (rosette diameter) was measured three weeks after germination. We found several significant results. First, seedling emerged earlier in wet soil (11.5+/- 4.3 days after planting) then dry soil (15.3 +/- 5.6 d). Second, wild type plants were significantly larger than the mutant genotypes, but the magnitude of the size advantage depended on the soil environment. In sandy soil the wild type plants were 20% larger then the non-phototropic mutant plants (P<0.0001), and in the clay soil, the wild type plants were only 12% larger then the non-phototropic mutant plants(P<0.01). These results agree with previous findings that the growth advantage associated with phototropism increases in dry conditions. These results led us to wonder what was happening below the soil surface. We asked do nonphototropic plants differ from wild type in their rooting profiles, due to impaired root phototropism of mutant genotypes. We tested this idea in another greenhouse experiment in which the same genotypes were grown under dry and wet soils resembling the moisture extremes of the first experiment. Seeds were planted along the sides of clear plastic window boxes to enable us to track the roots. All sides except the top of the boxes were wrapped in foil to prevent light from entering. One month later, the boxes were unwrapped and the roots traced to determine the length and distance that each had traveled through the soil. Measurements are currently in progress.Item Using mutant roundworms to understand development: glh-4 was caught! [abstract](University of Missouri--Columbia. Office of Undergraduate Research, 2004) Yee, Christopher; University of Missouri-Columbia. Office of Undergraduate Research; Undergraduate Research and Creative Achievements Forum (2004 : University of Missouri--Columbia)To understand development, scientists have utilized simple organisms including the soil roundworm Caenorhabditis elegans. The Bennett laboratory has utilized this nematode to study a family of proteins called germline RNA-helicases, or GLHs. Proteins similar to the GLHs are found in humans. A technique to temporarily knockout a gene's function, called RNA-interference, has revealed that these proteins are necessary for fertility and for establishing the reproductive system in C. elegans. However, strains of roundworms with genetic mutations in the genes that code for the GLHs are necessary to effectively study the protein's functions. While fishing to find a glh-4 deletion strain with millions of worms we had mutagenized, we were fortunate that the C. elegans Knockout Consortium in Vancouver, British Columbia found a glh-4 mutant and provided it to us. Initial analyses of the mutant strain glh-4 (gk225) by western blot analysis and by immunocytochemistry with anti-GLH-4 antibodies suggests that, as hoped, the mutation results in a strain of worms not producing the GLH-4 protein, a protein null. In addition, the glh-4 (gk225) strain was mated against normal wild-type worms for six generations to remove other mutations that may have been produced in the original mutagenesis. We are currently studying the mutant's phenotype and are generating a glh-1;glh-4 double with the glh- 1(ok439) strain, as combinatorial RNAi indicates the loss of both glh-1 and glh-4 results in the most severe germline defects. By studying these genes and proteins, we can obtain a better idea of the machinery behind development and reproduction in worms and ultimately humans.Item Anatomical organization of pathways in the locomotor command system of the lamprey [abstract](University of Missouri--Columbia. Office of Undergraduate Research, 2004) Wolf, Ryan; University of Missouri-Columbia. Office of Undergraduate Research; Undergraduate Research and Creative Achievements Forum (2004 : University of Missouri--Columbia)In vertebrates, locomotor behaviors are initiated by groups of neurons in the brain, called locomotor command systems, that project to neural networks in the spinal cord, called central pattern generators (CPGs). The output neural elements of the command system are reticulospinal (RS) neurons. The lamprey, a lower vertebrate, is an excellent model for studying locomotion because its swimming behavior is relatively simple and its nervous system is easier to analyze than those of more complex animals. Recent studies using larval sea lamprey (P. marinus) have hypothesized that RS neurons receive inputs from neurons in higher brain areas in the ventromedial diencephalon (VMD) and dorsolateral mesencephalon (DLM) (Paggett et al., in press). For example, VMD- or DLM-initiated locomotor activity is abolished when RS neurons activity is blocked. In addition, injection of horseradish peroxidase (HRP), an anatomical tracer, in the vicinity of RS neurons retrogradely labels a few neurons in the VMD and DLM. However, the numbers of labeled neurons in the VMD and DLM are lower than we would expect. Therefore, the above model would be significantly strengthened if better anatomical data could be obtained. In the present study, a different anatomical tracer, called biocytin, was injected into reticular nuclei in an attempt to retrogradely label larger numbers of neurons in the VMD and DLM. At present, we have shown that biocytin is an effective retrograde tracer, and we are determining if this technique can be used to support our model of the locomotor command system.Item Quantitative real-time RT-PCR determining extracellular matrix protein expression in osteogenesis imperfecta murine (oim) thoracic aortas [abstract](University of Missouri--Columbia. Office of Undergraduate Research, 2004) Wirth, David; University of Missouri-Columbia. Office of Undergraduate Research; Undergraduate Research and Creative Achievements Forum (2004 : University of Missouri--Columbia)Primary components of the thoracic aorta critical for tissue integrity are collagen and elastin. Collagen, a rod-like protein contributes to aortic strength and stiffness, while elastin, a highly extensible protein contributes to aortic compliance. Type I collagen, the predominate collagen in aortic tissue, is normally a heterotrimeric molecule composed of two proalpha 1(I) chains and one proalpha 2(I) chain. The osteogenesis imperfecta murine (oim) model is an exceptional system to study type I collagen's affect on aortic integrity because it is a functional null for the proalpha 2(I) collagen gene, synthesizing only homotrimeric type I collagen molecules composed of three proalpha 1(I) chains. Our biomechanical studies of oim mice demonstrate that the absence of proalpha 2(I) collagen chains significantly reduces thoracic aortic breaking strength and stiffness. Histological analysis suggested reduced collagen staining in oim/oim and heterozygote aortas. To further investigate the mechanism of reduced collagen staining, HPLC analysis was done to determine total collagen and crosslinking content. Results demonstrated a significant reduction of collagen content per tissue content and an increase of collagen crosslinks in oim/oim and heterozygote aortas compared to wildtype. The reduced collagen content and increased collagen crosslinks of oim/oim and heterozygote aortas prompted us to examine the pre-translational amounts of aortic extracellular matrix protein mRNAs. We determined the COL1A1, COL1A2, COL3A1, ELASTIN, LYSYL OXIDASE, and TUBULIN mRNA levels in thoracic aortas of oim/oim, heterozygote, and wildtype mice at 3, 8, and 18 months of age using quantitative real-time RT-PCR.Item Characterizing Babesia genes for candidate vaccine peptides [abstract](University of Missouri--Columbia. Office of Undergraduate Research, 2004) Williams, Rachel; University of Missouri-Columbia. Office of Undergraduate Research; Undergraduate Research and Creative Achievements Forum (2004 : University of Missouri--Columbia)Babesiosis is a tropical cattle disease caused by the parasite Babesia bovis. This parasite infects red blood cells in cattle in much the same way as the malaria parasite Plasmodium falciparum infects red blood cells in humans. It also shares other characteristics that make babesiosis a good model disease for malaria. Using a phage-display strategy, certain peptides have previously been selected which could serve as components in a vaccine for babesiosis. The main goals of this project are to determine if the selected peptides are “natural” peptides, that is, parts of actual parasite proteins; and to gather available information about the function of those proteins. To accomplish this, we probed a B. bovis cDNA library with the coding sequences of selected phage-displayed peptides. The sequenced cDNA clones were used to determine if the phage-displayed peptide sequence matched the open reading frame of the cDNA clones. These cDNA clones were further used to learn about our peptides' function and location in B. bovis by comparison of the cDNA sequence to that of homologous proteins and known motifs. So far we have characterized clones from 24 different probes. Out of those clones 10 showed homology to known or hypothetical proteins, and 5 are putative membrane proteins. Membraneassociated proteins and other proteins that are expressed on the outer side of the parasite fit the mold of good vaccine components.