Session D: 3:30PM – 5PM
SESSION D (3:30PM – 5PM)
Location: Theatre, A. Ray Olpin University Union
Pollinators Role in an Ongoing Speciation Event
Samantha Ingram, Utah Valley University
Faculty Mentor Michael Rotter, Utah Valley University
SESSION D 3:30-3:45PM
Science and Technology
There are many factors that contribute to speciation events. Importantly in plants, pollinators can have a large impact on breeding between different individuals. This discrimination of pollinators is driven by a variety of morphological traits in the plant, therefore possibly leading specific pollinators to having a strong plant preference. In the Western United States, rabbitbrush is a common shrub with over 20 different sub-species that co-exist and may exchange genes. Despite their interbreeding these sub-species appear as seemingly stable evolutionary units. This knowledge leads to the question: Do pollinators discriminate between sub-species of rabbitbrush? Studying these differences can be important for predicting gene flow and how speciation events may start to occur. To answer this question, we intend to complete a series of experiments comparing variables of two sub-species of rabbitbrush; viability of seeds, morphological floral measurements, identification of insect communities, observational field trials with fluorescent pigment as a proxy for gene flow, and chemical analysis. We expect that due to the floral morphological differences, pollinators will favor one sub-species of rabbitbrush over the other. Thereby, providing evidence of pollinator impact on speciation events through gene flow. This study will provide understanding of ongoing diversification events of rabbitbrush. Additionally, the knowledge found will contribute to the more general and deeper understanding of how ecological roles, between pollinator and plant, contribute to evolution.
Provitamin D3’s photochemical reaction and previtamin D3’s isomer-selective formation via phenylalanine
Tony Ochsner, Southern Utah University
Faculty Mentor Jacob Dean, Southern Utah University
SESSION D 3:50-4:05PM
Science and Technology
Vitamin D3 is an essential steroid for humans to maintain calcium levels and preserve bone density. The creation of vitamin D3 in the body is activated by light and is a well-studied reaction. The ring opening of its steroid precursor 7-dehydrocholesterol, or provitamin D3(PVD), is photo-initiated from UVB and some lower energy UVC wavelengths. Studies have shown a strong wavelength dependence on the final
product formation due to subsequent isomerization reactions. Previtamin D3 is the ring opened metastable intermediate, formed after the absorption of lower energy UVB wavelengths. It will eventually thermally rearrange to form the bioavailable vitamin D3. However, if previtamin D3 interact with a higher energy UVB or lower energy UVC photon this will trigger an isomerization and increase minor product formation, such as tachsterol or lumisterol. In this study the experiments were focused on maximizing previtamin D3 formation in the UCV region by minimizing secondary isomerization. This was accomplished by introducing phenylalanine(PHE), a known UVC absorber into a solution with PVD, for the purpose of converting UVC wavelengths into lower UBV energy. In the process, the energy is made available through energy transfer to initiate the ring opening reaction itself. Through several experiments and date analysis there is strong evidence that when illuminated with lower energy UVC wavelengths the PHE-PVD solution aided in the formation of previtamin D3. A secondary influence caused by phenylalanine was to diminish previtamin D3’s secondary isomerization by acting as an inbound energy down-shifter that suppresses isomerization. When a similar mixed solution was illuminated with lower energy UVB wavelengths the formation of previtamin D3 proceeded unimpeded by the phenylalanine.
Remediation of Benzo(a)pyrene in soils for urban agriculture using aerobic compost amendments
Victoire Soumano, Westminster College
Faculty Mentor Christy Clay, Westminster College
SESSION D 4:10-4:25PM
Science and Technology
Benzo(a)pyrene (BaP) pollution in urban soils is a concern for urban farmers and limits cities’ ability to use vacant land to grow food. BaP is a hydrophobic organic compound that forms as a result of incomplete combustion of organic materials from asphalt paving, diesel and gasoline emissions, wood burning, and burning of coal, oil, and soot from industry. Our research aims to develop a low cost ecological remediation method to reduce BaP concentration in urban soils to a level safe for food production. Previous studies suggest that soil microorganisms can break down organic pollutants such as BaP, however a successful method has yet to be determined. The ultimate goal of this project is to determine the effectiveness of BaP remediation using aerobically produced compost with a diverse and abundant microbial community. Currently we are developing a synchronous scanning fluorescence spectroscopy method to evaluate the soil at 90 locations on the farm to assess the extent of BaP contamination. The method and results of the soil assessment will be presented. In continued work, we will also measure BaP concentration after in situ amendment of aerobic compost in ratios of 1:1, 1:0.5, and 1:0.33, to determine the proportion required for BaP degradation. We hypothesize that the 1:1 soil ratio will decrease BaP concentration by half, simply by dilution, and more due to degradation by soil microorganisms. As for the other ratios, we expect them to decrease BaP concentration in the soils as a result of the microorganisms breaking down BaP molecules, perhaps at various levels.
Role of FliQ in flagellar secretion-specificity switch
Angus Wu, University of Utah
Faculty Mentor Fabienne Chevance, University of Utah
SESSION D 4:30-4:45PM
Science and Technology
The assembly of the bacterial flagellum in Salmonella is achieved via a flagellar type III secretion system (fT3SS), translocating flagellar proteins from the cytoplasm through the center of the growing organelle where they self-assemble at the distal end of a growing structure. Upon completion of an intermediate assembly structure (the hook-basal body or HBB), the fT3SS undergoes a secretion substrate specificity switch from early assembly proteins (HBB subunits) secretion to late substrate proteins (filament subunit) secretion. We previously isolated a spontaneous mutation in FliQ (G32D) that enables late substrate (FlgM-bla) secretion prior to HBB assembly. FliQ is a core component of the fT3SS. To explore how FliQ partakes in the flagellar specificity switch, FliQ was subjected to targeted doped oligo mutagenesis in order to identify other residues in FliQ that would cause a similar effect as the FliQ G32D mutant. We were able to isolate such a critical residue in at amino acid 48 (T48M) in FliQ. Subsequent targeted randomized (NNN) mutagenesis of amino acid codons 32 and 48 of FliQ revealed amino acid substitutions with similar secretion properties as the FliQ G32D and T48M alleles that are able to switch flagellar specificity prior to HBB assembly plus other substitutions that were defective in secretion. We therefore can conclude that both the G32 and T48 amino acid residues of FliQ are crucial to the function of FliQ and to the secretion-specificity switch. To test whether FliQ mutants lose or retain the ability to facilitate early protein secretion, we will construct a fusion product of β-lactamase protein lacking its Sec-dependent secretion signal (Bla) to the C-terminus of FlgE, a hook subunit protein (early secretion-substrate), as a reporter for detecting early flagellar protein secretion. In addition, all fliQ mutants will be complemented with wild type fliQ to characterize their dominant or recessive features. This in-depth research is a continuation of my UROP project, and this study should add its own unique contribution to the current understanding of the flagellar secretion-substrate specificity switch.