Theses and Dissertations at Montana State University (MSU)
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733
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Item The regulation and function of integrin alphaE (CD103) in human dendritic cells(Montana State University - Bozeman, College of Letters & Science, 2019) Roe, Mandi Marie; Chairperson, Graduate Committee: Diane Bimczok; Steve Swain, T. Andrew Sebrell, Marisa A. Sewell, Madison M. Collins, Brian A Perrino, Philip D. Smith, Lesley E. Smythies and Diane Bimczok were co-authors of the article, 'Differential regulation of CD103 (alphaE integrin) expression in human dendritic cells by retinoic acid and toll-like receptor ligands' in the journal 'Journal of leukocyte biology' which is contained within this thesis.; Steve Swain, Marziah Hashimi, Krista M. Woo and Diane Bimczok were co-authors of the article, 'A novel role of P38 MAPK signaling and NFAT in the RA-induced expression of CD103 in human dendritic cells' submitted to the journal 'Immunology' which is contained within this thesis.; Dissertation contains an article of which Mandi Marie Roe is not the main author.Retinoic acid (RA) is a master regulator of cellular signaling and function as well as an important mediator of immune development and maintenance. CD103 is a marker that is used to distinguish functional subsets of mucosal DCs. Despite the use of CD103 as a DC marker, the RA-induced pathway leading to CD103 expression is yet unknown. In addition, the function of DC CD103 has not been fully elucidated. In this dissertation research, we evaluated the regulation of CD103 expression on human DCs and investigated the function of DC CD103. We first found that CD103 expression is driven by RA and that CD103 is found in intracellular pockets in human DCs. However, the RA-induced increase of CD103 was abrogated upon stimulation of DCs with TLR ligands. To elucidate the RA-induced pathway of CD103 expression, we established the dependence on p38 MAPK signaling and NFAT through the use of specific inhibitors. Studies with RARalpha siRNA and the use of RAR-specific agonists show that CD103 expression is dependent on RARalpha signaling. To investigate further the intracellular CD103 expression, we demonstrated that CD103 was co-localized with endosomal markers and was actively internalized over time in DCs, suggesting CD103 undergoes endosomal recycling. Based upon imaging of gastric tissue showing CD103^+ DCs are most often within the gastric epithelial layer, we sought to understand the role of CD103 in DC adhesion. We investigated whether CD103 is involved in adhesion of DCs to the epithelium by co-culturing the DCs with HT-29 cells, which express E-cadherin on the entire cell surface. Interestingly, we found that CD103 was not a main driver of DC-epithelial adhesion, but that DC binding to the gastrointestinal epithelium was mediated by the interactions between DC E-cadherin and E-cadherin on the HT-29 cells. In summary, this research has contributed to the understanding of CD103 expression and function on human DCs. CD103 plays a minor role in the adhesion of DCs to the gastrointestinal mucosa, despite CD103^+ DCs close proximity to the gastric epithelium. RA drives the expression of CD103 on DCs mediated through RARalpha and p38 MAPK signaling and NFAT.Item Identification of economic wireworms using traditional and molecular methods(Montana State University - Bozeman, College of Agriculture, 2013) Etzler, Frank Eric; Chairperson, Graduate Committee: Michael A. Ivie; Kevin W. Wanner, Anuar Morales-Rodriquez and Michael A. Ivie were co-authors of the article, 'DNA barcoding to improve the species level management of wireworms' submitted to the journal 'Journal of economic entomology' which is contained within this thesis.; Michael A. Ivie was a co-author of the article, 'Review of the Limonius canus LeConte, 1853 (Coleoptera: Elateridae)' submitted to the journal 'The coleopterists bulletin' which is contained within this thesis.Interest in wireworms has grown in the past decade due to their increasing pest status, largely due to the removal of effective seed treatments from the market. Currently, there is no effective Integrated Pest Management (IPM) strategy to control for wireworms, due to the diverse number of species that make up complexes in cropland. The purpose of this study was to determine what wireworm species are present in Montana's croplands and develop tools to make species concepts accessible to non-specialists. This was done using DNA barcoding to associate wireworms with adults. DNA barcoding was done by amplifying the Cytochrome-Oxidase I (COI) region of the mitochondrial genome. Twenty-nine (29) species were successfully sequenced and 13 species had adult and larval associations made, including three new associations. In addition, a LUCID pictorial key was also created to help identify species occurring in Montana. A LUCID key is a computer-based key where a user identifies a specimen with the help of pictures of each character. During the wireworm study, one species-group in the genus Limonius was found to include many economic species, including two that are important in Montana. This group needed to be reevaluated due to controversies raised in a recent revision, many of which dealt with economic species. With the combined use of morphological characters and DNA data, eight species are now recognized as belonging to the group. All of these subprojects show the combined use of DNA and morphology as essential to fully understanding wireworm species. With a more precise knowledge of the species that make up the complexes in Montana's croplands, we can focus on developing IPM stratetgies for efficient control.Item Application of genomic assisted breeding for improvement of barley cultivars(Montana State University - Bozeman, College of Agriculture, 2014) Pauli, William Duke; Chairperson, Graduate Committee: Thomas Blake; Gary J. Muehlbauer, Kevin P. Smith, Blake Cooper, David Hole, Don E. Obert, Steven E. Ullrich and Thomas K. Blake were co-authors of the article, 'Association mapping of agronomic QTLs in US spring barley breeding germplasm' in the journal 'The plant genome' which is contained within this thesis.; Thomas K. Blake was a co-author of the article, 'Identification of malt quality marker-trait associations in elite barley breeding germplasm' submitted to the journal 'Journal of the American Society of Brewing Chemists' which is contained within this thesis.The use of genome-wide association studies (GWAS) to detect quantitative trait loci (QTL) controlling complex traits has become a popular approach for studying key traits in crop plants. The goal of this research was to identify regions of the barley (Hordeum vulgare L.) genome that impact both agronomic and malting quality traits. By identifying these regions of the genome and their associated diagnostic markers, we gain an understanding of the genetic architecture of the traits as well as develop informative markers that can be utilized for marker-assisted selection. We used the data generated by the Barley Coordinated Agricultural Program to identify marker-trait associations impacting agronomic performance using a Q+K mixed linear model accounting for population structure and relatedness among lines. This data was also used to develop a genotyping platform specific to the Montana State University (MSU) Barley Breeding Program. This genotyping platform was used to genotype 650 advance generation lines from eleven bi-parental families to investigate the genetic basis of malting quality traits and the regions of the barley genome impacting them. We detected 41 significant marker-trait associations for the agronomic traits we studied with 31 of those being previously detected in bi-parental mapping studies. We detected 54 significant marker-trait associations for the malting quality traits with 24 of those being previously reported. The combined results from both studies indicate that major genes impacting key traits in barley are still segregating in US germplasm as well as in the MSU germplasm. This demonstrates that there is useful standing genetic variation that can be utilized for superior barley cultivar development and further genetic gain. Furthermore, by identifying the beneficial alleles, and their associated markers, we can form a "catalog" of major genes and QTL impacting agronomic and malting quality traits which can be used for marker-assisted selection. This work also demonstrates the feasibility and utility of conducting GWAS in narrow germplasm arrays like those found in regional breeding programs and serves as a paradigm for other cereal breeding programs. Together, these studies show how genomic data can be leveraged for varietal improvement in regional plant breeding programs.