Browsing by Author "Laura Mathies, Committee Member"

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    Development of Novel Methodologies for the Photoregulation of Biological Processes.
    (2010-07-01) Georgianna, Wesleigh Edwards; Alexander Deiters, Committee Chair; Jonathan Lindsey, Committee Member; Lin He, Committee Member; David Muddiman, Committee Member; Laura Mathies, Committee Member
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    Disconnected, a C2H2 Zinc Finger Protein, has a role in Appendage Formation and Gene Regulation in Drosophila.
    (2008-02-15) Patel, Mukund; James W. Mahaffey, Committee Chair; Laura Mathies, Committee Member; Pat Estes, Committee Member; Steve Spiker, Committee Member
    One the biggest questions in developmental biology is how the Hox proteins direct such complex target gene regulation given that they have very little target specificity. The Homeotic⁄Hox proteins are evolutionarily conserved proteins that specify segment identity by regulating segment-specific batteries of target genes. One possible way to increase transcription specificity is through the use of cofactors. This has lead to the extensive searches to identify potential Hox cofactors. Although several Hox cofactors have been identified, only Extradenticle has been well characterized. Previously, our lab identified paralogous redundant genes disconnected (disco) and disco-related (disco-r) as genetic cofactors for the Hox genes Deformed and Sex combs reduced that are required for proper Drosophila embryonic head patterning. disco and disco-r encode C2H2 zinc finger transcription factors that are conserved among edysozoa, lophotrochozoa, and some deuterosomes. Here, I present a molecular characterization of Disco as a transcription factor. I determined that Disco is able to bind to sequences that contain TGACA at the core in vitro. Furthermore, I characterized the interaction of Disco with the corepressor CtBP. I also examine the significance of certain amino acid differences in the DNA-binding domain between ecdysozoa⁄lophothrochozoa and deuterosomes, concluding that one cysteine is required for complete Disco function. In addition to the molecular characterization, I also describe Disco's role during development of the adult Drosophila demonstrating that Disco is part of the appendage development network. This data is supported from studies in Tribolium castaneum done by Lisa Robertson and Nathaniel Grubbs. Several redundant C2H2 zinc finger genes have been identified in Drosophila including disco and disco-r that have roles in segmental patterning. Based on this we undertook a genome wide study to identify other novel, redundant C2H2 zinc finger genes that also function during segmental patterning. The results of this study are presented including identification two genes, CG5249 and CG11798. Lastly, the appendix contains data from a microarray experiment that examined transcriptional changes due to ectopic activation of Disco.
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    Genome Annotation of Meloidogyne hapla.
    (2010-08-03) Cromer, John; David Bird, Committee Chair; Charles Opperman, Committee Chair; Laura Mathies, Committee Member; Eric Stone, Committee Member
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    Larval Gene Expression and Genetic Variation in the Canine Hookworm, Ancylostoma caninum
    (2006-03-02) Moser, Jennifer Marie; Greg Gibson, Committee Chair; Prema Arasu, Committee Member; Ignazio Carbone, Committee Member; Laura Mathies, Committee Member
    The hookworm, Ancylostoma caninum is a canine parasite, and is responsible for anemia and death in infected puppies. Gene expression profiling was used to investigate transcript differences between two different forms of the third larval stage (L3s): infective free-living larvae and in vitro serum-stimulated larvae that mimic the initial stages of parasitism of a host. I developed an A. caninum cDNA microarray and used it to identify a set of 113 genes that are differentially regulated between infective and parasitic larval stages. Of the genes repressed upon serum stimulation, seven encode members of the 'Ancylostoma Secreted Protein' ASP family, while another transcript encoding a 24 kD excretory protein with similarity to ASP was up-regulated in serum-stimulated L3s. Thus, different members of a protein family that has important implications for the hookworm's parasitic lifestyle are regulated in a complementary manner in response to serum stimulation. Comparison of two strains of A. caninum from North Carolina and Maryland only identified a single gene, one of the members of the ASP family that was differentially repressed upon serum stimulation. Population genetic variation has previously been described contrasting samples from clone libraries of Baltimore and Shanghai strains of A. caninum, but variation within and among wild isolates has not been characterized. I quantified the genetic variation and population structure of several different geographical isolates of A. caninum at two loci. The cytochrome oxidase subunit 1 (cox-1) is a mitochondrial marker gene revealing moderate diversity within a Wake County isolate that is comparable to the level of variation observed in other parasitic nematodes. The protein coding gene asp-1, chosen for its possible use as a vaccine target, shows similar levels of genetic variation within Wake County as cox-1, and there is no evidence for selection acting on this locus. The genetic variation within a Maryland laboratory isolate is more limited, likely resulting from a founder event and subsequent inbreeding. I also provide evidence for gene flow both among Southeastern U.S. isolates and among global isolates, suggesting that the mobility of A. caninum's host animal is an important contributing factor to its parasite's population structure.