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Articles 1 - 9 of 9

Full-Text Articles in Molecular Biology

Identification And Characterization Of Mitochondrial Dna Variants In Alzheimer's Disease, Natasha Singh Hamblet Jul 1995

Identification And Characterization Of Mitochondrial Dna Variants In Alzheimer's Disease, Natasha Singh Hamblet

Theses and Dissertations in Biomedical Sciences

Alzheimer's Disease (AD) is a complex neurodegenerative disorder that affects a significant portion of the human population regardless of ethnicity or gender. A mitochondrial hypothesis of AD has been proposed based on a number of studies which establish altered oxidative phosphorylation (OXPHOS) and ATP synthesis in AD tissue. ATP demand is most prevalent in the brain; damage to OXPHOS could severely impair brain metabolism, thereby leading to a decline in cognitive function. Four out of five complexes in the OXPHOS pathway are partly encoded by mitochondrial DNA (mtDNA); thus, this may be a crucial site of lesions that alter ...


Investigation Of The Substrate Recognition Characteristics And Kinetics Of Mammalian Mitochondrial Dna Topoisomerase I, Zeki Topcu Jul 1995

Investigation Of The Substrate Recognition Characteristics And Kinetics Of Mammalian Mitochondrial Dna Topoisomerase I, Zeki Topcu

Theses and Dissertations in Biomedical Sciences

Topoisomerases are DNA-modifying enzymes found in prokaryotes, eukaryotes, viruses and organelles such as chloroplast and mitochondria. Information about these enzymes in eukaryotic systems is mostly limited to nuclear enzymes, although our laboratory has been characterizing the biochemical and biophysical properties of the mammalian mitochondrial topoisomerases. We have determined the polarity of the attachment of mitochondrial topoisomerase I to its substrate DNA. To study the substrate preference and kinetic parameters of mitochondrial topoisomerase I, selected regions of mammalian mitochondrial DNA (mtDNA) were inserted into pGEM plasmid vectors following a series of modification and optimization experiments of currently available methods for PCR-cloning ...


Identification And Characterization Of Genes Associated With V-Jun Induced Cell Transformation, Martin Toralballa Hadman Apr 1995

Identification And Characterization Of Genes Associated With V-Jun Induced Cell Transformation, Martin Toralballa Hadman

Biological Sciences Theses & Dissertations

The v-jun oncogene was initially identified as the causative agent for fibrosarcomas in chickens. Studies show that overexpression of v-Jun proteins transforms chicken embryo fibroblasts (CEF) in vitro, and forms tumors in chickens in vivo. The mechanisms for this are not clearly defined. Conceivably, overexpression of an unregulated transcription factor would cause cell transfonnation by illicit regulation of its target genes. In support of this, we show that in vivo v-Jun complexes exhibit differential binding to in vitro generated AP-1 and 'AP-1 like' target sequences, suggesting that the pattern of target gene expression is altered during cell transformation. With this ...


Pathogenicity Of Murine Cytomegalovirus Mutants, Victoria Jean Cavanaugh Apr 1995

Pathogenicity Of Murine Cytomegalovirus Mutants, Victoria Jean Cavanaugh

Theses and Dissertations in Biomedical Sciences

The purpose of this study was to identified nonessential murine cytomegalovirus (MCMV) genes involved in pathogenesis in vivo. Our approach to identifyjng these genes consisted of constructing MCMV mutants, and then analyzing these mutants in vitro and in vivo. Recombinant viruses (RV) expressing the β-glucuronidase marker gene were constructed by site-directed insertion and deletion mutagenesis of the MCMV Hind III-J and -I regions of the viral genome. Mutations were targeted to this region of the MCMV genome because the corresponding region of the human CMV genome is nonessential and is involved in down-regulating major histocompatibility complex (MHC) class I expression ...


Restriction Fragment Length Polymorphism In Sorghum (Sorghum Bicolor (L.) Moench): Characterization Of Genetic Diversity And Quantitative Trait Loci , Dario Ahnert Jan 1995

Restriction Fragment Length Polymorphism In Sorghum (Sorghum Bicolor (L.) Moench): Characterization Of Genetic Diversity And Quantitative Trait Loci , Dario Ahnert

Retrospective Theses and Dissertations

Restriction fragment length polymorphisms (RFLPs) were employed to investigate genetic diversity and quantitative trait loci (QTL) for morphological characters on sorghum (Sorghum bicolor (L.) Moench). The objectives of this research were accomplished by studying two different sets of genotypes. One set was composed of 105 elite inbred lines (47 B- and 58 R-lines) and the other of 152 F[subscript]2:3 lines. In the R- and B-lines set, the objectives were to define the level of genetic similarity (GS) and relationships within these lines. In the 152 F[subscript]2:3 lines set, the objectives were to characterize QTL ...


Sequence Variation Characteristics Of D-Loop, Rrna, Trna, And Polypeptide Coding Region Of Bovine Mitochondrial Dna , Jianming Wu Jan 1995

Sequence Variation Characteristics Of D-Loop, Rrna, Trna, And Polypeptide Coding Region Of Bovine Mitochondrial Dna , Jianming Wu

Retrospective Theses and Dissertations

By cloning and sequencing the mtDNA of cows from different maternal lineages, it was found that multiple heteroplasmic mtDNA states within the D-loop and rRNA genes of mtDNA existed extensively in Holstein cattle. Meanwhile, the nature and transmission of mtDNA were investigated. The mtDNA population in a specific animal was found to be a mixture of different genotypes. Because heteroplasmy was observed frequently and seemingly is persistent, selected amplification of specific mtDNA molecules may not be a part of mtDNA inheritance. At same time, four hypervariable sites were located at nt 169, 216, and 1594 between nt 352 to 364 ...


Rflp Mapping Of Quantitative Trait Loci For Reproductive, Morphological, And Seed Traits Of Soybean (Glycine Max L.) Across Environments , Heike Kross Jan 1995

Rflp Mapping Of Quantitative Trait Loci For Reproductive, Morphological, And Seed Traits Of Soybean (Glycine Max L.) Across Environments , Heike Kross

Retrospective Theses and Dissertations

Quantitative trait loci (QTL) and QTL x environment interaction were identified for 11 agronomic traits in soybean, when measured at two locations in each of two years in Iowa. The segregating population consisted of 76 F[subscript]2:5/F[subscript]2:6 families derived from the cross between the two soybean (Glycine max (L.) Merr.) cultivars 'Minsoy' (PI27.890) and 'Noir 1' (PI 290.136). A genetic linkage map consisting of 81 markers in 25 linkage groups was used to locate QTL by interval mapping. Analyses of variance was performed on 72 linked and unlinked markers to test for ...


Molecular Analyses Of Group 1 Late Embryogenic Abundant (Lea) Genes In Soybean (Glycine Max (L.) Merr.) , Éberson Sanches Calvo Jan 1995

Molecular Analyses Of Group 1 Late Embryogenic Abundant (Lea) Genes In Soybean (Glycine Max (L.) Merr.) , Éberson Sanches Calvo

Retrospective Theses and Dissertations

The entire soybean Sle gene family was cloned and characterized. The five Sle genes (Sle1-5) could be divided into two classes based on sequence identity. Sle1-4 map to 4 different linkage groups. Sle1 and Sle5 are expressed weeks earlier in seed development than Sle2 and Sle3. Sle4 is a pseudogene. Maximal levels of Sle mRNA accumulate in the seeds, before desiccation had occurred, and decline rapidly upon seed imbibition. Desiccation does not induce Sle expression in seeds. Unlike most of its homologs, ABA is not necessary to induce Sle expression in cultured embryos and only moderately increases Sle mRNA levels ...


Cloning And Characterization Of Two Chlorophyll Synthesis Genes Expressed During Tomato Fruit Development , Gary Francis Polking Jan 1995

Cloning And Characterization Of Two Chlorophyll Synthesis Genes Expressed During Tomato Fruit Development , Gary Francis Polking

Retrospective Theses and Dissertations

Full-length clones that encode tomato (Lycopersicon esculentum Mill.) glutamate-1-semialdehyde-2,1-aminomutase (GSAAM) and 5-aminolevulinic acid dehydratase (ALAD) were isolated and characterized. Sequence analysis showed that tomato GSAAM and ALAD clones exhibited a high level of homology to corresponding clones found in other plant species. The primary structure of GSAAM predicted a 481-amino acid precursor that comprised a 46.7 kDa, 437-amino acid mature protein and a transit peptide of 44 amino acids. The primary structure of ALAD predicted a 430-amino acid precursor that comprised a 41.7 kDa, 383-amino acid mature protein and a 47-amino acid transit sequence. Southern analysis showed ...