Open Access. Powered by Scholars. Published by Universities.®

Molecular Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 73

Full-Text Articles in Molecular Biology

The Analysis Of Global Gene Expression Related To Starch, Lipid And Protein Composition , Ling Li Jan 2006

The Analysis Of Global Gene Expression Related To Starch, Lipid And Protein Composition , Ling Li

Retrospective Theses and Dissertations

This dissertation provides a greater understanding of starch metabolism and its regulation by using mutants altered in starch accumulation, together with a combination of approaches such as global gene profiling, promoter::GUS/GFP analyses, and genetics;Starch debranching enzymes are critical for starch accumulation. The temporal and spatial co-expression of ISA1 and ISA2 is consistent with previous evidence that they co-function as a protein complex (ISA1/ISA2) for starch synthesis. The extensive temporal and spatial co-expression of ISA2 and ISA3 suggests they might also form a protein complex, taking part in starch metabolism. ISA3 protein is localized in leaf chloroplast ...


Neuronal Functions Of Ahr-1, The Caenorhabditis Elegans Homolog Of The Aryl Hydrocarbon Receptor , Hongtao Qin Jan 2006

Neuronal Functions Of Ahr-1, The Caenorhabditis Elegans Homolog Of The Aryl Hydrocarbon Receptor , Hongtao Qin

Retrospective Theses and Dissertations

The mammalian aryl hydrocarbon receptor (AHR) mediates the toxic effects of dioxins and related compounds. Toxicological and genetic studies have shown that AHR regulates important development events and physiological functions. Interestingly, AHR homologs are found in most metazoans, and studies of AHR regulation and function in invertebrate model systems may provide insight to the ancient functions of AHR. In this thesis, I analyze the endogenous functions of the ahr-1 gene in the nematode Caenorhabditis elegans. ahr-1:GFP is expressed in a subset of neurons. ahr-1 regulates the development of diverse neuronal cell types, including the AVM and PLM touch receptor ...


Repair Of Endonuclease- And Transposon-Induced Dna Double Strand Breaks By Host Factors In Arabidopsis , Zhuying Li Jan 2006

Repair Of Endonuclease- And Transposon-Induced Dna Double Strand Breaks By Host Factors In Arabidopsis , Zhuying Li

Retrospective Theses and Dissertations

The maize Ac/Ds transposable elements are members of the hAT transposon family. Ac/Ds transpose in diverse species and via a mechanism similar to that involved in V(D)J recombination. Here, we studied the repair of Ds transposition-induced hairpins by host factors in Arabidopsis. The results indicate that AtKu could position hairpin-opening to sites close to the hairpin apex. In the absence of AtMre11 or AtKu70, repair junctions have a higher frequency of small deletions (3-10bp) and larger deletions (11-50bp), respectively. Comparison of the repair of I-SceI- and Ds-induced DSB indicates that Ac transposase could influence Ds-induced DSB ...


Characterization And Interactions Of Tbx2 , Christian Nephi Paxton Jan 2006

Characterization And Interactions Of Tbx2 , Christian Nephi Paxton

Retrospective Theses and Dissertations

T-box (Tbx) proteins are dynamically expressed throughout embryogenesis and appear to have significant roles in a number of developmental processes. The T-box family is characterized by a highly conserved DNA binding domain. Over twenty mammalian T-box proteins have been identified, many of which have the demonstrated ability to regulate transcription. Both activators and repressors of gene transcription have been described within this family, but how their functions are performed is largely unknown;Tbx2 is a powerful transcriptional repressor with functional roles identified in cardiogenesis and limb development. However the functional domain(s) of Tbx2 are poorly characterized. Tbx2 contains a ...


Studies Of Hypoxia Response And Regulation Of Hypoxia-Inducible Factor Hif-1 In Caenorhabditis Elegans , Chuan Shen Jan 2006

Studies Of Hypoxia Response And Regulation Of Hypoxia-Inducible Factor Hif-1 In Caenorhabditis Elegans , Chuan Shen

Retrospective Theses and Dissertations

All aerobic organisms require molecular oxygen to generate metabolic energy for normal growth and survival. During evolution, multi-cellular organisms have developed and refined complex networks for adaptation to hypoxic environments at both systemic and cellular levels. Adaptation to hypoxia largely results from changes in the activity and expression of key proteins. These include proteins involved in increasing oxygen delivery to hypoxic tissues and proteins that facilitate glycolysis for anaerobic metabolism. The mammalian transcription factor hypoxia-inducible factor (HIF) is a master regulator of oxygen homeostasis. More than 100 target genes of HIF mediate broad systemic and local responses to hypoxia, including ...


Molecular Genetic Analyses Of Oilseed Brassica Germplasm: Determination Of Life Forms And Germplasm Management Strategies By Using Microsatellite Markers And Flowering Locus-C (Flc1 And Flc3) Gene Sequences , Von Mark V. Cruz Jan 2006

Molecular Genetic Analyses Of Oilseed Brassica Germplasm: Determination Of Life Forms And Germplasm Management Strategies By Using Microsatellite Markers And Flowering Locus-C (Flc1 And Flc3) Gene Sequences , Von Mark V. Cruz

Retrospective Theses and Dissertations

Molecular markers were utilized in conjunction with phenological and morphological information, and statistical methods for diversity analyses to address plant genetic resource conservation issues. The objectives of this study have been categorized into two sets. The first set pertains to exploratory surveys of genetic variation using molecular markers and DNA sequences to determine if microsatellite markers or variation in two copies of the FLOWERING LOCUS C gene (FLC1 and FLC3) can be used in determining life forms of fifty representative accessions of Brassica napus. The second set of objectives addresses good genebank practices and includes: characterization of flowering time of ...


Plant Genome Informatics: Evaluation And Analysis Of Genomic Dna Features Involved In The Transcriptional Processing Of Protein Coding Genes , Shannon Dwayne Schlueter Jan 2006

Plant Genome Informatics: Evaluation And Analysis Of Genomic Dna Features Involved In The Transcriptional Processing Of Protein Coding Genes , Shannon Dwayne Schlueter

Retrospective Theses and Dissertations

As biological data collection methods have become more cost effective and less time consuming, the necessity for computational tools to store, manage, and analyze this data has led to the creation of a broad field of research. Bioinformatics, while firmly rooted in the technology of information management, is now a mainstream component in the majority of scientific investigations. With the vast majority of effort in bioinformatics being applied to research on vertebrate species, researchers in the plant sciences have often been left with less than satisfactory tools. The research presented in this dissertation was done in an effort to advance ...


Recognition And Signal Transduction In The Expression Of Phytophthora Resistance In Soybean [Glycine Max (L) Merr] , Hongyu Gao Jan 2006

Recognition And Signal Transduction In The Expression Of Phytophthora Resistance In Soybean [Glycine Max (L) Merr] , Hongyu Gao

Retrospective Theses and Dissertations

Phytophthora sojae, a hemibiotrophic oomycete, is the causal pathogen of stem and root rot disease of soybean (Glycine max [L.] Merr). The annual soybean yield loss suffered from this disease is valued at about 300 million dollars. A series of single Rps genes protect soybean from the root and stem rot disease. In the last two decades Rps1-k has been the most stable and widely used Phytophthora resistance gene in the major soybean-producing regions of the United States;Two classes of CC-NB-LRR-type Rps1-k genes were isolated from the Rps1-k locus. Representative members from each gene class were expressed in transgenic ...


The Mechanism Of Arabidopsis Immutans Variegation , Aigen Fu Jan 2006

The Mechanism Of Arabidopsis Immutans Variegation , Aigen Fu

Retrospective Theses and Dissertations

The Arabidopsis immutans (im) is variegated with green sectors and white sectors containing defective plastids due to a nuclear gene mutation. IM is a plastid terminal oxidase (PTOX) sharing similarity with mitochondrial alternative oxidase (AOX). In order to better understand IM's biological roles and variegation mechanism of im, I characterized im plants at different levels;A structural model of IM, in which the diiron reaction center is composed of two conserved histidine and four glutamate residues, was tested by mutagenesis in vitro and in planta. It that these six conserved residues were found essential for IM activity and do ...


Functional Characterization Of The Rad51 Genes In Zea Mays And Their Roles In Mu Transposition , Jin Li Jan 2006

Functional Characterization Of The Rad51 Genes In Zea Mays And Their Roles In Mu Transposition , Jin Li

Retrospective Theses and Dissertations

In Saccharomyces cerevisiae, Rad51p plays a central role in homologous recombination and DNA repair. Double mutants of the two Zea mays L. rad51 homologs are viable, but male sterile and have ~22% of normal seed set. Light microscopic analyses of male meiosis in these plants reveal: many chromosomes are unpaired at diakinesis and over 33% of quartets carry cells that either lack a nucleolus or have two nucleoli, indicating that non-disjunction occurs at both meiotic divisions. FISH analysis shows that 70% pachytene cells have paired 5S rDNA loci. Thus, maize RAD51 is required for efficient chromosome pairing and proper chromosome ...


Qtl Mapping And Gene Discovery In Perennial Ryegrass (Lolium Perenne L.) , Yanwen Xiong Jan 2005

Qtl Mapping And Gene Discovery In Perennial Ryegrass (Lolium Perenne L.) , Yanwen Xiong

Retrospective Theses and Dissertations

Perennial ryegrass (Lolium perenne L.) has been used extensively for both forage and turf in temperate regions. To understand the genetic basis of winter hardiness and forage quality and molecular basis of cold acclimation of ryegrass, we mapped quantitative trait loci (QTL) that control winter hardiness and forage quality by using an interspecific ryegrass population and identified a C&barbelow;-repeat (CRT)/dehydration-responsive element (DRE) b&barbelow;inding f&barbelow;actors (CBF)-like gene in perennial ryegrass. Winter hardiness related traits including fall growth (FG), freezing tolerance (FT), and winter survival (WS) were measured over two years. A total of twenty-six QTLs were ...


Genome-Wide Analysis Of Splicing Related Genes And Alternative Splicing In Plants , Bing-Bing Wang Jan 2005

Genome-Wide Analysis Of Splicing Related Genes And Alternative Splicing In Plants , Bing-Bing Wang

Retrospective Theses and Dissertations

The phenomenon of pre-mRNA splicing in eukaryotes has been mostly studied in mammalian and yeast systems. The splicing machinery in plants is thought to be largely conserved relative to animal and fungal organisms. This thesis encompasses systematic studies of splicing-related genes and alternative splicing (AS) in plants. A total of 74 snRNA genes and 395 genes encoding splicing related proteins were identified in Arabidopsis, including the previously elusive U4atac snRNA gene. About 50% of the splicing related genes are duplicated in plants. The duplication ratios for splicing regulators are even higher, indicating that the splicing mechanism is generally conserved among ...


The Mechanism Of Var2 Leaf Variegation , Fei Yu Jan 2005

The Mechanism Of Var2 Leaf Variegation , Fei Yu

Retrospective Theses and Dissertations

The Arabidopsis f&barbelow;ilamentation t&barbelow;emperature s&barbelow;ensitive (FtsH) metalloprotease gene family comprises 12 members (AtFtH1-AtFtsH12 ), including three pairs of closely related genes that are targeted to chloroplasts (AtFtsH2 and AtFtsH8; AtFtsH1 and AtFtsH5; and AtFtsH7 and AtFtsH9). Mutations in AtFtsH5 ( var1) and AtFtsH2 (var2) give rise to variegated plants with green- and white-sectored leaves. Cells in the green sectors contain morphologically normal chloroplasts, whereas cells in the white sectors are blocked in chloroplast biogenesis. A major question is how chloroplasts arise in cells that have a mutant genotype. We have found by two-dimensional (2-D) green gel and gel filtration ...


Analysis Of Hoxa5 Expression And Function In Development Of The Central Nervous System , Milan Joksimovic Jan 2005

Analysis Of Hoxa5 Expression And Function In Development Of The Central Nervous System , Milan Joksimovic

Retrospective Theses and Dissertations

The Hox genes encode transcription factors that are indispensable for proper spatio-temporal patterning of the vertebrate body axes. In mouse, Hoxa5 transcripts are differentially expressed in specific mesoderm-derived structures and in the most anterior domain of expression in the central nervous system (CNS). However, the functional significance of any pattern of protein-coding RNAs must be verified by correlating the presence of the protein(s) and RNAs. Here we describe the dynamic pattern of HOXA5 protein during mouse embryogenesis. The HOXA5 protein is detected as early as embryonic day (E) 9.0, and is found, as development proceeds, in several mesoderm-derived ...


Investigation Of The Molecular Mechanism Of Fertility Restoration In Texas Cytoplasm Maize , David Stewart Skibbe Jan 2004

Investigation Of The Molecular Mechanism Of Fertility Restoration In Texas Cytoplasm Maize , David Stewart Skibbe

Retrospective Theses and Dissertations

Cytoplasmic male sterility (cms) is a maternally inherited inability to produce viable pollen. In Texas (T)-cytoplasm maize, the combined action of two restorer of fertility genes, rfl and rfla , can overcome the male sterile phenotype. Previous research established rf2a encodes a mitochondrial aldehyde dehydrogenase (ALDH) with broad substrate specificity. This broad substrate specificity complicates determining the molecular mechanism of rf2a-mediated fertility restoration. In response, a combination of transgenic, biochemical, reverse genetic, and genomic approaches were utilized. Three additional functional maize ALDH genes (rf2b, rf2c, and rf2d) with differing substrate specificities were identified. Each ALDH gene was characterized via in ...


The Central Role Of Acetyl-Coa In Plant Metabolism, As Examined Through Studies Of Atp Citrate Lyase And The Bio1 Mutant Of Arabidopsis , Elizabeth K. Winters Jan 2004

The Central Role Of Acetyl-Coa In Plant Metabolism, As Examined Through Studies Of Atp Citrate Lyase And The Bio1 Mutant Of Arabidopsis , Elizabeth K. Winters

Retrospective Theses and Dissertations

The acetyl-CoA/biotin network encompasses acetyl-CoA generation and utilization, biotin synthesis, recovery, and transport, and myriad metabolic processes requiring biotin-containing enzymes. To expand understanding of this network and its control, plants with altered levels of ACL (ATP citrate lyase) and BIO1 (adenosylmethionine-8-amino-7-oxononanoate synthase) were examined.;An inducible promoter provides a powerful method to test the effects of altered expression of specific genes. The synthetic GVG promoter, reported to be sterol-inducible in Arabidopsis thaliana, was inducible in Glycine max (soybean) when used to control the GUS reporter gene, or the ACLA or ACLB genes. It showed the same unique pattern in ...


The Essential Jil-1 Kinase Regulates Histone H3 Phosphorylation And Maintains Chromatin Structure In Drosophila , Weiguo Zhang Jan 2004

The Essential Jil-1 Kinase Regulates Histone H3 Phosphorylation And Maintains Chromatin Structure In Drosophila , Weiguo Zhang

Retrospective Theses and Dissertations

JIL-1 encodes a chromatin-associated tandem serine/threonine kinase in Drosophila melanogaster. JIL-1 predominantly associates with interbands on polytene chromosomes. It appears at higher levels on the X chromosome than on autosomes in males, and distributes about equally on all chromosomes in females. In addition, in males JIL-1 overlaps with the MSL (for male specific lethal) complex that specifically associates with the male X chromosome on which expression of most genes are upregulated.;We isolated JIL-1 mutants by inducing imprecise excision of an EP element inserted in JIL-1. We found that JIL-1 is required for viability of both females and males ...


Computational And Molecular Analysis Of Myb Gene Family, Cizhong Jiang Jan 2004

Computational And Molecular Analysis Of Myb Gene Family, Cizhong Jiang

Retrospective Theses and Dissertations

Myb proteins are defined by a highly conserved DNA-specific binding domain termed Myb, which is composed of approximately 50 amino acids with constantly spaced tryptophan residues. Multiple copies of Myb domains often exist as tandem repeats within a single protein. There are up to four tandem Myb repeats present in Myb proteins identified to date (termed R0R1R2R3 hereafter).;In our study, we collected additional Myb genes, and performed a series of phylogenetic analyses to explore the evolutionary origin of Myb genes. The results suggest that the Myb gene family originated from an ancient one Myb-box gene. One and two intragenic ...


Molecular And Genetic Characterization Of The Inheritance And Expression Of The Synthetic Porcine Alpha-Lactalbumin Transgene In Maize (Zea Mays L) , Earl H. Bicar Jan 2003

Molecular And Genetic Characterization Of The Inheritance And Expression Of The Synthetic Porcine Alpha-Lactalbumin Transgene In Maize (Zea Mays L) , Earl H. Bicar

Retrospective Theses and Dissertations

A codon-adjusted version of a gene encoding the porcine milk protein alpha-lactalbumin was synthesized to create maize with improved nutritional quality. Three expression vectors (P64, P45, P57) containing the synthetic gene were constructed and transformed into maize callus by particle bombardment. The constructs differed in their promoters and subcellular targeting domains. PCR analysis showed that the alpha-La transgene was integrated into the maize genome and transmitted to the F1 generation. Western blot analysis indicated that the transgenes were functional and the alpha-La protein accumulated in the target endosperm. Genomic Southern blot analysis detected no new rearrangements demonstrating stable transgene integration ...


Functional Divergence And Genome Evolution Of Vertebrate Protein Kinases (Kinome), Jianying Gu Jan 2003

Functional Divergence And Genome Evolution Of Vertebrate Protein Kinases (Kinome), Jianying Gu

Retrospective Theses and Dissertations

The emerging complete and nearly complete genome sequences have provided a significant amount of materials for large-scale comparative genomic analysis. Novel methods have been developed to elucidate the function of gene products and functional interacting networks. Many of these post-genomic attempts have focused on unveiling the evolutionary forces that have shaped the network organization. Among various evolutionary forces, duplication of functional domain, individual gene, chromosomal segment, or entire genome has long been thought as primary resource for the function novelties in a vast number of gene families. It is therefore intriguing to quantitatively trace the changes of evolutionary constraints after ...


Identification And Functional Analysis Of Thylakoid Membrane Proteome , Yingchun Wang Jan 2003

Identification And Functional Analysis Of Thylakoid Membrane Proteome , Yingchun Wang

Retrospective Theses and Dissertations

Membrane proteins play crucial roles in many biological functions. Identities and functions of most membrane proteins remain to be revealed. New technological breakthroughs in proteomics together with the availability of genomic sequence information make it possible to study functions of membrane proteins on a genome-wide scale. We used a multidisciplinary approach combining biochemistry, genetics, proteomics and bioinformatics to study the functions of the thylakoid proteome of Synechocystis sp. PCC6803. The thylakoid membrane proteins were separated into peripheral and integral fractions and resolved into 2-D gels with different pH ranges. The protein spots in the 2-D gels were subjected to peptide ...


The Mechanism Of Integration Preference To Heterochromatin Of Yeast Retrotransposon Ty5 , Weiwu Xie Jan 2003

The Mechanism Of Integration Preference To Heterochromatin Of Yeast Retrotransposon Ty5 , Weiwu Xie

Retrospective Theses and Dissertations

Ty5 is a retrotransposon in Saccharomyces cerevisiae. In wild type yeast strains, over 90% of Ty5 insertions occur at the telomeres or HM loci. These regions are bound in silent chromatin, which is analogous to heterochromatin of higher eukaryotes. Our laboratory previously described a targeting mutant of Ty5 that has an amino acid substitution near the C-terminus of integrase. Targeting to silent chromatin is reduced more than 20-fold in the mutant. We further defined the Ty5 targeting domain (TD) by saturation mutagenesis. All of the targeting mutations mapped to a stretch of six amino acids (LDSSPP). We tethered TD to ...


Characterization Of The Ftsyex Operon Of Escherichia Coli , Becky Graham Jan 2002

Characterization Of The Ftsyex Operon Of Escherichia Coli , Becky Graham

Retrospective Theses and Dissertations

The ftsYEX operon of Escherichia coli historically has been described as a cluster of essential cell division genes. Filamentation temperature-sensitive (fts) designates a class of mutants that displays normal cell morphology at the permissive temperature of 30°C, but filaments and dies at the restrictive temperature of 42°C. The first gene, ftsY, is known to encode an essential component of a protein localization system first described in eukaryotes, the signal recognition particle (SRP) pathway. The function of the following genes, ftsE and ftsX, are much less understood. It has been shown that FtsE and FtsX comprise a two-component ATP-binding ...


Studying The Replication Mechanism Of The Yeast Retrotransposon Ty5 By Molecular And Computational Approaches, Xiang Gao Jan 2001

Studying The Replication Mechanism Of The Yeast Retrotransposon Ty5 By Molecular And Computational Approaches, Xiang Gao

Retrospective Theses and Dissertations

The yeast retrotransposon Ty5 is a Ty1/copia element. It is in the Hemivirus genus of the Pseudoviridae family. The ability to genetically manipulate retrotransposons and the yeast host cell was taken advantage of to explore replication mechanisms unique to Ty5 and common to most retrotransposons. Because of the abundance and diversity of retroelement sequences, along with the fact that many retroelement enzymes have evolved unique functional specificities, computational approaches were also developed to study functional divergence in replication. By screening a randomly mutagenized Ty5 library, two mutations (Y68C, D252N) causing higher transposition frequencies were identified. Both mutations increased Ty5 ...


Molecular And Genetic Characterization Of Rf2, A Mitochondrial Aldehyde Dehydrogenase Gene Required For Male Fertility In Maize (Zea Mays L) , Xiangqin Cui Jan 2001

Molecular And Genetic Characterization Of Rf2, A Mitochondrial Aldehyde Dehydrogenase Gene Required For Male Fertility In Maize (Zea Mays L) , Xiangqin Cui

Retrospective Theses and Dissertations

T-cytoplasm induced male sterility (cms-T) is a maternally inherited inability to produce viable pollen in maize. The causal factor, the URF13 protein, is encoded by the mitochondrial genome and accumulates in the mitochondrial inner membrane. Fertility restoration of cms-T is mediated by the complementary action of two nuclear genes, rf1 and rf2. The rf2 gene was cloned via transposon tagging. Sequence analysis revealed that it has high sequence similarity to mammalian mitochondrial aldehyde dehydrogenases (mtALDHs). Sequence, mRNA, and protein analyses of the spontaneous mutant allele rf2-R213 demonstrated that the ALDH activity is necessary for rf2's function as a cms-T ...


Structure And Function Of A Novel Cap-Independent Translation Element In The 3' Untranslated Region Of A Viral Rna , Liang Guo Jan 2000

Structure And Function Of A Novel Cap-Independent Translation Element In The 3' Untranslated Region Of A Viral Rna , Liang Guo

Retrospective Theses and Dissertations

This research focuses on a cap-independent translation element (TE) we identified in the RNA of barley yellow dwarf virus (BYDV). Assisted by the TE, all messenger RNAs of BYDV, which include BYDV genomic RNA and subgenomic RNAs, are translated cap-independently. This allows uncapped, nonpolyadenylated BYDV RNAs to compete with capped and polyadenylated host mRNAs for the translation machinery. The core of the TE is a 105 nt sequence (TE105) located in the 3' UTR of BYDV genomic RNA. Due to its 3' position, at least two functions are necessary for TE105: 3 '--5' communication, and recruitment of translation machinery. TE105 ...


Biochemical Characterization And Positional Cloning Of The Var2 Variegation Mutant Of Arabidopsis Thaliana , Meng Chen Jan 1999

Biochemical Characterization And Positional Cloning Of The Var2 Variegation Mutant Of Arabidopsis Thaliana , Meng Chen

Retrospective Theses and Dissertations

Chloroplasts differentiation and development are highly coordinated with their host cells. To better elucidate the mechanisms involved in nuclear-chloroplast interactions, we characterized a nuclear encoded leaf variegation mutation called var2. While cotyledons appear normal, true leaves of var2 emerge as yellow, then turn into green-white sectors. The green sectors contain cells with normal chloroplasts, whereas the white sectors contain cells with abnormal plastid lacking of internal membrane structures. The phenotypes suggested that VAR2 might be involved in thylakoid biogenesis in early chloroplast differentiation. We cloned the VAR2 gene by a map-based method. Five original and two potential alleles were sequenced ...


Oxidizing Side Of The Photosystem I , Jun Sun Jan 1999

Oxidizing Side Of The Photosystem I , Jun Sun

Retrospective Theses and Dissertations

Photosynthesis converts solar energy into the biological sources of energy for the life on our planet. Photosystem I (PSI) is one of the two reaction centers of oxygenic photosynthesis. PSI is a multiheteromeric membrane-protein complex that catalyzes light-driven electron transfer from plastocyanin or cytochrome c6 to ferredoxin. The PsaA and PsaB subunits form the heterodimeric core that harbors the primary electron donor P700. On the oxidizing side of the PSI complex, plastocyanin or cytochrome c6 donates electrons to the P700 reaction center. The objective of this dissertation is to identify elements of molecular recognition on the oxidizing side of PSI ...


Genome Reorganization And Non-Linear Transposition In Maize , Jianbo Zhang Jan 1999

Genome Reorganization And Non-Linear Transposition In Maize , Jianbo Zhang

Retrospective Theses and Dissertations

Transposable elements have long been considered as potential agents of large-scale genome reorganization by virtue of their ability to induce chromosomal rearrangements such as deletions, duplications, inversions, and reciprocal translocations. Previous researchers have shown that particular configurations of transposon termini can induce chromosome rearrangements at high frequencies. By analyzing two derivatives of an unstable allele of the maize P1 (pericarp color) gene carrying both a full-length Ac (Activator) transposable element and a Ac terminal fragment termed fAc (fractured Ac) that were recovered from a classical maize ear twinned sector, it were found that the twinned alleles are a large inverted ...


Genetic Mobility And Instability Of Retroviral Vector In Vector Producer Cells For Gene Therapy, Won-Bin Young Jan 1999

Genetic Mobility And Instability Of Retroviral Vector In Vector Producer Cells For Gene Therapy, Won-Bin Young

Retrospective Theses and Dissertations

A primary biosafety issue of retroviral vector-mediated gene therapy is the genetic instability of retroviral vectors. Reverse transcription of vector RNA genome is initiated by viral reverse transcriptase (RT) in a virion particle after infection of a target cell. During reverse transcription, abnormal template switches between vector and occasionally co-packaged helper virus in a virion particle can therefore enable helper virus to regain replication elements from the vector and revert to replication-competent retrovirus (RCR). This research was undertaken to study the origins of RT enzyme activities and test the hypothesis that RT enzyme activities are contributed by both exogenous RT ...