Life Sciences Commons^™

A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan

Electronic Theses and Dissertations

A temperature-sensitive mutant of Escherichia coli affected in the alpha subunit of RNA polymerase has been investigated. Gene mapping and complementation experiments placed the mutation to temperature-sensitivity within the alpha operon at 72 min on the bacterial chromosome. The rate of RNA synthesis in vivo and the accumulation of ribosomal RNA were significantly reduced in the mutant at 44$\sp\circ$C. The thermostability at 44$\sp\circ$C of the purified holoenzyme from mutant cells was about 20% of that of the normal enzyme. Assays with T7 DNA as a template showed that the fraction of active enzyme competent for transcription was reduced as a …

Application Of Dna Fingerprints For Cell-Line Individualization, Dennis A. Gilbert, Yvonne Reid, Mitchell H. Gail, David Pee, Christine White, Robert J. Hay, Stephen J. O'Brien

Biology Faculty Articles

DNA fingerprints of 46 human cell lines were derived using minisatellite probes for hypervariable genetic loci. The incidence of 121 HaeIII DNA fragments among 33 cell lines derived from unrelated individuals was used to estimate allelic and genotypic frequencies for each fragment and for composite individual DNA fingerprints. We present a quantitative estimate of the extent of genetic difference between individuals, an estimate based on the percentage of restriction fragments at which they differ. The average percent difference (APD) among pairwise combinations from the population of 33 unrelated cell lines was 76.9%, compared with the APD in band sharing …

Dna Recombination And Natural Selection Pressure Sustain Genetic Sequence Diversity Of The Feline Mhc Class I Genes, Naoya Yuhki, Stephen J. O'Brien

Biology Faculty Articles

Sequence comparisons of seven distinct MHC class I cDNA clones revealed that feline class I molecules have a remarkable similarity to human HLA genes in their organization of functional domains as well as in the nonrandom partitioning of genetic variability according to the functional constraints ascribed to different regions of the MHC molecule. The distribution of the pattern of sequence polymorphism in the cat as compared with genetic diversity of human and mouse class I genes provides evidence for four coordinate factors that contribute to the origin and sustenance of abundant allele diversity that characterizes the MHC in the species. …

The Use Of Synthetic Oligodeoxyribonucleotides In Direct Analysis Of Single Nucleotide Variations And Inhibition Of Eukaryotic Gene Expression, Daniel Y. Wu

Loma Linda University Electronic Theses, Dissertations & Projects

The present thesis work contributes to two areas of molecular genetics, namely the development of methods for identifying single nucleotides and the understanding of the mechanism by which antisense oligonucleotides inhibit eukaryotic gene expression. Three single nucleotide detection methods are presented. The first method utilizes hybridization with synthetic oligonucleotide probes to detect single or multiple nucleotide differences between alleles in genomic DNA without electrophoretic separation. Total genomic DNA (either digested or undigested with restriction endonucleases) was immobilized in depressions in an agarose gel (in situ dots) and hybridized with radiolabeled, allele-specific oligonucleotide probes. We show that this method can be …

Effects Of Chemical Aneuploidogens On Taxol Purified Drosophila And Mouse Brain Microtubules Polymerization And Depolymerization In Vitro, Anil Sehgal

Biological Sciences Theses & Dissertations

The effects of aneuploidogens (aneuploidy causing agents) on taxol-purified microtubules from Drosophila and mouse brain in vitro were studied by using a spectrophotometric assay and electron microscopy. Colchicine, acetonitrile, propionitrile, acrylonitrile, dimethyl sulfoxide (DMSO), griseofulvin and cadmium chloride inhibited microtubule polymerization whereas methoxyethyl acetate (MEA) and methyl mercuric chloride (MMC) did not. All aneuploidogens tested (at 50mM) resulted in reduced rate of elongation of mouse brain microtubules. MMC, cadmium chloride and DMSO resulted in increased rates of Drosophila microtubule elongation whereas the rest of the drugs resulted in decreases. The in vitro results from Drosophila correlate well with the previously …

Characterization Of Hsd::Mudx128 Operon Fusion Mutant Of Escherichia Coli K-12, Marjorie Ann T. Reyno

Loma Linda University Electronic Theses, Dissertations & Projects

The study of the regulation of gene expression in complex genes can be facilitated by the use of operon fusions which place a well characterized lacZ gene under the control of a promoter of interest. An hsd::MudX128 operon fusion mutant of E. coli K-12 isolated by Prakash (1986) was observed to have a high β-galactosidase activity (1000 units), ten to twenty times higher than other hsd::MudX mutants. This β-galactosidase activity was suppressed to a very low level (25 units) by the introduction of an F’ plasmid, F'101, which carries the 98 min to 2 min region of the …

Prevalence And Implications Of Feline Coronavirus Infections Of Captive And Free-Ranging Cheetahs (Acinonyx Jubatus), J. L. Heeney, J. F. Evermann, A. J. Mckeirnan, L. Marker-Kraus, M. E. Roelke, M. Bush, D. E. Wildt, D. G. Meltzer, L. Colly, J. Lukas, V. J. Manton, T. Caro, Stephen J. O'Brien

Biology Faculty Articles

The extent and progression of exposure to feline infectious peritonitis (FIP) virus in the cheetah, Acinonyx jubatus, was monitored by a world-wide serological survey with indirect fluorescent antibody titers to coronavirus. The indirect fluorescent antibody assay was validated by Western blots, which showed that all indirect fluorescent antibody-positive cheetah sera detected both domestic cat and cheetah coronavirus structural proteins. There was a poor correlation between indirect fluorescent antibody results and the presence of coronaviruslike particles in cheetah feces, suggesting that electron microscopic detection of shed particles may not be an easily interpreted diagnostic parameter for FIP disease. Low, but …

Segregation Distortion In Inheritance Of Progressive Rod Cone Degeneration (Prcd) In Miniature Poodle Dogs, Gregory M. Acland, Susan Halloran-Blanton, Joann A. Boughman, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

Nucleotide Sequence And Further Characterization Of The Synechococcus Sp. Strain Pcc 7002 Reca Gene: Complementation Of A Cyanobacterial Reca Mutation By The Escherichia Coli Reca Gene, R C. Murphy, G E. Gasparich, D A. Bryant, R D. Porter

Gail Gasparich

Freshwater Fishes Of Shipstern Nature Reserve, Caspar F. A. Bijleveld

Physiology Faculty Research Publications

A survey of fishes in and around Shipstern Nature Reserve in Northern Belize, Central America, was carried out over a period of eight months, from February to September 1990. Its purpose was to establish a preliminary list of the fishes of Shipstern Nature Reserve, including descriptions, distribution and collecting data and additionally to describe some of the habitats in which the fishes were found. This study focuses on fishes considered to be freshwater species. These occurred for the greater part in brackish habitats. Nevertheless, a few fish considered as marine species were caught in the waters of the reserve and …

Preliminary Agronomic Evaluation And Characterization Of The Genetic Resources Of Trifolium And Ornithopus Species., R. Snowball

Experimental Summaries - Plant Research

Trial 91MD13

Location: Medina Vegetable Research Station

To evaluate and characterize new and old collections of Trifolium and Ornithopus species.

To regenerate lines to provide sufficient seed of high quality for long term storage in the Australian Trifolium Genetic Resource Centre (ATGRC).

Differences Between Merino Strains And Studs, Roger Lewer

Journal of the Department of Agriculture, Western Australia, Series 4

When commercial wool growers select Merino rams they often use the following pattern: the buyers first consider the main strains of Merinos in Western Australia - Bungaree, Collinsville and Peppin. They then study the 550 studs and numerous non-stud ram breeders in this State. Having chosen a breeder, they examine the rams on offer and buy their annual requirements from among these. Until recently, no objective information has been available on the differences between studs and strains in Western Australia's agricultural areas. However, as part of a major study at the Department of Agriculture's Great Southern Agricultural Research Institute, these …

Molecular And Cytogenetic Characterization Of De Novo Acrocentric Rearrangements In Humans, Lisa Gail Shaffer

Theses and Dissertations

I have studied 26 children who have a de novo rearrangement of the acrocentric chromosomes in order to understand the formation of these aberrations. The families include '25 probands ascertained for Robertsonian-type translocations, 13 between nonhomologous chromosomes and 12 between homologs, and one rea(21;21)(q22;q22). The parental origins of the de novo rearrangements were determined in 26/26 families using QFQ and NOR variants and/or RFLP analyses. While there was no overall difference in the sex distribution of the parents of origin, there were more maternally derived nonhomologous ("true" Robertsonian) translocations (8 mat: 5 pat) and more paternally derived homologous rearrangements (4 …

Genetics Of Interspecific Hybridization In The Triseriatus And Zoosophus Groups Of The Aedes (Protomacleaya) (Diptera: Culicidae)., David B. Taylor

David B. Taylor

Interspecific hybridization was used to examine the genetics of species divergence and phylogeny of mosquitoes in the Triseriatus and Zoosophus groups of Aedes (Protomacleaya). Aedes zoosophus Dyar & Knab exhibited a relatively high degree of reproductive compatibility with Triseriatus group species. Crosses between A. zoosophus and A. triseriatus (Say) produced fertile female and sterile, intersex, male progeny. Crosses between A. zoosophus females and A. brelandi Zavortink males were sterile with no egg embryonation observed. Crosses between A. zoosophus males and A. brelandi females and reciprocal crosses between A. zoosophus and A. hendersoni (Cockerell) produced sterile, intersex female and …