Biochemistry, Biophysics, and Structural Biology Commons^™

Trophic Transfer Of Fatty Acids, Sterols, And A Triterpenoid Alcohol Between Bacteria, A Ciliate, And The Copepod Acartia Tonsa, Melissa C. Ederington, George B. Mcmanus, H. Rodger Harvey

OES Faculty Publications

The incorporation of lipids into the copepod Acartia tonsa and its eggs was measured when it was fed either a bacterivorous ciliate (Pleuronema sp.) or a diatom (Thalassiosira weissflogii). Egg production was 10-fold higher on the diatom diet, whereas hatch success of eggs was the same for algal and ciliate diets. Adult copepods fed diatoms contained more total fatty acid and sterols than copepods fed the ciliate diet, and individual lipids reflected the dietary source. Eggs from diatom-fed copepods had fewer fatty acids but more sterols than eggs from copepods on a ciliate diet. Ciliate-fed copepods and …

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. …

In Vitro Expression Of Human Zona Pellucida Protein 3, Chih-Wei Chen

Theses and Dissertations in Biomedical Sciences

Human zona pellucida protein 3 (hZP3) is the putative receptor on the zona pellucida of the mature oocyte that recognizes and binds sperm, and therefore plays a critical role in fertilization.

A full length cDNA of hZP3 (1278 bp) was amplified from the human ovary mRNA by reverse transcription-polymerase chain reaction (RT-PCR). The hZP3 cDNA was subcloned into PSK and pREP4 expression vectors. The cDNA of hZP3 was further characterized by restriction mapping, PCR, auto-sequencing and Southern blot analysis by using an internal oligonucleotide probe, and found to be identical to the one reported by J. Dean. Using autosequencing, 289 …

Heterozygosity Mapping Of Partially Congenic Lines: Mapping Of A Semidominant Neurological Mutation, Wheels ( Whl), On Mouse Chromosome 4, Patrick M. Nolan, Patricia J. Sollars, Barbara A. Bohne, Warren J. Ewens, Gary E. Pickard, Maja Bucan

School of Veterinary and Biomedical Sciences: Faculty Publications

We identified a semidominant, chemically induced, mouse use mutation with a complex array of abnormal behaviors including bidirectional circling and hyperactivity, abnormal circadian rhythmicity and abnormal responses to light. In this report, we genetically and phenotypically characterized the circling/ waltzing component of the abnormal behavior. We mapped the locus controlling this trait by heterozygosity mapping of partially congenic lines carrying the mutagenized chromosome outcrossed to different inbred strains for three generations. Analysis of 68 PCR-based markers in 13 affected individuals indicated that the mutant locus, named Wheels (Whl), resides in the subcentromeric portion of mouse chromosome 4. The …

A Kinetic Investigation Of The Mechanism Of Muscle Contraction With A Series Of Nucleotides, Wei Jiang

Theses and Dissertations in Biomedical Sciences

Muscle contraction is thought to be accomplished by sliding of myosin filaments along actin filaments. Although actomyosin naturally uses ATP as an energy source, it can also use other nucleoside triphosphates (NTP) as substrates. In this work, the dependence of rate and equilibrium constants of the various steps in the muscle contraction mechanism upon nucleotide structure was investigated to unravel the dependence of the mechanical properties of the muscle upon changes in different biochemical steps of the mechanism.

The experiments measuring the dissociation of actomyosin by NTP (or mant-NTP) shows that both the rate constant of actomyosin-S1 dissociation and second …

Restoration Of Circadian Behavior By Anterior Hypothalamic Heterografts, Patricia J. Sollars, Daniel P. Kimble, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

The suprachiasmatic nucleus (SCN) of the anterior hypothalamus (AH) is a circadian oscillator and an important component of the mammalian circadian system. To determine whether the SCN is the dominant circadian pacemaker responsible for generating a species-typical characteristic of circadian rhythms [i.e., period length (T)], neural transplantation was conducted using fetal AH donors of different species and SCN-lesioned (SCNx) hosts. The circadian behavior of each of the three donor species is clearly distinguishable by its species-typical T. The extent of SCN pacemaker autonomy was assessed by noting whether the period of the restored circadian rhythm following heterograft transplantation was characteristic …

Certain Canine Weakly Β-Hemolytic Intestinal Spirochetes Are Phenotypically And Genotypically Related To Spirochetes Associated With Human And Porcine Intestinal Spirochetosis, Gerald E. Duhamel, Nagaraja Muniappa, Michelle R. Mathiesen, J. L. Johnson, J. Toth, R. O. Elder, A. R. Doster

School of Veterinary and Biomedical Sciences: Faculty Publications

Four canine weakly β-hemolytic intestinal spirochetes associated with intestinal spirochetosis (IS-associated WBHIS) were compared with IS-associated human and porcine WBHIS and the type species for Serpulina hyodysenteriae and S. innocens by using phenotypic and genotypic parameters. The IS-associated canine, human, and porcine WBHIS belonged to a phyletic group distinct from but related to previously described Serpulina type species.

Complementary Gradients In Expression And Binding Of Elf-1 And Mek4 In Development Of The Topographic Retinotectal Projection Map, Masaru Nakamoto

Biology Faculty Publications

Topographic maps with a defined spatial ordering of neuronal connections are a key feature of brain organization. Such maps are believed to develop in response to complementary position-specific labels in presynaptic and postsynaptic fields. However, the complementary labeling molecules are not known. In the well studied visual map of retinal axons projecting to the tectum, the labels are hypothesized to be in gradients, without needing large numbers of cell-specific molecules. We recently cloned ELF-1 as a ligand for Eph family receptors. Here, RNA hybridization shows matching expression gradients for ELF-1 in the tectum and its receptor Mek4 in the retina. …

Fish Analysis On Spontaneously Arising Micronuclei In The Icf Syndrome, Michael W. Stacey, M. S. Bennett, M. Hulten

Bioelectrics Publications

The ICF syndrome is a rare disorder where patients show undercondensation of the heterochromatic blocks of chromosomes 1, 9, and 16 along with variable immunodeficiency. The undercondensation of the heterochromatic block appears to be restricted to a portion of PHA stimulated T cells. Patients with this syndrome also show an increase in micronuclei formation. We have used dual colour FISH to investigate the chromosomal content of these micronuclei in PHA stimulated peripheral blood cultures, an EBV transformed B cell line, and also micronuclei observed in vivo from peripheral blood smears. Chromosome 1 appears to be present in a higher proportion …

Activation Of Transfer Rna-Guanine Ribosyltransferase By Protein Kinase C, Rana C. Morris, Bonnie J. Brooks, Panayota Eriotou, Deborah F. Kelly, Sandeep Sagar, K. Lenore Hart, Mark S. Elliot

Chemistry & Biochemistry Faculty Publications

Transfer RNA-guanine ribosyltransferase (TGRase) irreversibly incorporates queuine into the first position in the anticodon of four tRNA isoacceptors. Rat brain protein kinase C (PKC) was shown to stimulate rat liver TG Rase activity, TGRase preparations derived from rat liver have been observed to decrease in activity over time in storage at -20 or -70°C, Contamination of the samples by phosphatases was indicated by a p-nitrophenylphosphate conversion test, The addition of micromolar concentrations of the phosphatase inhibitors sodium pyrophosphate and sodium fluoride into TGRase isolation buffers resulted in a greater return of TGRase activity than without these inhibitors, Inactive TGRase preparations …