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Series

1988

Biological Sciences Faculty Publications

Articles 1 - 8 of 8

Full-Text Articles in Life Sciences

Probing The Alpha-Sarcin Region Of Escherichia-Coli 23s Rrna With A Cdna Oligomer, Gary A. White, Ted Wood, Walter E. Hill Nov 1988

Probing The Alpha-Sarcin Region Of Escherichia-Coli 23s Rrna With A Cdna Oligomer, Gary A. White, Ted Wood, Walter E. Hill

Biological Sciences Faculty Publications

The cause of 50S ribosomal subunit collapse reportedly triggered by hybridization of a 14-base cDNA probe to the alpha-sarcin region of 23S rRNA was investigated by physical measurement of probe-subunit complexes in varying buffer conditions. The results reported here show that this probe was unable to hybridize to its target site in the intact 50S subunit and the physical characteristics of 50S subunits remained unchanged in its presence. Subunit collapse was induced in buffer containing 20mM Tris-HCl (pH 7.5), 600 mM NH4Cl, 1 mM MgCl2, 1 mM DTT, and 0.1 mM EDTA in the absence of probe. The probe bound …

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Crystallization Of Trimeric Recombinant Human Tumor Necrosis Factor (Cachectin), M. J. Eck, B. Beutler, G. Kuo, J. P. Merryweather, S. R. Sprang Sep 1988

Crystallization Of Trimeric Recombinant Human Tumor Necrosis Factor (Cachectin), M. J. Eck, B. Beutler, G. Kuo, J. P. Merryweather, S. R. Sprang

Biological Sciences Faculty Publications

Crystals of tumor necrosis factor (TNF) have been obtained in two forms. Rhombohedral crystals grow in 1.8 to 2.0 M ammonium sulfite, pH 7.8 at 21°C, and tetragonal crystals grow in 2.6 M magnesium sulfate, pH 5.5 at 25°C. Analysis of TNF by isoelectric focusing under native and denaturing conditions indicates that TNF molecules exist as trimers in solution. The rhombohedral cachectin crystals belong to space group R3 and have unit cell constants a = b = c = 47.65 Å and α = β = γ = 88.1°. Density determinations and the space group indicate that the unit cell …

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Dna Probe Method For The Detection Of Specific Microorganisms In The Soil Bacterial Community, William Holben, Janet K. Jansson, Barry K. Chelm, James M. Tiedje Mar 1988

Dna Probe Method For The Detection Of Specific Microorganisms In The Soil Bacterial Community, William Holben, Janet K. Jansson, Barry K. Chelm, James M. Tiedje

Biological Sciences Faculty Publications

We developed a protocol which yields purified bacterial DNA from the soil bacterial community. The bacteria were first dispersed and separated from soil particles in the presence of polyvinylpolypyrrolidone, which removes humic acid contaminants by adsorption to this insoluble polymer. The soil bacteria were then collected by centrifugation and lysed by using a comprehensive protocol designed to maximize disruption of the various types of bacteria present. Total bacterial DNA was purified from the cell lysate and remaining soil contaminants by using equilibrium density gradients. The isolated DNA was essentially pure as determined by UV spectral analysis, was at least 48 …

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Identification Of Defined Sequences In Domain V Of E.Coli 23s Rrna In The 50s Subunit Accessible For Hybridization With Complementary Oligodeoxyribonucleotides, Richard T. Marconi, Walter E. Hill Feb 1988

Identification Of Defined Sequences In Domain V Of E.Coli 23s Rrna In The 50s Subunit Accessible For Hybridization With Complementary Oligodeoxyribonucleotides, Richard T. Marconi, Walter E. Hill

Biological Sciences Faculty Publications

The accessibility of specific sequences in domain V of E. coli 23s rRNA in the 50S subunit to complementary oligodeoxyribonucleotides (cDNA) has been investigated. The apparent percentage of subunits engaged in complex formation was determined by incubation of radiolabeled cDNA probe with 50S subunits, followed by nitrocellulose membrane filtration of the reaction mixtures and measurement of the bound radiolabeled cDNA probes by liquid scintillation counting of the filters. The site(s) of hybridization were determined by digestion of the RNA in the RNA/DNA heteroduplex by RNase H. The results of this study indicated that single-stranded sequences, 2058-2062, 2448-2454, 2467-2483, and 2497-2505 …

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Leafcutting And Diet Selection: Relative Influence Of Leaf Chemistry And Physical Features, Jerome J. Howard Feb 1988

Leafcutting And Diet Selection: Relative Influence Of Leaf Chemistry And Physical Features, Jerome J. Howard

Biological Sciences Faculty Publications

The effects of leaf toughness, trichome characteristics, nutrient and water availability, and secondary chemistry on diet selection by the leafcutting ant Atta cephalotes were determined using individuals of 49 woody plant species from a tropical deciduous forest in Costa Rica. The palatability of plants was measured by presenting whole leaves to leafcutting ant foragers on trails and counting the number of pieces cut from leaves. The effectiveness of physical barriers to leaf cutting was evaluated by measuring the speed with which ants were able to cut leaves of varying toughness, trichome densities, and trichome lengths. Plant secondary chemistry was highly …

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The Effects Of Siltation On Recruitment Of Spiny Lobsters, Panulirus Argus, William F. Herrnkind, Mark J. Butler, Richard A. Tankersley Jan 1988

The Effects Of Siltation On Recruitment Of Spiny Lobsters, Panulirus Argus, William F. Herrnkind, Mark J. Butler, Richard A. Tankersley

Biological Sciences Faculty Publications

Fewer juvenile pinry lobsters were found in areas of the Florida Keys where their primary habitat was heavily silted as compared with similar, less silted habitat. Several hypotheses explaining this relationship were tested, and the time-to-metamorphosis was compared for settling pueruli within silted and nonsilted algae stands. Limited postlarval settlement and avoidance of silted algal habitats by juveniles, probably accounts for the paucity of young lobsters in heavily silted sites. In addition, although juvenile lobsters are nonselective predators, lower prey availability in silted algae probably promotes transciency which, in turn, causes increased mortality by predation while juveniles are exposed.

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Evaluation Of Possible Reproductively Mediated Character Displacement In The Crayfishes, Orconectes Rusticus And O. Sanbornii, Mark J. Butler Iv Jan 1988

Evaluation Of Possible Reproductively Mediated Character Displacement In The Crayfishes, Orconectes Rusticus And O. Sanbornii, Mark J. Butler Iv

Biological Sciences Faculty Publications

Orconectes rusticus is replacing several species of crayfishes in north-central and northeastern North America, including O. sanbornii in Ohio. Recent evidence suggests that the species replacements may be driven by asymmetrical reproductive success favoring O. rusticus. Nonetheless, some sympatric associations appear locally persistent. Because crayfish demonstrate size assortative mating and there is a disparity in the sizes of the species, further divergence in the sizes of the species in sympatry could enhance reproductive isolation, ultimately providing a mechanism for character displacement. To test this hypothesis the size differentials between crayfish collected from allopatric and sympatric populations in east-central Ohio …

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Host Selection In Subterranean Termites: Factors Affecting Choice (Isoptera: Rhinotermitidae), Deborah Ann Waller Jan 1988

Host Selection In Subterranean Termites: Factors Affecting Choice (Isoptera: Rhinotermitidae), Deborah Ann Waller

Biological Sciences Faculty Publications

The effects of block size and species on preference were examined for the subterranean termite Reticulitermes sp. (Rhinotermitidae) in choice and no-choice tests. Termites significantly preferred Douglas fir over Ponderosa pine and red oak, irrespective of block size. The less-preferred woods were eaten in large amounts in no-choice tests, and all three woods appeared to be favorable for the termites and their gut protozoans. In single species tests, termites ate significantly more from larger blocks of Douglas fir, but ate similar amounts from large and small blocks of Ponderosa Pine and red oak. These results suggest that several factors can …

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