Biology Commons^™

Dna Synthesis, Methylation And Degradation During Conjugation In Tetrahymena Thermophila, Gail Singer Harrison, Kathleen M. Karrer

Biological Sciences Faculty Research and Publications

We have investigated the timing of DNA synthesis, methylation and degradation during macronuclear development in the ciliate, Tetrahymena thermophila. DNA synthesis was first detected in the anlagen early in macronuclear development, but the majority of DNA synthesis occurred later, after pair separation. Anlagen DNA was first detectably methylated at GATC sites 3–5 hours after its synthesis. Once initiated, de novo methylation was rapid and complete, occurring between 13.5 and 15 hours of conjugation. The level of methylation of GATC sites was constant throughout the remainder of conjugation, and was similar to that in mock-conjugated cells. Degradation of DNA in …

Rhizobium Phaseoli Symbiotic Mutants With Transposon Tn5 Insertions, K. Dale Noel, Araceli Sanchez, Leonor Fernandez, Jan Leemans, Miguel A. Cevallos

Biological Sciences Faculty Research and Publications

Rhizobium phaseoli CFN42 DNA was mutated by random insertion of Tn5 from suicide plasmid pJB4JI to obtain independently arising strains that were defective in symbiosis with Phaseolus vulgaris but grew normally outside the plant. When these mutants were incubated with the plant, one did not initiate visible nodule tissue (Nod-), seven led to slow nodule development (Ndv), and two led to superficially normal early nodule development but lacked symbiotic nitrogenase activity (Sna-). The Nod- mutant lacked the large transmissible indigenous plasmid pCFN42d that has homology to Klebsiella pneumoniae nitrogenase (nif) genes. The other mutants had normal plasmid content. In …

Financial Exigency: Need It Affect The Quality Of Biology Curricula?, Robert G. Thomson, Peter Abramoff

Biological Sciences Faculty Research and Publications

Declining enrollments and financial restraints require that science departments seek ways to meet academic commitments within the framework of reduced budgets and faculty resources without sacrificing quality programs. The following describes our evaluation of the role of the laboratory in the undergraduate biology curriculum and the positive effects achieved on our academic, financial, and faculty resources by separating labs from lecture courses and reducing the number of labs required for majors and nonmajors. Several years ago we experienced increased enrollments coupled with only modest increases in funds to deliver our undergraduate instructional programs. To resolve this problem we developed a …

Germ Line-Specific Dna Sequences Are Present On All Five Micronuclear Chromosomes In Tetrahymena Thermophila, Kathleen M. Karrer

Biological Sciences Faculty Research and Publications

The development of the macronucleus from the zygotic micronucleus in the ciliated protozoan Tetrahymena spp. involves the elimination of specific DNA sequences (M. C. Yao and M. Gorovsky, Chromosoma 48:1-18 1974). The present study demonstrates that micronucleus-specific DNA is present on all five of the micronuclear chromosomes. Fragments of micronuclear DNA from Tetrahymena thermophila were cloned in the plasmid vector pBR322. A procedure was developed to examine the organization of the cloned sequences in micro- and macronuclear DNA without nick translating each individual probe. Twenty-three percent of randomly selected DNA sequences examined by this method were micronucleus (germ line) specific. …

Effect Of Hindlimb Immobilization On The Fatigability Of Skeletal Muscle, Frank Arthur Witzmann, D. H. Kim, Robert H. Fitts

Biological Sciences Faculty Research and Publications

The soleus (SOL) and extensor digitorum longus (EDL) muscles of the rat were studied in situ (33.5ºC) after 6 wk of disuse atrophy produced by hindlimb immobilization (IM). IM resulted in depressed peak twitch (P_t) and tetanic (P₀) tension as well as a decreased rate of tension development (+dP/dt) and decline (-dP/dt) in the slow-twitch SOL. The fast-twitch EDL was affected to a lesser extent, because only P_o (g·cm^-2) and P_o,-dP/dt (g·cm^-2·ms^-1) were depressed after IM. Twitch duration, as measured by contraction …

Rhizobium Japonicum Mutants Defective In Symbiotic Nitrogen Fixation, K. Dale Noel, Gary Stacey, Lin E. Silver, Winston J. Brill, Shiv R. Tandon

Biological Sciences Faculty Research and Publications

Rhizobium japonicum strains 3I1b110 and 61A76 were mutagenized to obtain 25 independently derived mutants that produced soybean nodules defective in nitrogen fixation, as assayed by acetylene reduction. The proteins of both the bacterial and the plant portions of the nodules were analyzed by two-dimensional polyacrylamide gel electrophoresis. All of the mutants had lower-than-normal levels of the nitrogenase components, and all but four contained a prominent bacteroid protein not observed in wild-type bacteroids. Experiments with bacteria grown ex planta suggested that this protein was derepressed by the absence of ammonia. Nitrogenase component II of one mutant was altered in isoelectric point. …

Hindlimb Immobilization: Length-Tension And Contractile Properties Of Skeletal Muscle, Frank Arthur Witzmann, D. H. Kim, Robert H. Fitts

Biological Sciences Faculty Research and Publications

The effect of hindlimb immobilization (IM) on the contractile properties of fast and slow skeletal muscle was studied in rats following various periods of IM ranging from 1 to 42 days; muscle atrophy, muscle, fiber, and sarcomere length, and the length-tension characteristics were determined after 42 days of IM. The slow-twitch soleus (SOL), the fast-twitch extensor digitorum longus (EDL), and the fast-twitch superficial region of the vastus lateralis (SVL) all showed rapid atrophy following the onset of IM, reaching a new reduced steady-state weight by day 21. After 42 days of IM the passive tension (g) and active twitch …

Identification Of Interneurons With Contralateral, Caudal Axons In The Lamprey Spinal Cord: Synaptic Interactions And Morphology, James T. Buchanan

Biological Sciences Faculty Research and Publications

1. As part of a continuing investigation of the organization of the spinal cord of the lamprey, propriospinal interneurons with axons projecting contralaterally and caudally (CC interneurons) were surveyed with intracellular recordings. 2. CC interneurons were identified by recording their axon spikes extracellularly in the spinal cord during intracellular stimulation of the cell body. The axon projections of Cc interneurons were confirmed after intracellular injection and development of horseradish peroxidase. 3. Intracellular stimulation of CC interneurons produced synaptic potentials in myotomal motoneurons, lateral interneurons and other CC interneurons that lay caudally on the opposite side of the spinal cord. Most …

Activities Of Identified Interneurons, Motoneurons, And Muscle Fibers During Fictive Swimming In The Lamprey And Effects Of Reticulospinal And Dorsal Cell Stimulation, James T. Buchanan, Avis H. Cohen

Biological Sciences Faculty Research and Publications

1. Application of D-glutamate to the isolated spinal cord of the lamprey produces phasic activity in ventral roots, which is similar to that of the muscles of the intact swimming animal (5,18). Therefore, the isolated spinal cord may be used as a convenient model for the investigation of the generation of locomotor rhythms in a vertebrate. 2. Almost all slow muscle fibers exhibited excitatory junctional potentials (EJPs) during swimming activity. The number of EJPs per cycle increased with the intensity of ventral root (VR) bursting. Few twitch fibers were active, and these fired action potentials only during high intensities of …

Recovery Time Course In Contractile Function Of Fast And Slow Skeletal Muscle After Hindlimb Immobilization, Frank Arthur Witzmann, D. H. Kim, Robert H. Fitts

Biological Sciences Faculty Research and Publications

Contractile properties were evaluated in rats remobilized after 6 wk of hindlimb casting to evaluate the regenerative capacity of fast and slow skeletal muscles. Contractile parameters were determined in vitro (22ºC) in the type I soleus (SOL), type IIA and IIB extensor digitorum longus (EDL), and the type IIB superficial vastus lateralis (SVL). Immobilization (IM) shortened the SOL isometric twitch duration after which contraction time and half-relaxation time required 4 and 7 days to recover, respectively. In contrast, IM prolonged the twitch in the EDL and SVL and recovery required 14 and 7 days, respectively. Peak tetanic tension (g/cm^{2 …}

Diversity And Dynamics Of Indigenous Rhizobium Japonicum Populations, K. Dale Noel, Winston J. Brill

Biological Sciences Faculty Research and Publications

A simple method, based upon the separation of cellular proteins by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, has been devised for distinguishing between isolates of Rhizobium japonicum. Eleven laboratory strains, previously classified into five serogroups, were analyzed by gel electrophoresis. Groups determined subjectively according to protein patterns matched the serogroups, with one exception. Most strains within serogroups could be distinguished from one another. For studying the ecology of Rhizobium, an important advantage of this technique compared with serology or phage typing is that it discriminates among previously unencountered indigenous bacterial isolates as well as among known laboratory strains. …

Effects Of Thyrotoxicosis On Mitochondrial Enzymes Of Rat Soleus, James B. Courtright, Robert H. Fitts

Biological Sciences Faculty Research and Publications

Cytochrome oxidase, glycerol-3-phosphate dehydrogenase, and succinate dehydrogenase were measured in mitochondrial fractions obtained from rat soleus muscle of control and 8 week T₃ + T₄ treated animals. Under these conditions of prolonged treatment, there is a five-fold increase in the specific activities of both cytochrome oxidase and glycerols-3-phosphate dehydrogenase. Significant increases in total cellular mitochondrial content and enzyme activities were observed in T₃ + T₄ treated animals as compared to controls. These results indicate that thyrotoxicosis can induce selective changes in mitochondrial enzymes in slow twitch red (Type I) muscle fibers.

Contractile Properties Of Rat Soleus Muscle: Effects Of Training And Fatigue, Robert H. Fitts, J. O. Holloszy

Biological Sciences Faculty Research and Publications

The effects of exercise training and fatigue on the contractile properties of rat soleus muscles have been investigated. Prolonged exercise, consisting of 2 h or daily treadmill running, induced small but significant decrease in contraction time, one-half relaxation time, and maximum tetanic tension (Po), and increase in the peak rate of tension development (dP/dt) during a twitch, and an increase in maximum shortening velocity (Vmax). The 20% increase in Vmax was proportional to the previously reported increase in actomyosin ATPase induced by 2 h of daily running. These results indicate that prolonged training can induce modifications of the neurally determined …

Fine-Structure Map Of The Histidine Transport Genes In Salmonella Typhimurium, Giovanna Ferro-Luzzi Ames, K. Dale Noel, H. Taber, E. Negri Spudich, Kishiko Nikaido, J. Afong, F. Ardeshir

Biological Sciences Faculty Research and Publications

Afine-structure genetic map of the histidine transport region of the Salmonella typhimurium chromosome was constructed. Twenty-five deletion mutants were isolated and used for dividing the hisJ and hisP genes into 8 and 13 regions respectively. A total of 308 mutations, spontaneous and mutagen induced, have been placed in these regions by deletion mapping. The histidine transport operon is presumed to be constituted of genes dhuA, hisJ, and hisP, and the regulation of the hosP and hisJ genes by dhuA is discussed. The orientation of this operon relative to purF has been established by three-point crosses as being: purF …

Lactate And Contractile Force In Frog Muscle During Development Of Fatigue And Recovery, Robert H. Fitts, J. O. Holloszy

Biological Sciences Faculty Research and Publications

The relationship between lactic acid concentration and twitch tension was reevaluated in electrically stimulated frog sartorius muscle. If muscles stimulated under anaerobic conditions at a rate of 30 stimuli/min, contractile force decreased to 36% of the initial value in 15 min. Concomitantly lactate increased from 3.3 to 18.7 μmol/g of muscle. The correlation between the increase in lactate and the decrease in contractile force was significant (r = -0.99, P < 0.000001). Recovery occurred in two phases. A rapid increase in contractile force, which represented 20% of the total recovery, took place during the first 15 s and occurred concomitantly with an increase in ATP from 3.9 to 4.6 μmol/g. Lactate concentration did not change significantly during this period. The second phase of recovery of contractile force was complete in 50 min. Lactate concentration and contractile …

Phosphorylated Β-Guanidinopropionate As A Substitute For Phosphocreatine In Rat Muscle, Coy D. Fitch, Max Jellinek, Robert H. Fitts, K. M. Baldwin, J. O. Holloszy

Biological Sciences Faculty Research and Publications

To evaluate phosphorylated β-guanidinopropionate (β-GPAP) as a substitute for phosphocreatine (PC), hypoxic tibialis anterior muscles were stimulated to contract isometrically in situ until twitch tension fell to 25% of the peak value. Muscles from rats fed β-guanidinopropionic acid (β-GPA) failed to exhibit the staircase phenomenon, and they developed 28% less tension than control muscles. In control muscles lactate increased from 0.75 to 20.99, ADP increased from 0.89 to 1.20, ATP decreased from 5.09 to 2.73, and PC decreased from 15.78 to 1.52 μmol/g. In muscles from rats fed β-GPA, lactate increased from …

Skeletal Muscle Respiratory Capacity, Endurance, And Glycogen Utilization, Robert H. Fitts, F. W. Booth, W. W. Winder, J. O. Holloszy

Biological Sciences Faculty Research and Publications

This study was undertaken to evaluate the relationship between physical performance capacity and the mitochondrial content of skeletal muscle. Four groups of rats were trained by means of treadmill running 5 days/wk for 13 wk. One group ran 10 min/day, a second group ran 30 min/day, a third group ran 60 min/day, and a fourth group ran 120 min/day. The magnitude of the exercise-induced adaptive increase in gastrocnemius muscle respiratory capacity varied over a twofold range in the four groups. There were significant correlations between the levels of three mitochondrial markers (cytochrome c, citrate synthase, respiratory capacity) in the …

Immunodeficiency Diseases And Tumor Immunobiology, Rene J. Duquesnoy, Peter A. Abramoff

Biological Sciences Faculty Research and Publications

No abstract provided.

Effect Of Gibberellic Acid And Actinomycin D On The Formation And Distribution Of Rough Endoplasmic Reticulum In Barley Aleurone Cells, Eugene L. Vigil, Manfred Ruddat

Biological Sciences Faculty Research and Publications

Analysis of structural changes in barley aleurone cells during germination or following incubation of isolated layers in gibberellic acid with or without actinomycin D revealed extensive development of rough endoplasmic reticulum. Following the assembly of stacked rough endoplasmic reticulum, vesiculation occurred mainly in basal regions of the cell, resulting in a polar distribution of rough endoplasmic reticulum vesicles. It is postulated that these vesicles are involved in protein secretion, because smooth vesicles, derived from the rough endoplasmic reticulum, apparently become appressed to the plasma membrane. The increased α-amylase in the ambient medium and in cell homogenates correlated directly with formation …

Cellular And Secretory Proteins Of The Salivary Glands Of Sciara Coprophila During The Larval-Pupal Transformation, Anita Cavagnaro Been, Ellen M. Rasch

Biological Sciences Faculty Research and Publications

The cellular and secretory proteins of the salivary gland of Sciara coprophila during the stages of the larval-pupal transformation were examined by electrophoresis in 0.6 mm sheets of polyacrylamide gel with both SDS-continuous and discontinuous buffer systems. After SDS-electrophoresis, all electrophoretograms of both reduced and nonreduced proteins from single glands stained with Coomassie brilliant blue revealed a pattern containing the same 25 bands during the stages of the larval-pupal transformation. With the staining procedures used in this study, qualitative increases and decreases were detected in existing proteins and enzymes. There was no evidence, however, for the appearance of new protein …

Effects Of The Exogenous Hormone Cortisone Acetate On Drosophila Virilis Larvae, Margarita Midelfort

Bachelors’ Theses

Recent experiments published in the literature have questioned the importance of the appearance of chromosomal puffs during larval development in Dipterans since Sciara larvae fed the vertebrate hormone cortisone apparently show no puffs without impairment of normal development. We have used Drosophila virilis larvae to test these results because distinct morphological criteria can be used to assess the developmental age of third instar larvae and predict the appearance of a specific puff. We have found that even though ingestion of cortisone acetate by D. virilis larvae causes a marked delay in their development the chromosome puffs appear at the expected …

The Laboratory Curriculum At Marquette University, Peter A. Abramoff

Biological Sciences Faculty Research and Publications

No abstract provided.

Induction Of Cytokinin-Independent Tobacco Tissues By Substituted Fluorenes, Thomas W. Bednar, Elfriede M. Linsmaier-Bednar

Biological Sciences Faculty Research and Publications

Two morphactins and three aminofluorenes initiated the formation of compact tissue nodules in hormone-dependent tobacco callus cultures. These nodules, upon subculture, behaved like partially transformed plant tumors. They grew on cytokinin-free media, while control callus and nonnodule tissue still required an exogenous cytokinin source. The data indicate that substituted fluorenes, including carcinogenic aminofluorenes, can cause a neoplastic growth response in cultured tobacco tissues. Of particular interest in this study is the finding that a directed and heritable cellular change is induced in tobacco tissue in which a specific (the endogenous cytokinin) biosynthetic system is regularly and persistently activated.

Genetic And Metabolic Controls For Sulfate Metabolism In Neurospora Crassa: Isolation And Study Of Chromate-Resistant And Sulfate Transport-Negative Mutants, George A. Marzluf

Biological Sciences Faculty Research and Publications

Mutants of Neurospora resistant to chromate were selected and all were found to map at a single genetic locus designated as cys-13. The chromate-resistant mutants grow at a wild-type rate on minimal media but are partially deficient in the transport of inorganic sulfate, especially during the conidial stage. An unlinked mutant, cys-14, is sensitive to chromate but transports sulfate during the mycelial stage at only 25% of the wild-type rate; cys-14 also grows at a fully wild-type rate on minimal media. The double-mutant strain, cys-13;cys-14, cannot utilize inorganic sulfate for growth and completely lacks the capacity to …

Intercellular Migration Of Centrioles In The Germarium Of Drosophila Melanogaster. An Electron Microscopic Study, Anthony P. Mahowald, Joan M. Strassheim

Biological Sciences Faculty Research and Publications

A cluster of centrioles has been found in the early Drosophila oocyte. Since the oocyte is connected to 15 nurse cells by a system of intercellular bridges or ring canals, the possibility that the cluster of centrioles arose in the germarium from an intercellular migration of centrioles from the nurse cells to the oocyte was analyzed in serial sections for the electron microscope. Initially, all of the 16 cells of the future egg chambers possess centrioles, which are located in a juxtanuclear position. At the time the 16 cell cluster becomes arranged in a lens-shaped layer laterally across the germarium, …

Electrophoretic Demonstration Of The Hybrid Origin Of The Gynogenetic Teleost Poecilia Formosa, Peter Abramoff, Rezneat M. Darnell, Joseph Silvio Balsano

Biological Sciences Faculty Research and Publications

No abstract provided.

Structure Of The Trpc Cistron Specifying Indoleglycerol Phosphate Synthetase, And Its Localization In The Tryptophan Operon Of Escherichia Coli, Oliver H. Smith

Biological Sciences Faculty Research and Publications

No abstract provided.

A Study Of The Various Stages Of Corn Foliage And Their Scale Preventing Abilities In Sea Water Evaporators, Arthur J. Rehberger

Bachelors’ Theses

Previous work carried out at Marquette University has proved that seawater evaporator scale can be prevented if such things as dehydrated alfalfa foliage or dehydrated corn, oats, pea and grass foliage are added to the feed seawater.

The object of this work is to determine if the scale preventing ability of corn foliage varies with the maturity of the plant from which it is stripped. Also if the proven scale preventing ability of mature corn foliage changes while it is stored.

A Study Of Spermatogenesis In The Charales, Robert Korn

Bachelors’ Theses

Investigations on the nature of the antherozoid, or male gamete, in the Archegoniates has been of great cytological interest to numerous workers. An apparent consistency of certain characteristics in the antherozoids of the Bryophytes and the Pteridophytes has, also, undoubtably been of value in determining phylogenic relationships.

Albino Mutants In The Golden Hamster, Robert J. Kinney

Bachelors’ Theses

Coat color variations or other inherent changes in the golden hamster, Mesocricetus auratus Waterhouse, have been uncommon. With a few exceptions, these animals have been remarkably uniform since 1930, when they were reared in captivity for one first time.