Microbiology Commons^™

Salivary Acinar Cells From Aquaporin 5-Deficient Mice Have Decreased Membrane Water Permeability And Altered Cell Volume Regulation, Carissa M. Krane, James E. Melvin, Ha-Van Nguyen, Linda Richardson, Jennifer E. Towne, Thomas Doetschman, Anil G. Menon

Biology Faculty Publications

Aquaporins (AQPs) are channel proteins that regulate the movement of water through the plasma membrane of secretory and absorptive cells in response to osmotic gradients. In the salivary gland, AQP5 is the major aquaporin expressed on the apical membrane of acinar cells. Previous studies have shown that the volume of saliva secreted by AQP5-deficient mice is decreased, indicating a role for AQP5 in saliva secretion; however, the mechanism by which AQP5 regulates water transport in salivary acinar cells remains to be determined. Here we show that the decreased salivary flow rate and increased tonicity of the saliva secreted byAqp5 …

Nuclear Export Of 60s Ribosomal Subunits Depends On Xpo1p And Requires A Nuclear Export Sequence-Containing Factor, Nmd3p, That Associates With The Large Subunit Protein Rpl10p, Olivier Gadal, Daniela Strau, Jacques Kessl, Bernard Trumpower

Dartmouth Scholarship

Nuclear export of ribosomes requires a subset of nucleoporins and the Ran system, but specific transport factors have not been identified. Using a large subunit reporter (Rpl25p-eGFP), we have isolated several temperature-sensitive ribosomal export (rix) mutants. One of these corresponds to the ribosomal protein Rpl10p, which interacts directly with Nmd3p, a conserved and essential protein associated with 60S subunits. We find that thermosensitive nmd3 mutants are impaired in large subunit export. Strikingly, Nmd3p shuttles between the nucleus and cytoplasm and is exported by the nuclear export receptor Xpo1p. Moreover, we show that export of 60S subunits is Xpo1p dependent. We …

Aquaporin 5-Deficient Mouse Lungs Are Hyperresponsive To Cholinergic Stimulation, Carissa M. Krane, Christopher N. Fortner, Arthur R. Hand, Dennis W. Mcgraw, John N. Lorenz, Susan E. Wert, Jennifer E. Towne, Richard J. Paul, Jeffrey A. Whitsett, Anil G. Menon

Biology Faculty Publications

Although aquaporin 5 (AQP5) is the major water channel expressed in alveolar type I cells in the lung, its actual role in the lung is a matter of considerable speculation. By using immunohistochemical staining, we show that AQP5 expression in mouse lung is not restricted to type I cells, but is also detected in alveolar type II cells, and in tracheal and bronchial epithelium. Aqp5 knockout (Aqp5−/−) mice were used to analyze AQP5 function in pulmonary physiology. Compared with Aqp5+/+ mice, Aqp5−/− mice show a significantly increased concentration-dependent bronchoconstriction to intravenously administered Ach, as shown by …

Hawaiian Freshwater Polychaeta: A Potentially Substantial Trophic Component Of Stream Depositional Habitats, M. Eric Benbow, Albert J. Burky, Carl M. Way

Biology Faculty Publications

In this paper we report the widespread occurrence of large annelids (Polychaeta: Nereididae) in Hawaiian stream depositional habitats, drawing attention to the lack of knowledge of Hawaiian stream energetics. Specimens of Namalycastis sp. were collected from five Hawaiian Islands from May–July 1995 and from the island of Maui from July–December 1999 and April–July 2000. Most specimens collected were N. hawaiiensis, while two specimens of N. abiuma were collected from a single site on the island of Molokai. Specimens were collected from elevations ranging from 3–240 m; several collections were from sites above at least one major (> 15 m …

The Occurrence Of The Freshwater Clams, Musculium Partumeium (Say) And Pisidium Casertanum (Poli) (Bivalvia: Sphaeriidae), In The Hawaiian Islands, Albert J. Burky, Carl M. Way, Skippy Hau, M. Eric Benbow

Biology Faculty Publications

Sphaeriid clams were collected from an ancient, continuously cultivated taro pond complex at Ke‘anae Peninsula, Maui. Both species are known for adaptations for temporary pond habitats and could have been initially introduced by the earliest Hawaiian settlers transported with moist taro root stock from other areas of Oceania.

Identification Of The Transactivation Domain Of The Transcription Factor Sox-2 And An Associated Co-Activator, Tamara K. Nowling, Lance R. Johnson, Matthew S. Wiebe, Angie Rizzino

Nebraska Center for Virology: Faculty Publications

The importance of interactions between Sox and POU transcription factors in the regulation of gene expression is becoming increasingly apparent. Recently, many examples of the involvement of Sox-POU partnerships in transcription have been discovered, including a partnership between Sox-2 and Oct-3. Little is known about the mechanisms by which these factors modulate transcription. To better understand the molecular interactions involved, we mapped the location of the transactivation do-main of Sox-2. This was done in the context of its interaction with Oct-3, as well as its ability to transactivate as a fusion protein linked to the DNA-binding domain of Gal4. Both …

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.

Development Of The Suprarostral Plate Of Pipoid Frogs, Rafael O. De Sá, Charles C. Swart

Biology Faculty Publications

The rostral region of nonpipoid tadpoles has two sets of cartilages, the cornua trabeculae and the suprarostral cartilages, whereas the rostral region in pipoid larvae is occupied by a single and continuous cartilage, the suprarostral plate. The homology of this region in pipoid and nonpipoids tadpoles has been controversial. We examined the early formation and development of the suprarostral plate using serially cross-sectioned specimens of Rhinophrynus, Xenopus, and Hymenochirus. We conclude that the cartilaginous structures present in the rostral area of pipoid and nonpipoid larvae are homologous. Furthermore, we found two different developmental patterns among pipoid larvae. The chondrocranium …

Osteological Analysis Of The Killifish Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá

Biology Faculty Publications

Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the variation and utility of osteological characters for phylogenetic analysis was done using cleared and double-stained specimens representing 21 species of Cynolebias. This analysis showed that some of the characters previously used to diagnose this genus and some of the species are polymorphic. Osteologically, Cynolebias can be diagnosed by the following synapomorphies: (1) triangular-shaped parietal, (2) vomer positioned ventral to the parasphenoid, (3) long ventral process of the dentary, (4) teeth on fourth ceratobranchial, and (5) teeth on first epibranchial. In addition, characters that help …

Confocal Microscopy: A Powerful Tool For Biological Research, Amit Singh, K. P. Gopinathan

Biology Faculty Publications

Conventional light microscopy allows the observation of living as well as fixed cells and tissues to generate two-dimensional images. The out-of-focus information often obscures the ultrastructural details, especially in thick specimens with overlapping structures. The earliest available light microscopy visualized the objects in hydrated state in two-dimensions during their temporal development. The emergence of electron microscopy (EM) provided superb resolution of ultrastructural details, but it was applicable only for objects in the dehydrated state and thereby potentially introducing handling artifacts. The usefulness of optical methods, however, has been limited by the poor depth discrimination. Often, the fluorescence and reflectance images …

The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá

Biology Faculty Publications

The Biology of Xenopus presents a summary of current knowledge about a single genus resulting from a symposium held at the Zoological Society of London in September 1992. This approach to summarizing available information has also been taken for other taxa, such as Atelopus (Lotters, 1996). However, the task of compiling data for Xenopus is enormous relative to any other amphibian group, because Xenopus laevis has become a model system for molecular and development research (Cannatella and de Sa, 1993). Unfortunately, most of our knowledge of Xenopus is biased toward this single species. There are about 20 recognized species of …

Chondrocranial Morphology Of Leptodactylus Larvae (Leptodactylidae: Leptodactylinae): Its Utility In Phylogenetic Reconstruction, Peter M. Larson, Rafael O. De Sá

Biology Faculty Publications

Chondrocranial morphology of leptodactylid frogs is scarcely known and has not been completely described for any species of Leptodactylus. We describe the diversity of chondrocranial morphology in the genus Leptodactylus based on the analysis of 22 species, representing the four species groups: the fuscus Group, ocellatus Group, melanonotus Group, and pentadactylus Group. Furthermore, 26 characters are identified and used in a phylogenetic analysis. The phylogenetic analysis using Physalaemus, Crossodactylus, and Hylodes as outgroups suggests two monophyletic clades within Leptodactylus: the melanonotus-ocellatus clade and the pentadactylusfuscus clade. However, it does not support the monophyly of the species groups as currently recognized …

Recovery Of Rna Polymerase Ii Synthesis Following Dna Damage In Mutants Of Saccharomyces Cerevisiae Defective In Nucleotide Excision Repair, Michael S. Reagan, Errol C. Friedberg

Biology Faculty Publications

We have measured the kinetics of the recovery of mRNA synthesis in the inducible GAL10 and RNR3 genes after exposure of yeast cells to ultraviolet (UV) radiation. Such recovery is abolished in mutant strains defective in nucleotide excision repair (NER) of DNA, including a rad23 mutant. Mutants defective in the RAD7 or RAD16 genes, which are required for the repair of the non-transcribed strand but not the transcribed strand of transcriptionally active genes, show slightly faster recovery of RNA synthesis than wild-type strains. A strain deleted of the RAD26 gene, which is known to be required for strand-specific NER in …

Identification Of The Flii And Flij Components Of The Caulobacter Flagellar Type Iii Protein Secretion System, Craig Stephens, Chris Mohr, Charles Boyd, Janine Maddock, James Gober, Lucy Shapiro

Biology

Caulobacter crescentus is motile by virtue of a polar flagellum assembled during the predivisional stage of the cell cycle. Three mutant strains in which flagellar assembly was blocked at an early stage were isolated. The mutations in these strains mapped to an operon of two genes, fliI and fliJ, both of which are necessary for motility. fliI encodes a 50-kDa polypeptide whose sequence is closely related to that of the Salmonella typhimurium FliI protein, an ATPase thought to energize the export of flagellar subunits across the cytoplasmic membrane through a type III protein secretion system. fliJ encodes a 16-kDa hydrophilic …

Analysis Of Gene Expression During Embryonic Development In Mulberry Silkworm Bombyx Mori, Amit Singh, K. P. Gopinathan

Biology Faculty Publications

We have developed a method for dechorionation and devitellinization of the silkworm eggs without damage, to facilitate the analysis of gene expression during embryonic development of Bombyx mori. Making use of antibodies available from heterologous systems, the spatio-temporal expression patterns of peroxidase and proliferating cell nuclear antigen have been directly visualized in whole mount embryos at various stages of development without the need for generating transformed ·lines carrying specific reporter constructs. The B. mori system, previously unamenable for such studies, could thus serve as an attractive model for molecular analysis of insect development.

The attention lavished on Drosophila melanogaster as …

Enhancer Trap Technique: A Novel Tool For Identification And Developmental Characterization Of Genes Of Drosophila, Amit Singh

Biology Faculty Publications

The classical technique of mutational screen for identification of genes controlling early development has now approached saturation. A new era in genetic identification and developmental characterization of genes in Drosophila has commenced with the advent of the enhancer trap technique. This technique involves mobilization of a P-lacZ vector to diverse chromosomal locations in the fruit fly genome to bring it under the regulation of developmentally expressed genes or their enhancer elements. The technique offers a strikingly elegant method of gaining entry into fruit fly genes.

An Improved Method For Chemical Devitellinization Of X-Gal Stained Drosophila Embryos, Amit Singh, Madhuri Kango-Singh, P. Sinha

Biology Faculty Publications

In Drosophila developmental biological studies, X-gal staining is commonly employed to study the spatio-temporal expression of the lacZ reporter gene in the transformed flies or their embryos. Study of the lacZ pattern in embryos often suffers from the lack of an efficient and high yieldirrg technique for devitellinization of X-gal stained embryos. Devitellinization techniques employed during antibody staining, in situ hybridization or embryonic cuticular preparations generally do not give satisfactory results when used for similar purpose in X-gal stained embryos. This results in the flaky appearance of the blue stain. We present here an improved chemical devitellinization technique which gives …

Media Components Influence Viral Gene Expression Assays In Human Fetal Astrocyte Cultures, Micheline Mccarthy, Charles Wood, Larisa Fedoseyeva, Scott R. Whittemore

Nebraska Center for Virology: Faculty Publications

In vitro neurovirological studies of viral infectivity or viral gene expression may be confounded by the mulHple neural cell types and/or fibrob last contamination present in early passage cultures prepared from dissociated human central nervous system (eNS) tissue. We have developed highly enriched astrocyte cultures for neurovirological study by culturing in a serum-free defined medium, 816, supplemented with basic fibroblast growth factor (FGF-2). Subculture in this medium selects against fibroblast proliferation and favors sustained proliferation of a highly enriched glial fibrillary acidic protein (GFAP)-positive cell population. These astrocytes support productive replication of cytomegalovirus (CMV) and transient expression of transfected CMVand …

Translational Regulation Of The C-Jun Proto-Oncogene, Anil Sehgal

Theses and Dissertations in Biomedical Sciences

The v-jun oncogene was originally isolated from the ASV17 virus in 1987. Ever since its isolation, extensive work has been done to understand the role of the v-jun oncogene in cell transformation. The c-Jun protein is a transcription factor which binds to the DNA target TGACTCA. The c-Jun protein binds to DNA in the form of dimers. It can form homodimers with itself and heterodimers with Jun family (JunB and JunD), Fos family (FosB, Fra1 and Fra2), or with CREB family members through the leucine zipper motif. Because the c-jun proto-oncogene plays an important role in cell transformation, extensive work …

Development And Application Of A Thermistor Current Meter, Carl M. Way, Albert J. Burky, Christine Miller-Way

Biology Faculty Publications

This report provides details for the construction of a hot-bead thermistor current meter which is capable of measuring water velocities on a millimeter spatial scale and for the construction of a compact and accurate calibration system. Hot-bead thermistor current meters can be built with response times of 200 ms capable of measuring velocities between 0.1 and 80 cm s-1. The construction of a sturdy probe for application in lotic systems such as high gradient Hawaiian streams was achieved by the use of heavy-duty acrylic tubing, small stainless steel gas-chromatography tubing, and flexible Tygon spaghetti tubing. An acrylic handle anchors the …

Book Review: The Baculovirus Expression System: A Laboratory Guide (1992) King, L. A. & Possee, R. D., David D. Dunigan

Nebraska Center for Virology: Faculty Publications

The power of molecular biology is unleashed with the ability to clone and sequence genes, and then express these genes in heterologous systems. This sets the stage for the full analysis of proteins that are otherwise difficult to isolate and/or purify, especially when present at very low copy number per cell or when isolated from relatively precious materials. Overexpression of protein is now possible in a number of systems including prokaryotes (e.g., E. coli) and various eukaryotes (yeast, insects, and plants). The issue then becomes, which system (1) most closely reflects the homologous expression with respect to posttranslational modifications, …

Molecular And Cellular Analysis Of Chlamydia Trachomatis: Persistence And Reactivation, Kimberly R. Tau

Electronic Theses and Dissertations

Chlamydia trachomatis (CT) is the most prevalent sexually-transmitted infection in the United States. It has been suggested that CT infections can become latent. This has not been substantiated. CT persistence was examined at the molecular and cellular level in vitro and in vivo. Penicillin treatment of CT in vitro results in abnormal inclusions and reduced recovery of infectious CT. Penicillin did not inhibit initial stages of infection, but did downregulate CT rRNA levels after 25 hours post-inoculation (p.i.). DNA amplification was employed to differentiate between a resolved infection and a persistent one. Utilizing a primer pair that amplified a 144 …

Altered Expression Of Adenovirus 12 Dna-Binding Protein But Not Dna Polymerase During Abortive Infection Of Hamster Cells, Lynne A. Lucher, Benjawan Khuntirat, Jiansheng Zhao, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Replication of human adenovirus type 12 DNA is blocked in abortively infected baby hamster kidney cells. The activity and accumulation of adenovirus 12 DNA polymerase is equivalent in infected hamster and human cell extracts. However, the accumulation of adenovirus type 12 DNA-binding protein is approximately 120-fold lower in extracts from infected hamster cells when compared to infected permissive human cells. This difference in accumulation is not because of replication of viral DNA during productive infection, since this difference is observed in the presence of hydroxyurea. The DNA-binding protein from infected hamster cells retains the ability to bind denatured DNA-cellulose. An …

Immunosuppressive Activity Derived From The Uc729-6 Lymphoblastoid And M21-Hpb Melanoma Cell Lines, Charlene J. Repique

Loma Linda University Electronic Theses, Dissertations & Projects

Previous work conducted in our laboratories, using a murine model, suggested that soluble factors secreted by tumor cells suppress lymphocyte responses. To apply this premise to human tumors, we studied the effects of UC729-6 (lymphoblastoid B-cell) and M21-HPB (malignant melanoma) conditioned media (CM) on lymphocyte proliferation assays, as well as on the growth of other cells. The CM was collected at 2-5 day intervals from cultures of UC729-6 and M21- HPB cells in serum-free media. In assays using phytohemagglutinin (PHA) and concanavalin A (ConA), mononuclear peripheral blood cells from healthy human donors showed decreased [³H]-thymidine ([³H]-Tdr) …

A Simple Solid-Phase Electrophoretic Procedure For The Separation Of Plasmid Dna, Linda Ann Simurra

Biological Sciences Theses & Dissertations

A method was developed for extraction of plasmid DNA from bacterial cells embedded in agarose blocks. Cell - containing blocks were treated with various lysing reagents and inserted into the wells of an agarose gel. Upon electrophoresis the plasmid DNA migrated out of the embedding block and into the gel leaving intact chromosomal DNA in the well. This method was tested with various organisms and found to be effective for plasmid isolation. In comparison to "traditional" procedures, this new method is less tedious since chemical separation of plasmids is not required prior to electrophoresis. Also, a higher yield of plasmid …

Seasonal Responses Of Filtration Rates To Temperature, Oxygen Availability, And Particle Concentration Of The Freshwater Clam, Musculium Partumeium (Say), Albert J. Burky, Richard B. Benjamin, Denis G. Conover, Jennifer Detrick

Biology Faculty Publications

Seasonal filtration rates of a pond population of the freshwater pisidiid clam, Musculium par­tumeium (Say), were assessed by measuring the clearance of 2.02 µ.m latex beads from suspension and expressed in terms of FR = a(AFDW}b where FR = filtration rate (ml H20 · hr- 1 ) , AFDW = mg ash-free dry weight of a whole clam and "a" and "b" are constants. The a-values ( = FR of a 1-mg AFDW clam} vary seasonally with the highest rates corresponding to periods of maximum growth and reproduction in the spring and fall. Changes in "b" reflect the influence of …

Analysis Of Multiple Isoenzyme Expression Among Twenty-Two Species Of Mycoplasma And Acholeplasma, Stephen J. O'Brien, Janice M. Simonson, Marion W. Grabowski, Michael F. Barile

Biology Faculty Articles

Crude extracts of triple-cloned, purified cultures of 22 species of Mycoplasma and Acholeplasma were examined for expression of 21 isozyme systems routinely used to type mammalian cells. Nine previously described enzymes (purine nucleoside phosphorylase, adenylate kinase, dipeptidase, esterase, glyceraldehyde-3-phosphate dehydrogenase, glucose phosphate isomerase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and superoxide dismutase) and three enzymes not previously reported in mycoplasma (triose phosphate isomerase, inorganic pyrophosphatase, and acid phosphatase) were detected in some or all of the species examined. These findings provide new information on the enzymatic expressions of these organisms. Three of the isozyme systems (superoxide dismutase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase) …

Interpopulation Variation In Calcareous And Proteinaceous Shell Components In The Stream Limpet, Ferrissia Rivularis, Carl M. Way, Daniel J. Hornbach, Albert J. Burky

Biology Faculty Publications

Natural populations of the North American stream limpet, F. rivularis, were studied in upstate New York [USA], in a set of localities whose waters have a 15-fold range of dissolved Ca (4.6-67.6 mg/liter) and also range from oligotrophy to eutrophy. Shell component analyses (CaCO3, total organic C and total N) are reported as component mass-fractions (mg/g or .mu.g/g dry weight) and as values for a standard limpet shell of 35 mm aperture length (AL). More than 2-fold differences occur between populations in all 3 components, with relatively little variation occurring within each population. Expressed per standard limpet, CaCO3 values for …

Seasonal Metabolism Of The Sphaeriid Clam, Musculium Partumeium (Say), From A Permanent And A Temporary Pond, Carl M. Way, Daniel J. Hornbach, Albert J. Burky

Biology Faculty Publications

Seasonal metabolic rates were examined for the sphaeriid clam, Musculium partumeium (Say) from a permanent and a temporary pond. For the fall-born generation from the permanent pond and for the single generation from the temporary pond, metabolic rates peak during periods of greatest growth and reproduction. Metabolic rates were consistently higher for the permanent pond population. These rates for Musculium partumeium extend the available information on the family Sphaeriidae to the genus Musculium.

Growth Of Pisidium Casertanum (Poli) In West Central Ohio, Albert J. Burky, Daniel J. Hornbach, Carl M. Way

Biology Faculty Publications

Clarke (1973) states that Pisidium casertanum (Poli) is perhaps the most common species of Pisidium and is truly cosmopolitan, occurring throughout Eurasia, Africa, Australia, and South, Central and North America. Populations of these clams are reported in habitats ranging from ephemeral ponds to benthic zones of deep lakes. Our study describes Manuscript received 29 May 1979 and in revised form 25 July 1980 (#79-34). 2 Present address: Department of Biology, University of Virginia, Charlottesville, VA 22901. 3 Present address: Department of Zoology, Miami University, Oxford, OH 45056. 41 aspects of the life-cycle of P. casertanum in a spring-fed stream with …