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Glass Capillary Tube Feeding: A Method For Infecting Nymphal Ixodes Scapularis (Acari: Ixodidae) With The Lyme Disease Spirochete Borrelia Burgdorferi, Anne H. Broadwater, Daniel E. Sonenshine, Wayne L. Hynes, Shane Ceraul, Aravinda M. De Silva Jan 2002

Glass Capillary Tube Feeding: A Method For Infecting Nymphal Ixodes Scapularis (Acari: Ixodidae) With The Lyme Disease Spirochete Borrelia Burgdorferi, Anne H. Broadwater, Daniel E. Sonenshine, Wayne L. Hynes, Shane Ceraul, Aravinda M. De Silva

Biological Sciences Faculty Publications

We evaluated an artificial capillary feeding method to infect nymphal Ixodes scapularis (Say) ticks with Borrelia burgdorferi, the causative agent of Lyme disease. Thirty to 70% of the nymphs were infected after feeding for 2.5 h from glass capillary tubes filled with a solution of spirochetes. Capillary infection was stable and persisted in the nymphs for at least 10 d after feeding. Capillary feeding also maintained natural vector competence patterns because I. scapularis ticks acquired infection unlike Dermacentor variablis (Say), which did not become infected. Capillary infected I. scapularis nymphs were capable of transmitting the infection to naive mice …


The Response Of Mice To Infection By The Parasitic Nematode Trichinella: A Comparison Of Trichinella Spiralis And Trichinella Pseudospiralis, Barry Clayton Anderson Jan 2002

The Response Of Mice To Infection By The Parasitic Nematode Trichinella: A Comparison Of Trichinella Spiralis And Trichinella Pseudospiralis, Barry Clayton Anderson

Dissertations and Theses

The intracellular parasite Trichinella is a genus in phylum Nematoda that contains six named species including Trichinella spiralis and Trichinella pseudospiralis. These parasites infect a large variety of wild and domestic animals, human beings and a few species of birds. The parasitic strategies and the pathological effects on the host between trichinella spiralis and Trichinella pseudospiralis are quite different.

The purpose of this study is to gain an understanding of the physiological, immunological and pathological differences between these two species of Trichinella using infections in the mouse as a model. In the course of this research I have attempted to …


Embryology In Wax, Michael Dietrich Jan 2002

Embryology In Wax, Michael Dietrich

Dartmouth Scholarship

Book review of Embryos in Wax: Models from the Ziegler Studio by Nick Hopwood Whipple Museum of the History of Science, 2002.


Algal Blooms Reduce The Uptake Of Toxic Methylmercury In Freshwater Food Webs, Paul C. Pickhardt, Carol L. Folt, Celia Y. Chen, Bjoern Klaue, Joel D. Blum Jan 2002

Algal Blooms Reduce The Uptake Of Toxic Methylmercury In Freshwater Food Webs, Paul C. Pickhardt, Carol L. Folt, Celia Y. Chen, Bjoern Klaue, Joel D. Blum

Dartmouth Scholarship

Mercury accumulation in fish is a global public health concern, because fish are the primary source of toxic methylmercury to humans. Fish from all lakes do not pose the same level of risk to consumers. One of the most intriguing patterns is that potentially dangerous mercury concentrations can be found in fish from clear, oligotrophic lakes whereas fish from greener, eutrophic lakes often carry less mercury. In this study, we experimentally tested the hypothesis that increasing algal biomass reduces mercury accumulation at higher trophic levels through the dilution of mercury in consumed algal cells. Under bloom dilution, as algal biomass …


Single-Base-Pair Discrimination Of Terminal Mismatches By Using Oligonucleotide Microarrays And Neural Network Analyses, Hidetoshi Urakawa, Peter A. Noble, Said El Fantroussi, John J. Kelly, David A. Stahl Jan 2002

Single-Base-Pair Discrimination Of Terminal Mismatches By Using Oligonucleotide Microarrays And Neural Network Analyses, Hidetoshi Urakawa, Peter A. Noble, Said El Fantroussi, John J. Kelly, David A. Stahl

Biology: Faculty Publications and Other Works

The effects of single-base-pair near-terminal and terminal mismatches on the dissociation temperature (T(d)) and signal intensity of short DNA duplexes were determined by using oligonucleotide microarrays and neural network (NN) analyses. Two perfect-match probes and 29 probes having a single-base-pair mismatch at positions 1 to 5 from the 5' terminus of the probe were designed to target one of two short sequences representing 16S rRNA. Nonequilibrium dissociation rates (i.e., melting profiles) of all probe-target duplexes were determined simultaneously. Analysis of variance revealed that position of the mismatch, type of mismatch, and formamide concentration significantly affected the T(d) and signal intensity. …


Functional Morphology And Developmental Biology Of Zebrafish: Reciprocal Illumination From An Unlikely Couple, L. Patricia Hernández, Michael J.F. Barresi, Stephen H. Devoto Jan 2002

Functional Morphology And Developmental Biology Of Zebrafish: Reciprocal Illumination From An Unlikely Couple, L. Patricia Hernández, Michael J.F. Barresi, Stephen H. Devoto

Biological Sciences: Faculty Publications

Functional morphology has benefited greatly from the input of techniques and thinking from other disciplines. This has been especially productive in situations where each discipline has made significant contributions to a particular research topic. A combination of methodologies from functional morphology and developmental biology has allowed us to characterize feeding mechanics of first-feeding larval zebrafish (Danio rerio). Contrary to kinematic patterns commonly seen in adult teleosts, larval zebrafish showed no lateral abduction during the expansive phase of a suction-feeding event. Instead, dorsoventral expansion of the buccal chamber, more typical of patterns seen in primitive fishes, characterized the expansive phase. Moreover, …


Dipyridamole Reduces Oxidative Stress In Human Coronary Artery Endothelial And Hela Cell Models, Matthew E. Giangrante Jan 2002

Dipyridamole Reduces Oxidative Stress In Human Coronary Artery Endothelial And Hela Cell Models, Matthew E. Giangrante

Seton Hall University Dissertations and Theses (ETDs)

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Functional Requirement Of Aquaporin-5 In Plasma Membranes Of Sweat Glands, Lene N. Nejsum, Tae-Hwan Kwon, Uffe B. Jensen, Ornella Fumagalli, Jørgen Frøkiaer, Carissa M. Krane, Anil G. Menon, Landon S. King, Peter C. Agre, Søren Nielsen Jan 2002

Functional Requirement Of Aquaporin-5 In Plasma Membranes Of Sweat Glands, Lene N. Nejsum, Tae-Hwan Kwon, Uffe B. Jensen, Ornella Fumagalli, Jørgen Frøkiaer, Carissa M. Krane, Anil G. Menon, Landon S. King, Peter C. Agre, Søren Nielsen

Biology Faculty Publications

The distribution and function of aquaporins (AQPs) have not previously been defined in sweat glands. In this study, AQP1, AQP3, and AQP5 mRNA were demonstrated in rat paw by reverse transcription (RT)–PCR, but AQP2 and AQP4 were not. AQP1, AQP3, and AQP5 protein were confirmed in these tissues by immunoblotting. AQP1 was identified in capillary endothelial cells by immunohistochemical labeling, but not in sweat glands or epidermis. Abundant AQP3 expression was seen in basal levels of epidermis, but not in sweat glands. AQP2 and AQP4 were not observed in either skin or sweat glands. Immunohistochemical labeling revealed abundant AQP5 in …


Habitat Use Of Urban Bats In Springfield, Missouri, Sarah Jane Robertson Jan 2002

Habitat Use Of Urban Bats In Springfield, Missouri, Sarah Jane Robertson

Graduate Theses/Dissertations

During the summers of 1998-2000, the Anabat II bat detector system was placed in a mosaic of habitats within Springfield, Missouri and surrounding rural areas in southern Missouri to compare the activity indices of nine bat species between urban and rural environments. A total of 1,876 echolocation call sequences was recorded, identified to species and analyzed; 1,066 were from 42 Springfield sites, and 810 were from 22 rural locations. For all species combined, urban bat activity tended to be higher than rural activity, but those differences were only significant at the reading taken 3 hours after sunset. Eptesicus fuscus activity …


A Survey Of The Mammals Of The Archie Carr And Pelican Island National Wildlife Refuges, Joseph S. Weidlich Jan 2002

A Survey Of The Mammals Of The Archie Carr And Pelican Island National Wildlife Refuges, Joseph S. Weidlich

Retrospective Theses and Dissertations

ABSTRACT This summarizes a study conducted on the Archie Carr (ACNWR) and Pelican Island (PINWR) National Wildlife Refuges located on the barrier island complex of southern Brevard and northern Indian River counties, Florida. Major objectives of this study were designed to 1) survey the mammals of the ACNWR and PINWR, 2) perform a small mammal population demographic study in coastal scrub and maritime hammock habitats, and 3) document a population monitoring project of Peromyscus po/ionotus niveiventris in northern Indian River County at Treasure Shores Park, within ACNWR Segment 4. A total of7,279 trap nights was compiled during the survey portion …


Effects Of Gibberellic Acid Treatment For Pollen Sterility Induction On The Physiological Activity And Endogenous Hormone Levels Of The Seed In Safflower, Hasan Baydar Jan 2002

Effects Of Gibberellic Acid Treatment For Pollen Sterility Induction On The Physiological Activity And Endogenous Hormone Levels Of The Seed In Safflower, Hasan Baydar

Turkish Journal of Biology

In this research, our aim was to determine the effects of gibberellic acid, which was applied to safflower plants (Carthamus tinctorius L. cv. Dinçer 5-118) for pollen sterility induction, on some physiological activity and endogenous hormone levels of the seeds. Exogenously applied gibberellic acid (GA_3) strongly influenced the endogenous hormone levels of the seeds by decreasing the levels of GA_3 and zeatin, and increasing the levels of indole-3-acetic acid (IAA) and abscisic acid (ABA). The lowered endogenous GA_3/ABA and zeatin/IAA ratios in the seeds significantly decreased the germination percentage and hypocotyl elongation, respectively. The seeds from GA_3 treated plants had …


Methylation Of Adenine In The Nuclear Dna Of "Tetrahymena" Is Internucleosomal And Independent Of Histone H1, Kathleen M. Karrer, Teresa Ann Van Nuland Jan 2002

Methylation Of Adenine In The Nuclear Dna Of "Tetrahymena" Is Internucleosomal And Independent Of Histone H1, Kathleen M. Karrer, Teresa Ann Van Nuland

Biological Sciences Faculty Research and Publications

There are about 50 copies of each chromosome in the somatic macronucleus of the ciliated protozoan Tetrahymena. Approximately 0.8% of the adenine residues in the macronuclear DNA of Tetrahymena are methylated to N6-methyladenine. The degree of methylation varies between sites from a very low percentage to >90%. In this study a correlation was found between nucleosome positioning and DNA methylation. Eight GATC sites with different levels of methylation were examined. There was a direct correlation between the degree of methylation and proximity to linker DNA at these sites. Although methylation occurs preferentially in linker DNA, the patterns …


A Note On Cascade Climbing Of Migrating Goby And Shrimp Postlarvae In Two Maui Streams, M. Eric Benbow, Leslie Luchar Orzetti, Mollie D. Mcintosh, Albert J. Burky Jan 2002

A Note On Cascade Climbing Of Migrating Goby And Shrimp Postlarvae In Two Maui Streams, M. Eric Benbow, Leslie Luchar Orzetti, Mollie D. Mcintosh, Albert J. Burky

Biology Faculty Publications

In this study, we documented cascade climbing rates of 133 and 230 postlarvae of Lentipes concolor (O‘opu alamo‘o) and Atyoida bisulcata (Opae kahaole), respectively, from two streams on the island of Maui, Hawaii. Climbing measurements and observations were made of postlarvae at the water-substrate interface in cascade habitats of constricted water flow. Both species were observed to move in short bursts of forward progression within or above the pulsing water-substrate interface. Goby postlarval climbing rates ranged from 0.04 – 1.50 cm s–1 and were slower than shrimp rates which ranged from 0.30 – 3.06 cm s–1. The high variability is …


A Field Study Of The Northern Leopard Frog (Rana Pipiens) In The Potholes Reservoir Area, Washington, Heather Maranda Simmons Jan 2002

A Field Study Of The Northern Leopard Frog (Rana Pipiens) In The Potholes Reservoir Area, Washington, Heather Maranda Simmons

All Master's Theses

Northern Leopard Frogs (Rana pipiens) were studied in the Potholes Reservoir area in eastern Washington, which is a unique and dynamic system of ponds. The filling and drying cycles of the reservoir cause seasonal fluctuation on pond depth. My goal was to find frogs and document their use of these ponds. I conducted surveys of R. pipiens from April - September 2002.

I caught 178 R. pipiens adults and subadults throughout my field season, gathering weight and length data. I found two groups of egg masses in April, and noted their size, location and point of attachment. Findings were similar …


Complement Resistance In Agrobacterium Tumefaciens Isolates, Michael E. Mccormick Jan 2002

Complement Resistance In Agrobacterium Tumefaciens Isolates, Michael E. Mccormick

Honors Theses

The word "pathogen" ofen brings to mind morose images and other words such as "illness," "malaria," and "outbreak": words associated with animal pathogens, in particular, the ones that make us humans sick. However, some pathogens also affect another major kingdom, plants, and one of the more devastating pathogens to the plant kingdom is the bacteria Agrobacterium tumefaciens. This organism has a Type IV Secretion System that allows it to transfer a piece of t-DNA into the host cell; this DNA integrates into the eukaryotic genome and establishes in ction by utilizing the host's transcription machinery. This unique and effective means …


Shrimp Adjust Their Sex Ratio To Fluctuating Age Distributions, Eric Charnov, Robert Hannah Jan 2002

Shrimp Adjust Their Sex Ratio To Fluctuating Age Distributions, Eric Charnov, Robert Hannah

Biology Faculty & Staff Publications

Long-term data sets that quantitatively confirm basic ecological theory are rare for field populations. Highly variable recruitment often causes wide temporal variation in population age distribution and basic theory for adaptive sex ratio often predicts sex ratio tracking' to match the fluctuating age distribution. Using sex-changing shrimp as a model system, we test this in a new data set of 20 years duration. The new data support the theory, despite intense fishery exploitation that itself has greatly altered the age distribution in recent years.


Specimen Catalog, Part 4, Brian D. Frank Jan 2002

Specimen Catalog, Part 4, Brian D. Frank

Division of Mammals - Field Notes and Catalogs

No abstract provided.


Cold Acclimation Strategy Is Highly Variable Among The Sunfishes (Centrarchidae), Deidra R. Tschantz, Elizabeth L. Crockett, Peter H. Niewiarowski, Richard L. Londraville Jan 2002

Cold Acclimation Strategy Is Highly Variable Among The Sunfishes (Centrarchidae), Deidra R. Tschantz, Elizabeth L. Crockett, Peter H. Niewiarowski, Richard L. Londraville

Biology Faculty Research

We tested the hypothesis that the physiological strategy for acclimating to low body temperature is similar among closely related fish. Largemouth bass (Micropterus salmoides), green sunfish (Lepomis cyanellus), bluegill sunfish (Lepomis macrochirus), black crappie (Pomonix nigromaculatus), and white crappie (Pomonix annularis), all members of the family Centrarchidae, were acclimated to 5degrees and 25degreesC. Morphometric variables (total mass, total length, organ masses) and enzyme activities (hexokinase; lactate dehydrogenase; and cytochrome oxidase in heart, liver, and muscle) were measured in 5degreesC- and 25degreesC- acclimated fish at 5degrees and 25degreesC assay temperatures. Each species displayed a distinct physiological response to cold acclimation that …


Using Ecological Land Units In A Gap Analysis For Conservation Planning In A Southwestern Ohio Watershed, Christopher Lee Zimmerman Jan 2002

Using Ecological Land Units In A Gap Analysis For Conservation Planning In A Southwestern Ohio Watershed, Christopher Lee Zimmerman

Browse all Theses and Dissertations

Gap analysis is a method to identify insufficiency in biodiversity protection. In degraded agricultural landscapes, it requires information on the past, present, and the potential natural distribution of forest vegetation to construct a comprehensive nature reserve network. Using Geographic Information Systems (GIS), I conducted a biodiversity gap analysis to assess the representation of ecological land units (ELUs) supporting forest vegetation both within and external to the current reserve network in the Lower Twin Creek Watershed (LTCW), southwestern Ohio. I used this analysis to make conservation planning recommendations to the local park district. ELUs are based on relatively stable associations of …


Familial Amyotrophic Lateral Sclerosis-Associated Mutations Decrease The Thermal Stability Of Distinctly Metallated Species Of Human Copper/Zinc Superoxide Dismutase, Jorge A. Rodriguez, Joan S. Valentine, Daryl K. Eggers, James A. Roe, Ashutosh Tiwari, Robert H. Brown Jr., Lawrence J. Hayward Jan 2002

Familial Amyotrophic Lateral Sclerosis-Associated Mutations Decrease The Thermal Stability Of Distinctly Metallated Species Of Human Copper/Zinc Superoxide Dismutase, Jorge A. Rodriguez, Joan S. Valentine, Daryl K. Eggers, James A. Roe, Ashutosh Tiwari, Robert H. Brown Jr., Lawrence J. Hayward

Chemistry and Biochemistry Faculty Works

We report the thermal stability of wild type (WT) and 14 different variants of human copper/zinc superoxide dismutase (SOD1) associated with familial amyotrophic lateral sclerosis (FALS). Multiple endothermic unfolding transitions were observed by differential scanning calorimetry for partially metallated SOD1 enzymes isolated from a baculovirus system. We correlated the metal ion contents of SOD1 variants with the occurrence of distinct melting transitions. Altered thermal stability upon reduction of copper with dithionite identified transitions resulting from the unfolding of copper-containing SOD1 species. We demonstrated that copper or zinc binding to a subset of “WT-like” FALS mutants (A4V, L38V, G41S, G72S, D76Y, …


Morphology, Swimming Performance And Propulsive Mode Of Six Co-Occurring Hydromedusae, Sean Colin, John H. Costello Jan 2002

Morphology, Swimming Performance And Propulsive Mode Of Six Co-Occurring Hydromedusae, Sean Colin, John H. Costello

Arts & Sciences Faculty Publications

Jet propulsion, based on examples from the Hydrozoa, has served as a valuable model for swimming by medusae. However, cnidarian medusae span several taxonomic classes (collectively known as the Medusazoa) and represent a diverse array of morphologies and swimming styles. Does one mode of propulsion appropriately describe swimming by all medusae? This study examined a group of co-occurring hydromedusae collected from the waters of Friday Harbor, WA, USA, to investigate relationships between swimming performance and underlying mechanisms of thrust production. The six species examined encompassed a wide range of bell morphologies and swimming habits. Swimming performance (measured as swimming acceleration …


Testing For Toxic Effects Of Prey On Zooplankton Using Sole Versus Mixed Diets, Sean Colin, Hans G. Dam Jan 2002

Testing For Toxic Effects Of Prey On Zooplankton Using Sole Versus Mixed Diets, Sean Colin, Hans G. Dam

Arts & Sciences Faculty Publications

No abstract provided.


Prey Resource Utilization By Coexistent Hydromedusae From Friday Harbor, Washington, Usa, John H. Costello, Sean Colin Jan 2002

Prey Resource Utilization By Coexistent Hydromedusae From Friday Harbor, Washington, Usa, John H. Costello, Sean Colin

Arts & Sciences Faculty Publications

Prey selection patterns were quantified for a sympatric group of hydromedusae from Friday Harbor, WA. Selection patterns varied between species, but were largely replicable between sample dates and resembled dietary patterns found in similar studies from neighboring regions. Ambush-foraging medusae (Aglantha digitale, Sarsia tubulosa, and Proboscidactyla flavicirrata) fed primarily on crustacean and ciliated prey but the dietary niches of these hydromedusan species centered on different fractions of the available plankton. Consequently, little dietary overlap occurred between the ambush foraging hydromedusae. In contrast, the dietary niches of cruising predators (Aequorea victoria, Mitrocoma cellularia, and …


Stability Of Mrna In The Hyperthermophilic Archaeon Sulfolobus Solfataricus, Elisabetta Bini, Vidula Dikshit, Kristi Dirksen, Melissa Drozda, Paul H. Blum Jan 2002

Stability Of Mrna In The Hyperthermophilic Archaeon Sulfolobus Solfataricus, Elisabetta Bini, Vidula Dikshit, Kristi Dirksen, Melissa Drozda, Paul H. Blum

School of Biological Sciences: Faculty Publications

Archaea-like bacteria are prokaryotes but, in contrast, use eukaryotic-like systems for key aspects of DNA, RNA, and protein metabolism. mRNA is typically unstable in bacteria and stable in eukaryotes, but little information is available about mRNA half-lives in archaea. Because archaea are generally insensitive to antibiotics, examination of mRNA stability in the hyperthermophile, Sulfolobus solfataricus, required the identification of transcription inhibitors for half-life determinations. An improved lacS promoter-dependent in vitro transcription system was used to assess inhibitor action. Efficient inhibitors were distinguished as blocking both lacSp transcription in vitro and the incorporation of 3H-uracil into bulk RNA in …


Conformational Strictness Required For Maximum Activity And Stability Of Bovine Pancreatic Ribonuclease A As Revealed By Crystallographic Study Of Three Phe120 Mutants At 1.4 Å Resolution, Eri Chatani, Rikimaru Hayashi, Hideaki Moriyama, Tatzuo Ueki Jan 2002

Conformational Strictness Required For Maximum Activity And Stability Of Bovine Pancreatic Ribonuclease A As Revealed By Crystallographic Study Of Three Phe120 Mutants At 1.4 Å Resolution, Eri Chatani, Rikimaru Hayashi, Hideaki Moriyama, Tatzuo Ueki

School of Biological Sciences: Faculty Publications

The replacement of Phe120 with other hydrophobic residues causes a decrease in the activity and thermal stability in ribonuclease A (RNase A). To explain this, the crystal structures of wild-type RNase A and three mutants—F120A, F120G, and F120W—were analyzed up to a 1.4 Å resolution. Although the overall backbone structures of all mutant samples were nearly the same as that of wild-type RNase A, except for the C-terminal region of F120G with a high B-factor, two local conformational changes were observed at His119 in the mutants. First, His119 of the wild-type and F120W RNase A adopted an A position, whereas …


Species Richness, Latitude, And Scale-Sensitivity, S. Kathleen Lyons, Michael R. Willig Jan 2002

Species Richness, Latitude, And Scale-Sensitivity, S. Kathleen Lyons, Michael R. Willig

School of Biological Sciences: Faculty Publications

The latitudinal gradient of species richness is well documented for a variety of taxa in both terrestrial and aquatic environs. Moreover, a number of recent attempts to assess the effects of scale on the relationship have concluded that the latitudinal pattern is scale-invariant. Nonetheless, the power of those approaches is predicated on precise knowledge of the forms of the latitudinal gradient, the area relationship, and their interaction. We used a model developed by J. Pastor, A. Downing, and H. E. Erickson for assessing the effects of scale on the productivity–diversity gradient to avoid such complications. More specifically, for 253 sets …


A Novel Family Of Mobile Genetic Elements Is Limited To The Germline Genome In Tetrahymena Thermophila, Jeffrey D. Wuitschick, Jill A. Gershan, Andrew J. Lochowicz, Shuqiang Li, Kathleen M. Karrer Jan 2002

A Novel Family Of Mobile Genetic Elements Is Limited To The Germline Genome In Tetrahymena Thermophila, Jeffrey D. Wuitschick, Jill A. Gershan, Andrew J. Lochowicz, Shuqiang Li, Kathleen M. Karrer

Biological Sciences Faculty Research and Publications

In the ciliated protozoan Tetrahymena thermophila, extensive DNA elimination is associated with differentiation of the somatic macronucleus from the germline micronucleus. This study describes the isolation and complete characterization of Tlr elements, a family of approximately 30 micronuclear DNA sequences that are efficiently eliminated from the developing macronucleus. The data indicate that Tlr elements are comprised of an ∼22 kb internal region flanked by complex and variable termini. The Tlr internal region is highly conserved among family members and contains 15 open reading frames, some of which resemble genes encoded by transposons and viruses. The Tlr termini appear to …


Leptodactylus Silvanimbus, W. R. Heyer, Rafael O. De Sá, Sarah Muller Jan 2002

Leptodactylus Silvanimbus, W. R. Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Adult Leptodactylus silvanimhus are of moderate sized, the head is about as wide as long, and the hind limbs are moderate in length (see Table; also see Heyer and Thompson 2000 for definitions of adult size and leg length categories for Leptodacrylus). The male vocal sac is single and internal. Male forearms are hypertrophied in larger individuals. Adult males have two black thumb spines on each hand and lack chest spines. Individuals lack dorsolateral folds. The toe tips are narrow, not expanded. Females have weakly developed lateral toe fringes and males either have lateral toe ridges or weakly developed fringes. …


Analysis Of Protein Localization And Secretory Pathway Function Using The Yeast Saccharomyces Cerevisiae, Elizabeth Ann Vallen Jan 2002

Analysis Of Protein Localization And Secretory Pathway Function Using The Yeast Saccharomyces Cerevisiae, Elizabeth Ann Vallen

Biology Faculty Works

The isolation and characterization of mutants has been crucial in understanding a number of processes in the field of cell biology. In this exercise, students examine the effects of mutations in the secretory pathway on protein localization. Yeast strains deficient for synthesis of histidinol dehydrogenase are transformed with a plasmid encoding a chimeric protein. The chimera contains a signal sequence fused to histidinol dehydrogenase. A strain with a defect in the translocation of secretory proteins into the endoplasmic reticulum (ER) accumulates sufficient histidinol dehydrogenase in the cytoplasm to grow on media lacking histidine. In contrast, yeast proficient for secretion, or …


Investigation Of Four Classes Of Non-Nodulating White Sweetclover (Melilotus Alba Annua Desr.) Mutants And Their Responses To Arbuscular-Mycorrhizal Fungi, Michelle Lum Jan 2002

Investigation Of Four Classes Of Non-Nodulating White Sweetclover (Melilotus Alba Annua Desr.) Mutants And Their Responses To Arbuscular-Mycorrhizal Fungi, Michelle Lum

Biology Faculty Works

The nitrogen-fixing symbiosis between Rhizobiaceae and legumes is one of the best-studied interactions established between prokaryotes and eukaryotes. The plant develops root nodules in which the bacteria are housed, and atmospheric nitrogen is fixed into ammonia by the rhizobia and made available to the plant in exchange for carbon compounds. It has been hypothesized that this symbiosis evolved from the more ancient arbuscular mycorrhizal (AM) symbiosis, in which the fungus associates with roots and aids the plant in the absorption of mineral nutrients, particularly phosphate. Support comes from several fronts: 1) legume mutants where Nod- and Myc- co-segregate, and 2) …