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Vertical Migration Of The Toxic Dinoflagellate Karenia Brevis And The Impact On Ocean Optical Properties, Oscar Schofield, John Kerfoot, Kevin Mahoney, Mark A. Moline, Matthew Oliver, Steven Lohrenz, Gary Kirkpatrick Jun 2006

Vertical Migration Of The Toxic Dinoflagellate Karenia Brevis And The Impact On Ocean Optical Properties, Oscar Schofield, John Kerfoot, Kevin Mahoney, Mark A. Moline, Matthew Oliver, Steven Lohrenz, Gary Kirkpatrick

Biological Sciences

Vertical migration behavior is found in many harmful algal blooms; however, the corresponding impact on ocean optical properties has not been quantified. A near-monospecific population of the dinoflagellate Karenia brevis was encountered off the west coast of Florida. The community was tracked for 24 hours by following a Lagrangian drifter deployed at the beginning of the experiment. A suite of inherent optical and cellular measurements was made. Over the 24 hour period, the K. brevis population increased during the day with concentrations peaking in the late afternoon (1600 local daylight time) in the upper 2 m of the water column. …


Genetic And Maternal Determinants Of Effective Dispersal: The Effect Of Sire Genotype And Size At Birth In Side-Blotched Lizards, Barry Sinervo, Ryan Calsbeek, Tosha Comendant, Christiaan Both Jun 2006

Genetic And Maternal Determinants Of Effective Dispersal: The Effect Of Sire Genotype And Size At Birth In Side-Blotched Lizards, Barry Sinervo, Ryan Calsbeek, Tosha Comendant, Christiaan Both

Dartmouth Scholarship

We assessed genetic factors on progeny dispersal due to sire color morph genotypes in a field pedigree and lab crosses, and we measured maternal effects by studying both natural and experimentally induced egg size variation. Progeny were released into nature upon hatching, but we recorded dispersal distance at maturity, which reflects effective dispersal after viability selection has run its course. Progeny dispersal was significantly affected by sire genotype. Progeny from orange sires dispersed the farthest. Progeny from blue sires dispersed intermediate distances. Progeny from yellow sires were the most philopatric. Sire genotype effects interacted with egg size. In particular, enlarged …


Environmental Signals Generate A Differential And Coordinated Expression Of The Heme Receptor Gene Family Of Bartonella Quintana, James M. Battisti, Kate N. Sappington, Laura S, Smitherman, Nermi L. Parrow, Michael F. Minnick Jun 2006

Environmental Signals Generate A Differential And Coordinated Expression Of The Heme Receptor Gene Family Of Bartonella Quintana, James M. Battisti, Kate N. Sappington, Laura S, Smitherman, Nermi L. Parrow, Michael F. Minnick

Biological Sciences Faculty Publications

Of all bacteria, Bartonella quintana has the highest reported in vitro hemin requirement, yet an explanation for this remains elusive. To produce diseases such as trench fever, endocarditis, and bacillary angiomatosis, B. quintana must survive and replicate in the disparate environments of the Pediculus humanus corporis (body louse) gut and the human vasculature. We previously identified a five-member family of hemin binding proteins (Hbps) synthesized by B. quintana that bind hemin on the outer surface but share no similarity to known bacterial heme receptors. In the present study, we examine the transcription, regulation, and synthesis of this virulence factor family …


Role Of The Stable Signal Peptide And Cytoplasmic Domain Of G2 In Regulating Intracellular Transport Of The Junín Virus Envelope Glycoprotein Complex, Sudhakar S. Agnihothram, Joanne York, Jack H. Nunberg Jun 2006

Role Of The Stable Signal Peptide And Cytoplasmic Domain Of G2 In Regulating Intracellular Transport Of The Junín Virus Envelope Glycoprotein Complex, Sudhakar S. Agnihothram, Joanne York, Jack H. Nunberg

Biological Sciences Faculty Publications

Enveloped viruses utilize the membranous compartments of the host cell for the assembly and budding of new virion particles. In this report, we have investigated the biogenesis and trafficking of the envelope glycoprotein (GP-Q of the Junin arenavirus. The mature GP-C complex is unusual in that it retains a stable signal peptide (SSP) as an essential component in association with the typical receptor-binding (G1) and transmembrane fusion (G2) subunits. We demonstrate that, in the absence of SSP, the G1-G2 precursor is restricted to the endoplasmic reticulum (ER). This constraint is relieved by coexpression of SSP in trans, allowing transit of …


An Experimental Approach To Modeling The Strength Of Canine Teeth, Patricia W. Freeman, Cliff A. Lemen Jun 2006

An Experimental Approach To Modeling The Strength Of Canine Teeth, Patricia W. Freeman, Cliff A. Lemen

School of Natural Resources: Faculty Publications

The strength of canine teeth in several carnivores is found through direct fracture experiments. The average forces required to break the canines of adult animals are coyote 1170 N, red fox 533 N, bobcat 737 N and raccoon 512 N. Stresses created in teeth at the breaking load are predicted by finite-element analysis and beam theory. The ultimate tensile stress sustainable in these teeth is 338 MPa in adult animals. The large pulp cavity in the canines of young animals significantly weakens the bases of their teeth (by about 25%), but as the animal ages the pulp cavity decreases and …


Avian Affairs: A Study Of The Occurrence And Benefits Of Extra-Pair Breeding Behavior In Eastern Kingbirds (Tyrannus Tyrannus), Amy Catherine Dolan Jun 2006

Avian Affairs: A Study Of The Occurrence And Benefits Of Extra-Pair Breeding Behavior In Eastern Kingbirds (Tyrannus Tyrannus), Amy Catherine Dolan

Dissertations and Theses

Over three consecutive breeding seasons I examined the breeding system of Eastern Kingbirds in Malheur National Wildlife Refuge in SE, Oregon. To assess genetic paternity, I optimized seven microsatellite markers and determined that extra pair paternity was common. Extra-pair young were present in approximately 60% of nests, representing 47% of young. I examined implications of extra-pair paternity from three perspectives.

First, I examined the impact of extra-pair paternity on the opportunity for sexual selection within a socially monogamous system and identified correlates of male reproductive success. Some males were successful at the expense of others, and 24% of males did …


Growth, Feeding And Reproduction Of The Catfish Eremophilus Mutisii (Pisces : Trichomycteridae), From Artificial Reservoirs In Colombia, Gabriel Pinilla, Maritza Abril, Esperanza González Jun 2006

Growth, Feeding And Reproduction Of The Catfish Eremophilus Mutisii (Pisces : Trichomycteridae), From Artificial Reservoirs In Colombia, Gabriel Pinilla, Maritza Abril, Esperanza González

Faculty Publications

The catfish, Eremophilus mutisii, was cultured under different densities in artificial rainfall reservoirs at Caldas, Boyaca, Colombia. At capture, the average total length of the animals was 10 cm and the weight ranged between 9 and 10 g. These fish were in initial stages of sexual development. After a year in the reservoirs, they had increased in length and weight as follows (densities in parentheses): 5.22 cm and 27.23 g (0.5 individuals/m(2))); 1.98 cm and 8.79 g (1 individual/m(2)), and 2.45 cm and 0.82 g (2 individuals/m(2)). They were at the early stages of sexual maturity, and their condition …


Analysis Of An Sirs Age-Structured Epidemic Model With Vaccination And Vertical Transmission Of Disease, Mohammed El-Doma Jun 2006

Analysis Of An Sirs Age-Structured Epidemic Model With Vaccination And Vertical Transmission Of Disease, Mohammed El-Doma

Applications and Applied Mathematics: An International Journal (AAM)

An SIRS age-structured epidemic model for a vertically as well as horizontally transmitted disease under vaccination is investigated when the fertility, mortality and removal rates depend on age and the force of infection of proportionate mixing assumption type, and vaccination wanes over time. We prove the existence and uniqueness of solution to the model equations, and show that solutions of the model equations depend continuously on the initial age-distributions. Furthermore, we determine the steady states and obtain an explicitly computable threshold condition, in terms of the demographic and epidemiological parameters of the model; we then study the stability of the …


Remarks On The Stability Of Some Size-Structured Population Models I: Changes In Vital Rates Due To Population Only, Mohammed El-Doma Jun 2006

Remarks On The Stability Of Some Size-Structured Population Models I: Changes In Vital Rates Due To Population Only, Mohammed El-Doma

Applications and Applied Mathematics: An International Journal (AAM)

We consider a size-structured population model that has been studied in Calsina et al. (2003). We propose a different approach that provides direct stability results, and we correct a stability result given therein. In addition, we obtain global stability results that have not been given in Calsina et al. (2003).


The Environmental Impact Of Dietary Choice And Agriculture In California, Harold J. Marlow Jr. Jun 2006

The Environmental Impact Of Dietary Choice And Agriculture In California, Harold J. Marlow Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

Food demand influences agricultural production. Modern agricultural practices have resulted in polluted soil, air and water, eroded soil, dependence on imported oil, and loss of biodiversity. The goal of this research is to investigate the environmental impact of pesticide and fertilizer application, water consumption, and energy used to produce commodities for a vegetarian and non vegetarian diet in California. The working assumption is that greater number and amount of inputs are associated with greater environmental impact. The literature supports this notion. To accomplish this goal, dietary preferences were quantified using the Adventist Health Study and state agricultural data were collected …


Coexistence Of The Niche And Neutral Perspectives In Community Ecology, Mathew A. Leibold, Mark A. Mcpeek Jun 2006

Coexistence Of The Niche And Neutral Perspectives In Community Ecology, Mathew A. Leibold, Mark A. Mcpeek

Dartmouth Scholarship

The neutral theory for community structure and biodiversity is dependent on the assumption that species are equivalent to each other in all important ecological respects. We explore what this concept of equivalence means in ecological communities, how such species may arise evolutionarily, and how the possibility of ecological equivalents relates to previous ideas about niche differentiation. We also show that the co-occurrence of ecologically similar or equivalent species is not incompatible with niche theory as has been supposed, because niche relations can sometimes favor coexistence of similar species. We argue that both evolutionary and ecological processes operate to promote the …


Analysis Of Abalone (Haliotis Discus Hannai And Haliotis Tuberculata) Shellfish Histology And Pathology Using Microscopic And Molecular Methods, Leanne Harris Jun 2006

Analysis Of Abalone (Haliotis Discus Hannai And Haliotis Tuberculata) Shellfish Histology And Pathology Using Microscopic And Molecular Methods, Leanne Harris

Doctoral

The aims of this research project were to study the biology of abalone through a histological characterisation of two species of this shellfish, Haliotis tuberculata and Haliotis discus hannai using both histochemical and immunohistochemical techniques and to develop molecular methods for the detection and quantitation of common shellfish pathogens associated with abalone disease outbreaks. In the first part of this study immunohistochemistry was used to examine cell distribution structural and functional proteins in abalone tissues. Phenotypic antigen expression was analysed in abalone shellfish using an array of antibodies that react with a range of proteins in many different species. In …


A Minimally Invasive Method Of Piscine Tissue Collection And An Analysis Of Long-Term Field-Storage Conditions For Samples, James Campanella, John V. Smalley May 2006

A Minimally Invasive Method Of Piscine Tissue Collection And An Analysis Of Long-Term Field-Storage Conditions For Samples, James Campanella, John V. Smalley

Department of Biology Faculty Scholarship and Creative Works

Background: The acquisition of high-quality DNA for use in phylogenetic and molecular population genetic studies is a primary concern for evolutionary and genetic researchers. Many non-destructive DNA sampling methods have been developed and are used with a variety of taxa in applications ranging from genetic stock assessment to molecular forensics. Results: The authors have developed a field sampling method for obtaining high-quality DNA from sunfish (Lepomis) and other freshwater fish that employs a variation on the buccal swab method and results in the collection of DNA suitable for PCR amplification and polymorphism analysis. Additionally, since the circumstances of storage are …


Cellulose Synthase Encoding Polynucleotides And Uses Thereof, Vincent L. Chiang, Chandrashekhar P. Joshi, Luguang Wu, Daniel T. Carraway May 2006

Cellulose Synthase Encoding Polynucleotides And Uses Thereof, Vincent L. Chiang, Chandrashekhar P. Joshi, Luguang Wu, Daniel T. Carraway

Michigan Tech Patents

The invention relates to isolated polynucleotides encoding functional cellulose synthases and UDP-glucose binding domain thereof, transgenic plants and plant cells transformed with the polynucleotides. The invention further relates to methods of transforming plants and plant cells with cellulose synthase or UDP-encoding polynucleotides.


Cadherin2 (N-Cadherin) Plays An Essential Role In Zebrafish Cardiovascular Development, Brian Bagatto, Jessie Francl, Bei Liu, Qin Liu May 2006

Cadherin2 (N-Cadherin) Plays An Essential Role In Zebrafish Cardiovascular Development, Brian Bagatto, Jessie Francl, Bei Liu, Qin Liu

Biology Faculty Research

Background: Cadherins are cell surface adhesion molecules that play important roles in development of vertebrate tissues and organs. We studied cadherin2 expression in developing zebrafish heart using in situ hybridization and immunocytochemical methods, and we found that cadherin2 was strongly expressed by the myocardium of the embryonic zebrafish. To gain insight into cadherin2 role in the formation and function of the heart, we analyzed cardiac differentiation and performance in a cadherin2 mutant, glass onion (glo).


A Structural Analysis And Assessment Of The Bjorklunden Forest, Andrew Allan Link May 2006

A Structural Analysis And Assessment Of The Bjorklunden Forest, Andrew Allan Link

Lawrence University Honors Projects

A common assumption in ecology is that stability within an ecosystem is reached through equilibrium. In actuality, the mechanisms that help maintain a healthy ecosystem are based upon heterogeneity and scale multiplicity. This study assessed the vegetation organization at Bjorklunden as a function of time and space. Comparisons were made to previous research that demonstrated both similarities and differences in the vegetational components of the forest. Certain areas of the forest that were previously believed to be in a permanent steady-state were proved otherwise. While other areas that were thought to mature and climax, did not. The forest at Bjorklunden …


An Essential Role For Endocytosis Of Rhodopsin Through Interaction Of Visual Arrestin With The Ap-2 Adaptor, Nicholas R. Orem, Luxi Xia, Patrick J. Dolph May 2006

An Essential Role For Endocytosis Of Rhodopsin Through Interaction Of Visual Arrestin With The Ap-2 Adaptor, Nicholas R. Orem, Luxi Xia, Patrick J. Dolph

Dartmouth Scholarship

Previously, we have identified a class of retinal degeneration mutants in Drosophila in which the normally transient interaction between arrestin2 (Arr2) and rhodopsin is stabilized and the complexes are rapidly internalized into the cell body by receptor-mediated endocytosis. The accumulation of protein complexes in the cytoplasm eventually results in photoreceptor cell death. We now show that the endocytic adapter protein AP-2 is essential for rhodopsin endocytosis through an Arr2-AP-2beta interaction, and mutations in Arr2 that disrupt its interaction with the beta subunit of AP-2 prevent endocytosis-induced retinal degeneration. We further demonstrate that if the interaction between Arr2 and AP-2 is …


The Effects Of Nitrate Levels On The Response Of Pimephales Promelas To Conspecific Chemical Alarm Cues, Lucas J. Borgstrom May 2006

The Effects Of Nitrate Levels On The Response Of Pimephales Promelas To Conspecific Chemical Alarm Cues, Lucas J. Borgstrom

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.


Delimitating Species Boundaries Within The Liomys Pictus- Spectabilis Complex (Rodentia: Heteromyidae), Victoria L. Vance May 2006

Delimitating Species Boundaries Within The Liomys Pictus- Spectabilis Complex (Rodentia: Heteromyidae), Victoria L. Vance

Theses and Dissertations

Previous studies based on morphological, allozymic and mitochondrial sequence data have indicated that Liomys pictus is paraplyletic relative to L. spectabilis. The purpose of this study was to determine the species boundaries that exist within this complex. I estimated phylogenetic relationships within this complex using sequence data from 1,140 bp of the mitochondrial DNA cytochrome b gene and two nuclear introns from engrailed protein (190 bp) and myosin heavy chain (254 bp) genes for approximately 712 individuals representing 82 localities across the range of L. pictus and L. spectabilis. Maximum parsimony, maximum likelihood, and Bayesian analyses suggest that there are …


In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng May 2006

In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng

Honors Scholar Theses

The major histocompatibility complex (MHC) is a gene family responsible for many critical functions of the immune system in most vertebrates. The MHC consists of three classes differentiated by their structure and function, and MHC class I encodes antigen binding proteins as well as chaperone and accessory proteins such as tapasin. The purpose of this project is to reconstitute several human MHC class I molecules in their peptide-filled and peptide-deficient forms, and to purify these proteins for biochemical study. The expressed proteins include wild type and mutant variants of the fusion protein human leukocyte antigen HLA-B*0801-fos, and human beta-2-microglobulin (β2m). …


Evolutionary Epidemiology Of Endemic Gal¿Pagos Birds And Their Parasites, Noah Kerness Whiteman May 2006

Evolutionary Epidemiology Of Endemic Gal¿Pagos Birds And Their Parasites, Noah Kerness Whiteman

Dissertations

In order to better understand parasite diversification, I went to the Gal¿pagos Islands to study the ecology and evolution of a model bird-parasite system, which included four phylogenetically independent ectoparasite lineages infecting the Gal¿pagos Hawk (Aves: Buteo galapagoensis). The parasites comprised two lice (Insecta: Phthiraptera: Amblycera, Ischnocera), a lousefly (Diptera: Hippoboscidae) and an avian skin mite (Acari: Epidermoptidae). Ultimately, my goal was to examine ectoparasite evolutionary epidemiology and disease susceptibility in relation to the host¿s ecological and colonization history. At the outset, I hypothesized that parasite natural history was key in influencing the coalescent process. Accordingly, I found differences …


A Kinesin-Like Calmodulin-Binding Protein In Chlamydomonas: Evidence For A Role In Cell Division And Flagellar Functions, Erin E. Dymek, Daniel Goduti, Tal Kramer, Elizabeth F. Smith May 2006

A Kinesin-Like Calmodulin-Binding Protein In Chlamydomonas: Evidence For A Role In Cell Division And Flagellar Functions, Erin E. Dymek, Daniel Goduti, Tal Kramer, Elizabeth F. Smith

Dartmouth Scholarship

Kinesin-like calmodulin-binding protein, KCBP, is a novel member of the C-kinesin superfamily first discovered in flowering plants. This minus-end-directed kinesin exhibits Ca(2+)-calmodulin-sensitive motor activity in vitro and has been implicated in trichome morphogenesis and cell division. A homologue of KCBP is also found in the unicellular, biflagellate green alga Chlamydomonas reinhardtii (CrKCBP). Unlike plant cells, Chlamydomonas cells do not form trichomes and do not assemble a phragmoplast before cell division. To test whether CrKCBP is involved in additional microtubule-based processes not observed in plants, we generated antibodies against the putative calmodulin-binding domain and used these antibodies in biochemical and localization …


Application Of Polymerase Chain Reaction To Screen Rodents From New Mexico, Texas, Bolivia, And Nicaragua For Leishmania And An Assessment Of The Specificity Of Primers, Robert Alan Miranda May 2006

Application Of Polymerase Chain Reaction To Screen Rodents From New Mexico, Texas, Bolivia, And Nicaragua For Leishmania And An Assessment Of The Specificity Of Primers, Robert Alan Miranda

Theses & Dissertations

Polymerase chain reaction was used to screen rodents from four regions for Leishmania and to screen isolates of L. enriettii and L. hertigi using L. mexicana complex primers and L. (Viannia) primers to examine the specificity of these primers. Twenty-five rodent specimens from Bolivia, 42 from Nicaragua, 84 from New Mexico, and 74 from Texas were tested for Leishmania. Two Oryzomys acritus and two Oryzomys nitidus from Bolivia and one Neotoma micropus from Texas tested positive for Leishmania and additionally tested positive with L. mexicana complex-specific primers. Isolates of L enriettii and L hertigi reacted with L mexicana complex …


Selective Male Mortality In The Red Imported Fire Ant, Solenopsis Invicta, Gary Fritz, Robert Vander Meer, Catherine Preston May 2006

Selective Male Mortality In The Red Imported Fire Ant, Solenopsis Invicta, Gary Fritz, Robert Vander Meer, Catherine Preston

Faculty Research & Creative Activity

Males in polygyne populations of Solenopsis invicta are primarily sterile diploids and thought to not express the Gp-9 gene coding for a pheromone-binding protein affecting complex social behavior.We examined an aspect of the breeding system hitherto not considered—male Gp-9 genotypes in relation to sperm stored in queens. Four sites with varying frequencies of sympatric monogyne and polygyne colonies were sampled, including sexuals, workers, and broods from four colonies. Most queens were heterozygotes storing B sperm. Although predicted to be common, only 14 of 504 males were B or BB genotypes, suggesting strong selection. Increased frequency of polygyne colonies at each …


Book Review: Evolution In Four Dimensions By Eva Jablonka And Marion J. Lamb, William D. Stansfield May 2006

Book Review: Evolution In Four Dimensions By Eva Jablonka And Marion J. Lamb, William D. Stansfield

Biological Sciences

No abstract provided.


Selective Male Mortality In The Red Imported Fire Ant, Solenopsis Invicta, Gary N. Fritz, Robert K. Vander Meer, Catherine A. Preston May 2006

Selective Male Mortality In The Red Imported Fire Ant, Solenopsis Invicta, Gary N. Fritz, Robert K. Vander Meer, Catherine A. Preston

Faculty Research & Creative Activity

Males in polygyne populations of Solenopsis invicta are primarily sterile diploids and thought to not express the Gp-9 gene coding for a pheromone-binding protein affecting complex social behavior.We examined an aspect of the breeding system hitherto not considered—male Gp-9 genotypes in relation to sperm stored in queens. Four sites with varying frequencies of sympatric monogyne and polygyne colonies were sampled, including sexuals, workers, and broods from four colonies. Most queens were heterozygotes storing B sperm. Although predicted to be common, only 14 of 504 males were B or BB genotypes, suggesting strong selection. Increased frequency of polygyne colonies at each …


Sequence Analysis Of The Rdna Internal Transcribed Spacer 2 And Polymerase Chain Reaction Identification Of Anopheles Fluminensis (Diptera: Culicidae: Anopheles) In Bolivia, Corey L. Brelsfoard, Gary Fritz, Roberto Rodriguez May 2006

Sequence Analysis Of The Rdna Internal Transcribed Spacer 2 And Polymerase Chain Reaction Identification Of Anopheles Fluminensis (Diptera: Culicidae: Anopheles) In Bolivia, Corey L. Brelsfoard, Gary Fritz, Roberto Rodriguez

Faculty Research & Creative Activity

Anopheles fluminensis Root is a member of the Arribalzagia Series in the subgenus Anopheles. We report the first record of this species in the department of Cochabamba, Bolivia. This species was sampled from two locations in the foothills of the eastern Andes Mountains within the Chapare Valley. Larvae were collected in fast-flowing, shaded streams at the edges of rocky pools. We provide the first sequence data for the rDNA of An. fluminensis, a partial sequence of the 5.8S and the internal transcribed spacer 2 (ITS2). The ITS2 of An. fluminensis, sequenced from two individuals at one site, was at least …


Sequence Analysis Of The Rdna Internal Transcribed Spacer 2 And Polymerase Chain Reaction Identification Of Anopheles Fluminensis (Diptera: Culicidae: Anopheles) In Bolivia, Corey Brelsfoard, Gary Fritz, Roberto Rodriguez May 2006

Sequence Analysis Of The Rdna Internal Transcribed Spacer 2 And Polymerase Chain Reaction Identification Of Anopheles Fluminensis (Diptera: Culicidae: Anopheles) In Bolivia, Corey Brelsfoard, Gary Fritz, Roberto Rodriguez

Faculty Research & Creative Activity

Anopheles fluminensis Root is a member of the Arribalzagia Series in the subgenus Anopheles. We report the first record of this species in the department of Cochabamba, Bolivia. This species was sampled from two locations in the foothills of the eastern Andes Mountains within the Chapare Valley. Larvae were collected in fast-flowing, shaded streams at the edges of rocky pools. We provide the first sequence data for the rDNA of An. fluminensis, a partial sequence of the 5.8S and the internal transcribed spacer 2 (ITS2). The ITS2 of An. fluminensis, sequenced from two individuals at one site, was at least …


Exploring The Role Of Sac9 In Arabidopsis Thaliana Stress Response And Phosphoinositide Signaling, Elizabeth J. Drake May 2006

Exploring The Role Of Sac9 In Arabidopsis Thaliana Stress Response And Phosphoinositide Signaling, Elizabeth J. Drake

Biology

The SAC9 gene in Arabidopsis thaliana encodes a protein, Sac9, which is a putative 5-phosphatase involved in phosphoinositide stress signaling pathways in plants. The SAC domain of Sac9 has sequence homology with yeast and mammalian phosphoinositide phosphatases that catalyze the hydrolysis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2]. The loss of the Sac9 protein in A. thaliana leads to an increase in the quantity of PtdIns(4,5)P2 in the plant. This increase in PtdIns(4,5)P2 in the sac9-1 mutant A. thaliana likely causes plants grown under non-stress conditions to exhibit several phenotypes normally associated with stress. The focus of this thesis …


Systematics Of The Sympetrine Dragonflies With Emphasis On The Phylogeny, Taxonomy, And Historical Biogeography Of The Genus Sympetrum (Odonata: Libellulidae), Erik M. Pilgrim May 2006

Systematics Of The Sympetrine Dragonflies With Emphasis On The Phylogeny, Taxonomy, And Historical Biogeography Of The Genus Sympetrum (Odonata: Libellulidae), Erik M. Pilgrim

Biology

Within dragonflies and damselflies, the family Libellulidae is the largest. The systematics have never been analyzed in a phylogenetic context. Using both molecular and morphological characters, this dissertation is the first study to address the phylogenetics of the Libellulidae, the phylogenetics and historical biogeography of Sympetrum, and several species-level disputes within Sympetrum. Phylogenetic study of the family Libellulidae revealed that many of the libellulid subfamilies (Brachydiplactinae, Leucorrhininae, Sympetrinae, Trameinae, Trithemistinae, and Urothemistinae) were paraphyletic. Wing venation characters were not useful for delineating the hierarchy of taxa within Libellulidae. Study of the systematics of Sympetrum shows that S. navasi …