Digital Commons Network^™

Comparative Microbiota Of Rickettsia Felis-Uninfected And -Infected Colonized Cat Fleas, Ctenocephalides Felis, Walairat Pornwiroon, Michael T. Kearney, Claudia Husseneder, Lane D. Foil, Kevin R. Macaluso

Faculty Publications

Fleas serve as arthropod vectors for several emerging and re-emerging infectious disease causing agents including, Rickettsia felis. Although the prevalence of R. felis infection in colonies of fleas has been examined, the influence of the R. felis infection on flea microbiota has not been investigated. We identified three colonies of cat fleas, Ctenocephalides felis, with varying prevalence of R. felis infection (Louisiana State University (LSU), 93.8; Professional Laboratory and Research Services Inc. (PLRS), 16.4; Elward II (EL), 0) and subsequently utilized polymerase chain reaction amplification, restriction fragment length polymorphism analysis and sequencing of the 1.4-kb portions of 16S rRNA genes …

Footprints On Water: The Genetic Wake Of Dispersal Among Reefs, M. E. Hellberg

Faculty Publications

Analysis of genetic data can reveal past and ongoing demographic connections between reef populations. The history, extent, and geography of isolation and exchange help to determine which populations are evolutionarily distinct and how to manage threatened reefs. Here the genetic approaches undertaken to understand connectivity among reefs are reviewed, ranging from early allozyme studies on genetic subdivision, through the use of sequence data to infer population histories, to emerging analyses that pull the influences of the past connections away from the effects of ongoing dispersal. Critically, some of these new approaches can infer migration and isolation over recent generations, thus …

Description, Life History, And Parasitism Of A New Species Of Delphacid Planthopper (Hemiptera: Fulgoroidea), James T. Cronin, Stephen W. Wilson

Faculty Publications

Delphacodes scolochloa Cronin & Wilson (Hemiptera: Fulgoroidea) is a newly discovered delphacid planthopper that feeds and oviposits exclusively on the stems of sprangletop, Scolochloa festucacea (Willd.) Link (Poaceae: Pooidae), in the prairie pothole region of northeastern North Dakota. D. scolochloa is bivoltine. It is also wing dimorphic, but populations are composed predominantly of flightless brachypters. Macropters incur a substantial cost in terms of reduced longevity and fecundity relative to brachypters. The parasitoid complex attacking D. scolochloa consists of two egg parasitoids, Anagrus nigriventris Girault and Anagrus columbi Perkins (Hymenoptera: Mymaridae), and one undescribed dryinid. The proportion of eggs parasitized averages …

Status Of The Fire Ant Decapitating Fly Pseudacteon Tricuspis (Diptera: Phoridae) In Louisiana, Donald C. Henne, Seth J. Johnson, Sanford D. Porter

Faculty Publications

Eight releases of the South American fire ant decapitating fly, Pseudacteon tricuspis Borgmeier, were conducted in Louisiana from 1999 to 2006. Although P. tricuspis was initially recaptured at 88% of the release sites, four of the releases ultimately failed, so long-term establishment was only 43%. Fly populations from two releases have expanded out 50-80 km from their release sites (Fall 2006).

Fungi Isolated From Integument And Guts Of Coptotermes Formosanus And Their Antagonistic Effect On Gleophyllum Trabeum, Poornima Jayasimha, Gregg Henderson

Faculty Publications

In our earlier efforts to demonstrate the spread of a brown rot fungus, Gloeophyllum trabeum (Pers.) Murrill by Formosan subterranean termites, Coptotermes formosanus Shiraki, we found not only that C. formosanus does not spread G. trabeum but also that G. trabeum did not survive in the presence of C. formosanus. Further investigation of this antagonistic interaction between this termite and fungus led to a hypothesis that green-spored fungi may be carried by termites and that they play a role in suppressing the growth of G. trabeum. Fungal cultures were isolated from integument and guts of laboratory-maintained colonies of C. formosanus …

Dreams Of Africa In Alabama: The Slave Ship Clotilda And The Story Of The Last Africans Brought To America, Eric Love

Civil War Book Review

The Illicit Slave Trade

Historic And Contemporary Levels Of Genetic Variation In Two New Zealand Passerines With Different Histories Of Decline, S. S. Taylor, I. G. Jamieson, G. P. Wallis

Faculty Publications

We compared historic and contemporary genetic variation in two threatened New Zealand birds (saddlebacks and robins) with disparate bottleneck histories. Saddlebacks showed massive loss of genetic variation when extirpated from the mainland, but no significant loss of variation following a severe bottleneck in the 1960s when the last population was reduced from ∼1000 to 36 birds. Low genetic variation was probably characteristic of this isolated island population: considerably more genetic variation would exist in saddlebacks today if a mainland population had survived. In contrast to saddlebacks, contemporary robin populations showed only a small decrease in genetic variation compared with historical …

Novel Plant-Specific Cyclin-Dependent Kinase Inhibitors Induced By Biotic And Abiotic Stresses, Adrian Peres, Michelle L. Churchman, Srivaidehirani Hariharan, Kristiina Himanen, Aurine Verkest, Klaas Vandepoele, Zoltan Magyar, Yves Hatzfeld, Els Van Der Schueren, Gerrit T.S. Beemster, Valerie Frankard, John C. Larkin, Dirk Inzé, Lieven De Veylder

Faculty Publications

The EL2 gene of rice (Oryza sativa), previously classified as early response gene against the potent biotic elicitor N-acetylchitoheptaose and encoding a short polypeptide with unknown function, was identified as a novel cell cycle regulatory gene related to the recently reported SIAMESE (SIM) gene of Arabidopsis thaliana. Iterative two-hybrid screens, in vitro pull-down assays, and fluorescence resonance energy transfer analyses showed that Orysa; EL2 binds the cyclin-dependent kinase (CDK) CDKA1;1 and D-type cyclins. No interaction was observed with the plant-specific B-type CDKs. The amino acid motif ELERFL was identified to be essential for cyclin, but not for CDK binding. Orysa;EL2 …

Comparative Mitochondrial Genomics Of Snakes: Extraordinary Substitution Rate Dynamics And Functionality Of The Duplicate Control Region, Zhi J. Jiang, Todd A. Castoe, Christopher C. Austin, Frank T. Burbrink, Matthew D. Herron, Jimmy A. Mcguire, Christopher L. Parkinson, David D. Pollock

Faculty Publications

Background. The mitochondrial genomes of snakes are characterized by an overall evolutionary rate that appears to be one of the most accelerated among vertebrates. They also possess other unusual features, including short tRNAs and other genes, and a duplicated control region that has been stably maintained since it originated more than 70 million years ago. Here, we provide a detailed analysis of evolutionary dynamics in snake mitochondrial genomes to better understand the basis of these extreme characteristics, and to explore the relationship between mitochondrial genome molecular evolution, genome architecture, and molecular function. We sequenced complete mitochondrial genomes from Slowinski's corn …

Alvin Explores The Deep Northern Gulf Of Mexico Slope, Harry Roberts, Robert Carney, Mathew Kupchik, Charles Fisher, Kim Nelson, Erin Becker, Liz Goehring, Stephanie Lessard-Pilon, Guy Telesnicki, Bernie Bernard, James Brooks, Monika Bright, Erik Cordes, Stephane Hourdez, Jesse Hunt, William Shedd, Gregory Boland, Samantha Joye, Vladimir Samarkin, Meaghan Bernier, Marshall Bowles, Ian Macdonald, Helge Niemann, Cindy Petersen, Jeremy Potter

Faculty Publications

No abstract provided.

The Psbp Protein Is Required For Photosystem Ii Complex Assembly/Stability And Photoautotrophy In Arabidopsis Thaliana, Xiaoping Yi, Stefan R. Hargett, Haijun Liu, Laurie K. Frankel, Terry M. Bricker

Faculty Publications

Interfering RNA was used to suppress the expression of the genes At1g06680 and At2g30790 in Arabidopsis thaliana, which encode the PsbP-1 and PsbP-2 proteins, respectively, of photosystem II (PS II). A phenotypic series of transgenic plants was recovered that expressed intermediate and low amounts of PsbP. Chlorophyll fluorescence induction and QA- decay kinetics analyses were performed. Decreasing amounts of expressed PsbP protein led to the progressive loss of variable fluorescence and a marked decrease in the fluorescence quantum yield (FV/FM). This was primarily due to the loss of the J to I transition. Analysis of the fast fluorescence rise kinetics …

The Benefits Of Bathing Buds: Water Calyces Protect Flowers From A Microlepidopteran Herbivore, Jane E. Carlson, Kyle E. Harms

Faculty Publications

Protective floral structures may evolve in response to the negative effects of floral herbivores. For example, water calyces - liquid-filled, cup-like structures resulting from the fusion of sepals - may reduce floral herbivory by submerging buds during their development. Our observations of a water-calyx plant, Chrysothemis friedrichsthaliana (Gesneriaceae), revealed that buds were frequently attacked by ovipositing moths (Alucitidae), whose larvae consumed anthers and stigmas before corollas opened. Almost 25% of per-plant flower production was destroyed by alucitid larvae over two seasons, far exceeding the losses to all other floral herbivores combined. Experimental manipulation of water levels in calyces showed that …

Enhanced Electrogenerated Chemiluminescence In The Presence Of Fluorinated Alcohols, David J. Vinyard, Mark M. Richter

Faculty Publications

The electrdchemistry, UV-vis absorption, photoluminescence (PL), and coreactant electrogenerated chemiluminescence (ECL) of Ru(bpy)32+ (where bpy = 2,2′-bipyridine) have been obtained in a series of hydroxylic solvents. The solvents included fluorinated and nonfluorinafed alcohols and alcohol/water mixtures. Tri-n-propylamine was used as the oxidative-reductive ECL coreactant. Blue shifts of up to 30 nm in PL emission wavelength maximums are observed compared to a Ru(bpy)32+/H2O standard due to interactions of the polar excited state (i.e., *Ru(bpy)32+) with the solvent media. For example, Ru(bpy)32+ in water has an emission maximum of 599 nm while in the more polar hexafluoropropanol and trifluoroethanol it is 562 …

The Importance Of Data Partitioning And The Utility Of Bayes Factors In Bayesian Phylogenetics, Jeremy M. Brown, Alan R. Lemmon

Faculty Publications

As larger, more complex data sets are being used to infer phylogenies, accuracy of these phylogenies increasingly requires models of evolution that accommodate heterogeneity in the processes of molecular evolution. We investigated the effect of improper data partitioning on phylogenetic accuracy, as well as the type I error rate and sensitivity of Bayes factors, a commonly used method for choosing among different partitioning strategies in Bayesian analyses. We also used Bayes factors to test empirical data for the need to divide data in a manner that has no expected biological meaning. Posterior probability estimates are misleading when an incorrect partitioning …

Proposed Carbon Dioxide Concentrating Mechanism In Chlamydomonas Reinhardtii, James V. Moroney, Ruby A. Ynalvez

Faculty Publications

No abstract provided.

The Katanin Microtubule Severing Protein In Plants, David H. Burk, Ruiqin Zhong, Zheng Hua Ye

Faculty Publications

Katanin is a heterodimeric microtubule (MT) severing protein that uses energy from ATP hydrolysis to generate internal breaks along MTs. Katanin p60, one of the two subunits, possesses ATPase and MT-binding/ severing activities, and the p 80 subunit is responsible for targeting of katanin to certain subcellular locations. In animals, katanin plays an important role in the release of MTs from their nucleation sites in the centrosome. It is also involved in severing MTs into smaller fragments which can serve as templates for further polymerization to increase MT number during meiotic and mitotic spindle assembly. Katanin homologs are present in …

Evaluation Of Treatment Success And Patterns Of Reinfestation Of The Formosan Subterranean Termite (Isoptera: Rhinotermitidae), Claudia Husseneder, Dawn M. Simms, Claudia Riegel

Faculty Publications

Spread of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), is connected with the transport of infested wood, in particular, railroad ties. Therefore, efficient treatment of infestations, especially along railroads, is imperative to prevent further termite damage and spread. Evaluation of treatment success hinges on the ability to assign infestation sites to colonies and compare colony identity before and after treatment. Because colonies of the Formosan subterranean termite can be headed by a pair of reproductives (simple families) or by multiple reproductives (extended families), the question arises whether the breeding system of a colony influences treatment success and whether …

Layered Basal Defenses Underlie Non-Host Resistance Of Arabidopsis To Pseudomonas Syringae Pv. Phaseolicola, Jong Hyun Ham, Min Gab Kim, Sang Yeol Lee, David Mackey

Faculty Publications

Arabidopsis is a non-host for Pseudomonas syringae pv. phaseolicola NPS3121 (Pph), a bacterial pathogen of bean. Pph does not induce a hypersensitive response in Arabidopsis. Here we show that Arabidopsis instead resists Pph with multi-layered basal defense. Our approach was: (i) to identify defense readouts induced by Pph; (ii) to determine whether mutations in known Arabidopsis defense genes disrupt Pph-induced defense signaling; (iii) to determine whether heterologous type III effectors from pathogens of Arabidopsis suppress Pph-induced defense signaling, and (iv) to ascertain how basal defenses contribute to resistance against Pph by individually or multiply disrupting defense signaling pathways with mutations …

Seed Preferences Of Wintering Henslow's Sparrows, Jennifer K. Dimiceli, Philip C. Stouffer, Erik I. Johnson, Claudia Leonardi, Edgar B. Moser

Faculty Publications

The Henslow's Sparrow (Ammodramus henslowii), a species of conservation concern, winters primarily in longleaf pine (Pinus palustris) forest ecosystems in the southeastern U.S. These pine savannas have been reduced to 5% of their former range, with remaining patches requiring active management with fire to maintain characteristic structure and plant diversity. Wintering Henslow's Sparrow abundance tracks growing-season fires; bird abundance peaks in the winter following burning, then declines in subsequent winters. Fire also determines dominant plant species, suggesting that Henslow's Sparrows may respond to abundance of preferred seeds. To determine diet preferences of Henslow's Sparrows, we tested seeds from eight species …

An Ancestral Variant Of Secretogranin Ii Confers Regulation By Phox2 Transcription Factors And Association With Hypertension, Gen Wen, Jennifer Wessel, Weidong Zhou, Georg B. Ehret, Fangwen Rao, Mats Stridsberg, Sushil K. Mahata, Peter M. Gent, Madhusudan Das, Richard S. Cooper, Aravinda Chakravarti, Huilin Zhou, Nicholas J. Schork, Daniel T. O'Connor, Bruce A. Hamilton

Faculty Publications

Granins regulate secretory vesicle formation in neuroendocrine cells and granin-derived peptides are co-released with neurotransmitters as modulatory signals at sympathetic sites. We report evidence for association between a regulatory polymorphism in Secretogranin II (SCG2) and hypertension in African-American subjects. The minor allele is ancestral in the human lineage and is associated with disease risk in two case-control studies and with elevated blood pressure in a separate familial study. Mechanistically, the ancestral allele acts as a transcriptional enhancer in cells that express endogenous Scg2, whereas the derived allele does not. ARIX (PHOX2A) and PHOX2B are identified as potential transactivating factors by …

Development Of A Simplified And Standardized Protocol With Potential For High-Throughput For Sperm Cryopreservation In Zebrafish Danio Rerio, Huiping Yang, Carrie Carmichael, Zoltan M. Varga, Terrence R. Tiersch

Faculty Publications

Sperm cryopreservation offers potential for long-term storage of genetic resources. However, the current protocols for zebrafish Danio rerio are cumbersome and poorly reproducible. Our objective was to facilitate adoption of cryopreservation by streamlining methods from sperm collection through thawing and use. First, sperm activation was evaluated, and motility was completely inhibited when osmolality of the extender was ≥295-300 mOsmol/kg. To evaluate cryoprotectant toxicity, sperm were incubated with dimethyl sulfoxide (DMSO), N,N-dimethyl acetamide (DMA), methanol, or glycerol at 5, 10, and 15% concentrations. Based on motility, DMSO, DMA, and methanol (≤10%) were less toxic; therefore, sperm were cryopreserved using these cryoprotectants …

Structure And Mechanism Of The Genomically Encoded Fosfomycin Resistance Protein, Fosx, From Listeria Monocytogenes, Kerry L. Fillgrove, Svetlana Pakhomova, Matthew R. Schaab, Marcia E. Newcomer, Richard N. Armstrong

Faculty Publications

The fosfomycin resistance protein, FosX, catalyzes the hydration of the antibiotic fosfomycin, (1R,25)-epoxypropylphosphonic acid. Genes encoding the enzyme are found in several pathogenic microorganisms. The structure and mechanism of action of the genomically encoded FosX enzyme from Listeria monocytogenes (FosXLMATCC) obtained from the American Type Culture Collection are reported. The gene harbors 31 point mutations, and as a consequence, the protein differs in 10 amino acid residues from the previously reported FosX encoded in the genome of the EGD strain of L. monocytogenes (FosXLMEGD). The FosXLMATCC enzyme is shown to catalyze the addition of water to the C1 position of …

Unidirectional Na+ And Ca2+ Fluxes In Two Euryhaline Teleost Fishes, Fundulus Heteroclitus And Oncorhynchus Mykiss, Acutely Submitted To A Progressive Salinity Increase, Viviane Prodocimo, Fernando Galvez, Carolina A. Freire, Chris M. Wood

Faculty Publications

Na+ and Ca2+ regulation were compared in two euryhaline species, killifish (normally estuarine-resident) and rainbow trout (normally freshwater-resident) during an incremental salinity increase. Whole-body unidirectional fluxes of Na+ and Ca2+, whole body Na+ and Ca2+, and plasma concentrations (trout only), were measured over 1-h periods throughout a total 6-h protocol of increasing salinity meant to simulate a natural tidal flow. Killifish exhibited significant increases in both Na+ influx and efflux rates, with efflux slightly lagging behind efflux up to 60% SW, but net Na+ balance was restored by the time killifish reached 100% SW. Whole body Na+ did not change, …

Energizing An Invertebrate Embryo: Bafilomycin-Dependent Respiration And The Metabolic Cost Of Proton Pumping By The V-Atpase, Joseph A. Covi, Steven C. Hand

Faculty Publications

We examine herein the contribution of V-ATPase activity to the energy budget of aerobically developing embryos of Artemia franciscana and discuss the results in the context of quiescence under anoxia. 31P-NMR analysis indicates that intracellular pH and NTP levels are unaffected by acute incubation of dechorionated embryos with the V-ATPase inhibitor, bafilomycin A1. Bafilomycin A1 also has no significant effect on oxygen consumption by isolated mitochondria. Taken together, these data indicate that bafilomycin does not affect energy-producing pathways in the developing embryo. However, the V-ATPase inhibitor exhibits a concentration-dependent inhibition of oxygen consumption in aerobic embryos. A conservative analysis of …

In Search Of Polymorphic Alu Insertions With Restricted Geographic Distributions, Richard Cordaux, Deepa Srikanta, Jungnam Lee, Mark Stoneking, Mark A. Batzer

Faculty Publications

Alu elements are transposable elements that have reached over one million copies in the human genome. Some Alu elements inserted in the genome so recently that they are still polymorphic for insertion presence or absence in human populations. Recently, there has been an increasing interest in using Alu variation for studies of human population genetic structure and inference of individual geographic origin. Currently, this requires a high number of Alu loci. Here, we used a linker-mediated polymerase chain reaction method to preferentially identify low-frequency Alu elements in various human DNA samples with different geographic origins. The candidate Alu loci were …

Sines, Evolution And Genome Structure In The Opossum, Wanjun Gu, David A. Ray, Jerilyn A. Walker, Erin W. Barnes, Andrew J. Gentles, Paul B. Samollow, Jerzy Jurka, Mark A. Batzer, David D. Pollock

Faculty Publications

Short INterspersed Elements (SINEs) are non-autonomous retrotransposons, usually between 100 and 500 base pairs (bp) in length, which are ubiquitous components of eukaryotic genomes. Their activity, distribution, and evolution can be highly informative on genomic structure and evolutionary processes. To determine recent activity, we amplified more than one hundred SINE1 loci in a panel of 43 M. domestica individuals derived from five diverse geographic locations. The SINE1 family has expanded recently enough that many loci were polymorphic, and the SINE1 insertion-based genetic distances among populations reflected geographic distance. Genome-wide comparisons of SINE1 densities and GC content revealed that high SINE1 …

Louisiana Agriculture Summer, 2007, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

Genomic Organization And Imprinting Of The Peg3 Domain In Bovine, Joomyeong Kim, Anne Bergmann, Jung Ha Choo, Lisa Stubbs

Faculty Publications

Using multiple mammalian genomic sequences, we have analyzed the evolution and imprinting of several genes located in the Peg3 domain, including Mim1 (approved name, Mimt1), Usp29, Zim3, and Zfp264. A series of comparative analyses shows that the overall genomic structure of this 500-kb imprinted domain has been well maintained throughout mammalian evolution but that several lineage-specific changes have also occurred in each species. In the bovine domain, Usp29 has lost its protein-coding capability, Zim3 has been duplicated, and the expression of Zfp264 has become biallelic in brain and testis, which differs from paternal expression of mouse Zfp264 in brain. In …

Population Spread Of The Introduced Red Imported Fire Ant Parasitoid, Pseudacteon Tricuspis Borgmeier (Diptera: Phoridae), In Louisiana, D. C. Henne, S. J. Johnson, J. T. Cronin

Faculty Publications

Predicting the spread of introduced species, such as natural enemies used in classical biological control programs, requires quantitative data on the rates of spread. Here, the pattern of spread of Pseudacteon tricuspis Borgmeier (Diptera: Phoridae), a parasitoid of the red imported fire ant (Solenopsis invicta Buren; Hymenoptera: Formicidae), was monitored at two widely separated release sites in Louisiana, USA. At both sites, P. tricuspis range expansion (measured as the mean radius of the range from four cardinal directions) was accelerating during the first four years post-release. This pattern contrasts with a linear pattern expected with simple diffusion. This suggests that …

Localization Of Ligand Binding Site In Proteins Identified In Silico, M. Michal Brylinski, Marek Kochanczyk, Elzbieta Broniatowska, Irena Roterman

Faculty Publications

Knowledge-based models for protein folding assume that the early-stage structural form of a polypeptide is determined by the backbone conformation, followed by hydrophobic collapse. Side chain-side chain interactions, mostly of hydrophobic character, lead to the formation of the hydrophobic core, which seems to stabilize the structure of the protein in its natural environment. The fuzzy-oil-drop model is employed to represent the idealized hydrophobicity distribution in the protein molecule. Comparing it with the one empirically observed in the protein molecule reveals that they are not in agreement. It is shown in this study that the irregularity of hydrophobic distributions is aim-oriented. …