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Full-Text Articles in Life Sciences

Replication Cycle And Molecular Biology Of The West Nile Virus, Margo A. Brinton Dec 2013

Replication Cycle And Molecular Biology Of The West Nile Virus, Margo A. Brinton

Biology Faculty Publications

West Nile virus (WNV) is a member of the genus Flavivirus in the family Flaviviridae. Flaviviruses replicate in the cytoplasm of infected cells and modify the host cell environment. Although much has been learned about virion structure and virion-endosomal membrane fusion, the cell receptor(s) used have not been definitively identified and little is known about the early stages of the virus replication cycle. Members of the genus Flavivirus differ from members of the two other genera of the family by the lack of a genomic internal ribosomal entry sequence and the creation of invaginations in the ER membrane rather than …


Intracellular Recording, Sensory Field Mapping, And Culturing Identified Neurons In The Leech, Hirudo Medicinalis, Josh Titlow, Zana R. Majeed, John G. Nicholls, Robin L. Cooper Nov 2013

Intracellular Recording, Sensory Field Mapping, And Culturing Identified Neurons In The Leech, Hirudo Medicinalis, Josh Titlow, Zana R. Majeed, John G. Nicholls, Robin L. Cooper

Biology Faculty Publications

The freshwater leech, Hirudo medicinalis, is a versatile model organism that has been used to address scientific questions in the fields of neurophysiology, neuroethology, and developmental biology. The goal of this report is to consolidate experimental techniques from the leech system into a single article that will be of use to physiologists with expertise in other nervous system preparations, or to biology students with little or no electrophysiology experience. We demonstrate how to dissect the leech for recording intracellularly from identified neural circuits in the ganglion. Next we show how individual cells of known function can be removed from …


Neural Circuit Recording From An Intact Cockroach Nervous System, Josh Titlow, Zana R. Majeed, H. Bernard Hartman, Ellen Burns, Robin L. Cooper Nov 2013

Neural Circuit Recording From An Intact Cockroach Nervous System, Josh Titlow, Zana R. Majeed, H. Bernard Hartman, Ellen Burns, Robin L. Cooper

Biology Faculty Publications

The cockroach ventral nerve cord preparation is a tractable system for neuroethology experiments, neural network modeling, and testing the physiological effects of insecticides. This article describes the scope of cockroach sensory modalities that can be used to assay how an insect nervous system responds to environmental perturbations. Emphasis here is on the escape behavior mediated by cerci to giant fiber transmission in Periplaneta americana. This in situ preparation requires only moderate dissecting skill and electrophysiological expertise to generate reproducible recordings of neuronal activity. Peptides or other chemical reagents can then be applied directly to the nervous system in solution …


The Tadpole Of Leptodactylus Caatingae Heyer & Juncá, 2003 (Anura: Leptodactylidae): External Morphology, Internal Anatomy, And Natural History, Felipe De Madeiros Magalhães, Adrian Antonio Garda, Ralita Ferreira Amado, Rafael O. De Sá Nov 2013

The Tadpole Of Leptodactylus Caatingae Heyer & Juncá, 2003 (Anura: Leptodactylidae): External Morphology, Internal Anatomy, And Natural History, Felipe De Madeiros Magalhães, Adrian Antonio Garda, Ralita Ferreira Amado, Rafael O. De Sá

Biology Faculty Publications

We describe and illustrate the external morphology, oral disc, chondrocranium, and internal oral anatomy of Leptodactylus caatingae larvae. We analyze the internal oral anatomy using scanning electron microscopy of a larva in Gosner, stage 38 and chondrocranial anatomy is reported for Gosner stage 34. The tadpole at Gosner stage 38 has a globular body shape with low tail fins and a ventral oral disc bordered by two rows of marginal papillae on most of the disc, except for the anterior labium and a medial portion of the posterior labium where papillae are simple; a wide rostral gap is present, labial …


Novel Neuroprotective Function Of Apical-Basal Polarity Genecrumbs In Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration, Andrew Steffensmeier, Meghana Tare, Oorvashi Roy Puli, Rohan Modi, Jaison Nainaparampil, Madhuri Kango-Singh, Amit Singh Nov 2013

Novel Neuroprotective Function Of Apical-Basal Polarity Genecrumbs In Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration, Andrew Steffensmeier, Meghana Tare, Oorvashi Roy Puli, Rohan Modi, Jaison Nainaparampil, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD, OMIM: 104300), a progressive neurodegenerative disorder with no cure to date, is caused by the generation of amyloid-beta-42 (Aβ42) aggregates that trigger neuronal cell death by unknown mechanism(s). We have developed a transgenic Drosophilaeye model where misexpression of human Aβ42 results in AD-like neuropathology in the neural retina. We have identified an apical-basal polarity gene crumbs (crb) as a genetic modifier of Aβ42-mediated-neuropathology. Misexpression of Aβ42 caused upregulation of Crb expression, whereas downregulation of Crb either by RNAi or null allele approach rescued the Aβ42-mediated-neurodegeneration. Co-expression of full length Crb with Aβ42 increased severity of Aβ42-mediated-neurodegeneration, …


Nitric Oxide Regulates Neuronal Activity Via Calcium- Activated Potassium Channels, Lei Ray Zhong, Stephen Estes, Liana Artinian, Vincent Rehder Nov 2013

Nitric Oxide Regulates Neuronal Activity Via Calcium- Activated Potassium Channels, Lei Ray Zhong, Stephen Estes, Liana Artinian, Vincent Rehder

Biology Faculty Publications

Nitric oxide (NO) is an unconventional membrane-permeable messenger molecule that has been shown to play various roles in the nervous system. How NO modulates ion channels to affect neuronal functions is not well understood. In gastropods, NO has been implicated in regulating the feeding motor program. The buccal motoneuron, B19, of the freshwater pond snail Helisoma trivolvis is active during the hyper-retraction phase of the feeding motor program and is located in the vicinity of NO-producing neurons in the buccal ganglion. Here, we asked whether B19 neurons might serve as direct targets of NO signaling. Previous work established NO as …


Selective G-Quadruplex Dna Recognition By A New Class Of Designed Cyanines, Rupesh Nanjunda, Eric A. Owens, Leah E. Mickelson, Tyler L. Dost, Ekaterina M. Stroeva, Hang T. Huynh, Markus W. Germann, Maged M. Henary, W. David Wilson Nov 2013

Selective G-Quadruplex Dna Recognition By A New Class Of Designed Cyanines, Rupesh Nanjunda, Eric A. Owens, Leah E. Mickelson, Tyler L. Dost, Ekaterina M. Stroeva, Hang T. Huynh, Markus W. Germann, Maged M. Henary, W. David Wilson

Biology Faculty Publications

A variety of cyanines provide versatile and sensitive agents acting as DNA stains and sensors and have been structurally modified to bind in the DNA minor groove in a sequence dependent manner. Similarly, we are developing a new set of cyanines that have been designed to achieve highly selective binding to DNA G-quadruplexes with much weaker binding to DNA duplexes. A systematic set of structurally analogous trimethine cyanines has been synthesized and evaluated for quadruplex targeting. The results reveal that elevated quadruplex binding and specificity are highly sensitive to the polymethine chain length, heterocyclic structure and intrinsic charge of the …


Homeotic Gene Teashirt (Tsh) Has A Neuroprotective Function In Amyloid-Beta 42 Mediated Neurodegeneration, Michael T. Moran, Meghana Tare, Madhuri Kango-Singh, Amit Singh Nov 2013

Homeotic Gene Teashirt (Tsh) Has A Neuroprotective Function In Amyloid-Beta 42 Mediated Neurodegeneration, Michael T. Moran, Meghana Tare, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Background: Alzheimer's disease (AD) is a debilitating age related progressive neurodegenerative disorder characterized by the loss of cognition, and eventual death of the affected individual. One of the major causes of AD is the accumulation of Amyloid-beta 42 (Aβ42) polypeptides formed by the improper cleavage of amyloid precursor protein (APP) in the brain. These plaques disrupt normal cellular processes through oxidative stress and aberrant signaling resulting in the loss of synaptic activity and death of the neurons. However, the detailed genetic mechanism(s) responsible for this neurodegeneration still remain elusive.

Methodology/Principal Findings: We have generated a transgenic Drosophila eye model where …


Proprioception And Tension Receptors In Crab Limbs: Student Laboratory Exercises, Zana R. Majeed, Josh Titlow, H. Bernard Hartman, Robin L. Cooper Oct 2013

Proprioception And Tension Receptors In Crab Limbs: Student Laboratory Exercises, Zana R. Majeed, Josh Titlow, H. Bernard Hartman, Robin L. Cooper

Biology Faculty Publications

The primary purpose of these procedures is to demonstrate for teaching and research purposes how to record the activity of living primary sensory neurons responsible for proprioception as they are detecting joint position and movement, and muscle tension. Electrical activity from crustacean proprioceptors and tension receptors is recorded by basic neurophysiological instrumentation, and a transducer is used to simultaneously measure force that is generated by stimulating a motor nerve. In addition, we demonstrate how to stain the neurons for a quick assessment of their anatomical arrangement or for permanent fixation. Staining reveals anatomical organization that is representative of chordotonal organs …


Muc1 Regulates Expression Of Multiple Micrornas Involved In Pancreatic Tumor Progression, Including The Mir-200c/141 Cluster, Ashley M. Mohr, Jennifer M. Bailey, Michelle E. Lewallen, Xiang Liu, Prakash Radhakrishnan, Fang Yu, William Tapprich, Michael A. Hollingsworth Oct 2013

Muc1 Regulates Expression Of Multiple Micrornas Involved In Pancreatic Tumor Progression, Including The Mir-200c/141 Cluster, Ashley M. Mohr, Jennifer M. Bailey, Michelle E. Lewallen, Xiang Liu, Prakash Radhakrishnan, Fang Yu, William Tapprich, Michael A. Hollingsworth

Biology Faculty Publications

MUC1 is a transmembrane glycoprotein that modulates transcription via its cytoplasmic domain. We evaluated the capacity of MUC1 to regulate the global transcription of microRNAs in pancreatic cancer cells expressing MUC1. Results indicated that MUC1 regulated expression of at least 103 microRNAs. We evaluated further regulation of the microRNA transcript cluster miR-200c/141, which was among the most highly regulated microRNAs. We found that MUC1 directly interacted with ZEB1, a known transcriptional repressor of the miR-200c/141 cluster, at the promoter of miR-200c/141, and further reduced transcript production. These data indicate that signaling through MUC1 influences cancer progression by regulating transcription of …


Fight Or Flight: Parental Decisions About Predators At Nests Of Northern Bobwhites (Colinus Virginianus), Susan N. Ellis-Felege, Jonathan S. Burnam, William E. Palmer, D. Clay Sisson, John P. Carroll Oct 2013

Fight Or Flight: Parental Decisions About Predators At Nests Of Northern Bobwhites (Colinus Virginianus), Susan N. Ellis-Felege, Jonathan S. Burnam, William E. Palmer, D. Clay Sisson, John P. Carroll

Biology Faculty Publications

Patterns of nest defense against predators by ground-nesting bird species in the wild are poorly understood, largely because of a historical inability to directly monitor nests. Most nest-defense studies have observed responses elicited from artificial predators or human observers presented to nesting birds, and few have attempted to present these events in the context of predator—prey relationships found in the wild. We hypothesized that predator threat level (e.g., the threat posed to the clutch or to the clutch and the attending adult), parental characteristics, clutch investment, and future reproductive opportunities would influence avian nest-defense decisions. During 1999–2006, we examined predation …


‘Clustering’ Sirpα Into The Plasma Membrane Lipid Microdomains Is Required For Activated Monocytes And Macrophages To Mediate Effective Cell Surface Interactions With Cd47, Binh Ha, Zhiyuan Lv, Zhen Bian, Xiugen Zhang, Aarti Mishra, Yuan Liu Oct 2013

‘Clustering’ Sirpα Into The Plasma Membrane Lipid Microdomains Is Required For Activated Monocytes And Macrophages To Mediate Effective Cell Surface Interactions With Cd47, Binh Ha, Zhiyuan Lv, Zhen Bian, Xiugen Zhang, Aarti Mishra, Yuan Liu

Biology Faculty Publications

SIRPα, an ITIMs-containing signaling receptor, negatively regulates leukocyte responses through extracellular interactions with CD47. However, the dynamics of SIRPα-CD47 interactions on the cell surface and the governing mechanisms remain unclear. Here we report that while the purified SIRPα binds to CD47 and that SIRPα is expressed on monocytes and monocytic THP-1 or U937, these SIRPα are ineffective to mediate cell binding to immobilized CD47. However, cell binding to CD47 is significantly enhanced when monocytes transmigrating across endothelia, or being differentiated into macrophages. Cell surface labeling reveals SIRPα to be diffused on naïve monocytes but highly clustered on transmigrated monocytes and …


Activation Of High And Low Affinity Dopamine Receptors Generates A Closed Loop That Maintains A Conductance Ratio And Its Activity Correlate, Wulf-Dieter C. Krenz, Ryan M. Hooper, Anna R. Parker, Astrid A. Prinz, Deborah J. Baro Oct 2013

Activation Of High And Low Affinity Dopamine Receptors Generates A Closed Loop That Maintains A Conductance Ratio And Its Activity Correlate, Wulf-Dieter C. Krenz, Ryan M. Hooper, Anna R. Parker, Astrid A. Prinz, Deborah J. Baro

Biology Faculty Publications

Neuromodulators alter network output and have the potential to destabilize a circuit. The mechanisms maintaining stability in the face of neuromodulation are not well described. Using the pyloric network in the crustacean stomatogastric nervous system, we show that dopamine (DA) does not simply alter circuit output, but activates a closed loop in which DA-induced alterations in circuit output consequently drive a change in an ionic conductance to preserve a conductance ratio and its activity correlate. DA acted at low affinity type 1 receptors (D1Rs) to induce an immediate modulatory decrease in the transient potassium current (I A ) of a …


Lactobacillus Plantarum Dk119 As A Probiotic Confers Protection Against Influenza Virus By Modulating Innate Immunity, Min-Kyung Park, Vu Ngo, Young-Man Kwon, Young-Tae Lee, Sieun Yoo, Young-Hee Choo, Sung-Moon Hong, Hye Suk Hwang, Eun-Ju Ko, Yu-Jin Jung, Dae-Won Moon, Eun-Ji Jeong, Min-Chul Kim, Yu-Na Lee, Ji-Hun Jang, Joon-Suk Oh, Cheol-Hyun Kim, Sang-Moon Kang Oct 2013

Lactobacillus Plantarum Dk119 As A Probiotic Confers Protection Against Influenza Virus By Modulating Innate Immunity, Min-Kyung Park, Vu Ngo, Young-Man Kwon, Young-Tae Lee, Sieun Yoo, Young-Hee Choo, Sung-Moon Hong, Hye Suk Hwang, Eun-Ju Ko, Yu-Jin Jung, Dae-Won Moon, Eun-Ji Jeong, Min-Chul Kim, Yu-Na Lee, Ji-Hun Jang, Joon-Suk Oh, Cheol-Hyun Kim, Sang-Moon Kang

Biology Faculty Publications

Lactobacillus plantarum DK119 (DK119) isolated from the fermented Korean cabbage food was used as a probiotic to determine its antiviral effects on influenza virus. DK119 intranasal or oral administration conferred 100% protection against subsequent lethal infection with influenza A viruses, prevented significant weight loss, and lowered lung viral loads in a mouse model. The antiviral protective efficacy was observed in a dose and route dependent manner of DK119 administration. Mice that were treated with DK119 showed high levels of cytokines IL-12 and IFN-c in bronchoalveolar lavage fluids, and a low degree of inflammation upon infection with influenza virus. Depletion of …


High-Throughput Rna Sequencing Of Pseudomonas-Infected Arabidopsis Reveals Hidden Transcriptome Complexity And Novel Splice Variants, Brian E. Howard, Qiwen Hu, Ahmet Can Babaoglu, Manan Chandra, Monica Borghi, Xiaoping Tan, Luyan He, Heike Winter-Sederoff, Walter Gassmann, Paola Veronese, Steffen Heber Oct 2013

High-Throughput Rna Sequencing Of Pseudomonas-Infected Arabidopsis Reveals Hidden Transcriptome Complexity And Novel Splice Variants, Brian E. Howard, Qiwen Hu, Ahmet Can Babaoglu, Manan Chandra, Monica Borghi, Xiaoping Tan, Luyan He, Heike Winter-Sederoff, Walter Gassmann, Paola Veronese, Steffen Heber

Biology Faculty Publications

We report the results of a genome-wide analysis of transcription in Arabidopsis thaliana after treatment with Pseudomonas syringae pathovar tomato. Our time course RNA-Seq experiment uses over 500 million read pairs to provide a detailed characterization of the response to infection in both susceptible and resistant hosts. The set of observed differentially expressed genes is consistent with previous studies, confirming and extending existing findings about genes likely to play an important role in the defense response to Pseudomonas syringae. The high coverage of the Arabidopsis transcriptome resulted in the discovery of a surprisingly large number of alternative splicing (AS) events …


Dreadds In Drosophila: A Pharmacogenetic Approach For Controlling Behavior, Neuronal Signaling, And Physiology In The Fly, Jaime Becnel, Oralee Johnson, Zana R Majeed, Vi Tran, Bangning Yu, Bryan L. Roth, Robin L. Cooper, Edmund K. Kerut, Charles D. Nichols Sep 2013

Dreadds In Drosophila: A Pharmacogenetic Approach For Controlling Behavior, Neuronal Signaling, And Physiology In The Fly, Jaime Becnel, Oralee Johnson, Zana R Majeed, Vi Tran, Bangning Yu, Bryan L. Roth, Robin L. Cooper, Edmund K. Kerut, Charles D. Nichols

Biology Faculty Publications

We have translated a powerful genetic tool, designer receptors exclusively activated by designer drugs (DREADDs), from mammalian systems to Drosophila melanogaster to selectively, rapidly, reversibly, and dose-dependently control behaviors and physiological processes in the fly. DREADDs are muscarinic acetylcholine G protein-coupled receptors evolved for loss of affinity to acetylcholine and for the ability to be fully activated by an otherwise biologically inert chemical, clozapine-N-oxide. We demonstrate its ability to control a variety of behaviors and processes in larvae and adults, including heart rate, sensory processing, diurnal behavior, learning and memory, and courtship. The advantages of this particular technology include the …


Transcriptome Analysis Of Two Buffalograss Cultivars, Michael Wachholtz, Tiffany Heng-Moss, Paul Twigg, Lisa Baird, Guoqing Lu, Keenan Amundsen Sep 2013

Transcriptome Analysis Of Two Buffalograss Cultivars, Michael Wachholtz, Tiffany Heng-Moss, Paul Twigg, Lisa Baird, Guoqing Lu, Keenan Amundsen

Biology Faculty Publications

Background: Buffalograss [Buchloë dactyloides (Nutt.) Engel. syn. Bouteloua dactyloides (Nutt.) Columbus] is a United States native turfgrass species that requires less irrigation, fungicides and pesticides compared to more commonly used turfgrass species. In areas where water is limited, interest in this grass species for lawns is increasing. While several buffalograss cultivars have been developed through buffalograss breeding, the timeframe for new cultivar development is long and is limited by a lack of useful genetic resources. Two high throughput next-generation sequencing techniques were used to increase the genomic resources available for buffalograss.

Results: Total RNA was extracted and …


The Genus Odontophrynus (Anura: Odontophrynidae): A Larval Perspective, Filipe Augusto C. Do Nascimento, Tamí Mott, José A. Langone, Christine A. Davis, Rafael O. De Sá Aug 2013

The Genus Odontophrynus (Anura: Odontophrynidae): A Larval Perspective, Filipe Augusto C. Do Nascimento, Tamí Mott, José A. Langone, Christine A. Davis, Rafael O. De Sá

Biology Faculty Publications

The genus Odontophrynus consists of 11 species of medium-sized frogs distributed across south and east South America. This study examines and describes the chondrocrania and oral cavities of 0. americanus, 0. maisuma, 0. carvalhoi, and 0. cu/tripes, and reviews current knowledge about the larval external morphology of the genus. Twenty-one tadpoles were cleared and double-stained for chondrocranium description and five tadpoles were dissected for analysis in a scanning electron microscope. The presence of a tectum parientale may be considered here as a putative synapomorphy of the genus. The 0. americanus and 0. cu/tripes species groups were partially differentiated by the …


Recurrent Modification Of A Conserved Cis-Regulatory Element Underlies Fruit Fly Pigmentation Diversity, William A. Rogers, Joseph R. Salomone, David J. Tacy, Eric M. Camino, Kristen A. Davis, Mark Rebeiz, Thomas M. Williams Aug 2013

Recurrent Modification Of A Conserved Cis-Regulatory Element Underlies Fruit Fly Pigmentation Diversity, William A. Rogers, Joseph R. Salomone, David J. Tacy, Eric M. Camino, Kristen A. Davis, Mark Rebeiz, Thomas M. Williams

Biology Faculty Publications

The development of morphological traits occurs through the collective action of networks of genes connected at the level of gene expression. As any node in a network may be a target of evolutionary change, the recurrent targeting of the same node would indicate that the path of evolution is biased for the relevant trait and network. Although examples of parallel evolution have implicated recurrent modification of the same gene and cis-regulatory element (CRE), little is known about the mutational and molecular paths of parallel CRE evolution. InDrosophila melanogaster fruit flies, the Bric-à-brac (Bab) transcription factors control the development …


Pharmacological Analysis Of Dopamine Modulation In The Drosophila Melanogaster Larval Heart, Josh S. Titlow, Jenna M. Rufer, Kayla E. King, Robin L. Cooper Jul 2013

Pharmacological Analysis Of Dopamine Modulation In The Drosophila Melanogaster Larval Heart, Josh S. Titlow, Jenna M. Rufer, Kayla E. King, Robin L. Cooper

Biology Faculty Publications

Dopamine (DA) and other neurotransmitters affect nonneuronal tissues in insects by circulating in the hemolymph. In several organisms, DA has been shown to modulate distinct aspects of cardiac function but the signal transduction pathways that mediate dopaminergic effects on the heart are not well characterized. Here, we used a semiintact Drosophila melanogaster larva preparation and drugs targeting DA receptors and canonical second messenger pathways to identify signaling cascades that mediate the effect of DA on a myogenic heart. DA has a positive chronotropic effect that is mimicked by SKF38393 (type‐1 DA receptor agonist) and quinpirole (type‐2 DA receptor agonist). SCH23390 …


White-Tailed Deer (Odocoileus Virginianus) Positively Affect The Growth Of Mature Northern Red Oak (Quercus Rubra) Trees., R W. Lucas, R Salguero-Gomez, D B. Cobb, Bonnie G. Waring, F Anderson, W J. Mcshea, B B. Casper Jul 2013

White-Tailed Deer (Odocoileus Virginianus) Positively Affect The Growth Of Mature Northern Red Oak (Quercus Rubra) Trees., R W. Lucas, R Salguero-Gomez, D B. Cobb, Bonnie G. Waring, F Anderson, W J. Mcshea, B B. Casper

Biology Faculty Publications

Understanding and predicting the effects of deer (Cervidae) on forest ecosystems present significant challenges in ecosystem ecology. Deer herbivory can cause large changes in the biomass and species composition of forest understory plant communities, including early life-cycle trees (i.e., seedlings and saplings). Such changes can impact juvenile to adult transitions and the future age structure and species composition of mature forests. Changes to understory vegetation also impact flow of energy and nutrients in forest ecosystems. Studies examining the influence of deer on mature trees, however, are rare and rely on extrapolating effects from early life cycle stages of trees. We …


Effect Of Diurnal Fluctuating Versus Constant Temperatures On Germination Of 445 Species From The Eastern Tibet Plateau, Kun Liu, Jerry M. Baskin, Carol C. Baskin, Haiyan Bu, Guozhen Du, Miaojun Ma Jul 2013

Effect Of Diurnal Fluctuating Versus Constant Temperatures On Germination Of 445 Species From The Eastern Tibet Plateau, Kun Liu, Jerry M. Baskin, Carol C. Baskin, Haiyan Bu, Guozhen Du, Miaojun Ma

Biology Faculty Publications

Germination response to fluctuating temperatures is a mechanism by which seeds detect gaps in vegetation canopies and depth of burial in soil, and it is very important for plants. Thus, studies on the effect of fluctuating temperature on germination at the community level are valuable for understanding community structure and biodiversity maintenance. We determined the effects of two alternating temperatures (5/25°C and 10/20°C) and one constant temperature (15°C) on seed germination of 445 species in a grassland community on the eastern Tibet Plateau. Seed mass was determined for each species, and data on habitat, type of life cycle, altitudinal distribution …


Variation In Salamander Tail Regeneration Is Associated With Genetic Factors That Determine Tail Morphology, Gareth J. Voss, D. Kevin Kump, John A. Walker, S. Randal Voss Jul 2013

Variation In Salamander Tail Regeneration Is Associated With Genetic Factors That Determine Tail Morphology, Gareth J. Voss, D. Kevin Kump, John A. Walker, S. Randal Voss

Biology Faculty Publications

Very little is known about the factors that cause variation in regenerative potential within and between species. Here, we used a genetic approach to identify heritable genetic factors that explain variation in tail regenerative outgrowth. A hybrid ambystomatid salamander (Ambystoma mexicanum x A. andersoni) was crossed to an A. mexicanum and 217 offspring were induced to undergo metamorphosis and attain terrestrial adult morphology using thyroid hormone. Following metamorphosis, each salamander’s tail tip was amputated and allowed to regenerate, and then amputated a second time and allowed to regenerate. Also, DNA was isolated from all individuals and genotypes were …


The Distribution Of Fruit And Seed Toxicity During Development For Eleven Neotropical Trees And Vines, Noelle G. Beckman Jul 2013

The Distribution Of Fruit And Seed Toxicity During Development For Eleven Neotropical Trees And Vines, Noelle G. Beckman

Biology Faculty Publications

Secondary compounds in fruit mediate interactions with natural enemies and seed dispersers, influencing plant survival and species distributions. The functions of secondary metabolites in plant defenses have been well-studied in green tissues, but not in reproductive structures of plants. In this study, the distribution of toxicity within plants was quantified and its influence on seed survival was determined in Central Panama. To investigate patterns of allocation to chemical defenses and shifts in allocation with fruit development, I quantified variation in toxicity between immature and mature fruit and between the seed and pericarp for eleven species. Toxicity of seed and pericarp …


Cryptopatches Are Essential For The Development Of Human Galt, Tomonori Nochi, Paul W. Denton, Angela Wahl, J. Victor Garcia Jun 2013

Cryptopatches Are Essential For The Development Of Human Galt, Tomonori Nochi, Paul W. Denton, Angela Wahl, J. Victor Garcia

Biology Faculty Publications

Abnormal gut-associated lymphoid tissue (GALT) in humans is associated with infectious and autoimmune diseases, which cause dysfunction of the gastrointestinal (GI) tract immune system. To aid in investigating GALT pathologies in vivo, we bioengineered a human-mouse chimeric model characterized by the development of human GALT structures originating in mouse cryptopatches. This observation expands our mechanistic understanding of the role of cryptopatches in human GALT genesis and emphasizes the evolutionary conservation of this developmental process. Immunoglobulin class switching to IgA occurs in these GALT structures, leading to numerous human IgAproducing plasma cells throughout the intestinal lamina propria. CD4+ T cell depletion …


Evolution Of A Higher Intracellular Oxidizing Environment In Caenorhabditis Elegans Under Relaxed Selection, Joanna Joyner-Matos, Kiley A. Hicks, Dustin Cousins, Michelle Keller, Dee R. Denver, Charles F. Baer, Suzanne Estes Jun 2013

Evolution Of A Higher Intracellular Oxidizing Environment In Caenorhabditis Elegans Under Relaxed Selection, Joanna Joyner-Matos, Kiley A. Hicks, Dustin Cousins, Michelle Keller, Dee R. Denver, Charles F. Baer, Suzanne Estes

Biology Faculty Publications

We explored the relationship between relaxed selection, oxidative stress, and spontaneous mutation in a set of mutation-accumulation (MA) lines of the nematode Caenorhabditis elegans and in their common ancestor. We measured steady-state levels of free radicals and oxidatively damaged guanosine nucleosides in the somatic tissues of five MA lines for which nuclear genome base substitution and GC-TA transversion frequencies are known. The two markers of oxidative stress are highly correlated and are elevated in the MA lines relative to the ancestor; point estimates of the per-generation rate of mutational decay (DM) of these measures of oxidative stress are similar to …


Germline Transgenic Methods For Tracking Cells And Testing Gene Function During Regeneration In The Axolotl, Shahryar Khattak, Maritta Schuez, Tobias Richter, Dunja Knapp, Saori L. Haigo, Tatiana Sandoval-Guzmán, Kristyna Hradlikova, Annett Duemmler, Ryan R. Kerney, Elly M. Tanaka Jun 2013

Germline Transgenic Methods For Tracking Cells And Testing Gene Function During Regeneration In The Axolotl, Shahryar Khattak, Maritta Schuez, Tobias Richter, Dunja Knapp, Saori L. Haigo, Tatiana Sandoval-Guzmán, Kristyna Hradlikova, Annett Duemmler, Ryan R. Kerney, Elly M. Tanaka

Biology Faculty Publications

The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum(axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent control of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we inducibly …


Use Of Image Cytometry For Quantification Of Pathogenic Fungi In Association With Host Cells, Charlotte A. Berkes, Leo Li-Ying Chan, Alisha Wilkinson, Benjamin Paradis Jun 2013

Use Of Image Cytometry For Quantification Of Pathogenic Fungi In Association With Host Cells, Charlotte A. Berkes, Leo Li-Ying Chan, Alisha Wilkinson, Benjamin Paradis

Biology Faculty Publications

Studies of the cellular pathogenesis mechanisms of pathogenic yeasts such as Candida albicans, Histoplasma capsulatum, and Cryptococcus neoformans commonly employ infection of mammalian hosts or host cells (i.e. macrophages) followed by yeast quantification using colony forming unit analysis or flow cytometry. While colony forming unit enumeration has been the most commonly used method in the field, this technique has disadvantages and limitations, including slow growth of some fungal species on solid media and low and/or variable plating efficiencies, which is of particular concern when comparing growth of wild-type and mutant strains. Flow cytometry can provide rapid quantitative information regarding yeast …


Stromal Tumor Microenvironment In Chronic Lymphocytic Leukemia: Regulation Of Leukemic Progression, Ashima Shukla, Nagendra K. Chaturvedi, Adam K. Ahrens, Christine E. Cutucache, Amit K. Mittal, Philip Bierman, Dennis D. Weisenburger, Runqing Lu, Shantaram S. Joshi May 2013

Stromal Tumor Microenvironment In Chronic Lymphocytic Leukemia: Regulation Of Leukemic Progression, Ashima Shukla, Nagendra K. Chaturvedi, Adam K. Ahrens, Christine E. Cutucache, Amit K. Mittal, Philip Bierman, Dennis D. Weisenburger, Runqing Lu, Shantaram S. Joshi

Biology Faculty Publications

Chronic Lymphocytic Leukemia (CLL), the most prevalent adult leukemia in western countries, which is highly heterogeneous with a very variable clinical outcome. Emerging evidence indicates that the stromal tumor microenvironment (STME) and stromal associated genes (SAG) play important roles in the pathogenesis and progression of CLL. However, the precise mechanisms by which STME and SAG are involved in this process remain unknown. In an attempt to explore the role of STME in this process, we examined the expression levels of stromal associated genes using gene expression profiling (GEP) of CLL cells from lymph nodes (LN) (n=15), bone marrow (BM) (n=18), …


Behavioral And Neurogenomic Transcriptome Changes In Wild-Derived Zebrafish With Fluoxetine Treatment, Ryan Y. Wong, Sarah E. Oxendine, John Godwin May 2013

Behavioral And Neurogenomic Transcriptome Changes In Wild-Derived Zebrafish With Fluoxetine Treatment, Ryan Y. Wong, Sarah E. Oxendine, John Godwin

Biology Faculty Publications

Background: Male and female vertebrates typically differ in a range of characteristics, from morphology to physiology to behavior, which are influenced by factors such as the social environment and the internal hormonal and genetic milieu. However, sex differences in gene expression profiles in the brains of vertebrates are only beginning to be understood. Fishes provide a unique complement to studies of sex differences in mammals and birds given that fish show extreme plasticity and lability of sexually dimorphic characters and behaviors during development and even adulthood. Hence, teleost models can give additional insight into sexual differentiation. The goal of …