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2014

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Corn (Zea Mays) Emergence And Early Growth As Influenced By Tansymustard (Descurainia Pinnata) Residue, Rodrigo Werle, Leonardo L. Perez, Lowell D. Sandell, John L. Lindquist Jan 2014

Corn (Zea Mays) Emergence And Early Growth As Influenced By Tansymustard (Descurainia Pinnata) Residue, Rodrigo Werle, Leonardo L. Perez, Lowell D. Sandell, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Farmers have observed reduced early growth of corn in the presence of tansymustard [Descurainia pinnata (Walt.) Britt.], a winter annual weed of the Brassicaceae family. A greenhouse study was conducted to evaluate the effect of tansymustard on corn (Zea mays L.) emergence and early growth. Treatments included corn growing in pots with only tansymustard root residue, with only tansymustard shoot residue, and with whole tansymustard plant residue (roots plus shoots); tansymustard plants treated with glyphosate 2 days after planting (DAP) corn seeds; and a control (no tansymustard residue). Corn emergence was recorded and biomass measured after 4 weeks of …


Homogeneous Low-Molecular-Weight Heparins With Reversible Anticoagulant Activity, Yongmei Xu, Chao Cai, Kasemsiri Chandarajoti, Po-Hung Hsieh, Lingyun Li, Truong Q. Pham, Erica M. Sparkenbaugh, Juzheng Sheng, Nigel S. Key, Rafal Pawlinski, Edward N. Harris, Robert J. Linhardt, Jian Liu Jan 2014

Homogeneous Low-Molecular-Weight Heparins With Reversible Anticoagulant Activity, Yongmei Xu, Chao Cai, Kasemsiri Chandarajoti, Po-Hung Hsieh, Lingyun Li, Truong Q. Pham, Erica M. Sparkenbaugh, Juzheng Sheng, Nigel S. Key, Rafal Pawlinski, Edward N. Harris, Robert J. Linhardt, Jian Liu

Department of Biochemistry: Faculty Publications

Low-molecular-weight heparins (LMWHs) are carbohydrate-based anticoagulants clinically used to treat thrombotic disorders, but impurities, structural heterogeneity or functional irreversibility can limit treatment options. We report a series of synthetic LMWHs prepared by cost-effective chemoenzymatic methods. The high activity of one defined synthetic LMWH against human factor Xa (FXa) was reversible in vitro and in vivo using protamine, demonstrating that synthetically accessible constructs can have a critical role in the next generation of LMWHs.


Pharmacological Correction Of Obesity-Induced Autophagy Arrest Using Calcium Channel Blockers, Hwan-Woo Park, Haeli Park, Ian A. Semple, Insook Jang, Seung-Hyun Ro, Myungjin Kim, Victor A. Cazares, Edward L. Stuenkel, Jung-Jae Kim, Jeong Sig Kim, Jun Hee Lee Jan 2014

Pharmacological Correction Of Obesity-Induced Autophagy Arrest Using Calcium Channel Blockers, Hwan-Woo Park, Haeli Park, Ian A. Semple, Insook Jang, Seung-Hyun Ro, Myungjin Kim, Victor A. Cazares, Edward L. Stuenkel, Jung-Jae Kim, Jeong Sig Kim, Jun Hee Lee

Department of Biochemistry: Faculty Publications

Autophagy deregulation during obesity contributes to the pathogenesis of diverse metabolic disorders. However, without understanding the molecular mechanism of obesity interference in autophagy, development of therapeutic strategies for correcting such defects in obese individuals is challenging. Here we show that a chronic increase of the cytosolic calcium concentration in hepatocytes during obesity and lipotoxicity attenuates autophagic flux by preventing the fusion between autophagosomes and lysosomes. As a pharmacological approach to restore cytosolic calcium homeostasis in vivo, we administered the clinically approved calcium channel blocker verapamil to obese mice. Such treatment successfully increases autophagosome–lysosome fusion in liver, preventing accumulation of …


Hepatoprotective Role Of Sestrin2 Against Chronic Er Stress, Hwan-Woo Park, Haeli Park, Seung-Hyun Ro, Insook Jang, Ian A. Semple, David N. Kim, Myungjin Kim, Myeongjin Nam, Deqiang Zhang, Lei Yin, Jun Hee Lee Jan 2014

Hepatoprotective Role Of Sestrin2 Against Chronic Er Stress, Hwan-Woo Park, Haeli Park, Seung-Hyun Ro, Insook Jang, Ian A. Semple, David N. Kim, Myungjin Kim, Myeongjin Nam, Deqiang Zhang, Lei Yin, Jun Hee Lee

Department of Biochemistry: Faculty Publications

Upon prolonged endoplasmic reticulum (ER) stress, cells attenuate protein translation to prevent accumulation of unfolded proteins. Here we show that Sestrin2 is critical for this process. Sestrin2 expression is induced by an ER stress-activated transcription factor CCAATenhancer- binding protein beta (c/EBPβ). Once induced, Sestrin2 halts protein synthesis by inhibiting mammalian target of rapamycin complex 1 (mTORC1). As Sestrin2-deficient cells continue to translate a large amount of proteins during ER stress, they are highly susceptible to ER stress-associated cell death. Accordingly, dietary or genetically induced obesity, which does not lead to any pathological indication other than simple fat accumulation in the …


Eutrophication Weakens Stabilizing Effects Of Diversity In Natural Grasslands, Yann Hautier, Eric W. Seabloom, Elizabeth T. Borer, Peter B. Adler, W. Stanley Harpole, Helmut Hillebrand, Eric M. Lind, Andrew S. Macdougall, Carly J. Stevens, Jonathan D. Bakker, Yvonne M. Buckley, Chengjin Chu, Scott L. Collins, Pedro Daleo, Ellen I. Damschen, Kendi F. Davies, Philip A. Fay, Jennifer Firn, Daniel S. Gruner, Virginia L. Jin, Julia A. Klein, Johannes M. H. Knops, Kimberly J. La Pierre, Wei Li, Rebecca L. Mcculley, Brett A. Melbourne, Joslin L. Moore, Lydia R. O’Halloran, Suzanne M. Prober, Anita C. Risch, Mahesh Sankaran, Martin Schuetz, Andy Hector Jan 2014

Eutrophication Weakens Stabilizing Effects Of Diversity In Natural Grasslands, Yann Hautier, Eric W. Seabloom, Elizabeth T. Borer, Peter B. Adler, W. Stanley Harpole, Helmut Hillebrand, Eric M. Lind, Andrew S. Macdougall, Carly J. Stevens, Jonathan D. Bakker, Yvonne M. Buckley, Chengjin Chu, Scott L. Collins, Pedro Daleo, Ellen I. Damschen, Kendi F. Davies, Philip A. Fay, Jennifer Firn, Daniel S. Gruner, Virginia L. Jin, Julia A. Klein, Johannes M. H. Knops, Kimberly J. La Pierre, Wei Li, Rebecca L. Mcculley, Brett A. Melbourne, Joslin L. Moore, Lydia R. O’Halloran, Suzanne M. Prober, Anita C. Risch, Mahesh Sankaran, Martin Schuetz, Andy Hector

School of Biological Sciences: Faculty Publications

Studies of experimental grassland communities1–7 have demonstrated that plant diversity can stabilize productivity through species asynchrony, in which decreases in the biomass of some species are compensated for by increases in others1,2. However, it remains unknown whether these findings are relevant to natural ecosystems, especially those for which species diversity is threatened by anthropogenic global change8–11. Here we analyse diversity–stability relationships from 41 grasslands on five continents and examine how these relationships are affected by chronic fertilization, one of the strongest drivers of species loss globally8. Unmanipulated communities with more species had greater …


Genes And Junk In Plant Mitochondria—Repair Mechanisms And Selection, Alan C. Christensen Jan 2014

Genes And Junk In Plant Mitochondria—Repair Mechanisms And Selection, Alan C. Christensen

School of Biological Sciences: Faculty Publications

Plant mitochondrial genomes have very low mutation rates. In contrast, they also rearrange and expand frequently. This is easily understood if DNA repair in genes is accomplished by accurate mechanisms, whereas less accurate mechanisms including nonhomologous end joining or break-induced replication are used in nongenes. An important question is how different mechanisms of repair predominate in coding and noncoding DNA, although one possible mechanismis transcription-coupled repair (TCR). This work tests the predictions of TCR and finds no support for it. Examination of the mutation spectra and rates in genes and junk reveals what DNA repair mechanisms are available to plant …


Dehydration Stress Memory Genes Of Zea Mays; Comparison With Arabidopsis Thaliana, Yong Ding, Laetitia Virlouvet, Ning Liu, Jean-Jack Riethoven, Michael E. Fromm, Zoya Avramova Jan 2014

Dehydration Stress Memory Genes Of Zea Mays; Comparison With Arabidopsis Thaliana, Yong Ding, Laetitia Virlouvet, Ning Liu, Jean-Jack Riethoven, Michael E. Fromm, Zoya Avramova

School of Biological Sciences: Faculty Publications

Background: Pre-exposing plants to diverse abiotic stresses may alter their physiological and transcriptional responses to a subsequent stress, suggesting a form of “stress memory”. Arabidopsis thaliana plants that have experienced multiple exposures to dehydration stress display transcriptional behavior suggesting “memory” from an earlier stress. Genes that respond to a first stress by up-regulating or down-regulating their transcription but in a subsequent stress provide a significantly different response define the ‘memory genes’ category. Genes responding similarly to each stress form the ‘non-memory’ category. It is unknown whether such memory responses exists in other Angiosperm lineages and whether memory is an evolutionarily …


Effect Of The Internet Commerce On Dispersal Modes Of Invasive Alien Species, Magdalena Lenda, Piotr Skorka, Johannes M.H. Knops, Dawid Moron, William J. Sutherland, Karolina Kuszewska, Michal Woyciechowski Jan 2014

Effect Of The Internet Commerce On Dispersal Modes Of Invasive Alien Species, Magdalena Lenda, Piotr Skorka, Johannes M.H. Knops, Dawid Moron, William J. Sutherland, Karolina Kuszewska, Michal Woyciechowski

School of Biological Sciences: Faculty Publications

The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant …


Estimating The Frequency Of Cry1f Resistance In Field Populations Of The European Corn Borer (Lepidoptera: Crambidae), Blair D. Siegfried, Murugesan Rangasamy, Haichuan Wang, Terence A. Spencer, Chirakkal V. Haridas, Brigitte Tenhumberg, Douglas V. Sumerford, Nicholas P. Storer Jan 2014

Estimating The Frequency Of Cry1f Resistance In Field Populations Of The European Corn Borer (Lepidoptera: Crambidae), Blair D. Siegfried, Murugesan Rangasamy, Haichuan Wang, Terence A. Spencer, Chirakkal V. Haridas, Brigitte Tenhumberg, Douglas V. Sumerford, Nicholas P. Storer

School of Biological Sciences: Faculty Publications

Background: Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) have suppressed European corn borer populations and reduced the pest status of this insect throughout much of the US corn belt. A major assumption of the high-dose/refuge strategy proposed for insect resistance management and Bt corn is that the frequency of resistance alleles is low so that resistant pests surviving exposure to Bt corn will be rare. Results: The frequency of resistance to the Cry1F Bt toxin was estimated using two different screening tools and compared with annual susceptibility monitoring based on diagnostic bioassays and LC50 …


Variation In The Local Population Dynamics Of The Short-Lived Opuntia Macrorhiza (Cactaceae), Chirakkal V. Haridas, Kathleen H. Keeler, Brigitte Tenhumberg Jan 2014

Variation In The Local Population Dynamics Of The Short-Lived Opuntia Macrorhiza (Cactaceae), Chirakkal V. Haridas, Kathleen H. Keeler, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Spatio-temporal variation in demographic rates can have profound effects for population persistence, especially for dispersal-limited species living in fragmented landscapes. Long-term studies of plants in such habitats help with understanding the impacts of fragmentation on population persistence but such studies are rare. In this work we reanalyzed demographic data from seven years of the short-lived cactus Opuntia macrorhiza var. macrorhiza at five plots in Boulder, Colorado. Previous work combining data from all years and all plots predicted a stable population (deterministic log λ ≈ 0). This approach assumed that all five plots were part of a single population. Since the …


The Body-Size Dependence Of Mutual Interference, John P. Delong Jan 2014

The Body-Size Dependence Of Mutual Interference, John P. Delong

School of Biological Sciences: Faculty Publications

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new data set on interference and consumer body size. The stabilizing effect …


Leaky Termination At Premature Stop Codons Antagonizes Nonsense-Mediated Mrna Decay In S. Cerevisiae, Kim M. Keeling, Jessica Lanier, Ming Du, Joe Salas-Marco, Lin Gao, Anisa Kaenjak-Angeletti, David M. Bedwell Jan 2014

Leaky Termination At Premature Stop Codons Antagonizes Nonsense-Mediated Mrna Decay In S. Cerevisiae, Kim M. Keeling, Jessica Lanier, Ming Du, Joe Salas-Marco, Lin Gao, Anisa Kaenjak-Angeletti, David M. Bedwell

School of Biological Sciences: Faculty Publications

The Nonsense-Mediated mRNA Decay (NMD) pathway mediates the rapid degradation of mRNAs that contain premature stop mutations in eukaryotic organisms. It was recently shown that mutations in three yeast genes that encode proteins involved in the NMD process, UPF1, UPF2, and UPF3, also reduce the efficiency of translation termination. In the current study, we compared the efficiency of translation termination in a upf∆ strain and a [PSI+] strain using a collection of translation termination reporter constructs. The [PSI+] state is caused by a prion form of the polypeptide chain release factor eRF3 that limits its availability …


Loss Of Sirt1 Function Improves Intestinal Anti-Bacterial Defense And Protects From Colitis-Induced Colorectal Cancer, Giuseppe Lo Sasso, Dongryeol Ryu, Laurent Mouchiroud, Samodha C. Fernando, Christopher L. Anderson, Elena Katsyuba, Alessandra Piersigilli, Michael O. Hottiger, Kristina Schoonjans, Johan Auwerx Jan 2014

Loss Of Sirt1 Function Improves Intestinal Anti-Bacterial Defense And Protects From Colitis-Induced Colorectal Cancer, Giuseppe Lo Sasso, Dongryeol Ryu, Laurent Mouchiroud, Samodha C. Fernando, Christopher L. Anderson, Elena Katsyuba, Alessandra Piersigilli, Michael O. Hottiger, Kristina Schoonjans, Johan Auwerx

School of Biological Sciences: Faculty Publications

Dysfunction of Paneth and goblet cells in the intestine contributes to inflammatory bowel disease (IBD) and colitisassociated colorectal cancer (CAC). Here, we report a role for the NAD+-dependent histone deacetylase SIRT1 in the control of anti-bacterial defense. Mice with an intestinal specific Sirt1 deficiency (Sirt1int-/-) have more Paneth and goblet cells with a consequent rearrangement of the gut microbiota. From a mechanistic point of view, the effects on mouse intestinal cell maturation are mediated by SIRT1-dependent changes in the acetylation status of SPDEF, a master regulator of Paneth and goblet cells. Our results suggest that targeting …


Effects Of Nitrogen And Phosphorus Fertilization On Soil Carbon Fractions In Alpine Meadows On The Qinghai-Tibetan Plateau, Jin Hua Li, Yu Jie Yang, Bo Wen Li, Wen Jin Li, Gang Wang, Johannes M. H. Knops Jan 2014

Effects Of Nitrogen And Phosphorus Fertilization On Soil Carbon Fractions In Alpine Meadows On The Qinghai-Tibetan Plateau, Jin Hua Li, Yu Jie Yang, Bo Wen Li, Wen Jin Li, Gang Wang, Johannes M. H. Knops

School of Biological Sciences: Faculty Publications

In grassland ecosystems, N and P fertilization often increase plant productivity, but there is no concensus if fertilization affects soil C fractions. We tested effects of N, P and N+P fertilization at 5, 10, 15 g m-2 yr-1 (N5, N10, N15, P5, P10, P15, N5P5, N10P10, and N15P15) compared to unfertilized control on soil C, soil microbial biomass and functional diversity at the 0– 20 cm and 20–40 cm depth in an alpine meadow …


Immunity Of The Saccharomyces Cerevisiae Ssy5 Mrna To Nonsense-Mediated Mrna Decay, Jesseeca Obenoskey, Dakota R. Lane, Audrey L. Atkin, Bessie W. Kebaara Jan 2014

Immunity Of The Saccharomyces Cerevisiae Ssy5 Mrna To Nonsense-Mediated Mrna Decay, Jesseeca Obenoskey, Dakota R. Lane, Audrey L. Atkin, Bessie W. Kebaara

School of Biological Sciences: Faculty Publications

The nonsense-mediated mRNA decay (NMD) pathway is a specialized pathway that triggers the rapid degradation of select mRNAs. Initially, identified as a pathway that degrades mRNAs with premature termination codons, NMD is now recognized as a pathway that also regulates some natural mRNAs. Since natural mRNAs do not typically contain premature termination codons, these mRNAs contain features that target them to NMD. In Saccharomyces cerevisiae mRNAs with a typically long 3’UTRs are usually degraded by NMD, however in some conditions a constitutively expressed SSY5 mRNA with multiple NMD targeting signals including an atypically long 3’-UTR is an exception. We investigated …


Genome-Wide Gene Expression Effects Of Sex Chromosome Imprinting In Drosophila, Bernardo Lemos, Alan T. Branco, Pan-Pan Jiang, Daniel L. Hartl, Colin D. Meiklejohn Jan 2014

Genome-Wide Gene Expression Effects Of Sex Chromosome Imprinting In Drosophila, Bernardo Lemos, Alan T. Branco, Pan-Pan Jiang, Daniel L. Hartl, Colin D. Meiklejohn

School of Biological Sciences: Faculty Publications

Imprinting is well-documented in both plant and animal species. In Drosophila, the Y chromosome is differently modified when transmitted through the male and female germlines. Here, we report genome-wide gene expression effects resulting from reversed parent-of-origin of the X and Y chromosomes. We found that hundreds of genes are differentially expressed between adult male Drosophila melanogaster that differ in the maternal and paternal origin of the sex chromosomes. Many of the differentially regulated genes are expressed specifically in testis and midgut cells, suggesting that sex chromosome imprinting might globally impact gene expression in these tissues. In contrast, we observed much …


Atx1/Atcompass And The H3k4me3 Marks: How Do They Activate Arabidopsis Genes?, Michael E. Fromm, Zoya Avramova Jan 2014

Atx1/Atcompass And The H3k4me3 Marks: How Do They Activate Arabidopsis Genes?, Michael E. Fromm, Zoya Avramova

School of Biological Sciences: Faculty Publications

Despite the proven correlation between gene transcriptional activity and the levels of tri-methyl marks on histone 3 lysine4 (H3K4me3) of their nucleosomes, whether H3K4me3 contributes to, or “registers,” activated transcription is still controversial. Other questions of broad relevance are whether histone-modifying proteins are involved in the recruitment of Pol II and the general transcription machinery and whether they have roles other than their enzyme activities. We address these questions as well as the roles of the ARABIDOPSIS HOMOLOG OF TRITHORAX1 (ATX1), of the COMPASS-related (AtCOMPASS) protein complex, and of their product, H3K4me3, at ATX1-dependent genes. We suggest that the ambiguity …


Role Of An Archaeal Pita Transporter In The Copper And Arsenic Resistance Of Metallosphaera Sedula, An Extreme Thermoacidophile, Samuel Mccarthy, Chenbing Al, Garrett Wheaton, Rahul Tevatla, Valerie Eckrich, Robert Kelly, Paul H. Blum Jan 2014

Role Of An Archaeal Pita Transporter In The Copper And Arsenic Resistance Of Metallosphaera Sedula, An Extreme Thermoacidophile, Samuel Mccarthy, Chenbing Al, Garrett Wheaton, Rahul Tevatla, Valerie Eckrich, Robert Kelly, Paul H. Blum

School of Biological Sciences: Faculty Publications

Thermoacidophilic archaea, such as Metallosphaera sedula, are lithoautotrophs that occupy metal-rich environments. In previous studies, an M. sedula mutant lacking the primary copper efflux transporter, CopA, became copper sensitive. In contrast, the basis for supranormal copper resistance remained unclear in the spontaneous M. sedula mutant, CuR1. Here, transcriptomic

analysis of copper-shocked cultures indicated that CuR1 had a unique regulatory response to metal challenge corresponding to the upregulation of 55 genes. Genome resequencing identified 17 confirmed mutations unique to CuR1 that were likely to change gene function. Of these, 12 mapped to genes with annotated function associated with transcription, metabolism, …


Identification And Codon Reading Properties Of 5-Cyanomethyl Uridine, A New Modified Nucleoside Found In The Anticodon Wobble Position Of Mutant Haloarchaeal Isoleucine Trnas, Debabrata Mandal, Caroline Köhrer, Dan Su, Ramesh Babu, Clement T.Y. Chan, Yuchen Liu, Dieter Söll, Paul H. Blum, Masayasu Kuwahara, Peter C. Dedon, Uttam L. Rajbhandary Jan 2014

Identification And Codon Reading Properties Of 5-Cyanomethyl Uridine, A New Modified Nucleoside Found In The Anticodon Wobble Position Of Mutant Haloarchaeal Isoleucine Trnas, Debabrata Mandal, Caroline Köhrer, Dan Su, Ramesh Babu, Clement T.Y. Chan, Yuchen Liu, Dieter Söll, Paul H. Blum, Masayasu Kuwahara, Peter C. Dedon, Uttam L. Rajbhandary

School of Biological Sciences: Faculty Publications

Most archaea and bacteria use a modified C in the anticodon wobble position of isoleucine tRNA to base pair with A but not with G of the mRNA. This allows the tRNA to read the isoleucine codon AUA without also reading the methionine codon AUG. To understand why a modified C, and not U or modified U, is used to base pair with A, we mutated the C34 in the anticodon of Haloarcula marismortui isoleucine tRNA (tRNA2Ile) to U, expressed the mutant tRNA in Haloferax volcanii, and purified and analyzed the tRNA. Ribosome binding experiments show that …


Endogenous Aba Extraction And Measurement From Arabidopsis Leaves, Ning Liu, Yong Ding, Michael Fromm, Zoya Avramova Jan 2014

Endogenous Aba Extraction And Measurement From Arabidopsis Leaves, Ning Liu, Yong Ding, Michael Fromm, Zoya Avramova

School of Biological Sciences: Faculty Publications

The endogenous messenger, the phytohormone abscisic acid (ABA) plays a major role in plant’s adaption to drought, salinity, cold and other abiotic stresses. In addition to abiotic stress signaling, ABA is involved also in developmental regulation and in responses to diverse biotic stresses. Dehydration stress results in a strong increase in endogenous ABA levels, which can be perceived by RCAR/PYR1/PYL receptors, initiating the ABA signaling pathway to coordinate the genome-wide gene expression, and plants adaptive physiological responses. ABA biosynthesis triggered by environmental cues as well as developmental signals occurs predominantly in vascular parenchyma cells. The measurement of ABA content in …


Aba Signaling Is Necessary But Not Sufficient For Rd29b Transcriptional Memory During Successive Dehydration Stresses In Arabidopsis Thaliana, Laetitia Virlouvet, Yong Ding, Hiroaki Fujii, Zoya Avramova, Michael Fromm Jan 2014

Aba Signaling Is Necessary But Not Sufficient For Rd29b Transcriptional Memory During Successive Dehydration Stresses In Arabidopsis Thaliana, Laetitia Virlouvet, Yong Ding, Hiroaki Fujii, Zoya Avramova, Michael Fromm

School of Biological Sciences: Faculty Publications

Plants subjected to a prior dehydration stress were seen to have altered transcriptional responses during a subsequent dehydration stress for up to 5 days after the initial stress. The abscisic acid (ABA) inducible RD29B gene of Arabidopsis thaliana was strongly induced after the first stress and displayed transcriptional memory with transcript levels nine-fold higher during the second dehydration stress. These increased transcript levels were due to an increased rate of transcription and are associated with an altered chromatin template during the recovery interval between the dehydration stresses. Here we use a combination of promoter deletion/substitutions, mutants in the trans-acting …


Quorum Sensing Activity And Control Of Yeast-Mycelium Dimorphism In Ophiostoma Floccosum, Alexander Berrocal, Claudia Oviedo, Kenneth W. Nickerson, José Navarrete Jan 2014

Quorum Sensing Activity And Control Of Yeast-Mycelium Dimorphism In Ophiostoma Floccosum, Alexander Berrocal, Claudia Oviedo, Kenneth W. Nickerson, José Navarrete

School of Biological Sciences: Faculty Publications

Quorum sensing (QS) activity in Ophiostoma fungi has not been described. We have examined the growth conditions on the control of dimorphism in Ophiostoma floccosum, an attractive biocontrol agent against blue-stain fungi, and its relationship with QS activity. In a defined culture medium with l-proline as the N source, a high inoculum size (107 c.f.u. ml-1) was the principal factor that promoted yeast-like growth. Inoculum size effect can be explained by the secretion of a QS molecule(s) (QSMs) responsible for inducing yeast morphology. QSM candidates were extracted from spent medium and their structure was determined by GC–MS. …


An Assembly Of Proteins And Lipid Domains Regulates Transport Of Phosphatidylserine To Phosphatidylserine Decarboxylase 2 In Saccharomyces Cerevisiae, Wayne R. Riekhof, Wen-I Wu, Jennifer L. Jones, Mrinalini Nikrad, Mallory M. Chan, Christopher J. R. Loewen, Dennis R. Voelker Jan 2014

An Assembly Of Proteins And Lipid Domains Regulates Transport Of Phosphatidylserine To Phosphatidylserine Decarboxylase 2 In Saccharomyces Cerevisiae, Wayne R. Riekhof, Wen-I Wu, Jennifer L. Jones, Mrinalini Nikrad, Mallory M. Chan, Christopher J. R. Loewen, Dennis R. Voelker

School of Biological Sciences: Faculty Publications

Background: The machinery for interorganelle phosphatidylserine (PtdSer) transport is poorly defined at the molecular level.

Results: Molecular interaction studies identify specific protein-protein and protein-lipid interactions in PtdSer transport.

Conclusion: A protein and lipid interaction network defines key participants in PS transport to the locus of PtdSer-decarboxylase 2.

Significance: This study identifies important molecular participants involved in non-vesicular phospholipid traffic.


The Importance Of Rare Species: A Trait-Based Assessment Of Rare Species Contributions To Functional Diversity And Possible Ecosystem Function In Tall-Grass Prairies, Meha Jain, Dan F.B. Flynn, Case M. Prager, Georgia M. Hart, Caroline M. Devan, Farshid S. Ahrestani, Matthew I. Palmer, Daniel E. Bunker, Johannes M. H. Knops, Claire F. Jouseau, Shahid Naeem Jan 2014

The Importance Of Rare Species: A Trait-Based Assessment Of Rare Species Contributions To Functional Diversity And Possible Ecosystem Function In Tall-Grass Prairies, Meha Jain, Dan F.B. Flynn, Case M. Prager, Georgia M. Hart, Caroline M. Devan, Farshid S. Ahrestani, Matthew I. Palmer, Daniel E. Bunker, Johannes M. H. Knops, Claire F. Jouseau, Shahid Naeem

School of Biological Sciences: Faculty Publications

The majority of species in ecosystems are rare, but the ecosystem consequences of losing rare species are poorly known. To understand how rare species may influence ecosystem functioning, this study quantifies the contribution of species based on their relative level of rarity to community functional diversity using a trait-based approach. Given that rarity can be defined in several different ways, we use four different definitions of rarity: abundance (mean and maximum), geographic range, and habitat specificity. We find that rarer species contribute to functional diversity when rarity is defined by maximum abundance, geographic range, and habitat specificity. However, rarer species …


Nocturnal Homing In The Tropical Amblypygid Phrynus Pseudoparvulus (Class Arachnida, Order Amblypygi), Eileen Hebets, E.J. Gering, Verner P. Bingman, Daniel D. Wiegmann Jan 2014

Nocturnal Homing In The Tropical Amblypygid Phrynus Pseudoparvulus (Class Arachnida, Order Amblypygi), Eileen Hebets, E.J. Gering, Verner P. Bingman, Daniel D. Wiegmann

Eileen Hebets Publications

Arthropods are renowned for their navigational capabilities, with numerous examples known from insects and crustaceans. Early studies of amblypygids (Class Arachnida, Order Amblypygi) also suggest complex nocturnal navigation, despite their apparent lack of visual adaptations to the low-light conditions of a tropical understory. In a series of two studies, we use the tropical amblypygid, Phrynus pseudoparvulus, to assess their nocturnal homing ability. Our first experiment displaced and tracked resident and nonresident individuals. Resident individuals, displaced up to 4.5 m from their home refuges and released onto their home tree, were more likely to return to their previously occupied refuge than …


Why American Higher Education Needs Parasitologists, John J. Janovy Jr. Jan 2014

Why American Higher Education Needs Parasitologists, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Addresses four topics that characterize the discipline of parasitology and are largely missing from our national conversation in the United States about education, especially at the college and university level. Those topics are the production of transferable skills; our perceptions of the world, especially the natural world; access to reasonably difficult problems in natural settings; and intellectual epidemiology, or the movement of ideas, innovations, and cultural items through populations. These topics have been a part of the author's discussions with fellow parasitologists for at least half a century, beginning with his choice to pursue a graduate degree under the supervision …


Detection Of Predator Cues Alters Mating Tactics In Male Wolf Spiders, Dustin J. Wilgers, Daniel Wickwire, Eileen Hebets Jan 2014

Detection Of Predator Cues Alters Mating Tactics In Male Wolf Spiders, Dustin J. Wilgers, Daniel Wickwire, Eileen Hebets

Eileen Hebets Publications

Males of the wolf spider, Rabidosa punctulata, exhibit condition-dependent alternative mating tactics, whereby small, poor condition males engage in multimodal courtship while large, good condition males adopt a direct mount tactic that forgoes courtship. This study explores the possibility that tactic-specific costs can help explain this unintuitive pattern of mating tactic expression. Specifically, we hypothesize that courtship signaling is costly with respect to eavesdropping by predators and that males can alter their tactic expression based upon the perceived environmental predation risk. We test this by first examining the risk of predation associated with different mating tactics. We use a …


Demographic Variation And Habitat Specialization Of Tree Species In A Diverse Tropical Forest Of Cameroon, David Kenfack, George B. Chuyong, Richard Condit, Sabrina E. Russo, Duncan W. Thomas Jan 2014

Demographic Variation And Habitat Specialization Of Tree Species In A Diverse Tropical Forest Of Cameroon, David Kenfack, George B. Chuyong, Richard Condit, Sabrina E. Russo, Duncan W. Thomas

School of Biological Sciences: Faculty Publications

Background: Many tree species in tropical forests have distributions tracking local ridge-slope-valley topography. Previous work in a 50-ha plot in Korup National Park, Cameroon, demonstrated that 272 species, or 63% of those tested, were significantly associated with topography.

Methods: We used two censuses of 329,000 trees ≥1 cm dbh to examine demographic variation at this site that would account for those observed habitat preferences. We tested two predictions. First, within a given topographic habitat, species specializing on that habitat (‘residents’) should outperform species that are specialists of other habitats (‘foreigners’). Second, across different topographic habitats, species should perform best …


Bridging Physics And Biology Teaching Through Modeling, Anne-Marie Hoskinson, Brian A. Couch, Benjamin M. Zwickl, Kathleen A. Hinko, Marcos D. Caballero Jan 2014

Bridging Physics And Biology Teaching Through Modeling, Anne-Marie Hoskinson, Brian A. Couch, Benjamin M. Zwickl, Kathleen A. Hinko, Marcos D. Caballero

School of Biological Sciences: Faculty Publications

As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life science majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both sciences that rely on observations and measurements to construct models of the natural world. In this article, we propose that efforts to bridge the teaching of these …


The Roles Of Cis- And Trans-Regulation In The Evolution Of Regulatory Incompatibilities And Sexually Dimorphic Gene Expression, Colin D. Meiklejohn, Joseph D. Coolon, Daniel L. Hartl, Patricia J. Wittkopp Jan 2014

The Roles Of Cis- And Trans-Regulation In The Evolution Of Regulatory Incompatibilities And Sexually Dimorphic Gene Expression, Colin D. Meiklejohn, Joseph D. Coolon, Daniel L. Hartl, Patricia J. Wittkopp

School of Biological Sciences: Faculty Publications

Evolutionary changes in gene expression underlie many aspects of phenotypic diversity within and among species. Understanding the genetic basis for evolved changes in gene expression is therefore an important component of a comprehensive understanding of the genetic basis of phenotypic evolution. Using interspecific introgression hybrids, we examined the genetic basis for divergence in genome-wide patterns of gene expression between Drosophila simulans and Drosophila mauritiana. We find that cis-regulatory and trans-regulatory divergences differ significantly in patterns of genetic architecture and evolution. The effects of cis-regulatory divergence are approximately additive in heterozygotes, quantitatively different between males and females, …