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Articles 1 - 29 of 29
Full-Text Articles in Life Sciences
Coexistence Of Sympatric Taxa Of Chamaecrista Section Xerocalyx: Addressing The Interplay Between Morphology And Biotic Interactions, Beatriz Baker-Méio
Coexistence Of Sympatric Taxa Of Chamaecrista Section Xerocalyx: Addressing The Interplay Between Morphology And Biotic Interactions, Beatriz Baker-Méio
Dissertations
Animal-plant interactions may prevent gene flow and promote divergent selection among closely related plants, ultimately leading to formation of new species. This may be the case for Chamaecrista sect. Xerocalyx, in which two or more of the 24 varieties often are encountered in the same area, with marked morphological and phenological differences among them. Over a broad geographical range, however, the morphological gaps among varieties disappear. Several biotic interactions contribute to the fitness of Chamaecrista species. Their flowers are pollinated by bees, and herbivores attack their leaves, flowers, fruits, and seeds. In addition, all species produce extrafloral nectar, which …
Proposed Coherent Trapping Of A Population Of Electrons In A C60 Molecule Induced By Laser Excitation, Thomas George, G.P. Zhang
Proposed Coherent Trapping Of A Population Of Electrons In A C60 Molecule Induced By Laser Excitation, Thomas George, G.P. Zhang
Chemistry & Biochemistry Faculty Works
This Letter demonstrates the possibility of generating coherent population trapping in C60. Similar to a three-level Λ system, C60 has a forbidden transition between the highest occupied molecular orbital (HOMO) (|a⟩) and the lowest unoccupied molecular orbital (LUMO) (|c⟩), but a dipole-allowed transition between HOMO and LUMO+1 (|b⟩) and between |b⟩ and |c⟩. We employ two cw laser fields, one coupling and one probe. The strong coupling field is switched on first to resonantly excite the transition between |b⟩ and |c⟩. After a delay, the probe is switched on; the coherent interaction between the coupling and probe fields traps the …
Spite Versus Cheats: Competition Among Social Strategies Shapes Virulence In Pseudomonas Aeruginosa, R. Inglis, Sam Brown, Sam Brown, Angus Buckling
Spite Versus Cheats: Competition Among Social Strategies Shapes Virulence In Pseudomonas Aeruginosa, R. Inglis, Sam Brown, Sam Brown, Angus Buckling
Biology Department Faculty Works
Social interactions have been shown to play an important role in bacterial evolution and virulence. The majority of empirical studies conducted have only considered social traits in isolation, yet numerous social traits, such as the production of spiteful bacteriocins (anticompetitor toxins) and iron-scavenging siderophores (a public good) by the opportunistic pathogen Pseudomonas aeruginosa, are frequently expressed simultaneously. Crucially, both bacteriocin production and siderophore cheating can be favored under the same competitive conditions, and we develop theory and carry out experiments to determine how the success of a bacteriocin-producing genotype is influenced by social cheating of susceptible competitors and the resultant …
Freq-Seq: A Rapid, Cost-Effective, Sequencing-Based Method To Determine Allele Frequencies Directly From Mixed Populations, Lon Chubiz, Ming-Chun Lee, Nigel Delaney, Christopher Marx
Freq-Seq: A Rapid, Cost-Effective, Sequencing-Based Method To Determine Allele Frequencies Directly From Mixed Populations, Lon Chubiz, Ming-Chun Lee, Nigel Delaney, Christopher Marx
Biology Department Faculty Works
No abstract provided.
Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Peter Stevens, Zhenxiang Xi, Brad Ruhfel, Hanno Schaefer, André Amorim, M. Sugumaran, Kenneth Wurdack, Peter Endress, Merran Matthews, Sarah Mathews, Charles Davis
Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Peter Stevens, Zhenxiang Xi, Brad Ruhfel, Hanno Schaefer, André Amorim, M. Sugumaran, Kenneth Wurdack, Peter Endress, Merran Matthews, Sarah Mathews, Charles Davis
Biology Department Faculty Works
The angiosperm order Malpighiales includes ∼16,000 species and constitutes up to 40% of the understory tree diversity in tropical rain forests. Despite remarkable progress in angiosperm systematics during the last 20 y, relationships within Malpighiales remain poorly resolved, possibly owing to its rapid rise during the mid-Cretaceous. Using phylogenomic approaches, including analyses of 82 plastid genes from 58 species, we identified 12 additional clades in Malpighiales and substantially increased resolution along the backbone. This greatly improved phylogeny revealed a dynamic history of shifts in net diversification rates across Malpighiales, with bursts of diversification noted in the Barbados cherries (Malpighiaceae), cocas …
Daily Energy Expenditure In Precocial Shorebird Chicks: Smaller Species Perform At Higher Levels, Robert Ricklefs, Karen Krijgsveld, G. Visser
Daily Energy Expenditure In Precocial Shorebird Chicks: Smaller Species Perform At Higher Levels, Robert Ricklefs, Karen Krijgsveld, G. Visser
Biology Department Faculty Works
We measured daily energy expenditure (DEE) during the development periods of precocial chicks of five species of Arctic shorebirds spanning a broad range in size, in order to investigate the relationships between DEE, body size, and growth rate. We also quantified the effect of weather conditions on the energy expenditure of chicks to establish the impact of cold arctic weather on their time and energy budgets. We used the doubly labeled water method to measure DEE at ambient temperatures in an outside enclosure on the subarctic tundra at Churchill, Manitoba, Canada. Growth rate was highest in the smallest species, and …
Transcriptional Cross Talk Within The Mar-Sox-Rob Regulon In Escherichia Coli Is Limited To The Rob And Marrab Operons, Lon Chubiz, George Glekas, Christopher Rao
Transcriptional Cross Talk Within The Mar-Sox-Rob Regulon In Escherichia Coli Is Limited To The Rob And Marrab Operons, Lon Chubiz, George Glekas, Christopher Rao
Biology Department Faculty Works
Bacteria possess multiple mechanisms to survive exposure to various chemical stresses and antimicrobial compounds. In the enteric bacterium Escherichia coli, three homologous transcription factors—MarA, SoxS, and Rob—play a central role in coordinating this response. Three separate systems are known to regulate the expression and activities of MarA, SoxS, and Rob. However, a number of studies have shown that the three do not function in isolation but rather are coregulated through transcriptional cross talk. In this work, we systematically investigated the extent of transcriptional cross talk in the mar-sox-rob regulon. While the three transcription factors were found to have the potential …
Reinterpreting Bateman Gradients: Multiple Mating And Selection In Both Sexes Of A Songbird Species, N.M. Gerlach, J.W Mcglothlin, P.G Parker, E.D Ketterson
Reinterpreting Bateman Gradients: Multiple Mating And Selection In Both Sexes Of A Songbird Species, N.M. Gerlach, J.W Mcglothlin, P.G Parker, E.D Ketterson
Biology Department Faculty Works
Bateman’s principle, which states that male reproductive success should increase with multiple mating, whereas female reproductive success should not, has long been used to explain sex differences in behavior. The statistical relationship between mating success and reproductive success, or Bateman gradient, has been proposed as a way to quantify sex differences in sexual selection. We used a long-term data set on the distribution of paternity in the socially monogamous dark-eyed junco to examine the effect of multiple mating on lifetime reproductive success and to determine the relative contributions of within-pair and extra-pair mating. Both sexes exhibited a strong positive Bateman …
Adrenal Steroids Uniquely Influence Sexual Motivation Behavior In Male Rats, George Taylor, Joshua Dearborn, Susan Maloney
Adrenal Steroids Uniquely Influence Sexual Motivation Behavior In Male Rats, George Taylor, Joshua Dearborn, Susan Maloney
Psychology Faculty Works
The androgenic adrenal steroids dehydroepiandrosterone (DHEA) and 4α-androstenedione (4-A) have significant biological activity, but it is unclear if the behavioral effects are unique or only reflections of the effects of testosterone (TS). Gonadally intact male Long-Evans rats were assigned to groups to receive supplements of DHEA, 4-A, TS, corticosteroid (CORT), all at 400 µg steroid/kg of body weight, or vehicle only for 5 weeks. All males were tested in a paradigm for sexual motivation that measures time and urinary marks near an inaccessible receptive female. It was found that DHEA and 4-A supplements failed to influence time near the estrous …
Urban Development In Costa Rica: The Direct And Indirect Impacts On Local And Regional Avian Assemblages, Jeff L. Norris
Urban Development In Costa Rica: The Direct And Indirect Impacts On Local And Regional Avian Assemblages, Jeff L. Norris
Dissertations
Urban development, the pinnacle of human land use, has drastic effects on native ecosystems and the species they contain. For the first time in recorded history there are more people living in cities than in the rural areas surrounding them. Furthermore, the global rate of urbanization continues increasing; raising serious concerns for earth's tropical regions as they harbor a disproportionate amount of the earth's species, and where the impacts of urban development on natural communities are poorly known. Therefore, for my dissertation research I investigated the impacts of urban development on avian community structure and organization at both local and …
Preserved Self-Awareness Following Extensive Bilateral Brain Damage To The Insula, Anterior Cingulate, And Medial Prefrontal Cortices, Carissa Philippi, Justin Feinstein, Sahib Khalsa, Antonio Damasio, Daniel Tranel, Gregory Landini, Kenneth Williford, David Rudrauf
Preserved Self-Awareness Following Extensive Bilateral Brain Damage To The Insula, Anterior Cingulate, And Medial Prefrontal Cortices, Carissa Philippi, Justin Feinstein, Sahib Khalsa, Antonio Damasio, Daniel Tranel, Gregory Landini, Kenneth Williford, David Rudrauf
Psychology Faculty Works
No abstract provided.
Herbivore Pressure Increases Toward The Equator, Robert Marquis, Diego Salazar
Herbivore Pressure Increases Toward The Equator, Robert Marquis, Diego Salazar
Biology Department Faculty Works
Increases in species diversity and density from higher to lower latitudes are well documented. Nevertheless, the consequences of these changes in diversity for structuring ecological communities and influencing biotic evolution are largely unknown. It is widely believed that this increase in species diversity is associated with increased intensity of ecological interactions closer to the equator. For plant–herbivore interactions in particular, the predictions are that, at lower latitudes, plants will be attacked by more individual herbivores, more herbivore species, and more specialized herbivores and, therefore, will suffer greater damage. We used a large-scale latitudinal transect from Mexico to Bolivia to quantify …
Tcp Transcription Factor, Branch Angle Defective 1 (Bad1), Is Required For Normal Tassel Branch Angle Formation In Maize, Fang Bai, Renata Reinheimer, Diego Durantini, Elizabeth Kellogg, Robert Schmidt
Tcp Transcription Factor, Branch Angle Defective 1 (Bad1), Is Required For Normal Tassel Branch Angle Formation In Maize, Fang Bai, Renata Reinheimer, Diego Durantini, Elizabeth Kellogg, Robert Schmidt
Biology Department Faculty Works
In grass inflorescences, a structure called the “pulvinus” is found between the inflorescence main stem and lateral branches. The size of the pulvinus affects the angle of the lateral branches that emerge from the main axis and therefore has a large impact on inflorescence architecture. Through EMS mutagenesis we have identified three complementation groups of recessive mutants in maize having defects in pulvinus formation. All mutants showed extremely acute tassel branch angles accompanied by a significant reduction in the size of the pulvinus compared with normal plants. Two of the complementation groups correspond to mutations in the previously identified genes, …
Five Nuclear Loci Resolve The Polyploid History Of Switchgrass (Panicum Virgatum L.) And Relatives, Jimmy Triplett, Yunjing Wang, Jinshun Zhong, Elizabeth Kellogg
Five Nuclear Loci Resolve The Polyploid History Of Switchgrass (Panicum Virgatum L.) And Relatives, Jimmy Triplett, Yunjing Wang, Jinshun Zhong, Elizabeth Kellogg
Biology Department Faculty Works
Polyploidy poses challenges for phylogenetic reconstruction because of the need to identify and distinguish between homoeologous loci. This can be addressed by use of low copy nuclear markers. Panicum s.s. is a genus of about 100 species in the grass tribe Paniceae, subfamily Panicoideae, and is divided into five sections. Many of the species are known to be polyploids. The most well-known of the Panicum polyploids are switchgrass (Panicum virgatum) and common or Proso millet (P. miliaceum). Switchgrass is in section Virgata, along with P. tricholaenoides, P. amarum, and P. amarulum, whereas P. miliaceum is in sect. Panicum. We have …
The Effect Of Photoperiod On Regulation Of Key Components Of The Life Cycle In The Bumble Bee Bombus Impatiens L. (Hymenoptera: Apidae)., Edgar Javier Hernandez
The Effect Of Photoperiod On Regulation Of Key Components Of The Life Cycle In The Bumble Bee Bombus Impatiens L. (Hymenoptera: Apidae)., Edgar Javier Hernandez
Dissertations
This study investigates how photoperiod affects internal characteristics of colonies of the temperate bumble bee Bombus impatiens particularly; development, reproduction, and social behavior. To answer this question I used an experimental approach using commercially obtained colonies of B. impatiens kept under controlled environmental conditions, and using the exposure to photoperiod as the only variable. Eight different photoperiod treatments were evaluated over the social phase of the colony’s life cycle. Colonies exposed to photoperiods that simulate the species natural temperate photoperiod exhibited larger growth rates, higher, oviposition rates, and higher brood survival than colonies exposed to constant photoperiods. Similarly, colonies exposed …
Host-Parasite Interactions In Galapagos Seabirds, Iris Ilena Levin
Host-Parasite Interactions In Galapagos Seabirds, Iris Ilena Levin
Dissertations
Parasites exhibit a wide range of life history strategies that contribute to different dispersal abilities, host specialization, transmission modes, life-cycle complexity and population structure. Understanding dispersal rates in hosts and parasites is instrumental in defining the scale at which coevolution may be occurring. In order to better understand how and when parasites move between different hosts, I studied a seabird – Hippoboscid fly ectoparasite (and vector) – Haemosporidian parasite system in the Galapagos Islands. I began by describing the Haemosporidian parasites of Galapagos seabirds, discovering a Plasmodium species parasite in Galapagos Penguins (Sphensicus mendiculus), and a new clade of Hippoboscid-vectored …
Evolution And Biogeography Of Fire-Eye Antbirds (Genus Pyriglena): Insights From Molecules And Songs, Marcos Maldonado Coelho
Evolution And Biogeography Of Fire-Eye Antbirds (Genus Pyriglena): Insights From Molecules And Songs, Marcos Maldonado Coelho
Dissertations
The importance of climatic and geologic factors as drivers of population differentiation and speciation in the Neotropical region has long been appreciated. However, many questions remain regarding their roles underlying the processes and patterns of diversification. Studies conducted in distinct regions containing a suite of geological and ecological conditions constitute ideal scenarios to assess the role of Pleistocene climatic changes, rivers, and mountain building as historical diversification mechanisms. In chapters 1 and 2, I used an integrative approach combining molecular phylogenetics, phylogeography and population genetics to elucidate the importance of climatic and geological factors as engines of diversification. I focused …
Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenases Interact With Phospholipase Dδ To Transduce Hydrogen Peroxide Signals In The Arabidopsis Response To Stress, Xuemin Wang, Liang Guo, Shivakumar Devaiah, Rama Narasimhan, Xiangqing Pan, Yanyan Zhang, Wenhua Zhang
Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenases Interact With Phospholipase Dδ To Transduce Hydrogen Peroxide Signals In The Arabidopsis Response To Stress, Xuemin Wang, Liang Guo, Shivakumar Devaiah, Rama Narasimhan, Xiangqing Pan, Yanyan Zhang, Wenhua Zhang
Biology Department Faculty Works
Reactive oxygen species (ROS) are produced in plants under various stress conditions and serve as important mediators in plant responses to stresses. Here, we show that the cytosolic glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenases (GAPCs) interact with the plasma membrane–associated phospholipase D (PLDδ) to transduce the ROS hydrogen peroxide (H2O2) signal in Arabidopsis thaliana. Genetic ablation of PLDδ impeded stomatal response to abscisic acid (ABA) and H2O2, placing PLDδ downstream of H2O2 in mediating ABA-induced stomatal closure. To determine the molecular link between H2O2 and PLDδ, GAPC1 and GAPC2 were identified to bind to PLDδ, and the interaction was demonstrated by coprecipitation …
Analysis Of The Condition-Specific Regulation Of Puf3p Activity And Puf3p-Mediated Translational Repression Of Mrna In Saccharomyces Cerevisiae, Melanie A. Miller
Analysis Of The Condition-Specific Regulation Of Puf3p Activity And Puf3p-Mediated Translational Repression Of Mrna In Saccharomyces Cerevisiae, Melanie A. Miller
Dissertations
The Puf family of proteins regulates aspects of eukaryotic development such as embryonic development, and memory formation by promoting translational repression and/or degradation of targeted mRNAs in the cytoplasm. Yeast Puf3p regulates mitochondria biogenesis and function by modulating the stabilities of nuclear-transcribed mitochondrial mRNAs in response to different carbon sources. Dextrose simulates rapid Puf3p-mediated degradation of its mRNA targets via decay complex recruitment. Ethanol, galactose, or raffinose promotes stabilization of mRNA targets, as Puf3p-mediated decay activity is severely inhibited or abolished. In this work, I have established that carbon source-induced inhibition of Puf3p activity is not due to decreased transcription …
2-Allylphenyl Glycosides As Complementary Building Blocks For Oligosaccharide And Glycoconjugate Synthesis, Hemali Premathilake, Alexei Demchenko
2-Allylphenyl Glycosides As Complementary Building Blocks For Oligosaccharide And Glycoconjugate Synthesis, Hemali Premathilake, Alexei Demchenko
Chemistry & Biochemistry Faculty Works
The O-allylphenyl (AP) anomeric moiety was investigated as a new leaving group that can be activated for chemical glycosylation under a variety of conditions, through both direct and remote pathways. Differentiation between the two activation pathways was achieved in a mechanistic study. The orthogonal-type activation of the AP moiety along with common thioglycosides allows for the execution of efficient oligosaccharide assembly.
Isolated Amyloid-Β(1−42) Protofibrils, But Not Isolated Fibrils, Are Robust Stimulators Of Microglia, Geeta Paranjape, Lisa Gouwens, David Osborn, Michael Nichols
Isolated Amyloid-Β(1−42) Protofibrils, But Not Isolated Fibrils, Are Robust Stimulators Of Microglia, Geeta Paranjape, Lisa Gouwens, David Osborn, Michael Nichols
Chemistry & Biochemistry Faculty Works
Senile plaques composed of amyloid-β protein (Aβ) are an unshakable feature of the Alzheimer’s disease (AD) brain. Although there is significant debate on the role of the plaques in AD progression, there is little disagreement on their role in stimulating a robust inflammatory response within the context of the disease. Significant inflammatory markers such as activated microglia and cytokines are observed almost exclusively surrounding the plaques. However, recent evidence suggests that the plaque exterior may contain a measurable level of soluble Aβ aggregates. The observations that microglia activation in vivo is selectively stimulated by distinct Aβ deposits led us to …
Contribution Of The Mnr2 Protein To Magnesium Homeostasis In Saccharomyces Cerevisiae, Nilambari Prafulla Pisat
Contribution Of The Mnr2 Protein To Magnesium Homeostasis In Saccharomyces Cerevisiae, Nilambari Prafulla Pisat
Dissertations
Magnesium is an essential metal nutrient with diverse roles in biology. To maintain the optimal function of key biological processes, intracellular Mg2+ concentration is tightly regulated. Despite the importance of this process however, relatively little is known about mechanisms of Mg2+ homeostasis in eukaryotic cells. An understanding of homeostasis starts with defining the function of key transport proteins that allow the passage of Mg2+ ions across the membranes. Yeast geneticists have identified four proteins from Bakers' yeast (Saccharomyces cerevisiae) involved in regulating the accumulation of Mg2+ within the cell (Alr1 and Alr2) and within the mitochondrial compartment (Mrs2 and Lpe10). …
Crosstalk Between Phospholipase D And Sphingosine Kinase In Plant Stress Signaling, Xuemin Wang, Liang Guo
Crosstalk Between Phospholipase D And Sphingosine Kinase In Plant Stress Signaling, Xuemin Wang, Liang Guo
Biology Department Faculty Works
The activation of phospholipase D (PLD) produces phosphatidic acid (PA), whereas plant sphingosine kinase (SPHK) phosphorylates long-chain bases to generate long-chain base-1-phosphates such as phytosphingosine-1-phosphate (phyto-S1P). PA and phyto-S1P have been identified as lipid messengers. Recent studies have shown that PA interacts directly with SPHKs in Arabidopsis, and that the interaction promotes SPHK activity. However, SPHK and phyto-S1P act upstream of PLDα1 and PA in the stomatal response to abscisic acid (ABA). These findings indicate that SPHK/phyto-S1P and PLD/PA are co-dependent in the amplification of lipid messengers, and that crosstalk between the sphingolipid- and phospholipid-mediated signaling pathways may play important …
Levels Of Arabidopsis Thaliana Leaf Phosphatidic Acids, Phosphatidylserines, And Most Trienoate-Containing Polar Lipid Molecular Species Increase During The Dark Period Of The Diurnal Cycle, Xuemin Wang, Sara Maatta, Brad Scheu, Mary Roth, Pamela Tamura, Maoyin Li, Todd Williams, Ruth Welti
Levels Of Arabidopsis Thaliana Leaf Phosphatidic Acids, Phosphatidylserines, And Most Trienoate-Containing Polar Lipid Molecular Species Increase During The Dark Period Of The Diurnal Cycle, Xuemin Wang, Sara Maatta, Brad Scheu, Mary Roth, Pamela Tamura, Maoyin Li, Todd Williams, Ruth Welti
Biology Department Faculty Works
Previous work has demonstrated that plant leaf polar lipid fatty acid composition varies during the diurnal (dark–light) cycle. Fatty acid synthesis occurs primarily during the light, but fatty acid desaturation continues in the absence of light, resulting in polyunsaturated fatty acids reaching their highest levels toward the end of the dark period. In this work, Arabidopsis thaliana were grown at constant (21°C) temperature with 12-h light and 12-h dark periods. Collision induced dissociation time-of-flight mass spectrometry (MS) demonstrated that 16:3 and 18:3 fatty acid content in membrane lipids of leaves are higher at the end of the dark than at …
Connections Between Sphingosine Kinase And Phospholipase D In The Abscisic Acid Signaling Pathway In Arabidopsis, Xuemin Wang, Liang Guo, Girish Mishra, Jennifer E. Markham, Maoyin Li, Amanda Tawfall, Ruth Welti
Connections Between Sphingosine Kinase And Phospholipase D In The Abscisic Acid Signaling Pathway In Arabidopsis, Xuemin Wang, Liang Guo, Girish Mishra, Jennifer E. Markham, Maoyin Li, Amanda Tawfall, Ruth Welti
Biology Department Faculty Works
Phosphatidic acid (PA) and phytosphingosine 1-phosphate (phyto-S1P) both are lipid messengers involved in plant response to abscisic acid (ABA). Our previous data indicate that PA binds to sphingosine kinase (SPHK) and increases its phyto-S1P-producing activity. To understand the cellular and physiological functions of the PA-SPHK interaction, we isolated Arabidopsis thaliana SPHK mutants sphk1-1 and sphk2-1 and characterized them, together with phospholipase Dα1 knock-out, pldα1, in plant response to ABA. Compared with wild-type (WT) plants, the SPHK mutants and pldα1 all displayed decreased sensitivity to ABA-promoted stomatal closure. Phyto-S1P promoted stomatal closure in sphk1-1 and sphk2-1, but not in pldα1, whereas …
Medial Pfc Damage Abolishes The Self-Reference Effect, Carissa Philippi, Melissa Duff, Natalie Denburg, Daniel Tranel, David Rudrauf
Medial Pfc Damage Abolishes The Self-Reference Effect, Carissa Philippi, Melissa Duff, Natalie Denburg, Daniel Tranel, David Rudrauf
Psychology Faculty Works
No abstract provided.
Philopatry Drives Genetic Differentiation In An Island Archipelago: Comparative Population Genetics Of Galapagos Nazca Boobies (Sula Granti) And Great Frigatebirds (Fregata Minor), Iris Levin, Patricia Parker
Philopatry Drives Genetic Differentiation In An Island Archipelago: Comparative Population Genetics Of Galapagos Nazca Boobies (Sula Granti) And Great Frigatebirds (Fregata Minor), Iris Levin, Patricia Parker
Biology Department Faculty Works
Seabirds are considered highly mobile, able to fly great distances with few apparent barriers to dispersal. However, it is often the case that seabird populations exhibit strong population genetic structure despite their potential vagility. Here we show that Galapagos Nazca booby (Sula granti) populations are substantially differentiated, even within the small geographic scale of this archipelago. On the other hand, Galapagos great frigatebird (Fregata minor) populations do not show any genetic structure. We characterized the genetic differentiation by sampling five colonies of both species in the Galapagos archipelago and analyzing eight microsatellite loci and three mitochondrial genes. Using an F‐statistic …
[Accepted Article Manuscript Version (Postprint)] Plant Peroxisomes: Biogenesis And Function, Jianping Hu, Alison Baker, Bonnie Bartel, Nicole Linka, Robert Mullen, Sigrun Reumann, Bethany Zolman
[Accepted Article Manuscript Version (Postprint)] Plant Peroxisomes: Biogenesis And Function, Jianping Hu, Alison Baker, Bonnie Bartel, Nicole Linka, Robert Mullen, Sigrun Reumann, Bethany Zolman
Biology Department Faculty Works
Peroxisomes are eukaryotic organelles that are highly dynamic both in morphology and metabolism. Plant peroxisomes are involved in numerous processes, including primary and secondary metabolism, development, and responses to abiotic and biotic stresses. Considerable progress has been made in the identification of factors involved in peroxisomal biogenesis, revealing mechanisms that are both shared with and diverged from non-plant systems. Furthermore, recent advances have begun to reveal an unexpectedly large plant peroxisomal proteome and have increased our understanding of metabolic pathways in peroxisomes. Coordination of the biosynthesis, import, biochemical activity, and degradation of peroxisomal proteins allows for highly dynamic responses of …
Direct Infusion Mass Spectrometry Of Oxylipin-Containing Arabidopsis Membrane Lipids Reveals Varied Patterns In Different Stress Responses, Xuemin Wang, Hieu Sy Vu, Pamela Tamura, Nadezhda Galeva, Ratnesh Chaturvedi, Mary Roth, Todd Williams, Jyoti Shah, Ruth Welti
Direct Infusion Mass Spectrometry Of Oxylipin-Containing Arabidopsis Membrane Lipids Reveals Varied Patterns In Different Stress Responses, Xuemin Wang, Hieu Sy Vu, Pamela Tamura, Nadezhda Galeva, Ratnesh Chaturvedi, Mary Roth, Todd Williams, Jyoti Shah, Ruth Welti
Biology Department Faculty Works
Direct infusion electrospray ionization triple quadrupole precursor scanning for three oxidized fatty acyl anions revealed 86 mass spectral peaks representing polar membrane lipids in extracts from Arabidopsis (Arabidopsis thaliana) infected with Pseudomonas syringae pv tomato DC3000 expressing AvrRpt2 (PstAvr). Quadrupole time-of-flight and Fourier transform ion cyclotron resonance mass spectrometry provided evidence for the presence of membrane lipids containing one or more oxidized acyl chains. The membrane lipids included molecular species of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, digalactosyldiacylglycerol, monogalactosyldiacylglycerol, and acylated monogalactosyldiacylglycerol. The oxidized chains were identified at the level of chemical formula and included C(18)H(27)O(3) (abbreviated 18:4-O, to indicate four double bond …