Biology Commons^™

Draft Genome Sequence Of A Dictyoglomus Sp. From An Enrichment Culture Of A New Zealand Geothermal Spring, Anna-Louise Reysenbach, John A. Donaho, John F. Kelley, Emily St. John, Christina Turner, Mircea Podar, Matthew B. Stott

Biology Faculty Publications and Presentations

A draft genome of a novel Dictyoglomus sp., NZ13-RE01, was obtained from a New Zealand hot spring enrichment culture. The 1,927,012-bp genome is similar in both size and G+C content to other Dictyoglomus spp. Like its relatives, Dictyoglomus sp. NZ13-RE01 encodes many genes involved in complex carbohydrate metabolism.

Draft Genome Sequence Of A Novel Thermofilum Sp. Strain From A New Zealand Hot Spring Enrichment Culture, Anna-Louise Reysenbach, John A. Donaho, Todd M. Hinsch, John F. Kelley, Kathleen Kouba, Mircea Podar, Matthew B. Stott

Biology Faculty Publications and Presentations

A draft genome of a new Thermofilum sp. strain was obtained from an enrichment culture metagenome. Like its relatives, Thermofilum sp. strain NZ13 is adapted to organic-rich thermal environments and has to depend on other organisms and the environment for some key amino acids, purines, and cofactors.

Replication Rapidly Recovers And Continues In The Presence Of Hydroxyurea In Escherichia Coli, Samvel A. Nazaretyan, Neda Savic, Michael Sadek, Brandy J. Hackert, Justin Courcelle, Charmain T. Courcelle

Biology Faculty Publications and Presentations

In both prokaryotes and eukaryotes, hydroxyurea is suggested to inhibit DNA replication by inactivating ribonucleotide reductase and depleting deoxyribonucleoside triphosphate pools. In this study, we show that the inhibition of replication in Escherichia coli is transient even at concentrations of 0.1 M hydroxyurea and that replication rapidly recovers and continues in its presence. The recovery of replication does not require the alternative ribonucleotide reductases, NrdEF and NrdDG, or translesion DNA polymerases, Pol II, Pol IV, or Pol V. Ribonucleotides are incorporated at higher frequencies during replication in the presence of hydroxyurea. However, these do not contribute significantly to the observed …

Morphological Correlates And Behavioral Functions Of Sound Production In Loricariid Catfish, With A Focus On Pterygoplichthys Pardalis (Castelnau, 1855), Monique Renee Slusher

Dissertations and Theses

The Neotropical catfish Pterygoplichthys pardalis produces a harsh stridulation sound upon manual capture. This stridulation sound is made on the abduction of the pectoral fin spine, and is accomplished by friction of a ridged dorsal condyle against a rough spinal fossa of the cleithrum in the pectoral girdle. The sound produced has an average frequency of 121 Hz, and is used with other anti-predator adaptations such as bony subdermal armor and defensive fin-spreading. Pterygoplichthys pardalis does not display behavioral modification in response to conspecific stridulation sound, and therefore it is likely that stridulation sound in P. pardalis is being used …

Water Transport In The Lateral Line Canal Of The Intertidal Fish Xiphister Mucosus (Girard 1858) And Its Significance To Evaporative Water With Preliminary Observations Of The Metabolic Consequences Of Water Loss, Whitney Anne Gayer

Dissertations and Theses

The lateral line canal system is a sensory organ found in all teleost fish that has a wide range of morphological variation. Variation in morphology may often be the result of evolutionary necessity where the need for function dictates form. Xiphister mucosus is an amphibious Stichaeid fish that inhabits the rocky intertidal zone of the northeastern Pacific Ocean. The rocky intertidal is considered an extreme environment where crashing waves and ebbing tides may require the specialization of adaptations for surviving the many abiotic stressors encountered there.

The lateral line trunk canal of Xiphister is regarded as unique among teleosts with …

Constitutive Map-Kinase Activation Suppresses Germline Apoptosis In Nth-1 Dna Glycosylase Deficient C. Elegans, Henok Kassahun, Tamina Sengupta, Alfonso Schiavi, Suzanne Estes, Silvia Maglioni, Hanne K. Skjeldam, Katarzyna Arczewska, Nicole L. Brockway, Lars Eide, Natascia Ventura, Hilde Nilsen

Biology Faculty Publications and Presentations

Oxidation of DNA bases, an inevitable consequence of oxidative stress, requires the base excision repair (BER) pathway for repair. Caenorhabditis elegans is a well-established model to study phenotypic consequences and cellular responses to oxidative stress. To better understand how BER affects phenotypes associated with oxidative stress, we characterised the C. elegans nth-1 mutant, which lack the only DNA glycosylase dedicated to repair of oxidative DNA base damage, the NTH-1 DNA glycosylase. We show that nth-1 mutants have mitochondrial dysfunction characterised by lower mitochondrial DNA copy number, reduced mitochondrial membrane potential, and increased steady-state levels of reactive oxygen species. Consistently, nth-1 …

Lyttr Regulatory Systems: A Potential New Class Of Prokaryotic Sensory System, Zhengzhong Zou, Hua Qin, Amanda E. Brenner, Rahul Raghavan, Jess A. Millar, Qiang Gu, Zhoujie Xie, Jens Kreth, Justin Merritt

Biology Faculty Publications and Presentations

The most commonly studied prokaryotic sensory signal transduction systems include the one-component systems, phosphosignaling systems, extracytoplasmic function (ECF) sigma factor systems, and the various types of second messenger systems. Recently, we described the regulatory role of two separate sensory systems in Streptococcus mutans that jointly control bacteriocin gene expression, natural competence development, as well as a cell death pathway, yet they do not function via any of the currently recognized signal transduction paradigms. These systems, which we refer to as LytTR Regulatory Systems (LRS), minimally consist of two proteins, a transcription regulator from the LytTR Family and a transmembrane protein …

Quantitative Effects Of Soil Salinity On The Symbiosis Of Wild Lima Bean (Phaseolus Lunatus L.) And Bradyrhizobium In Costa Rica, Daniel J. Ballhorn, Emily R. Wolfe, Jess Tyler, Wren Ronan, Scott Sands-Gouner, Curran Shaw, Mehmet Ali Balkan, Stefanie Kautz

Biology Faculty Publications and Presentations

Global climate change and local anthropogenic activities are increasing soil salinization with permanent negative effects on agricultural and ecosystem productivity. While salt stress is known to affect plant performance, its effects on the association with key microbial plant symbionts, such as legume-associated nitrogen-fixing rhizobia, are less understood. In this field study conducted in Costa Rica (Puntarenas), we used sympatrically-occurring wild lima bean (Phaseolus lunatus L.) and Bradyrhizobium to quantify biomass production of unfertilized rhizobial (R+) and fertilized rhizobia-free (R-) plants at different levels of experimentally manipulated salinity in native soil. In response to salt stress, nodulation was significantly reduced even …

Multiple Acquisitions Of Pathogen-Derived Francisella Endosymbionts In Soft Ticks, Jonathan G. Gerhart, H. Auguste Dutcher, Amanda E. Brenner, Abraham S. Moses, Libor Grubhoffer, Rahul Raghavan

Biology Faculty Publications and Presentations

Bacterial endosymbionts of ticks are of interest due to their close evolutionary relationships with tick-vectored pathogens. For instance, whereas many ticks contain Francisella-like endosymbionts (FLEs), others transmit the mammalian pathogen Francisella tularensis. We recently sequenced the genome of an FLE present in the hard tick Amblyomma maculatum (FLE-Am) and showed that it likely evolved from a pathogenic ancestor. In order to expand our understanding of FLEs, in the current study we sequenced the genome of an FLE in the soft tick Ornithodoros moubata and compared it to the genomes of FLE-Am, Francisella persica—an FLE in the soft tick Argus (Persicargas) …

Baseline Mrna Expression Differs Widely Between Common Laboratory Strains Of Zebrafish, Lindsay Holden, Kim H. Brown

Biology Faculty Publications and Presentations

Common strains of wildtype zebrafish (Danio rerio) have unique genomic features including SNPs and CNV, but strain information often goes unreported in the literature. As a result, the confounding effects of interstrain variation makes repetition of studies in zebrafish challenging. Here we analyze hepatic mRNA expression patterns between three common zebrafish strains (AB, Tuebingen (TU), and WIK) using Agilent 4 × 44 K gene expression microarrays to establish baseline mRNA expression across strains and between sexes. We observed wide variation in sex-specific gene expression within AB and WIK strains (141 genes in AB and 67 genes in WIK), …

Identification Of Novel Mites (Miniature Inverted-Repeat Transposable Elements) In Coxiella Burnetii: Implications For Protein And Small Rna Evolution, Shaun Wachter, Rahul Raghavan, Jenny Wachter, Michael F. Minnick

Biology Faculty Publications and Presentations

Background: Coxiella burnetii is a Gram-negative gammaproteobacterium and zoonotic agent of Q fever. C. burnetii’s genome contains an abundance of pseudogenes and numerous selfish genetic elements. MITEs (miniature invertedrepeat transposable elements) are non-autonomous transposons that occur in all domains of life and are thought to be insertion sequences (ISs) that have lost their transposase function. Like most transposable elements (TEs), MITEs are thought to play an active role in evolution by altering gene function and expression through insertion and deletion activities. However, information regarding bacterial MITEs is limited. Results: We describe two MITE families discovered during research on small non-coding …

Comparative Genetic And Genomic Analysis Of The Novel Fusellovirus Sulfolobus Spindle-Shaped Virus 10, David Andrew Goodman, Kenneth M. Stedman

Biology Faculty Publications and Presentations

Viruses that infect thermophilic Archaea are unique in both their structure and genetic makeup. The lemon-shaped fuselloviruses—which infect members of the order Sulfolobales, growing optimally at 80 C and pH 3—are some of the most ubiquitous and best studied viruses of the thermoacidophilic Archaea. Nonetheless, much remains to be learned about these viruses. In order to investigate fusellovirus evolution, we have isolated and characterized a novel fusellovirus, Sulfolobus spindle-shaped virus 10 (formerly SSV-L1). Comparative genomic analyses highlight significant similarity with both SSV8 and SSV9, as well as conservation of promoter elements within the Fuselloviridae. SSV10 encodes five ORFs with no …

Connecting Chemistry To Community With Deliberative Democracy, Regis Komperda, Jack Barbera, Erin Shortlidge, Gwen Shusterman, Stem Education And Equity Institute, Portland State University

Biology Faculty Publications and Presentations

Science education communities have called for rethinking curricula to improve student understanding of the nature of science and the role of science in addressing controversial modern issues such as climate change, energy policy, and pollution levels. One approach to meeting this call is integrating these topics into class activities that require students to use discussion and scientific approaches to solve problems and deliberate potential policy solutions. Deliberative democracy (DD) is one such active learning approach in which students work in peer groups to reach a consensus on a scientific topic relevant to both real-world issues and course content. During DD …

Genome-Wide Screening Of Potential Rnase Y-Processed Mrnas In The M49 Serotype Streptococcus Pyogenes Nz131, Zhiyun Chen, Rahul Raghavan, Fengxia Qi, Justin Merritt, Jens Kreth

Biology Faculty Publications and Presentations

RNase Y is a major endoribonuclease in Group A streptococcus (GAS) and other Gram‐positive bacteria. Our previous study showed that RNase Y was involved in mRNA degradation and processing in GAS. We hypothesized that mRNA processing regulated the expression of important GAS virulence factors via altering their mRNA stabilities and that RNase Y mediated at least some of the mRNA‐processing events. The aims of this study were to (1) identify mRNAs that were processed by RNase Y and (2) confirm the mRNA‐processing events. The transcriptomes of Streptococcus pyogenes NZ131 wild type and its RNase Y mutant (Δrny) were …

The Genome Of Austrofundulus Limnaeus Offers Insights Into Extreme Vertebrate Stress Tolerance And Embryonic Development, Josiah Tad Wagner, Param Priya Singh, Amie L. Romney, Claire L. Riggs, Patrick Minx, Steven Cody Woll, Jake Roush, Wesley C. Warren, Anne Brunet, Jason E. Podrabsky

Center for Life in Extreme Environments Publications

Background: The annual killifish Austrofundulus limnaeus inhabits ephemeral ponds in northern Venezuela, South America, and is an emerging extremophile model for vertebrate diapause, stress tolerance, and evolution. Embryos of A. limnaeus regularly experience extended periods of desiccation and anoxia as a part of their natural history and have unique metabolic and developmental adaptations. Currently, there are limited genomic resources available for gene expression and evolutionary studies that can take advantage of A. limnaeus as a unique model system.

Results: We describe the first draft genome sequence of A. limnaeus. The genome was assembled de novo using a merged assembly strategy …

Investigating The Role Of Small Noncoding Rnas In Vertebrate Anoxia Tolerance, Claire Louise Riggs

Dissertations and Theses

Very few vertebrates survive extended periods of time without oxygen. Entry into metabolic depression is central to surviving anoxia, which is supported by overall suppression of protein synthesis, yet requires increased expression of specific proteins. Studying the rapid and complex regulation of gene expression associated with survival of anoxia may uncover new mechanisms of cellular biology and transform our understanding of cells, as well as inform prevention and treatment of heart attack and stroke in humans. Small non-coding RNAs (sncRNAs) have emerged as regulators of gene expression that can be rapidly employed, can target individual genes or suites of genes, …

Genetic Analysis Of The Major Capsid Protein Of The Archaeal Fusellovirus Ssv1: Mutational Flexibility And Conformational Change, Eric A. Iverson, David A. Goodman, Madeline E. Gorchels, Kenneth M. Stedman

Biology Faculty Publications and Presentations

Viruses with spindle or lemon-shaped virions are rare in the world of viruses, but are common in viruses of archaeal extremophiles, possibly due to the extreme conditions in which they thrive. However, the structural and genetic basis for the unique spindle shape is unknown. The best-studied spindle-shaped virus, Sulfolobus Spindle-shaped Virus 1 (SSV1), is composed mostly of the major capsid protein VP1. Similar to many other viruses, proteolytic cleavage of VP1 is thought to be critical for virion formation. Unlike half of the genes in SSV1, including the minor capsid protein gene VP3, the VP1 gene does not tolerate …

Transcriptomic Regulation Of Alternative Phenotypic Trajectories In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Amie L. Romney

Dissertations and Theses

The Annual Killifish, Austrofundulus limnaeus, survives the seasonal drying of their pond habitat in the form of embryos entering diapause midway through development. The diapause trajectory is one of two developmental phenotypes. Alternatively, individuals can "escape" entry into diapause and develop continuously until hatching. The alternative phenotypes of A. limnaeus are a form of developmental plasticity that provides this species with a physiological adaption for surviving stressful environments. The developmental trajectory of an embryo is not distinguishable morphologically upon fertilization and phenotype is believed to be influenced by maternal provisioning within the egg based on observations of offspring phenotype …

Dynamics Of Prochlorococcus And Synechococcus At Station Aloha Revealed Through Flow Cytometry And High-Resolution Vertical Sampling, Ger J. Van Den Engh, Joseph K. Doggett, Anne W. Thompson, Martina A. Doblin, Carla N.G. Gimpel, David M. Karl

Biology Faculty Publications and Presentations

The fluorescence and scattering properties of Prochlorococcus and Synechococcus at Station ALOHA as measured by flow cytometry (termed the FCM phenotype) vary with depth and over a variety of time scales. The variation in FCM phenotypes may reflect population selection or physiological acclimation to local conditions. Observations before, during, and after a storm with deep water mixing show a short-term homogenization of the FCM phenotypes with depth, followed by a return to the stable pattern over the time span of a few days. These dynamics indicate that, within the upper mixed-layer, the FCM phenotype distribution represents acclimation to ambient light. …

A Metabolic Hypothesis For The Evolution Of Temperature Effects On The Arterial Pco2 And Ph Of Vertebrate Ectotherms, Stanley S. Hillman, Michael Scott Hedrick

Biology Faculty Publications and Presentations

Body temperature increases in ectothermic vertebrates characteristically lead to both increases in arterial PCO2 (PaCO2) and declines in resting arterial pH (pHa) of about 0.017 pH units/°C increase in temperature. This ‘alphastat’ pH pattern has previously been interpreted as being evolutionarily-driven by the maintenance of a constant protonation state on the imidazole moiety of histidine protein residues, hence stabilizing protein structure-function. Analysis of the existing data for interclass responses of ectothermic vertebrates show different degrees of PaCO2 increases and pH declines with temperature between the classes with reptiles>amphibians>fish. The PaCO2 at the temperature where maximal aerobic metabolism (VO2max) …

An Efficient Pipeline To Generate Data For Studies In Plastid Population Genomics And Phylogeography, Brendan F. Kohrn, Jessica M. Persinger, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Premise of the study: Seed dispersal contributes to gene flow and is responsible for colonization of new sites and range expansion. Sequencing chloroplast haplotypes offers a way to estimate contributions of seed dispersal to population genetic structure and enables studies of population history. Whole‐genome sequencing is expensive, but resources can be conserved by pooling samples. Unfortunately, haplotype associations among single‐nucleotide polymorphisms (SNPs) are lost in pooled samples, and treating SNP allele frequencies as independent markers provides biased estimates of genetic structure.

Methods: We developed sampling methodologies and an application, CallHap, that uses a least‐squares algorithm to evaluate the fit between …

Plasma Cell Survival In The Absence Of B Cell Memory, Erika Hammarlund, Archana Thomas, Ian J. Amanna, Lindsay Holden, Ov D. Slayden, Byung S. Park, Lina Gao, Mark K. Slifka

Biology Faculty Publications and Presentations

Pre-existing serum antibodies play an important role in vaccine-mediated protection against infection but the underlying mechanisms of immune memory are unclear. Clinical studies indicate that antigen-specific antibody responses can be maintained for many years, leading to theories that reactivation/differentiation of memory B cells into plasma cells is required to sustain long-term antibody production. Here, we present a decade-long study in which we demonstrate site-specific survival of bone marrow-derived plasma cells and durable antibody responses to multiple virus and vaccine antigens in rhesus macaques for years after sustained memory B cell depletion. Moreover, BrdU+ cells with plasma cell morphology can be …

Adaptive Evolution Under Extreme Genetic Drift In Oxidatively Stressed Caenorhabditis Elegans, Stephen Fuller Christy, Riana I. Wernick, Michael James Lue, Griselda Velasco, Dana K. Howe, Dee R. Denver, Suzanne Estes

Biology Faculty Publications and Presentations

A mutation-accumulation (MA) experiment with Caenorhabditis elegans nematodes was conducted in which replicate, independently evolving lines were initiated from a low-fitness mitochondrial electron transport chain mutant, gas-1. The original intent of the study was to assess the effect of electron transport chain dysfunction involving elevated reactive oxygen species production on patterns of spontaneous germline mutation. In contrast to results of standard MA experiments, gas-1 MA lines evolved slightly higher mean fitness alongside reduced among-line genetic variance compared with their ancestor. Likewise, the gas-1 MA lines experienced partial recovery to wildtype reactive oxygen species levels. Whole-genome sequencing and analysis revealed that …

Use Of Gene Editing In Usda Research, Mark R. Mclellan, Patsy Brannon, Adriana Campa, Carrie Castille, Steven Daley-Laursen, Roch Gaussoin, Govind Kannan, Mark Lawrence, Dawn Thilmany

Biology Faculty Publications and Presentations

The Science Advisory Council was established in FY2016 as a subcommittee of the National Agricultural Research, Extension, Education, and Economics (NAREEE) Advisory Board by the Chief Scientist as a result of recommendations from the 2012 report on Agricultural Preparedness by the President’s Council of Advisors on Science and Technology. The Council's charge is to provide advice and guidance, on a scientific basis, on the overall strength, practicality, and direction of agricultural research, including emerging technology and scientific issues and report any findings publicly to the NAREEE Advisory Board.

The USDA Chief Scientist first asked the Council to examine rigor and …

Expanding Metabolic Diversity Of Two Archaeal Phyla: Nanoarchaeota And Korarchaeota, John Forad Kelley

Dissertations and Theses

Culture independent studies have revealed a greater diversity of Archaea than the two kingdoms initially defined by Carl Woese. Culturing species from the newly discovered archaeal lineages, as with the majority of microbes, has been difficult. To overcome the culturing dilemma, metagenomics is being used to reconstruct environmental genomes. Two metagenomic studies are presented in this thesis, with the aim of recovering newly proposed archaeal genomes from the Nanoarchaeota and Korarchaeota.

In the first study, a sediment sample, NZ13, was collected from a terrestrial New Zealand hot spring. Along with the sediment sample, two complex enrichments were sequenced on an …

Evolution And Metabolic Potential Of Francisella-Like Endosymbionts Of Ticks, Jonathan Graham Gerhart

Dissertations and Theses

Endosymbiosis in arthropods involves intracellular bacteria that supply an array of benefits to the host. Endosymbionts likely enhance the health of ticks by provisioning amino acids such as cysteine and tyrosine, and cofactors such as biotin and folic acid that are not available in blood--the sole nutrient source of ticks. Endosymbionts of ticks are of special interest due to their close evolutionary relationship with tick-vectored pathogens that impact livestock and human health. For example, ticks typically contain Coxiella-like endosymbionts (CLEs) that are the closest relatives of the human pathogen Coxiella burnetii. In order to understand the evolutionary relationship …

The Cul3 Ubiquitin Ligase: An Essential Regulator Of Diverse Cellular Processes, Brittney Marie Davidge

Dissertations and Theses

Cul3 forms E3 ubiquitin ligase complexes that regulate a variety of cellular processes. This dissertation describes Cul3's role in several of these pathways and provides new mechanistic details regarding the role of Cul3 in eukaryotic cells. Cyclin E is an example of a protein that is regulated in a Cul3-dependent manner. Cyclin E is a cell cycle regulator that controls the beginning of DNA replication in mammalian cells. Increased levels of cyclin E are found in some cancers, in addition, proteolytic removal of the cyclin E N-terminus occurs in some cancers and is associated with tumorigenesis. Cyclin E levels are …

Winter Diet Of Bobolink, A Long-Distance Migratory Grassland Bird, Inferred From Feather Isotopes, Rosalind B. Renfrew, Jason M. Hill, Daniel H. Kim, Christopher Romanek, Noah G. Perlut

Biology Faculty Publications and Presentations

Effective conservation of migratory bird populations depends on advancements in our understanding of processes throughout the life cycle. Fundamental information about wintering ecology (e.g., habitat use and diet composition) remains limited, which limits assessment of threats to populations during winter. Bobolink (Dolichonyx oryzivorus) is a year-round grassland obligate and Nearctic-Neotropical migrant that undergoes 2 complete molts each year, including a complete prealternate molt on the South American wintering grounds. This unusual winter molt provides a rare opportunity to examine, using stable isotope analysis, the timing and contribution of foraging resources in the Bobolink diet prior to northbound migration from disparate …

Arginine Vasotocin And Neuropeptide Y Vary With Seasonal Life-History Transitions In Garter Snakes, Ashley R. Lucas, Daelyn Y. Richards, Lucy M. Ramirez, Deborah Lutterschmidt

Biology Faculty Publications and Presentations

Transitions between life-history stages are often accompanied by dramatic behavioral switches that result from a shift in motivation to pursue one resource over another. While the neuroendocrine mechanisms that regulate such behavioral transitions are poorly understood, arginine vasotocin (AVT) and neuropeptide Y (NPY) are excellent candidates because they modulate reproductive and feeding behavior, respectively. We asked if seasonal changes in AVT and NPY are concomitant with the seasonal migration to and from the feeding grounds in red-sided garter snakes (Thamnophis sirtalis parietalis). Male and female snakes were collected in different migratory states during both the spring and fall. The total …

Intestinal Microbiota Diversity Of Pre-Smolt Steelhead (Oncorhynchus Mykiss) Across Six Oregon And Washington Hatcheries, Christina Carrell Yildirimer

Dissertations and Theses

The Pacific Northwest is known for its once-abundant wild salmonid populations that have been in decline for more than 50 years due to habitat destruction and commercial overexploitation. To compensate, federal and state agencies annually release hundreds of thousands of hatchery-reared fish into the wild. However, accumulating data indicate that hatchery fish have lower fitness in natural environments, and that hatchery rearing negatively influences return rates of anadromous salmonids. Recently, mounting evidence revealed that the richness and diversity of intestinal microbial species influence host health. We examined the gut microbiota of pre-migratory hatchery-reared steelhead (Oncorhynchus mykiss) to assess …