Digital Commons Network^™

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 …

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 …

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 …

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 …

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 …

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 …

Experimental Evolution With Caenorhabditis Nematodes, Henrique Teotónio, Suzanne Estes, Patrick C. Phillips, Charles F. Baer

Biology Faculty Publications and Presentations

The hermaphroditic nematode Caenorhabditis elegans has been one of the primary model systems in biology since the 1970s, but only within the last two decades has this nematode also become a useful model for experimental evolution. Here, we outline the goals and major foci of experimental evolution with C. elegans and related species, such as C. briggsae and C. remanei, by discussing the principles of experimental design, and highlighting the strengths and limitations of Caenorhabditis as model systems. We then review three exemplars of Caenorhabditis experimental evolution studies, underlining representative evolution experiments that have addressed the: (1) maintenance of genetic …

Horizontally Acquired Biosynthesis Genes Boost Coxiella Burnetii's Physiology, Abraham S. Moses, Jess A. Millar, Matteo Bonazzi, Paul A. Beare, Rahul Raghavan

Biology Faculty Publications and Presentations

Coxiella burnetii, the etiologic agent of acute Q fever and chronic endocarditis, has a unique biphasic life cycle, which includes a metabolically active intracellular form that occupies a large lysosome-derived acidic vacuole. C. burnetii is the only bacterium known to thrive within such an hostile intracellular niche, and this ability is fundamental to its pathogenicity; however, very little is known about genes that facilitate Coxiella's intracellular growth. Recent studies indicate that C. burnetii evolved from a tick-associated ancestor and that the metabolic capabilities of C. burnetii are different from that of Coxiella-like bacteria found in ticks. Horizontally acquired genes that …

Females Are The Brighter Sex: Differences In External Fluorescence Across Sexes And Life Stages Of A Crab Spider, Erin E. Brandt, Susan E. Masta

Biology Faculty Publications and Presentations

Fluorescence is increasingly recognized to be widespread in nature. In particular, some arachnids fluoresce externally, and in spiders the hemolymph fluoresces. In this study, we examined the external fluorescence and the fluorophores of different sexes and life stages of the crab spider Misumena vatia (Clerk 1757), a sit-and-wait predator that feeds on insects as they visit flowers. We designed novel instrumentation to measure external fluorescence in whole specimens. We found that although males and females possess internal fluorophores with similar properties, the external expression of fluorescence varies across sexes and life stages. Spiders fluoresce brightly as immatures. Females maintain their …

Accumulation And Expression Of Multiple Antibiotic Resistance Genes In Arcobacter Cryaerophilus That Thrives In Sewage, Jess A. Millar, Rahul Raghavan

Biology Faculty Publications and Presentations

We explored the bacterial diversity of untreated sewage influent samples of a wastewater treatment plant in Tucson, AZ and discovered that Arcobacter cryaerophilus, an emerging human pathogen of animal origin, was the most dominant bacterium. The other highly prevalent bacteria were members of the phyla Bacteroidetes and Firmicutes, which are major constituents of human gut microbiome, indicating that bacteria of human and animal origin intermingle in sewage. By assembling a near-complete genome of A. cryaerophilus, we show that the bacterium has accumulated a large number of antibiotic resistance genes (ARGs) probably enabling it to thrive in the wastewater. We also …

Transcriptomic Analysis Of Maternally Provisioned Cues For Phenotypic Plasticity In The Annual Killifish, Austrofundulus Limnaeus, Amie L. Romney, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Background: Genotype and environment can interact during development to produce novel adaptive traits that support life in extreme conditions. The development of the annual killifsh Austrofundulus limnaeus is unique among vertebrates because the embryos have distinct cell movements that separate epiboly from axis formation during early development, can enter into a state of metabolic dormancy known as diapause and can survive extreme environmental conditions. The ability to enter into diapause can be maternally programmed, with young females producing embryos that do not enter into diapause. Alternately, embryos can be programmed to “escape” from diapause and develop directly by both maternal …

Pcr-Activated Cell Sorting As A General, Cultivation-Free Method For High-Throughput Identification And Enrichment Of Virus Hosts, Shaun W. Lim, Shea T. Lance, Kenneth M. Stedman, Adam R. Abate

Biology Faculty Publications and Presentations

Characterizing virus-host relationships is critical for understanding the impact of a virus on an ecosystem, but is challenging with existing techniques, particularly for uncultivable species. We present a general, cultivation-free approach for identifying phage-associated bacterial cells. Using PCR-activated cell sorting, we interrogate millions of individual bacteria for the presence of specific phage nucleic acids. If the nucleic acids are present, the bacteria are recovered via sorting and their genomes analyzed. This allows targeted recovery of all possible host species in a diverse population associated with a specific phage, and can be easily targeted to identify the hosts of different phages …

Each To Their Own Cure: Faculty Who Teach Course-Based Undergraduate Research Experiences Report Why You Too Should Teach A Cure, Erin E. Shortlidge, Gita Bangera, Sara Brownell

Biology Faculty Publications and Presentations

Course-based undergraduate research experiences (CUREs) meet national recommendations for integrating research experiences into life science curricula. As such, CUREs have grown in popularity and many research studies have focused on student outcomes from CUREs. Institutional change literature highlights that understanding faculty is also key to new pedagogies succeeding. To begin to understand faculty perspectives on CUREs, we conducted semi-structured interviews with 61 faculty who teach CUREs regarding why they teach CUREs, what the outcomes are, and how they would discuss a CURE with a colleague. Using grounded theory, participant responses were coded and categorized as tangible or intangible, related to …

Editorial: Genetics, Genomics And –Omics Of Thermophiles, Kian Mau Goh, Kok-Gan Chan, Rajesh Kumar Sani, Edgardo Ruben Donati, Anna-Louise Reysenbach

Biology Faculty Publications and Presentations

Thermophilic Archaea and Bacteria occupy heated environments. Advancement of next-generation sequencing (NGS), single-cell analyses, and combinations of –omics and microscopic technologies have resulted in the discovery of new thermophiles. This e-book consists of a review, and 10 original articles authored by 94 authors. The main aim of this Research Topic of Frontiers in Microbiology was to provide a platform for researchers to describe recent findings on the ecology of thermophiles using NGS, functional genomics, comparative genomics, gene evolution, and extremozyme discovery.

Rolling Circle Mutagenesis Of Gst-Mcherry To Understand Mutation, Gene Expression, And Regulation, Jessica Cole, Amanda Ferguson, Verónica A. Segarra, Susan Walsh

Biology Faculty Publications and Presentations

Undergraduates are often familiar with textbook examples of human mutations that affect coding regions and the subsequent disorders, but they may struggle with understanding the implications of mutations in the regulatory regions of genes. We have designed a laboratory sequence that will allow students to explore the effect random mutagenesis can have on protein function, expression, and ultimately phenotype. Students design and perform a safe and time-efficient random mutagenesis experiment using error-prone rolling circular amplification of a plasmid expressing the inducible fusion protein glutathione S-transferase (GST)-mCherry. Mutagenized and wild-type control plasmid DNA, respectively, are then purified and transformed into bacteria …

Cephalopod Biodiversity In The Vicinity Of Bear Seamount, Western North Atlantic Based On Exploratory Trawling From 2000 To 2014, Elizabeth K. Shea, Heather Judkins, Michelle D. Staudinger, Valerie H. Dimkovikj

Biology Faculty Publications and Presentations

Bear Seamount (BSM) is the most inshore seamount in the New England Seamount chain. It is located within the U.S. Exclusive Economic Zone and is contained within the recently established Northeast Canyons and Seamounts Marine National Monument. In 2000, the National Oceanic and Atmospheric Administration’s (NOAA) National Systematics Laboratory began an exploratory trawling program to document nekton diversity at BSM and its vicinity. Here, we summarize eight exploratory sampling cruises conducted between 2000 and 2014, and describe the cephalopod biodiversity and assemblage structure around BSM. Over the course of 174 deep–midwater and 56 bottom tows, 5088 cephalopods were identified, measured, …

Is Biomass A Reliable Estimate Of Plant Fitness?, Brett Steven Younginger, Dagmara Sirova, Mitchell B. Cruzan, Daniel J. Ballhorn

Biology Faculty Publications and Presentations

The measurement of fitness is critical to biological research. Although the determination of fitness for some organisms may be relatively straightforward under controlled conditions, it is often a difficult or nearly impossible task in nature. Plants are no exception. The potential for long-distance pollen dispersal, likelihood of multiple reproductive events per inflorescence, varying degrees of reproductive growth in perennials, and asexual reproduction all confound accurate fitness measurements. For these reasons, biomass is frequently used as a proxy for plant fitness. However, the suitability of indirect fitness measurements such as plant size is rarely evaluated. This review outlines the important associations …

Insulin-Like Growth Factor Signaling Regulates Developmental Trajectory Associated With Diapause In Embryos Of The Annual Killifish Austrofundulus Limnaeus, S. Cody Woll, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Annual killifishes exhibit a number of unique life history characters including the occurrence of embryonic diapause, unique cell movements associated with dispersion and subsequent reaggregation of the embryonic blastomeres, and a short postembryonic life span. Insulin-like growth factor (IGF) signaling is known to play a role in the regulation of metabolic dormancy in a number of animals but has not been explored in annual killifishes. The abundance of IGF proteins during development and the developmental effects of blocking IGF signaling by pharmacological inhibition of the insulin-like growth factor I receptor (IGF1R) were explored in embryos of the annual killifish Austrofundulus …

Embryonic Development Of The Annual Killifish Austrofundulus Limnaeus: An Emerging Model For Ecological And Evolutionary Developmental Biology Research And Instruction, Jason E. Podrabsky, Claire L. Riggs, Amie L. Romney, S. Cody Woll, Josiah T. Wagner, Kristin M. Culpepper, Timothy Grant Cleaver

Biology Faculty Publications and Presentations

Background: Austrofundulus limnaeus is an annual killifish from the Maracaibo basin of Venezuela. Annual killifishes are unique among vertebrates in their ability to enter into a state of dormancy at up to three distinct developmental stages termed diapause I, II, and III. These embryos are tolerant of a wide variety of environmental stresses and develop relatively slowly compared with nonannual fishes.

Results: These traits make them an excellent model for research on interactions between the genome and the environment during development, and an excellent choice for developmental biology laboratories. Furthermore, A. limnaeus is relatively easy to maintain in a laboratory …

Passive Warming Reduces Stress And Shifts Reproductive Effort In The Antarctic Moss, Polytrichastrum Alpinum, Erin E. Shortlidge, Sarah M. Eppley, Hans Kohler, Todd N. Rosenstiel, Gustavo E. Zúñiga, Angélica Casanova-Katny

Biology Faculty Publications and Presentations

Background and Aims: The Western Antarctic Peninsula is one of the most rapidly warming regions on Earth, and many biotic communities inhabiting this dynamic region are responding to these well-documented climatic shifts. Yet some of the most prevalent organisms of terrestrial Antarctica, the mosses, and their responses to warming have been relatively overlooked and understudied. In this research, the impacts of 6 years of passive warming were investigated using open top chambers (OTCs), on moss communities of Fildes Peninsula, King George Island, Antarctica.

Methods: The effects of experimental passive warming on the morphology, sexual reproductive effort and stress physiology of …

Small Noncoding Rna Expression During Extreme Anoxia Tolerance Of Annual Killifish (Austrofundulus Limnaeus) Embryos, Claire L. Riggs, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Small noncoding RNAs (sncRNA) have recently emerged as specific and rapid regulators of gene expression, involved in a myriad of cellular and organismal processes. MicroRNAs, a class of sncRNAs, are differentially expressed in diverse taxa in response to environmental stress, including anoxia. In most vertebrates, a brief period of oxygen deprivation results in severe tissue damage or death. Studies on sncRNA and anoxia have focused on these anoxia-sensitive species. Studying sncRNAs in anoxia-tolerant organisms may provide insight into adaptive mechanisms supporting anoxia tolerance. Embryos of the annual killifish Austrofundulus limnaeus are the most anoxia-tolerant vertebrates known, surviving over 100 days …