Biology Commons^™

Bio Buzz Newsletter, Issue 16, December 2018, Department Of Biology

Biology Buzz Newsletter

No abstract provided.

Understanding The Impacts Of Current And Future Environmental Variation On Central African Amphibian Biodiversity, Courtney A. Miller

University of New Orleans Theses and Dissertations

Global climate change is projected to impact multiple levels of biodiversity by imposing strong selection pressures on existing populations, triggering shifts in species distributions, and reorganizing entire communities. The Lower Guineo-Congolian region in central Africa, a reservoir for amphibian diversity, is predicted to be severely affected by future climate change through rising temperatures and greater variability in rainfall. Geospatial modelling can be used to assess how environmental variation shapes patterns of biological variation – from the genomic to the community level – and use these associations to predict patterns of biological change across space and time. The overall goal of …

Repeats Of Unusual Size In Plant Mitochondrial Genomes: Identification, Incidence And Evolution, Emily L. Wynn, Alan C. Christensen

School of Biological Sciences: Faculty Publications

Plant mitochondrial genomes have excessive size relative to coding capacity, a low mutation rate in genes and a high rearrangement rate. They also have abundant non-tandem repeats often including pairs of large repeats which cause isomerization of the genome by recombination, and numerous repeats of up to several hundred base pairs that recombine only when the genome is stressed by DNA damaging agents or mutations in DNA repair pathway genes. Early work on mitochondrial genomes led to the suggestion that repeats in the size range from several hundred to a few thousand base pair are underrepresented. The repeats themselves are …

Mrna, Rrna And Dna Quantitative Stable Isotope Probing With H218o Indicates Use Of Old Rrna Among Soil Thaumarchaeota, Katrina Papp, Bruce A. Hungate, Egbert Schwartz

Civil and Environmental Engineering and Construction Faculty Research

RNA is considered to be a short-lived molecule, indicative of cellular metabolic activity, whereas DNA is thoughtto turn over more slowly because living cells do not always grow and divide. To explore differences in the ratesof synthesis of these nucleic acids, we used H218O quantitative stable isotope probing (qSIP) to measure theincorporation of18O into 16S rRNA, the 16S rDNA,amoAmRNA and theamoAgene of soil Thaumarchaeota.Incorporation of18O into the thaumarchaealamoAmRNA pool was faster than into the 16S rRNA pool,suggesting that Thaumarchaea were metabolically active while using rRNA molecules that were likely synthe-tized prior to H218O addition. Assimilation rates of18O into 16S rDNA …

The Evolution Of Diet Breadth In Melissodes Bees (Apidae: Eucerini), Karen W. Wright

Biology ETDs

The relationship between phytophagous insects and their host plants has interested scientists since Darwinian times. Using modern phylogenetic inference, we are able to investigate these patterns using, not only the phylogenies of the insects, but the evolutionary relationships among the plants they feed on as well. The relationships between bees and the plants they pollinate were traditionally seen as mutualistic and were treated separately from the research investigating the antagonistic relationships between phytophagous insects and their host plants. However, recent phylogenetic studies have made great progress including bee-host relationships in with the larger body of work on phytophagous insects.

The …

Minimum Information About An Uncultivated Virus Genome (Miuvig), Simon Roux, Evelien M. Adriaenssens, Bas E. Dutilh, Eugene V. Koonin, Andrew M. Kropinski, Mart Krupovic, Jens H. Kuhn, Rob Lavigne, J Rodney Brister, Arvind Varsani, Clara Amid, Ramy K. Aziz, Seth R. Bordenstein, Peer Bork, Mya Breitbart, Guy R. Cochrane, Rebecca A. Daly, Christelle Desnues, Melissa B. Duhaime, Joanne B. Emerson, François Enault, Jed A. Fuhrman, Pascal Hingamp, Philip Hugenholtz, Bonnie L. Hurwitz, Natalie N. Ivanova, Jessica M. Labonté, Kyung-Bum Lee, Rex R. Malmstrom, Manuel Martinez-Garcia, Ilene Karsch Mizrachi, Hiroyuki Ogata, David Páez-Espino, Marie-Agnès Petit, Catherine Putonti, Thomas Rattei, Alejandro Reyes, Francisco Rodriguez-Valera, Karyna Rosario, Lynn Schriml, Frederik Schulz, Grieg F. Steward, Matthew B. Sullivan, Shinichi Sunagawa, Curtis A. Suttle, Ben Temperton, Susannah G. Tringe, Rebecca Vega Thurber, Nicole S. Webster, Katrine L. Whiteson, Steven W. Whilhelm, K Eric Wommack, Tanja Woyke, Kelly C. Wrighton, Pelin Yilmaz, Takashi Yoshida, Mark J. Young, Natalya Yutin, Lisa Zeigler Allen, Nikos C. Kyrpides, Emiley A. Eloe-Fadrosh

Bioinformatics Faculty Publications

We present an extension of the Minimum Information about any (x) Sequence (MIxS) standard for reporting sequences of uncultivated virus genomes. Minimum Information about an Uncultivated Virus Genome (MIUViG) standards were developed within the Genomic Standards Consortium framework and include virus origin, genome quality, genome annotation, taxonomic classification, biogeographic distribution and in silico host prediction. Community-wide adoption of MIUViG standards, which complement the Minimum Information about a Single Amplified Genome (MISAG) and Metagenome-Assembled Genome (MIMAG) standards for uncultivated bacteria and archaea, will improve the reporting of uncultivated virus genomes in public databases. In turn, this should enable more robust comparative …

Life History And Habitat Of The Rare Patch-Nosed Salamander (Urspelerpes Brucei), Carlos D. Camp, Tyler L. Brock, Todd W. Pierson, Joseph Milanovich, John C. Maerz

Biology: Faculty Publications and Other Works

We examined the life history and habitat characteristics for the Patch-nosed Salamander, Urspelerpes brucei. Body-size measurements of individuals captured using litter bags and by hand from 2008 to 2010 indicated that the larval period lasts at least 2 y, salamanders attain reproductive maturity at or shortly after metamorphosis, and adults have very little variation in body size. Occupied streams are characterized by small size, little water, and narrow, steep-walled ravines. Within occupied streams, larval capture rate was significantly and negatively related to mean water depth, underscoring the importance of protecting headwaters. We hypothesize that the only known population of U. …

Prokaryotic Diversity And Aqueous Geochemistry Of Subsurface Environments Of The Death Valley Regional Flow System, Joshua David Sackett

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation summarizes over four years of effort towards the completion of a Ph.D. in Biological Sciences. The work presented in this document covers a broad range of topics, but a central unifying theme is prokaryotic life in the continental subsurface. The work presented in each chapter relied heavily on cultivation-independent methods for assessing prokaryotic communities, including prokaryotic community structure reconstruction from high-throughput sequencing of 16S rRNA gene libraries and single-cell genome analysis of novel uncultivated bacteria.

Chapter 2 examines the aqueous geochemistry and prokaryotic diversity of Devils Hole, a cavernous limnocrene and sole natural habitat for the critically endangered …

A Force Sensor That Converts Fluorescence Signal Into Force Measurement Utilizing Short Looped Dna, Golam Mustafa, Cho-Ying Chuang, William A. Roy, Mohamed M. Farhath, Nilisha Pokhrel, Yue Ma, Kazuo Nagawawa, Edwin Antony, Matthew J. Comstock, Soumitra Basu, Hamza Balci

Biological Sciences Faculty Research and Publications

A force sensor concept is presented where fluorescence signal is converted into force information via single-molecule Förster resonance energy transfer (smFRET). The basic design of the sensor is a ~100 base pair (bp) long double stranded DNA (dsDNA) that is restricted to a looped conformation by a nucleic acid secondary structure (NAS) that bridges its ends. The looped dsDNA generates a tension across the NAS and unfolds it when the tension is high enough. The FRET efficiency between donor and acceptor (D&A) fluorophores placed across the NAS reports on its folding state. Three dsDNA constructs with different lengths were bridged …

The Role Of Apolipoprotein E In Regulating Tau Pathogenesis And Neurodegeneration In A Tauopathy Mouse Model, Yang Shi

Arts & Sciences Electronic Theses and Dissertations

APOE4 is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). APOE4 increases brain amyloid-β (Aβ) pathology relative to other APOE isoforms. However, whether APOE independently influences tau pathology, the other pathological hallmark of AD and other tauopathies, or tau-mediated neurodegeneration, is not clear. By generating P301S tau transgenic mice on either a human APOE knock in (KI) or APOE knockout (KO) background, we show that the presence of human APOE, regardless of APOE isoforms, leads to various degrees of brain atrophy in 9-month old P301S mice, whereas APOE ablation strongly protects against neurodegeneration. In particular, P301S/E4 mice develop …

The Splice Is Not Right: Splice-Site-Creating Mutations In Cancer Genomes, Reyka Glencora Jayasinghe

Arts & Sciences Electronic Theses and Dissertations

Accurate interpretation of cancer mutations in individual tumors is a prerequisite for precision medicine. Large-scale sequencing studies, such as The Cancer Genome Atlas (TCGA) project, have worked to address the functional consequences of genomic mutations, with the larger goal of determining the underlying mechanisms of cancer initiation and progression. Many studies have focused on characterizing non-synonymous somatic mutations that alter amino acid sequence, as well as splice disrupting mutations at splice donors and acceptors. Current annotation methods typically classify mutations as disruptors of splicing if they fall on the consensus intronic dinucleotide splice donor, GT, the splice acceptor, AG. Splice …

Using Clay Models To Measure Seasonal Predation On Eastern Red-Backed Salamanders, Emma Perry

Honors Program Theses and Projects

One of the many gaps we have in our knowledge of salamanders is that of predation. Most studies suggest that salamanders are eaten mainly by birds and snakes, but there are still several unanswered questions: What other types of animals tend to prey on salamanders? Is there any difference in predator type during different times of the year? In order to answer these questions, I studied predation on one particular species of salamander, Plethodon cinereus (eastern red-backed salamander). Models of the two primary color morphs of P. cinereus (striped and unstriped) were created using impressionable clay to determine types and …

Miniscule Differences Between Sex Chromosomes In The Giant Genome Of A Salamander, Melissa C. Keinath, Nataliya Y. Timoshevskaya, Vladimir A. Timoshevskiy, S. Randal Voss, Jeramiah J. Smith

Biology Faculty Publications

In the Mexican axolotl (Ambystoma mexicanum), sex is determined by a single Mendelian factor, yet its sex chromosomes do not exhibit morphological differentiation typical of many vertebrate taxa that possess a single sex-determining locus. As sex chromosomes are theorized to differentiate rapidly, species with undifferentiated sex chromosomes provide the opportunity to reconstruct early events in sex chromosome evolution. Whole genome sequencing of 48 salamanders, targeted chromosome sequencing and in situ hybridization were used to identify the homomorphic sex chromosome that carries an A. mexicanum sex-determining factor and sequences that are present only on the W chromosome. Altogether, …

Regulation Of Canonical And Non-Canonical Hippo Pathway Components In Mitosis And Cancer, Seth Stauffer

Theses & Dissertations

The Hippo pathway is conserved regulator of organ size through control of proliferation, apoptosis, and stem-cell self-renewal. In addition to this important function, many of the canonical signaling members have also been shown to be regulated during mitosis. Importantly, Hippo pathway components are frequently dysregulated in cancers and have attracted attention as possible targets for improved cancer therapeutics. Further exploration of Hippo-YAP (yes-associated protein) signaling has revealed new regulators and effectors outside the canonical signaling network and has revealed a larger non-canonical network of signaling proteins in which canonical Hippo pathway components crosstalk with important cellular homeostasis and apoptosis signaling …

Employing Natural History Collections In The Aid Of Conservation: Streamlining An Approach To Model Species Distributions En Masse For The Preservation Of Biodiversity, Alice Fornari

Master's Projects and Capstones

Using species distribution models (SDMs) in Natural History Collections (NHCs) can influence how humans implement conservation changes in flora and fauna communities and ecosystems. Through the use of legacy data (old NHCs and their associated locality/collection information), data correction (background data or pseudo absences added to presence-only data), and the SDM software, Maxent (and its associated geographic information systems or GIS projected models), it has been shown that it is feasible to create a low budget protocol/setup to project the past, present and future of species population changes. This has been done in the past few decades as more collections …

Gene Flow Mediates The Role Of Sex Chromosome Meiotic Drive During Complex Speciation, Colin D. Meiklejohn, Emily L. Landeen, Kathleen E. Gordon, Thomas Rzatkiewicz, Sarah B. Kingan, Anthony J. Geneva, Jeffrey P. Vedanayagam, Christina A. Muirhead, Daniel Garrigan, Daven C. Presgraves, David L. Stern

School of Biological Sciences: Faculty Publications

During speciation, sex chromosomes often accumulate interspecific genetic incompatibilities faster than the rest of the genome. The drive theory posits that sex chromosomes are susceptible to recurrent bouts of meiotic drive and suppression, causing the evolutionary build- up of divergent cryptic sex-linked drive systems and, incidentally, genetic incompatibilities. To assess the role of drive during speciation, we combine high-resolution genetic mapping of X-linked hybrid male sterility with population genomics analyses of divergence and recent gene flow between the fruitfly species, Drosophila mauritiana and D. simulans. Our findings reveal a high density of genetic incompatibilities and a corresponding dearth of gene …

Effect Of Temperature Change On Synaptic Transmission At Crayfish Neuromuscular Junctions, Yuechen Zhu, Leo De Castro, Robin L. Cooper

Biology Faculty Publications

Ectothermic animals in areas characterised by seasonal changes are susceptible to extreme fluctuations in temperature. To survive through varied temperatures, ectotherms have developed unique strategies. This study focuses on synaptic transmission function at cold temperatures, as it is a vital component of ectothermic animals' survival. For determining how synaptic transmission is influenced by an acute change in temperature (20°C to 10°C within a minute) and chronic cold (10°C), the crayfish (Procambarus clarkii) neuromuscular junction (NMJ) was used as a model. To simulate chronic cold conditions, crayfish were acclimated to 15°C for 1 week and then to 10°C for …

Shedding Light On The Role Of Opaque1 In Asymmetric Cell Division In Maize, Janette Y. Mendoza

Biology ETDs

Asymmetric cell division (ACD) is important for cell fate and tissue patterning. Many aspects of ACD in plants, however, are still unclear. The process of ACD can be broadly broken down into three phases: (1) cell polarization, (2) division plane establishment and maintenance, and (3) cell division and cytokinesis. Stomatal development in maize has proven to be a useful model for understanding the ACD mechanism. Previous studies have identified several proteins important for all three phases of ACD. Actin is important in each of the phases of ACD, suggesting an actin motor such as myosin may also be important for …

Physella Acuta, Comparative Immunology And Evolutionary Aspects Of Gastropod Immune Function, Jonathan H. Schultz

Biology ETDs

Gastropod immunobiology has benefitted from investigations focused on the planorbid snail Biomphalaria glabrata, intermediate host for the human parasite Schistosoma mansoni. Though such concentrated efforts have elucidated fascinating aspects of invertebrate immunity, they have not provided full knowledge regarding the evolution of immune function among other gastropod species. This dissertation presents the importance of making strategic choices regarding which organisms to select for comparative immunology. Herein, the choice was made to investigate the immunobiology of Physella acuta, a freshwater snail species of the Physidae, a sister family to Planorbidae to which B. glabrata belongs. Benefiting greatly from …

Cryo-Em Structures Of Eastern Equine Encephalitis Virus Reveal Mechanisms Of Virus Disassembly And Antibody Neutralization, Saif Hasan, Chengqun Sun, Arthur S. Kim, Yasunori Watanabe, Chun-Liang Chen, Thomas Klose, Geeta Buda, Max Crispin, Michael S. Diamond, William B. Klimstra, Michael G. Rossmann

Department of Biological Sciences Faculty Publications

Alphaviruses are enveloped pathogens that cause arthritis and encephalitis. Here, we report a 4.4-Å cryoelectron microscopy (cryo-EM) structure of eastern equine encephalitis virus (EEEV), an alphavirus that causes fatal encephalitis in humans. Our analysis provides insights into viral entry into host cells. The envelope protein E2 showed a binding site for the cellular attachment factor heparan sulfate. The presence of a cryptic E2 glycan suggests how EEEV escapes surveillance by lectin-expressing myeloid lineage cells, which are sentinels of the immune system. A mechanism for nucleocapsid core release and disassembly upon viral entry was inferred based on pH changes and capsid …