Biology Commons^™

The Slit-Binding Ig1 Domain Is Required For Multiple Axon Guidance Activities Of Drosophila Robo2, Lafreda J. Howard, Marie C. Reichert, Timonthy A. Evans

Biological Sciences Faculty Publications and Presentations

Drosophila Robo2 is a member of the evolutionarily conserved Roundabout (Robo) family of axon guidance receptors. Robo receptors signal midline repulsion in response to Slit ligands, which bind to the N-terminal Ig1 domain in most family members. In the Drosophila embryonic ventral nerve cord, Robo1 and Robo2 signal Slit-dependent midline repulsion, while Robo2 also regulates the medial-lateral position of longitudinal axon pathways and acts non-autonomously to promote midline crossing of commissural axons. While Robo2 signals midline repulsion in response to Slit, it is less clear whether Robo2's other activities are also Slit-dependent. To determine which of Robo2's axon guidance roles …

The Saga Of Endocrine Fgfs, Phuc Phan, Bibhuti Ballav Saikia, Shivakumar Sonnaila, Shilpi Agrawal, Zeina Ismael Ibrahem Alraawi, Thallapuranam Krishnaswamy Suresh Kumar, Shilpa Iyer

Biological Sciences Faculty Publications and Presentations

Fibroblast growth factors (FGFs) are cell-signaling proteins with diverse functions in cell development, repair, and metabolism. The human FGF family consists of 22 structurally related members, which can be classified into three separate groups based on their action of mechanisms, namely: intracrine, paracrine/autocrine, and endocrine FGF subfamilies. FGF19, FGF21, and FGF23 belong to the hormone-like/endocrine FGF subfamily. These endocrine FGFs are mainly associated with the regulation of cell metabolic activities such as homeostasis of lipids, glucose, energy, bile acids, and minerals (phosphate/active vitamin D). Endocrine FGFs function through a unique protein family called klotho. Two members of this family, α-klotho, …

A Wild Yeast Laboratory Activity: From Isolation To Brewing, Amanda N. Scholes, Erik D. Pollock, Jeffrey A. Lewis

Biological Sciences Faculty Publications and Presentations

Microbial fermentation is a common form of metabolism that has been exploited by humans to great benefit. Industrial fermentation currently produces a myriad of products ranging from biofuels to pharmaceuticals. About one-third of the world’s food is fermented, and the brewing of fermented beverages in particular has an ancient and storied history. Because fermentation is so intertwined with our daily lives, the topic is easily relatable to students interested in real-world applications for microbiology. Here, we describe the curriculum for a guided inquiry-based laboratory course that combines yeast molecular ecology and brewing. The rationale for the course is to compare …

Clinehelpr: An R Package For Genomic Cline Outlier Detection And Visualization, Bradley T. Martin, Tyler K. Chafin, Marlis R. Douglas, Michael E. Douglas

Biological Sciences Faculty Publications and Presentations

Background

Patterns of multi-locus differentiation (i.e., genomic clines) often extend broadly across hybrid zones and their quantification can help diagnose how species boundaries are shaped by adaptive processes, both intrinsic and extrinsic. In this sense, the transitioning of loci across admixed individuals can be contrasted as a function of the genome-wide trend, in turn allowing an expansion of clinal theory across a much wider array of biodiversity. However, computational tools that serve to interpret and consequently visualize ‘genomic clines’ are limited, and users must often write custom, relatively complex code to do so.

Results

Here, we introduce the ClineHelpR R-package …

Stage- And Sex-Specific Transcriptome Analyses Reveal Distinctive Sensory Gene Expression Patterns In A Butterfly, David A. Ernst, Erica L. Westerman

Biological Sciences Faculty Publications and Presentations

Background

Animal behavior is largely driven by the information that animals are able to extract and process from their environment. However, the function and organization of sensory systems often change throughout ontogeny, particularly in animals that undergo indirect development. As an initial step toward investigating these ontogenetic changes at the molecular level, we characterized the sensory gene repertoire and examined the expression profiles of genes linked to vision and chemosensation in two life stages of an insect that goes through metamorphosis, the butterfly Bicyclus anynana.

Results

Using RNA-seq, we compared gene expression in the heads of late fifth instar …

Leigh Syndrome: A Tale Of Two Genomes, Ajibola B. Bakare, Edward J. Lesnefsky, Shilpa Iyer

Biological Sciences Faculty Publications and Presentations

Leigh syndrome is a rare, complex, and incurable early onset (typically infant or early childhood) mitochondrial disorder with both phenotypic and genetic heterogeneity. The heterogeneous nature of this disorder, based in part on the complexity of mitochondrial genetics, and the significant interactions between the nuclear and mitochondrial genomes has made it particularly challenging to research and develop therapies. This review article discusses some of the advances that have been made in the field to date. While the prognosis is poor with no current substantial treatment options, multiple studies are underway to understand the etiology, pathogenesis, and pathophysiology of Leigh syndrome. …

Of Biodiversity, Boundaries, And Distribution: The Myxomycetes Of The Philippines And Beyond, Sittie Aisha Bustamante Macabago

Graduate Theses and Dissertations

This dissertation contains a compilation of independently performed studies primarily focusing on the myxomycetes (plasmodial slime molds) from the Philippines and integrating local and worldwide data to demonstrate regional and global trends. The major themes include the following: (I) a review of the diverse group of spore-producing amoeboid protists, including the myxomycetes; (II-IV) diversity assessments in three different groups of islands in the Philippine archipelago; (V) mapping the myxomycetes found in the Philippines for databasing and analyzing the geocoded data; (VI) a study on regional boundaries, including the Philippines, using myxomycete species composition; and, (VII) creating a global species distribution …

Ruvb-Like Protein 2 Interacts With The Ns1 Protein Of Influenza A Virus And Affects Apoptosis That Is Counterbalanced By Type I Interferons, Yimeng Wang, Jianhong Zhou, Samuel G. Mackintosh, Yuchun Du

Biological Sciences Faculty Publications and Presentations

The NS1 protein of influenza A virus (IAV) plays important roles in viral pathogenesis and host immune response. Through a proteomic approach, we have identified RuvB-like proteins 1 and 2 (RuvBL1 and RuvBL2) as interacting partners of the NS1 protein of IAVs. Infection of human lung A549 cells with A/PR/8/34 (PR8) virus resulted in reductions in the protein levels of RuvBL2 but not RuvBL1. Further studies with RuvBL2 demonstrated that the NS1-RuvBL2 interaction is RNA-independent, and RuvBL2 binds the RNA-binding domain of the NS1. Infection of interferon (IFN)-deficient Vero cells with wild-type or delNS1 PR8 virus reduced RuvBL2 protein levels …

An In Vitro Model Of Tumor Heterogeneity Resolves Genetic, Epigenetic, And Stochastic Sources Of Cell State Variability, Corey A. Hayford, Darren R. Tyson, C. Jack Robbins Iii, Peter L. Frick, Vito Quaranta, Leonard Harris

Biomedical Engineering Faculty Publications and Presentations

Tumor heterogeneity is a primary cause of treatment failure and acquired resistance in cancer patients. Even in cancers driven by a single mutated oncogene, variability in response to targeted therapies is well known. The existence of additional genomic alterations among tumor cells can only partially explain this variability. As such, nongenetic factors are increasingly seen as critical contributors to tumor relapse and acquired resistance in cancer. Here, we show that both genetic and nongenetic factors contribute to targeted drug response variability in an experimental model of tumor heterogeneity. We observe significant variability to epidermal growth factor receptor (EGFR) inhibition among …

The Importance Of Pre- And Postcopulatory Sexual Selection Promoting Adaptation To Increasing Temperatures, Miguel Gomez-Llano, Eve Scott, Erik I. Svensson

Biological Sciences Faculty Publications and Presentations

Global temperatures are increasing rapidly affecting species globally. Understanding if and how different species can adapt fast enough to keep up with increasing temperatures is of vital importance. One mechanism that can accelerate adaptation and promote evolutionary rescue is sexual selection. Two different mechanisms by which sexual selection can facilitate adaptation are pre- and postcopulatory sexual selection. However, the relative effects of these different forms of sexual selection in promoting adaptation are unknown. Here, we present the results from an experimental study in which we exposed fruit flies Drosophila melanogaster to either no mate choice or 1 of 2 different …

Quantifying Mitochondrial Dynamics In Patient Fibroblasts With Multiple Developmental Defects And Mitochondrial Disorders, Ajibola B. Bakare, Julienne Daniel, Joshua Stabach, Anapaula Rojas, Austin Bell, Brooke Henry, Shilpa Iyer

Biological Sciences Faculty Publications and Presentations

Mitochondria are dynamic organelles that undergo rounds of fission and fusion and exhibit a wide range of morphologies that contribute to the regulation of different signaling pathways and various cellular functions. It is important to understand the differences between mitochondrial structure in health and disease so that therapies can be developed to maintain the homeostatic balance of mitochondrial dynamics. Mitochondrial disorders are multisystemic and characterized by complex and variable clinical pathologies. The dynamics of mitochondria in mitochondrial disorders is thus worthy of investigation. Therefore, in this study, we performed a comprehensive analysis of mitochondrial dynamics in ten patient-derived fibroblasts containing …

Temperature-Dependent Macrophage Activity In Rainbow Trout, Danica Mcgrevey

Biological Sciences Undergraduate Honors Theses

Fever is an essential component of the immune response. Fever enhances immune responses as well as creates an environment in which the body has advantages over pathogens. Macrophages are often the first cells that come in contact with pathogens, as they reside in tissues. They are important for their engulfment of pathogens that results in the digestion of the pathogen, but they also produce nitric oxide and cytokines that contribute to immune response in a variety of ways, including initiating adaptive immunity and directing the production and activity of other immune cells. We were curious about macrophages from other temperature …

Involvement Of The Ino80 Chromatin Remodeling Complex In Cell Division And Genomic Stability, Ethan Chen

Biomedical Engineering Undergraduate Honors Theses

Cell division is a vital biological process for growth and development in both single and multi-cellular organisms—whereby the cell must duplicate its organelles and genome in entirety and appropriately distribute the copied contents to the daughter cells. Cells undergo a cycle of two distinct phases: interphase and mitosis. During interphase, the cell replicates its genomic DNA (in the form of chromosomes) located within the nucleus. DNA replication is carried out in a euchromatin state, where the chromosome structure is loose and easily accessible by DNA polymerase and other replication enzymes. Upon the completion of replication, chromatin is condensed into highly …

Hydrologic Variation Influences Stream Fish Assemblage Dynamics Through Flow Regime And Drought, Daniel D. Magoulick, Matthew P. Dekar, Shawn W. Hodges, Mandy K. Scott, Michael R. Rabalais, Christopher M. Bare

Biological Sciences Faculty Publications and Presentations

Hydrologic variation can play a major role in structuring stream fish assemblages and relationships between hydrology and biology are likely to be influenced by flow regime. We hypothesized that more variable flow regimes would have lower and more variable species richness, higher species turnover and lower assemblage stability, and greater abiotic environment-fish relationships than more stable flow regimes. We sampled habitats (pool, run, and riffle) in three Runoff/Intermittent Flashy streams (highly variable flow regime) and three Groundwater Flashy streams (less variable flow regime) seasonally (spring, early summer, summer and autumn) in 2002 (drought year) and 2003 (wet year). We used …

How Acetylation Regulates Metabolic Enzyme Function During Environmental Shifts, Jared Canonigo

Biological Sciences Undergraduate Honors Theses

Organisms such as Saccharomyces cerevisiae can regulate the mechanisms of proteins through post-translational modification. These modifications play a vital role in functional proteomic activity because they can regulate protein activity, localization, and interaction with other cellular molecules. Such modifications include phosphorylation, methylation, and acetylation. The metabolic mechanisms of yeast became of keen interest to our lab because our lab noticed many stress defense proteins were being acetylated during stress heat shock. Notably, Adh1p and Adh2p showed both an increase and a decrease in acetylation at two lysine residues (K315 and K314) overtime during heat shock respectively, though the exact function …

Color Of Pan Trap Influences Sampling Of Bees In Livestock Pasture Ecosystem, Roshani S. Acharya, Timothy Leslie, Emily Fitting, Joan Burke, Kelly Loftin, Neelendra K. Joshi

Entomology and Plant Pathology Faculty Publications and Presentations

The decline in insect pollinators has increased the importance of accurately monitoring pollinator diversity and abundance over time. Sampling techniques include the use of passive insect traps such as pan traps, yet there is still discussion over their utility and effectiveness in different ecosystems. The objective was to examine four different colors of pan traps (blue, green, yellow, and purple) for their utility in sampling bees in native forages rotationally grazed by sheep and to compare the relative abundance, richness, similarity, and community assemblage patterns among the four trap colors. Most bees were from the Halictidae family (89%). The most …

Climate-Driven Impacts On Himalayan Aquatic Biodiversity: A Case Study Involving Snowtrout (Cyprinidae: Schizothorax), Riri Wiyanti Retnaningtyas

Graduate Theses and Dissertations

Monitoring biodiversity, to include its relative dispersal and contraction, has become a conservation task of great importance, particularly given the catastrophic and ongoing loss of habitat due to climate change. However, the timing, direction, and magnitude of these rates vary across taxa and ecosystems. Predicting specific impacts of climate change can thus be difficult and this, in turn, hampers management action. Metrics are needed to not only quantify contemporary requirements of species, but also predict potential distributions that fluctuate in lockstep with climate.

Montane ecosystems in the Himalayas are highly impacted by climate change, yet remain largely understudied due to …

A Spatially Explicit Model Of Stabilizing Selection For Improving Phylogenetic Inference, Jeremy M. Beaulieu, Brian C. O'Meara, Michael A. Gilchrist

Biological Sciences Faculty Publications and Presentations

Ultraconserved elements (UCEs) are stretches of hundreds of nucleotides with highly conserved cores flanked by variable regions. Although the selective forces responsible for the preservation of UCEs are unknown, they are nonetheless believed to contain phylogenetically meaningful information from deep to shallow divergence events. Phylogenetic applications of UCEs assume the same degree of rate heterogeneity applies across the entire locus, including variable flanking regions. We present a Wright-Fisher model of selection on nucleotides (SeION) which includes the effects of mutation, drift, and spatially varying, stabilizing selection for an optimal nucleotide sequence. The SeION model assumes the strength of stabilizing selection …

Are Populations Of Economically Important Bonefish And Queen Conch 'Open' Or 'Closed' In The Northern Caribbean Basin?, Marlis R. Douglas, Tyler Chafin, Julie E. Claussen, David P. Philipp, Michael E. Douglas

Biological Sciences Faculty Publications and Presentations

Demographics of co-occurring species can often be diagnosed through population genomic analyses of single nucleotide polymorphisms (SNPs). These data can define population structure, gene flow, and candidate regions in the genome that potentially reflect local adaptations. They can also gauge whether populations are demographically “open” or “closed” (i.e., with global or local recruitment). We derived SNPs from double-digest restriction-site associated DNA (ddRAD) to test the demographics of commercially important bonefish Albula vulpes (N = 117) and queen conch Lobatus gigas (N = 60) from two northeast Caribbean Basin islands (Grand Bahama to the north and Eleuthera to the …

Conserved And Divergent Aspects Of Robo Receptor Signaling And Regulation Between Drosophila Robo1 And C. Elegans Sax-3, Trant Daiber, Christine J. Vanderzwan-Butler, Greg J. Bashaw, Timonthy A. Evans

Biological Sciences Faculty Publications and Presentations

The evolutionarily conserved Roundabout (Robo) family of axon guidance receptors control midline crossing of axons in response to the midline repellant ligand Slit in bilaterian animals including insects, nematodes, and vertebrates. Despite this strong evolutionary conservation, it is unclear whether the signaling mechanism(s) downstream of Robo receptors are similarly conserved. To directly compare midline repulsive signaling in Robo family members from different species, here we use a transgenic approach to express the Robo family receptor SAX-3 from the nematode Caenorhabditis elegans in neurons of the fruit fly, Drosophila melanogaster. We examine SAX-3’s ability to repel Drosophila axons from the …

Migration Phenology And Patterns Of American Woodcock In Central North America Derived Using Satellite Telemetry, Joseph D. Moore, David E. Andersen, Tom Cooper, Jeffrey P. Duguay, Shaun L. Oldenburger, C. Al Stewart, David G. Krementz

Biological Sciences Faculty Publications and Presentations

American woodcock Scolopax minor (hereafter woodcock) migration ecology is poorly understood, but has implications for population ecology and management, especially related to harvest. To describe woodcock migration patterns and phenology, we captured and equipped 73 woodcock with satellite tracking devices in the Central Management Region (analogous to the Mississippi Flyway) of North America and documented migration paths of 60 individual woodcock and 87 autumn or spring woodcock migrations during 2014-2016. Woodcock migration at the scale of the Central Management Region was more synchronous in spring than in autumn, but unlike most other migratory birds, average duration of autumn migration (31 …

Eimeria Lancasterensis (Apicomplexa: Eimeriidae), Three Nematodes (Heligmosomoidea: Boehmiellidae, Heligmonellidae), And A Flea (Siphonaptera: Ceratophyllidae) From The Eastern Fox Squirrel, Sciurus Niger (Rodentia: Sciuridae) In Arkansas, Chris T. Mcallister, John A. Hnida, Henry W. Robison, Lance A, Durden, Christopher Whipps

Journal of the Arkansas Academy of Science

In Arkansas, the eastern fox squirrel (Sciurus niger) is a common inhabitant of the state. Although information is available on ectoparasites of this host in Arkansas, little is known about the endoparasites of this squirrel. A single specimen from Montgomery County was examined and found to harbor the following: a coccidian (Eimeria lancasterensis), three nematodes, Boehmiella wilsoni, Citellinema bifurcatum, and Sciurodendrium hassalli, and a flea, Orchopeas howardi. We document these nematodes from an Arkansas S. niger for the first time, and add mensural and molecular information on E. lancasterensis from this host.

Novel Reproductive Data On Pealip Redhorse, Moxostoma Pisolabrum (Cypriniformes: Catostomidae), From Northeastern Arkansas, Chris T. Mcallister, Henry W. Robison, Ethan T. Woodyard, Thomas Graham Rosser, Thomas J. Fayton

Journal of the Arkansas Academy of Science

Little is known about the natural history of the Pealip Redhorse (Moxostoma pisolabrum), particularly on its reproductive biology in Arkansas. We examined 11 female M. pisolabrum collected in late February 2020 and 2021 from the Black River, Lawrence County. Egg mass (g) represented 9‒14% of the total weight of these gravid females. This is the first time information on female reproduction in this species has been reported from any population of M. pisolabrum in the state.

New Distributional Records For Ectoparasites (Acari: Laelapidae, Myocoptidae) Of The Woodland Vole, Microtus Pinetorum (Rodentia: Cricetidae) From Polk County, Arkansas, Chris T. Mcallister, Lance A, Durden

Journal of the Arkansas Academy of Science

The woodland vole, Microtus pinetorum is a common Arkansas rodent found statewide. To our knowledge, it has been surveyed only once in the state for ectoparasites. Here, a single specimen was examined and found to be infested with 3 species of mites, including Androlaelaps fahrenholzi, Laelaps alaskensis, and Myocoptes japonensis. This is the first time L. alaskensis and M. japonensis have been reported from Arkansas.

Spatial And Temporal Variation In Aedes Albopictus Prevalence Across Arkansas, Alyssa N. Jones, Eric C. Lovely, Douglas G. Barron

Journal of the Arkansas Academy of Science

Aedes albopictus is a well-known vector species of mosquito that is responsible for the transmission of many arboviruses such as Zika, chikungunya, and dengue. The objective of this study was to quantify spatial and temporal variation of Ae. albopictus prevalence in Arkansas. We used egg abundance as a proxy for mosquito prevalence. Across 2 years, we worked with the Arkansas Department of Health to collect mosquito eggs using oviposition traps. Eggs were desiccated, counted, and later rehydrated in rearing chambers and raised through adulthood for species determination (>99% Ae. albopictus). We determined mean egg abundance by month, year, …

Selected Helminth Parasites (Cestoda, Nematoda) Of Bobcat, Lynx Rufus (Carnivora: Felidae), In Northeastern Arkansas, Chris T. Mcallister, Henry W. Robison, Ethan T. Woodyard, Thomas Graham Rosser

Journal of the Arkansas Academy of Science

The bobcat, Lynx rufus is a relatively common Arkansas carnivore that ranges statewide. Although there is a great deal of information on the natural history of this species in the state, there have been few studies where parasites have been documented in Arkansas bobcats. Here, a single specimen was examined and found to be infected with a tapeworm, Taenia rileyi and 2 nematodes, Toxoascaris leonina and Toxocara cati. We document the first record of T. rileyi from Arkansas and the first report of T. leonina from a bobcat in the state.

Prescribed Burning Reduces Species Richness Of Wood-Decay Fungi In The Forests Of Northwest Arkansas, N. Alshammari, Thamer H. Albalawi, Steven Lee Stephenson

Biological Sciences Faculty Publications and Presentations

The present study, which was carried out at three localities in the Ozark Mountains of northwest Arkansas, investigated the effects of prescribed burning on wood-decomposing fungi using samples of decaying woody debris (DWD) placed in plastic incubation chambers. One of the localities had not been subjected to recent prescribed burning, whereas the other localities contained both an unburned area as well as an area recently subjected to burning. In all three localities, small pieces of decaying woody debris (DWD) were collected, placed in the incubation chambers and the latter kept moist for any extended period of time. Pieces of DWD …

Geometric Morphometric Analyses Define Riverine And Lacustrine Species Flocks Of Himalayan Snowtrout (Cyprinidae: Schizothorax) In Nepal, Binod Regmi, Marlis R. Douglas, David R. Edds, Michael E. Douglas

Biological Sciences Faculty Publications and Presentations

Freshwater fishes in the river and lake systems in the Himalayas and Tibetan Plateau are morphologically diverged but the evolutionary relationship of putative subspecies separated in these freshwater systems has not been explored. Snowtrout (Schizothorax spp.) are minnows (Cyprinidae) broadly distributed in Asia. Body shapes of 3 Lake Rara (northwest Nepal) endemics (S. macrophthalmus, S. nepalensis, S. raraensis) and 2 widely distributed riverine species (S. progastus, S. richardsonii) across 3 drainages in Nepal (i.e. Karnali, Gandaki, and Koshi Rivers) were studied using geometric morphometry. Data were derived from museum voucher specimens/tissues collected …

The Effects Of Multiple Stressors On Stream Communities: The Convergence Of Drought, Nutrient Pollution, And Invasive Species, Robert Joseph Fournier Iii

Graduate Theses and Dissertations

Freshwater systems experience multi-faceted degradation from a variety of ecological and environmental stressors. Three common stressors in these systems, drought, nutrient pollution, and invasive species, have wide-ranging effects on stream population- community- and ecosystem dynamics. We have a broad understanding of how each of these stressors works to influence stream systems independently. However, we still know relatively little about if, and how, these stressors might interact when they co-occur. Though drought is a natural part of many stream systems, all three of these stressors can be exacerbated or facilitated by anthropogenic actions. Accordingly, as human population and resource use continue …

Neogene And Quaternary Events Shaped Diversification And Speciation In Bhutanese Rheophilic Fishes Of The Family Nemacheilidae (Cypriniformes) And Sisoridae (Siluriformes), Karma Wangchuk

Graduate Theses and Dissertations

Biogeography of the Himalayan region [to include the Qinghai-Tibetan Plateau (QTP)] evolved over a ~30M year span, catalyzed by the collision of the Indian and Eurasian plates. The resulting uplift produced major ecological and climatic effects, that in turn drove the diversification of biodiversity. As a result, the QTP is designated as a global biodiversity hotspot particularly vulnerable to cumulative climatic effects, including shrinking distributions, declining numbers, and local extinctions. Understanding how the biodiversity within the Himalaya/ QTP was established and maintained is a necessary first step in prioritizing conservation efforts.

Fishes in global montane regions, such as the Himalaya, …