Digital Commons Network^™

Key Habitat Features Facilitate The Presence Of Barred Owls In Developed Landscapes, Marion A. Clement, Kyle Barrett, Robert F. Baldwin

Publications

As urbanization continues to transform landscapes, it is imperative to find ways to conserve biodiversity within fragmented habitats. Forest interior dwelling birds are particularly vulnerable to development pressures because they require large tracts of forest to support their life cycles. Although Barred Owls (Strix varia) are frequently described as an obligate mature forest species, they have been found in urbanized landscapes. To determine if certain habitat characteristics, such as mature trees, facilitate the presence of Barred Owls in developed regions, we modeled Barred Owl occupancy probability along a development gradient in the Piedmont region of the southeastern United …

Sibling Sex, But Not Androgens, Shapes Phenotypes In Perinatal Common Marmosets (Callithrix Jacchus), Brett M. Frye, Lisa G. Rapaport, Michael W. Sears, Talia Melber, Suzette D. Tardif

Publications

When offspring share a womb, interactions among fetuses can impart lasting impressions on phenotypic outcomes. Such intrauterine interactions often are mediated by sex steroids (estrogens and androgens) produced by the developing fetuses. In many mammals, intrauterine interactions between brothers and sisters lead to masculinization of females, which can induce fitness consequences. Many litter-bearing primates, though, seem to escape androgen-mediated litter effects, begging why? Here, we investigated how the sex composition (i.e., same- or mixed-sex) of litters influences perinatal outcomes in the common marmoset monkey (Callithrix jacchus), using a combination of physiological, morphological, and behavioural assays. We hypothesized that …

Phylogenetic Origins For Severe Acetaminophen Toxicity In Snake Species Compared To Other Vertebrate Taxa, Peter Van Den Hurk, Harold M.I. Kerkkamp

Publications

While it has been known for a while that some snake species are extremely sensitive to acetaminophen, the underlying mechanism for this toxicity has not been reported. To investigate if essential detoxification enzymes are missing in snake species that are responsible for biotransformation of acetaminophen in other vertebrate species, livers were collected from a variety of snake species, together with samples from alligator, snapping turtle, cat, rat, and cattle. Subcellular fractions were analyzed for enzymatic activities of phenol-type sulfotransferase and UDP‑glucuronosyltransferase, total glutathione S‑transferase, and N‑acetyltransferase. The results showed that none of the snake species, together …

Sibling Sex, But Not Androgens, Shapes Phenotypes In Perinatal Common Marmosets (Callithrix Jacchus), Brett M. Frye, Lisa G. Rapaport, Talia Melber, Michael W. Sears, Suzette D. Tardif

Publications

When offspring share a womb, interactions among fetuses can impart lasting impressions on phenotypic outcomes. Such intrauterine interactions often are mediated by sex steroids (estrogens and androgens) produced by the developing fetuses. In many mammals, intrauterine interactions between brothers and sisters lead to masculinization of females, which can induce fitness consequences. Many litter-bearing primates, though, seem to escape androgen-mediated litter effects, begging why? Here, we investigated how the sex composition (i.e., same- or mixed-sex) of litters influences perinatal outcomes in the common marmoset monkey (Callithrix jacchus), using a combination of physiological, morphological, and behavioural assays. We hypothesized that …

Evidence For Divergent Patterns Of Local Selection Driving Venom Variation In Mojave Rattlesnakes (Crotalus Scutulatus), Jason L. Strickland, Cara F. Smith, Andrew J. Mason, Drew R. Schield, Miguel Borja, Gamaliel Castañeda-Gaytán, Carol L. Spencer, Lydia L. Smith, Ann Trápaga, Nassima M. Bouzid, Gustavo Campillo-García, Oscar A. Flores-Villela, Daniel Antonio-Rangel, Stephen P. Mackessy, Todd A. Castoe, Darin R. Rokyta, Christopher L. Parkinson

Publications

Snake venoms represent an enriched system for investigating the evolutionary processes that lead to complex and dynamic trophic adaptations. It has long been hypothesized that natural selection may drive geographic variation in venom composition, yet previous studies have lacked the population genetic context to examine these patterns. We leverage range-wide sampling of Mojave Rattlesnakes (Crotalus scutulatus) and use a combination of venom, morphological, phylogenetic, population genetic, and environmental data to characterize the striking dichotomy of neurotoxic (Type A) and hemorrhagic (Type B) venoms throughout the range of this species. We find that three of the four previously identified …

Variation In Regional And Landscape Effects On Occupancy Of Temperate Bats In The Southeastern U.S., Benjamin D. Neece, Susan C. Loeb, David S. Jachowski

Publications

Habitat loss, wind energy development, and the disease white-nose syndrome are major threats contributing to declines in bat populations in North America. In the southeastern US in particular, the recent arrival of white-nose syndrome and changes in landscape composition and configuration have driven shifts in bat species populations and distributions. Effective management strategies which address these large-scale, community-level threats require landscape-scale analyses. Our objective was to model the relationship between ecoregional and landscape factors and occupancy by all bat species in South Carolina, USA, during summer. We conducted acoustic surveys from mid-May through July 2015 and 2016 and evaluated temporally …

Water-Soluble Cranberry Extract Inhibits Vibrio Cholerae Biofilm Formation Possibly Through Modulating The Second Messenger 3’, 5’ - Cyclic Diguanylate Level, Daniel B. Pederson, Yuqing Dong, Levi B. Blue, Sara V. Smith, Min Cao

Publications

Quorum sensing (QS) and nucleotide-based second messengers are vital signaling systems that regulate bacterial physiology in response to changing environments. Disrupting bacterial signal transduction is a promising direction to combat infectious diseases, and QS and the second messengers are undoubtedly potential targets. In Vibrio cholerae, both QS and the second messenger 3’, 5’—cyclic diguanylate (c-di-GMP) play a central role in controlling motility, motile-to-sessile life transition, and virulence. In this study, we found that water-soluble extract from the North American cranberry could significantly inhibit V. cholerae biofilm formation during the development/maturation stage by reducing the biofilm matrix production and …

Comparative Venom-Gland Transcriptomics And Venom Proteomics Of Four Sidewinder Rattlesnake (Crotalus Cerastes) Lineages Reveal Little Differential Expression Despite Individual Variation, Erich Hofmann, Rhett M. Rautsaw, Jason L. Strickland, Matthew L. Holding, Michael P. Hogan, Andrew J. Mason, Darin R. Rokyta, Christopher L. Parkinson

Publications

Changes in gene expression can rapidly influence adaptive traits in the early stages of lineage diversification. Venom is an adaptive trait comprised of numerous toxins used for prey capture and defense. Snake venoms can vary widely between conspecific populations, but the influence of lineage diversification on such compositional differences are unknown. To explore venom differentiation in the early stages of lineage diversification, we used RNA-seq and mass spectrometry to characterize Sidewinder Rattlesnake (Crotalus cerastes) venom. We generated the first venom-gland transcriptomes and complementary venom proteomes for eight individuals collected across the United States and tested for expression differences …

Comparative Venom-Gland Transcriptomics And Venom Proteomics Of Four Sidewinder Rattlesnake (Crotalus Cerastes) Lineages Reveal Little Differential Expression Despite Individual Variation, Erich P. Hofmann, Rhett M. Rautsaw, Jason L. Strickland, Matthew L. Holding, Michael P. Hogan, Andrew J. Mason, Darin R. Rokyta, Christopher L. Parkinson

Publications

Changes in gene expression can rapidly influence adaptive traits in the early stages of lineage diversification. Venom is an adaptive trait comprised of numerous toxins used for prey capture and defense. Snake venoms can vary widely between conspecific populations, but the influence of lineage diversification on such compositional differences are unknown. To explore venom differentiation in the early stages of lineage diversification, we used RNA-seq and mass spectrometry to characterize Sidewinder Rattlesnake (Crotalus cerastes) venom. We generated the first venom-gland transcriptomes and complementary venom proteomes for eight individuals collected across the United States and tested for expression differences …

Glucose Signaling Is Important For Nutrient Adaptation During Differentiation Of Pleomorphic African Trypanosomes, Yijian Qiu, Jillian E. Milanes, Jessica A. Jones, Rooksana E. Noorai, Vijay Shankar, James C. Morris

Publications

The African trypanosome has evolved mechanisms to adapt to changes in nutrient availability that occur during its life cycle. During transition from mammalian blood to insect vector gut, parasites experience a rapid reduction in environmental glucose. Here we describe how pleomorphic parasites respond to glucose depletion with a focus on parasite changes in energy metabolism and growth. Long slender bloodstream form parasites were rapidly killed as glucose concentrations fell, while short stumpy bloodstream form parasites persisted to differentiate into the insect-stage procyclic form parasite. The rate of differentiation was lower than that triggered by other cues but reached physiological rates …

Bacteria And Competing Herbivores Weaken Top–Down And Bottom–Up Aphid Suppression, Carmen K. Blubaugh, Lynne Carpenter-Boggs, John P. Reganold, Robert N. Schaeffer, William E. Snyder

Publications

Herbivore suppression is mediated by both plant defenses and predators. In turn, plant defenses are impacted by soil fertility and interactions with soil bacteria. Measuring the relative importance of nutritional and microbial drivers of herbivore resistance has proven problematic, in part because it is difficult to manipulate soil-bacterial community composition. Here, we exploit variation in soil fertility and microbial biodiversity across 20 farms to untangle suppression of aphids (Brevicoryne brassicae) through bottom–up and top–down channels. We planted Brassica oleracea plants in soil from each farm, manipulated single and dual infestations of aphids alone or with caterpillars (Pieris …

Core Bacterial Community Composition Of A Cryptoendolithic Ecosystem In The Grand Staircase-Escalante National Monument, Utah, Sukhpreet Kaur, Harry D. Kurtz Jr.

Publications

Cryptoendolithic bacterial communities in the Jurassic Navajo Sandstones play an important ecological role in this ecosystem. Developing a better understanding of the role of these cryptoendolithic communities required a deeper knowledge of the microbial diversity present. We analyzed the bacterial diversity in eight sandstones samples from several microgeological features associated with a large sandstone dome. Cryptoendolithic bacterial diversity is clustered into three distinct groups which correlated with topography, suggesting the duration of water retention might be a factor. Comparisons of diversity between each cluster showed that a core bacterial community exists in this habitat. The overall bacterial community structure was …

Sexual Selection And Mixed Sex Expression: Adolescent Protandry, Phenotypic Tradeoffs And ‘Unconventional' Sex Allocation Estimates In A Protandric-Simultaneous Hermaphrodite, J. Antonio Baeza

Publications

In protandric-simultaneous (PS) hermaphrodites, individuals invariably reproduce as males first and later in life as simultaneous hermaphrodites. In this study, the shrimp Lysmata wurdemanni (Gibbes, 1850) was used as a model to (i) test for the role of sexual selection (male-male competition) in explaining the early male phase and size-dependent sex allocation (SDSA) in PS hermaphrodites, (ii) examine the tradeoff between the male and female function in hermaphrodites, and (iii) determine if SDSA also takes place in the form of sex-specific behaviors and anatomical structures. In L. wurdemanni, male mating ability was size- and sex-dependent; greater for small than …

Characterization Of A Soybean (Glycine Max L. Merr.) Germplasm Collection For Root Traits, Harrison Gregory Fried, Sruthi Narayanan, Benjamin Fallen

Publications

Root systems that improve resource uptake and penetrate compacted soil (hardpan) are important for improving soybean (Glycine max L. Merr.) productivity in optimal and sub-optimal environments. The objectives of this research were to evaluate a soybean germplasm collection of 49 genotypes for root traits, determine whether root traits are related with plant height, shoot dry weight, chlorophyll index, and seed size, and identify genotypes that can penetrate a hardpan. Plants were maintained under optimal growth conditions in a greenhouse. Single plants were grown in mesocosms, constructed of two stacked columns (top and bottom columns had 25 and 46 cm …

Plasticity Reveals Hidden Resistance To Extinction Under Climate Change In The Global Hotspot Of Salamander Diversity, Eric A. Riddell, Jonathan P. Odom, Jason D. Damm, Michael W. Sears

Publications

Extinction rates are predicted to rise exponentially under climate warming, but many of these predictions ignore physiological and behavioral plasticity that might buffer species from extinction. We evaluated the potential for physiological acclimatization and behavioral avoidance of poor climatic conditions to lower extinction risk under climate change in the global hotspot of salamander diversity, a region currently predicted to lose most of the salamander habitat due to warming. Our approach integrated experimental physiology and behavior into a mechanistic species distribution model to predict extinction risk based on an individual’s capacity to maintain energy balance with and without plasticity. We assessed …

In Vitro Mineral Nutrition Of Curcuma Longa L. Affects Production Of Volatile Compounds In Rhizomes After Transfer To The Greenhouse, Rabia F. El-Hawaz, Mary H. Grace, Alan Janbey, Mary Ann Lila, Jeffrey W. Adelberg

Publications

Background

Turmeric is a rich source of bioactive compounds useful in both medicine and cuisine. Mineral concentrations effects (PO43−, Ca2+, Mg2+, and KNO3) were tested during in vitro rhizome development on the ex vitro content of volatile constituents in rhizomes after 6 months in the greenhouse. A response surface method (D-optimal criteria) was repeated in both high and low-input fertilizer treatments. Control plants were grown on Murashige and Skoog (MS) medium, acclimatized in the greenhouse and grown in the field. The volatile constituents were investigated by GC-MS.

Results

The total content of volatiles was affected by fertilizer treatments, and in …

Avian Tail Ontogeny, Pygostyle Formation, And Interpretation Of Juvenile Mesozoic Specimens, Dana J. Rashid, Kevin Surya, Luis M. Chiappe, Nathan Carroll, Kimball L. Garrett, Bino Varghese, Alida Bailleul, Jingmai K. O'Connor, Susan C. Chapman, John R. Horner

Publications

The avian tail played a critical role in the evolutionary transition from long- to short-tailed birds, yet its ontogeny in extant birds has largely been ignored. This deficit has hampered efforts to effectively identify intermediate species during the Mesozoic transition to short tails. Here we show that fusion of distal vertebrae into the pygostyle structure does not occur in extant birds until near skeletal maturity, and mineralization of vertebral processes also occurs long after hatching. Evidence for post-hatching pygostyle formation is also demonstrated in two Cretaceous specimens, a juvenile enantiornithine and a subadult basal ornithuromorph. These findings call for reinterpretations …

Genetic Analyses In Lake Malawi Cichlids Identify New Roles For Fgf Signaling In Scale Shape Variation, R. Craig Albertson, Kenta C. Kawasaki, Emily R. Tetrault, Kara E. Powder

Publications

Elasmoid scales are the most common epithelial appendage among vertebrates, however an understanding of the genetic mechanisms that underlie variation in scale shape is lacking. Using an F2 mapping cross between morphologically distinct cichlid species, we identified >40 QTL for scale shape at different body positions. We show that while certain regions of the genome regulate variation in multiple scales, most are specific to scales at distinct positions. This suggests a degree of regional modularity in scale development. We also identified a single QTL for variation in scale shape disparity across the body. Finally, we screened a QTL hotspot for …

Avs Corner, May 2018, Farzana Ferdous (Advisor), Emily Alexander, Caitlin Mathews, Megan Tamakloe, Meghan Courey

AVS Corner

No abstract provided.

Neonatal Subventricular Zone Neural Stem Cells Release Extracellular Vesicles That Act As A Microglial Morphogen, Mary C. Morton, Victoria N. Neckles, Caitlin M. Seluzicki, Jennie C. Holmberg, David M. Feliciano

Publications

Subventricular zone (SVZ) neural stem cells (NSCs) are the cornerstone of the perinatal neurogenic niche. Microglia are immune cells of the nervous system that are enriched in the neonatal SVZ. Although microglia regulate NSCs, the extent to which this interaction is bi-directional is unclear. Extracellular vesicles (EVs) are cell-derived particles that encase miRNA and proteins. Here, we demonstrate that SVZ NSCs generate and release EVs. Neonatal electroporated fluorescent EV fusion proteins were released by NSCs and subsequently cleared from the SVZ. EVs were preferentially targeted to microglia. Small RNA sequencing identified miRNAs within the EVs that regulate microglia physiology and …

Alterations In Wheat Pollen Lipidome During High Day And Night Temperature Stress, Sruthi Narayanan, P.V. Vara Prasad, Ruth Welti

Publications

Understanding the adaptive changes in wheat pollen lipidome under high temperature (HT) stress is critical to improving seed set and developing HT tolerant wheat varieties. We measured 89 pollen lipid species under optimum and high day and/or night temperatures using electrospray ionization-tandem mass spectrometry in wheat plants. The pollen lipidome had a distinct composition compared to that of leaves. Unlike in leaves, 34:3 and 36:6 species dominated the composition of extraplastidic phospholipids in pollen under optimum and HT conditions. The most HT-responsive lipids were extraplastidic phospholipids, PC, PE, PI, PA, and PS. The unsaturation levels of the extraplastidic phospholipids decreased …

Climbing Ability Of Teneral And Sclerotized Adult Bed Bugs And Assessment Of Adhesive Properties Of The Exoskeletal Fluid Using Atomic Force Microscopy, Kevin R. Hinson, Vladimir Reukov, Eric P. Benson, Patricia A. Zungoli, William C. Bridges, Brittany R. Ellis, Jinbo Song

Publications

We observed that teneral adults (<1 h post-molt) of Cimex lectularius L. appeared more adept at climbing a smooth surface compared to sclerotized adults. Differences in climbing ability on a smooth surface based on sclerotization status were quantified by measuring the height to which bed bugs climbed when confined within a glass vial. The average maximum height climbed by teneral (T) bed bugs (n = 30, height climbed = 4.69 cm) differed significantly (P< 0.01) from recently sclerotized (RS) bed bugs (n = 30, height climbed = 1.73 cm at ~48 h post molt), sclerotized group 1 (S1) bed bugs (n = …

Avs Corner, December 2017, Farzana Ferdous (Advisor), Caitlin Mathews, Emily Alexander, Brooke Redmond, Meghan Courey, Erika Jones, Wendy Guzman, Peyton Voirin, Morgan Forte

AVS Corner

No abstract provided.

Recurrent Sublethal Warming Reduces Embryonic Survival, Inhibits Juvenile Growth, And Alters Species Distribution Projections Under Climate Change, Michael A. Carlo, Eric A. Riddell, Ofir Levy, Michael W. Sears

Publications

The capacity to tolerate climate change often varies across ontogeny in organisms with complex life cycles. Recently developed species distribution models incorporate traits across life stages; however, these life-cycle models primarily evaluate effects of lethal change. Here, we examine impacts of recurrent sublethal warming on development and survival in ecological projections of climate change. We reared lizard embryos in the laboratory under temperature cycles that simulated contemporary conditions and warming scenarios. We also artificially warmed natural nests to mimic laboratory treatments. In both cases, recurrent sublethal warming decreased embryonic survival and hatchling sizes. Incorporating survivorship results into a mechanistic species …

Spread Of Common Native And Invasive Grasses And Ruderal Trees Following Anthropogenic Disturbances In A Tropical Dry Forest, Xavier A. Jaime, Skip J. Van Bloem, Frank H. Koch, Stacy A.C. Nelson

Publications

Introduction

A fundamental challenge to the integrity of tropical dry forest ecosystems is the invasion of non-native grass species. These grasses compete for resources and fuel anthropogenic wildfires. In 2012, a bulldozer from the Puerto Rico Electric Power Authority cleared a 570-m trail from a state road into a mature dry forest section of Guánica Forest to control a wildfire. We monitored colonization by a non-native invasive grass (Megathyrsus maximus), a highly invasive tree (Leucaena leucocephala), and a native grass (Uniola virgata), as well as natural regeneration, along the bulldozer trail. We determined whether …

Reproductive Performance Of The Marine Green Porcelain Crab Petrolisthes Armatus Gibbes, 1850 In Its Introduced Range Favors Further Range Expansion, Ann Wassick, J. Antonio Baeza, Amy Fowler, Dara Wilber

Publications

Invasive marine crustaceans can exhibit population-level variation in reproductive traits that are consistent with a response to stressful conditions near the range edge, or alternatively, that may favor establishing new exotic populations. Reproductive characteristics of the green porcelain crab Petrolisthes armatus Gibbes, 1850 were not previously known in its invasive range in the Atlantic waters of the southeastern USA. We compared fecundity estimates, size at sexual maturity, and various other morphological aspects among crabs collected from two sites at each of four locations spanning approximately 230 km from North Inlet, South Carolina (SC), to Savannah, Georgia (GA), USA. Reproductive output …

Adaptability And Stability Of Reproductive And Vegetative Phases Of Peach Trees In Subtropical Climate, Filipe Bittencourt Machado De Souza, Rafael Pio, João Paulo Rodrigues Alves Delfino Barbosa, Gregory Lynn Reighard, Maraisa Hellen Tadeu, Paula Nogueira Curi

Publications

The peach tree (Prunus persica) is a fruit species native to temperate climates that requires a chill during its hibernal period to overcome dormancy. However, due to genetic breeding, varieties are currently grown in subtropical and tropical regions where there are low occurrences of chill during this phenological stage. This study evaluated the adaptability and stability of the reproductive and vegetative phases of peach tree cultivars in a subtropical climate. An experiment was designed in randomized blocks with split time plots, with 23 peach tree cultivars and four replications, with each replication consisting of one plant and four …

Homologous Recombination In Protozoan Parasites And Recombinase Inhibitors, Andrew A. Kelso, Sarah M. Waldvogel, Adam J. Luthman, Michael G. Sehorn

Publications

Homologous recombination (HR) is a DNA double-strand break (DSB) repair pathway that utilizes a homologous template to fully repair the damaged DNA. HR is critical to maintain genome stability and to ensure genetic diversity during meiosis. A specialized class of enzymes known as recombinases facilitate the exchange of genetic information between sister chromatids or homologous chromosomes with the help of numerous protein accessory factors. The majority of the HR machinery is highly conserved among eukaryotes. In many protozoan parasites, HR is an essential DSB repair pathway that allows these organisms to adapt to environmental conditions and evade host immune systems …

Warming And Elevated Co2 Alter The Suberin Chemistry In Roots Of Photosynthetically Divergent Grass Species, Vidya Suseela, Nishanth Tharayil, Elise Pendall, Apparao M. Rao

Publications

A majority of soil carbon (C) is either directly or indirectly derived from fine roots, yet roots remain the least understood component of the terrestrial carbon cycle. The decomposability of fine roots and their potential to contribute to soil C is partly regulated by their tissue chemical composition. Roots rely heavily on heteropolymers such as suberins, lignins and tannins to adapt to various environmental pressures and to maximize their resource uptake functions. Since the chemical construction of roots is partly shaped by their immediate biotic/abiotic soil environments, global changes that perturb soil resource availability and plant growth could potentially alter …

Assessing Alternative Silvicultural Prescriptions For Mid-Rotation, Unthinned, Spruce-Fir Stands In Maine, Patrick Hiesl, Mindy S. Crandall, Aaron R. Weiskittel, Anil R. Kizha

Publications

Determining the optimal timing and type of entry in mid-rotation, unthinned stands can be complicated by a variety of economic and biological factors. In this analysis, long-term data from the Commercial Thinning Research Network was used to project spruce-fir (Picea spp.—Abies balsamea (L.) Mill.) stand growth on six different sites across Maine following six alternative thinning treatments (33% and 50% relative density removal paired with low, crown, and dominant thinning methods). Results showed that the low-thinning treatment performed best in terms of maximum net present value, stand age at time of maximum net present value, and average merchantable …