Carole Browne, with Mary Lou Voytko, WFUHS Neurobiology & Anatomy
Effects of Estrogen on Cholinergic Indices in Surgically Menopausal Monkeys
Awarded $15,000 for the period 5/6/05 to 5/15/06
Source: WFU Cross-Campus Collaborative Research Support Fund

Ovarian hormone deficiency resulting from natural or surgical menopause can bring on changes in cognitive functioning, especially memory and attention. Several studies of postmenopausal women indicated that estrogen replacement therapy (ERT) improved memory and attention, but its neurobiological mechanisms have not been well defined. It may affect the basal forebrain cholinergic system (BFCS) neurons located in the nucleus basalis of Meynert that project to cortical regions and in the medial septal/diagonal band nuclei (MS/DB) that project to hippocampus. These brain regions are important for learning, memory, and attention.

This project will investigate the effects of chronic ERT on the cholinergic system of surgically menopausal young adult and middle-aged monkeys. The data will be used as pilot data for an RO1 application to the National Institute on Aging for a project to determine the extent to which age influences the effects of ERT on cholinergic indices in monkey models of menopause and the degree to which these effects correlate with behavioral indices.

Robert Browne
Population Genetics Structure and Species Composition of Ground Beetle Communities in the Boreal Forest ‘Sky Island’ in the Southern Appalachian Mountains
Awarded $9,600 for the period 5/1/05 to 4/30/06
Source: WFU Science Research Fund

Flightless ground beetles will be collected from 12 spruce-fir forests in the southeastern United States to test whether species presence correlates with spruce-fir island size, altitude, presence of conifer forest, level of past fire disturbance, and level of logging intensity. Multiple sampling techniques will allow more complete species inventories, while determining seasonal and annual variations in the communities’ composition. Each technique’s efficiency can also be compared and assessed . Molecular techniques will be used to quantify genetic distances among select taxon units and to analyze population genetic structure.

William E. Conner

• see also Michelle DaCosta

• Sound Strategies: Acoustic Mimicry and Jamming in the Bat-Moth Arms Race
  Awarded $185,223 for the period 07/01/06 to 6/30/09
  Source: NSF

Insectivorous bats with ultrasonic sonar exert enormous selective pressure on nocturnal insects. In response, insects have evolved the ability to hear bat cries, to evade their hunting maneuvers, and tiger moths (Arctiidae) utter an ultrasonic reply. Using a novel learning approach, we have shown that the bats only respond to the sounds of arctiids when they are paired with defensive chemistry. The sounds are a warning to the bats that the moth is unpalatable – an aposematic signal.

Although the sounds of arctiids have so far been shown to have this single function, they are extremely diverse in structure. Using free-flying naïve red bats and tethered tiger moths, this project explores the other evolutionary forces may contribute to this diversity. It asks whether some palatable tiger moth species mimic the sounds of unpalatable species to gain an advantage and whether some species have modified their warning signals in a way that allows them to “jam” the echolocation sonar system of the bat and mask their presence.

A team of graduate and undergraduate students will study these questions in the Wake Forest Bat Facility directed by Professor Conner. The results will be shared with children through an educational website devoted to bats and moths. Wake Forest undergraduates will also teach in the summer ecology camp at Archbold Biological Station in Lake Placid, FL.

• Chemical Ecology of the Tiger Moth Genus Utethesia and its Tournefortia Hostplant Complex: Implications for the Conservation of Endemic Species in the Galapagos Islands
  Awarded $10,000 for the period 3/8/04 to 1/15/07
  Source: National Geographic Society

James F. Curran

• Analysis of protein synthesis in E. coli by high-throughput pyrosequencing
  Awarded $10,000, Spring 2007
  Source: WFU Science Research Fund


Protein synthesis is a critical step in gene expression. The basic mechanics of the translational process are understood but almost nothing is known about how ribosomes process messages. This project aims to provide a snapshot of the message sequences that are translated during standard growth conditions. A new method, pyrosequencing, can simultaneously determine the sequences for several hundred thousand short RNAs. Ribosomes will be isolated; any mRNA not protected by them will be digested; and the protected sequences pyrosequenced. Their pattern will tell us the relative frequency at which all messages are translated, and the distribution of ribosomes will tell us a great deal about how they move over messages. The project brings a powerful new technology to the Wake Forest biomedical research community. .
• AREA: Does the Ribosomal E Site Help Hold the Reading Frame?
  Awarded $209,205 for the period 7/1/06 to 6/30/09
  Source: National Institutes of Health (NIH)

Maintaining the translational reading frame is a fundament feature of protein synthesis. Ribosomes contain an exit, or E, site for deacylated tRNA, which passes through after completing its translational role. Except for transient interactions with the exiting tRNA, however, no clear function has been identified for the E site. Recent evidence suggests the hypothesis that deacylated tRNA in the ribosomal E site helps to prevent frameshifting. This project will test it by determining whether message nucleotides and tRNA in the E site are associated with increased or decreased frameshifting at the RF2 programmed frameshift site. Preliminary work shows that the E site triplet is important, although the mechanism is not yet clear. The project will also determine whether the E site holds tRNA until an aminoacl-tRNA is selected at the A site. If so, then the E site tRNA might have an important functional role during translation of the A site. If not, then it may have a transient role, possibly in message translocation. From 3-6 undergraduate students and 2-3 MS-level graduate students will perform much of the work.

• The Roles of the Ribosomal E Site in Translation
  Awarded $8,000 for the period 6/1/05 to 5/31/06
  Source: WFU Science Research Fund

  Recent work suggests that the ribosomal E (exit) site may play critical roles in maintaining the translational reading frame. Specific tests of this hypothesis will use standard molecular cloning techniques to enable the assay of effects on gene expression in living E. coli. .

• with Rebecca Alexander, Chemistry, and WSSU
  Research Infrastructure in Minority Institution Grant (RIMI)
  Awarded $15,595 for the period 9/30/06 to 9/29/07
  Source: National Institutes of Health (NIH), Subcontract with Winston-Salem State University

Bacteria significantly overproduce a protein called CsdA when the environmental temperature drops. CsdA may work to unwind RNA, because at low temperatures, a possible increase in RNA secondary structure would inhibit mRNA translation at the ribosome. In collaboration with PI Pamela Jones, a microbiologist at Winston-Salem State University, Dr. Curran will assay CsdA mutations in vivo, looking for translation defects and growth phenotypes, while Dr. Alexander will purify CsdA mutants and assay the effect on RNA binding and unwinding in vitro, to learn what protein motifs in CsdA contribute to the observed functions.

Michelle DaCosta, with William Conner
Defensive Signaling Behaviors and the Influence of Predator Learning on Communication Modalities in the Chetheisa Species in the Galapagos Islands
Awarded $10,000 for the period 9/1/07-8/31/09
Source: National Science Foundation

Aposematism is a term to describe adaptations—colors, sounds, odors, or other perceivable characteristics—that warn predators off, as opposed to crypsis, which means avoiding detection. In Lepidoptera, unpalatable species are often aposematic, while undefended species tend to be cryptic. Birds, their major diurnal predators, can detect signals in both the visual and ultraviolet regions of the spectrum and learn to avoid aposematic prey. Lizards also detect visual signals but rely more on movement than aposematism.

How predator pressure, evolutionary history, and geography interact to favor aposematism or crypsis remains unclear. This project focuses on the defensive signaling of four species of tigermoth, one of which,distributed throughout the Americas, including the Galapagos Islands, is aposematic; the remaining three, endemic to the Galapagos islands, are cryptic, the only cryptic species in the genus, even though they feed on toxic plants. Objectives include 1) quantifying the defensive signaling behaviors (aposematic vs. cryptic); 2) determining if both birds and lizards can learn to avoid aposematic prey; and 3) reconstructing the evolutionary history of these speciesusing molecular data.  

Susan Fahrbach

• FIBR: BeeSpace – An interactive Environment for Analyzing Nature and Nurture in Societal Roles
  Awarded $114,183 for the period 9/1/04 to 8/31/08
  Source: NSF/University of Illinois

The project focuses on the honey bee to elucidate the relationship between genes and animal social life on an unprecedented whole-genome scale. Its interactive environment integrates molecular description with information from ecology, evolution, behavioral science, and physiology. All the roles of a worker honey bee within her society will be functionally analyzed by combining microarray analysis, large-scale brain in situ hybridization, and a novel approach to informatics that links all sources from current genomic databases to the existing scientific and natural history literatures on honey bees. The resulting database will localize the expression of many bee genes to precise regions of the brain for all major social roles. A novel software environment, called BeeSpace, enables users to navigate interactively across sources for hypothesis development and testing. The prototype will be tested in 15 laboratories studying honey bees and related organisms and provide research experiences at the graduate, undergraduate, high school, and middle school levels, with training and minority outreach.

• Muscarinic Regulation of Plasticity in the Brain
  Awarded $64,800 for the period 4/1/07 to 3/31/08
  Source: NIH

  This project is designed to elucidate how experience translates into changes in brain structure that enhance adult performance. It is based on the surprising demonstration that treating foraging honey bees with a muscarinic agonist, pilocarpine, induces growth of the mushroom bodies, the insect brain center for learning and memory, resulting in a brain plasticity identical to that produced by a week of foraging experience.

  Investigations aim to determine:
  1. how signaling via cholinergic pathways is related to foraging-induced increases in the volume of mushroom body neuropil, using a novel rearing technique called experience-replacement;
  2. the cellular phenotype of pilocarpine-induced changes in mushroom body neurons (Kenyon cells) using the golgi technique; and
  3. genes expressed in the mushroom bodies responsive to signaling via muscarinic pathways, using whole bee genome microarrays and confirming results with quantitative RT-PCR and in situ hybridization.

  The honey bee provides a superb model system for these studies because appropriate tools, such as a sequenced genome, are available and the effects of experience on brain structure are better understood in the honey bee than in any other insect. Nervous system function at the molecular level is highly conserved across the animal kingdom; thus, experiments that can be efficiently performed using the simpler insect system are likely to reveal how learning changes the brain in all animals, including humans. Such understanding is the first step in developing therapies to improve human learning after brain damage or with the decline that accompanies aging.

• Role of Orphan Nuclear Hormone Receptors in the Adult Honey Bee Brain
  Awarded $103,688 for the period 9/1/05 to 8/31/06, Year 2
  Source: NSF

  The honey bee brain serves as a model for neuronal plasticity coupled with behavioral development; in other words, how the brain changes with age. In honey bee colonies, a critical feature of social organization is age-based division of labor among workers. They tend the queen, rear larval brood, and maintain the physical structure of the hive for the first 2 to 3 weeks of adult life then switch to foraging outside the hive for their final 1 to 3 weeks, and studies show predictable changes in foragers’ brain structure, including the expansion of the neuropil of the mushroom bodies, the primary arthropod brain region associated with learning and memory with some similarities to the vertebrate hippocampus. More specifically, Golgi analyses have shown that the brain volume changes associated with foraging reflect growth of Kenyon cell dendrites.

This project seeks to identify the mechanisms that permit Kenyon cells in the adult bee brain to grow in response to changes in experience. Members of the nuclear hormone receptor (NHR) superfamily are candidate regulators of neuronal structure. Analysis of a Bee Brain EST Database revealed that 6 homologs of Drosophilia melanogaster NHRs are expressed in the adult bee brain. Quantitative real-time PCR, in situ hybridization, and manipulation of gene expression in primary cultures of Kenyon cells will be used to test two hypotheses:
1. Neuronal populations showing dendritic growth during behavioral development in the adult honey bee will be characterized by the expression of NHRs; and
2. Process outgrowth with require signaling though NHR-activated pathways.

These studies will contribute new knowledge of the mechanisms of structural plasticity in the adult nervous system and the insect members of the NHR superfamily. Participating graduate and undergraduate students will learn to use several new bioinformatics tools to exploit the Honey Bee Genome Project.

• Functional Genomics of Chronobiological Plasticity in the Honey Bee
  Awarded $9,775 for the period 9/1/07 to 8/31/08
  Source: United States-Israel Binational Science Foundation (BSF)

The project integrates a genomic approach to study complex behavior: the molecular biology of the honey bee circadian clock and socially mediated chronobiological plasticity. Bioinformatic and phylogenetic analyses will identify bee homologs for all pivotal clock genes; and immunocytochemistry and in situ hybridization will be used to determine the spatial expression of clock genes under varying light conditions. Hypotheses include:
1) all clock genes are expressed in pacemaker cells;
2) expression of most or all of these genes will oscillate with circadian rhythm;
3) their phase will shift after alterations in photoperiod; and
4) oscillations in arrhythmic nurses will be smaller than in rhythmic foragers.

Preliminary results suggest that in some ways, the honey bee clock more resembles that of the mouse than the fly. Taking into account the structural and functional conservation of the circadian clock, findings may provide new insights into circadian plasticity in general.

Erik Johnson
Genetic Manipulation of a Neuroendocrine Circuit in Drosophila
Awarded $10,000 for the period 12/1/05 to 11/30/06
Source: WFU Science Research Fund

In Drosophila, at least four different diuretic peptide hormones control osmotic balance. Evaluation of their expression patterns and dedicated receptors has revealed a neuroendocrine circuit within the brain. Both the molecular components and the anatomical organization of Drosophila diuretic hormone signaling are similar to specific mammalian neuropeptide signaling pathways. We will test hypotheses that activating one hormone receptor affects the release of its co-expressed hormone by either facilitating, inhibiting, or modulating secretion profiles.

Kathleen A. Kron

• Collaborative Research: Systematics and Evolution of the Wintergreen Group (Gaultherieae, Ericaceae)
  Awarded $122,720 for the period 8/1/07 to 8/31/08
  Source: NSF

The wintergreen group is a clade of about 250 species in the blueberry and rhododendron family. Its best-known species is probably G. procumbens, the source of wintergreen oil, commonly used in the confection industry and medicine, but many species are important to the terrestrial shrub layer in pioneer habitats. Their unusual distribution between the Americas and the lands bordering the Pacific, in tropical, subtropical, and north and south temperate zones, makes them attractive for testing hypotheses on intercontinental historical biogeography from the Late Cretaceous period to the present.

This collaborative study aims 1) to determine Gaultherieae phylogenetic relationships with nucleotide sequence data from the chloroplast and nuclear genomes and morphological characters; 2) to identify and to monograph strongly supported, morphologically diagnosable clades of reasonable size; and 3) to test hypotheses about morphological evolution, particularly of the fruit and anthers, and historical biogeography in a phylogenetic context. Three graduate and three undergraduate students will receive training. Data and results will be made available via www.ericaceae.org and a web-based interactive system, Plone, to anyone interested in plants of the Pacific Rim, Asian and South American biodiversity, ecology, pollination biology, and ecophysiology.

• Ericaceae in the Central Andes: Bolivia and Adjacent Peru
  Awarded: $7,000 for the period 7/1/05 to 1/31/08
  Source: NSF

  This cooperative research program focuses on a flora of the Ericaceae in Bolivia and southern Peru, two poorly collected areas that are being rapidly deforested. The Principal Investigator, James Luteyn, New York Botanical Garden, and members of several South American herbaria are collecting ericaceous plants for research purposes, writing identification keys, and providing the basis for future monographs and revisionary work.

  Dr. Kron will use DNA sequence data to place the discovered taxa within the phylogenetic framework of the remaining neotropical blueberries and wintergreens. Results will contribute to a better understanding of the evolution of South American Ericaceae, a more robust phylogeny for the “Andean Clade”, and help to identify artificially delineated taxa from natural (monophyletic) ones. The specimens collected by Luteyn and collaborators will be housed in herbaria in South America and the New York Botanical Garden, and results disseminated electronically and via scholarly journals and identification keys. In addition, Colombian students will receive training in modern taxonomic techniques and standard field practice.

• Evolutionary Relationships in the Rhubarb Family (Polygonaceae), using Data from NuclearGgenes LEAFY and AGAMOUS
  Awarded $10,000 for the period 5/1/05 to 4/30/06
  Source: WFU Science Research Fund

  The rhubarb family is a group of flowering plants that contains many species of economic or agricultural importance. The flowers of most of the members have a unique tepal arrangement. This project will study the evolution of the perianth arrangement and other features, including fruit diversification, dispersal mechanisms, reproductive biology, and ocrea. It expands my consistently funded research program from the Ericaceae (blueberries & rhododendrons) to include the rhubarb family. Data from two neglected nuclear genes will be used to study evolution in the Polygonaceae.

• Evolution and Diversification of Azaleas and Rhododendrons (Rhododendron, Rhodoreae, Ericaceae)
  Awarded $9,000 supplement for the period 5/28/04 to 2/28/06
  Source: NSF

This investigation into the relationships of Ericoideae requires higher quality material of species Erica (Ericeae) than currently available to the laboratory. Preliminary studies indicate that Erica may be the sister group to the remaining Ericoideae, which could influence our interpretation of this large and diverse group's history. Erica's distinct Europe-Africa (that is, north-south) distribution is very different from all other groups of Ericaceae, which are typically distributed east-west.

Supplemental funds will enable Dr. Kron and two graduate students to travel to South Africa, where most species of Erica occur, to consult with resident molecular and morphological experts and to obtain DNA for a planned cooperative effort. Dr. Kron will also confer with others interested in Erica's evolution and encourage the participation of both African and American students in a comprehensive study. Ultimately, Dr. Kron plans to elucidate Erica's diversification patterns and to compare them with the patterns of other members of Ericaceae in other areas of the world with similar climates. This information will be used to investigate the functional ecological aspects of leaf anatomy and physiology in the context of phylogenetic relationships.

Raymond F. Kuhn

• Diagnostic Assay and Nutraceutical for Enteric Septicemia of Catfish (ESC)
  Awarded $75,000 for the period 8/1/07 to 1/31/09
  Source: North Carolina Biotechnology Center

The aquaculture industry is burgeoning in response to decreased wild fish populations and increasing demand for sustainable sources of protein. The predominant species farmed in the United States, 95% in the southeast, is the channel catfish. While total US catfish sales in 2005 were approximately $482 million and estimated to grow 8% per year, the global aquaculture market totals about $60.9 billion. US fish farmers operate under thin profit margins threatened by imports and infectious diseases.

Catfish are durable but susceptible to bacterial infections that contribute to losses as high as 30%. In most cases, they are treated by antibiotics in the feed, which is expensive, and consumers are concerned about antibiotic contamination. This project aims to develop a quick, cost-effective test to diagnose enteric septicemia of catfish (ESC), the major cause of mortality from bacterial infection. Following the development of antibodies in experimentally infected fish, a proprietary nutraceutical will be tested. Should it protect fish from infection, it can be produced cost-effectively and avoid the use of antibiotics.

• Chytridiomycosis in amphibians
  Awarded $6,731, Spring 2007
  Source: WFU Science Research Fund

Amphibian populations are declining at alarming rates throughout the world. Since 1987, an estimated 43 percent have been drastically reduced, and 34 species are now extinct. Die-offs are attributed to infection caused by the chytrid fungus, Batrachochytridium dendrobatidis. The project aims to develop two immunological assays to detect the infection in frogs. They will assist in studying the epidemiology of the disease, predicting its future spread, and possibly developing a means to control it.

Anita McCauley

• Acquisition of a laser scanning confocal microscope for research and training in biology and physics at Wake Forest
  Awarded $385,220 for the period 8/1/07 to 7/31/09
  Source: National Science Foundation

The Microscopy Core Facility will acquire an urgently needed laser scanning confocal microscope (LSCM). It will enable faculty, graduate students, and undergraduates to conduct and to publish research on plasticity in the brain, hormonal regulation of proteins in plant roots, stress response systems, gene expression and protein localization in Drosophila, chemoreception and plasticity in the moth antennal lobe, blood clot formation, and optical properties of nanoparticles. Forty percent of biology graduate students use the Core Facility for research; 50 percent take a microscopy course; and this impact will increase with the requested LSCM: ~270 undergraduate students will be exposed to it each year and 11 graduate students will immediately increase their competitiveness with peers at larger institutions. In addition, faculty from three local institutions, including the HBCU Winston-Salem State University, will use the LSCM for undergraduate research and education; it will be incorporated in the Biology department’s multiday symposium, Perspectives in Biology (PIB), which brings together leading researchers and regional faculty from 21 institutions; and it will be part of ongoing community outreach events, including regularly scheduled tours by high-school students from urban and rural NW North Carolina.

• A Stereomicroscope Imaging System for Faculty/Student Research in the Microscopy Core Facility at Wake Forest University
  Awarded $52,999 for the period 5/1/05 to 4/30/08
  Source: NSF

The Biology department has purchased a research-grade, epi-fluorescent stereomicroscope coupled with an image-acquisition and analysis system. These imaging capabilities will enable faculty, graduate students, and undergraduates to conduct research on structure and function, responses to physiological conditions, and gene expression and protein localization in intact, often living organisms and to perform time-apse imaging of animal behavior.

• with Mary Lou Voytko, Neurobiology and Anatomy
  Estrogen modulation of leptin synthesis and signaling
  Awarded $19,936; $16,386 Reynolda Campus, $3,550 Health Sciences
  Source: WFU Cross-Campus Collaborative Research Support Fund

  The hormone leptin is secreted by adipocytes, and its circulating level is proportional to the abundance of fat deposits. It functions by sending signals to specific receptors in the brain and peripheral tissues that reduce appetite and burn excess fat when stores reach higher-than- normal levels. Rodents and humans with defects in the genes encoding either leptin or leptin receptors have been shown to become morbidly obese, yet how leptin signals are sent and how and why leptin synthesis and signaling vary among individuals are unknown. One clear and consistent difference, found in humans and other mammals, is a much higher blood concentration of leptin in females than males, but little is known about the molecular mechanisms that account for this difference and whether changes in leptin levels are associated with altered leptin responses. A signal likely to enhance leptin synthesis is the female sex hormone estrogen, which is more abundant in females, and whose concentration changes with the female reproductive cycle in parallel with changes in leptin levels. This project aims (1) to determine whether estrogen levels are sufficient to modulate circulating levels of leptin and the soluble leptin receptor in the blood of nonhuman primates; and (2) to alter transcription of the gene encoding leptin and leptin receptor in fat cells grown in culture. Together, these experiments should provide evidence for estrogen control of leptin synthesis and signaling in primates and determine whether the mechanisms include transcriptional changes in the genes encoding leptin and its receptor.

• Ethylene and Auxin Crosstalk in Control of Root Architecture
  Awarded $340,000 for the period 8/15/06 to 8/14/09
  Source: US Department of Agriculture (USDA)
  
  
  Appropriate root growth orientation and extensive branching are essential for efficient nutrient and moisture retention and maximal plant productivity. Auxin’s importance in regulating these processes has long been appreciated, while a role for ethylene has not been clearly established. This study uses a genetic approach to ask if ethylene regulates root orientation and branching and how crosstalk between auxin and ethylene defines root architecture. Experiments investigate whether elevated levels of ethylene and known ethylene signaling mutants alter root gravitropism and branching in opposite ways, using two agriculturally important species. The genetic model Arabidopsis thaliana and the crop plant Lycopersicon esculentum (tomato) each offer unique experimental advantages. In Arabidopsis, many well-characterized ethylene signaling mutants are available along with reporters and transgenic lines that can be used to examine the molecular mechanisms by which ethylene and auxin signaling interface. Tomato offers a more limited set of ethylene-insensitive mutants and transgenics but has a rapidly expanding research community and set of molecular tools and many agriculturally important members. Examination of hormonal control of root development in two species will help to determine its universality across the plant kingdom.

• Control of Lateral Root Development by Membrane Trafficking Machinery
  Awarded $9,859.80
  Source: WFU Science Research Fund

Asymmetrically localized membrane proteins determine the polarity of the hormone auxin’s movement and modulate plant development. Dr. Muday’s laboratory has isolated a protein that is part of the auxin transport protein and may determine its polar localization. Using the sequences of proteins isolated from affinity chromatography, they have identified a Rab GTPase protein that controls membrane trafficking and may facilitate the formation of polar auxin transport complexes. This project’s goal is to characterize the candidate protein and to determine how it functions to regulate auxin transport and lateral root development.

• With Gary Miller, Health and Exercise Science
  Metabolic Hormone Levels and Obesity, Weight-loss Ability, and Osteoarthritis
  Awarded $10,000
  Source: WFU Science Research Fund

While more than 65 percent of US adults are now considered overweight or obese, neither the cause of this epidemic nor the mechanisms underlying the comorbidities associated with it are understood. Hormones secreted by fat cells, adipocytokines, may provide insight, but their alteration in obesity, osteoarthritis, and older adults and their role in weight loss is not clear. This project will examine levels of these hormones and their receptor for a connection to body weight, osteoarthritis, and weight loss. The overall goal is to understand the metabolic alterations associated with obesity in older adults.

• Auxin and Actin Control of Root Development
  Awarded $10,000 for the period 12/1/04 to 11/30/05
  Source: WFU Science Research Fund

  Root development begins with the formation of a primary root in the embryo. After seeds germinate and roots emerge, new branches form along the primary root, beginning when quiescent cells divide to form lateral root primordia. Signals that initiate this conversion include the plant hormone auxin and the reorganization of cells, including changes in the actin network that organizes the cytoplasm. The proposed experiments will examine the relationship between auxin transport, changes in actin networks, and lateral root formation, using cell biology, biochemistry, and genetic analyses.

• Analysis of Phenotypic Plasticity in Arabidopsis Roots in an Ecological Context
  Awarded $9,997 for the period 6/03 to 6/04
  Source: WFU Science Research Fund

The growth and development of plants is highly sensitive to the environment. Root growth and development are versatile and change in response to light and temperature. Dr. Muday will explore the ecological significance of root growth patterns in the field to determine if patterns under natural conditions resemble those in the laboratory and if they correlate with greater reproductive success. The award supports the purchase of equipment to monitor field growth conditions and to analyze complex root patterns in order to amass pilot data for a proposal to the National Science Foundation.

• Regulation of Auxin Transport by Phosphoylation and Flavonoids during Gravitropism in Arabidopsis
  Awarded $99,683 for the period 7/1/03 to 6/30/04, Year 3 of 3
  Source: National Aeronautics and Space Administration (NASA)
  
  To understand the mechanisms that control plants’ ability to change their growth and developmental patterns in response to gravity, the project’s experimental approach combines the use of Arabidopsis plants, which have gene mutations that alter the regulation of auxin transport and gravity response; transgenic plants that provide information on changes in gene expression; and computer-aided analysis of plant gravity response. The experiments examine the synthesis of compounds that act to change the activity of auxin transporters or phosphorylation states that regulate auxin transport during plant gravity response. Preliminary evidence indicates that mutants that synthesize no flavonoids or have reduced phosphatase activity exhibit significantly delayed gravitropic bending. Both in vitro and in vivo evidence indicates that flavonoids are natural regulators of auxin transport. The localization of expression of flavonoid biosynthetic enzymes and flavonoid accumulation will be examined in concert with measurements of gravitropism to determine if the amount or distribution of these compounds affects gravitropic bending. Additionally, the role of phosphorylation in auxin transport regulation will be examined using Arabidopsis with mutations that affect phosphatase or kinase activity. Finally, the possibility that phosphoylation and flavonoid sysnthesis are interconnected regulatory mechanisms will be studied. The phosphorylation state of transcription factors may affect the transcription of genes encoding flavonoid biosynthetic enzymes, or flavonoids may act as kinase or phosphatase inhibitors. Together, these experiments should provide a clear sense of how flavonoids and phosphorylation act to regulate auxin transport and why alterations in either flavonoid synthesis or phosphorylation reduce plants’ ability to respond to gravity. 

 Miles Ross Silman

• Conservation Implications of Climate Change and Fire in the Eastern Andes: Impacts on Plant Distribution and Montane Ecosystems
  Awarded $277,190 for the period 6/1/07-7/31/09
  Source: Gordon and Betty Moore Foundation Andes to Amazon Program

The eastern slope of the Andes, which harbors Earth’s highest biodiversity, is threatened by climate change. The project investigates 1) the ecology of plant distribution; 2) the relationships between ecosystem and climate; and 3) the historic relationships between plant community ecosystem and climate. Specifically, it focuses on the anthropogenic tree line, the limit to trees caused by human activities, which bars natural plant migration in response to climate change. Resulting data will inform effective conservation strategies.

• Collaborative Research: Understanding the Role of Landcover and Landform in the Spatial Organization of the Diurnal Cycle of Orographic Clouds and Rainfall
  Awarded $127,307 for the period 9/1/07–8/31/10
  Source: National Science Foundation

Cloud formation depends on large-scale circulation and local effects of geomorphology and vegetation, which is also highly dependent on it. This project uses two elevation gradients, one in the Himalayas and the other in the tropical Andes. The results will be the first comprehensive look at cloud formation on humid continental mountains and crucial to understanding future ecosystem responses to climate change.

• REU Supplement to Vegetation and Paleoecology of an Amazon-Andean Elevational Transect
  Award $7,443 for the period 5/2/06 to 3/31/07
  Source: NSF

  Funds support the participation of one undergraduate student in a project that seeks to answer a key question in Andean distributional ecology. Its novel methodology for Neotropical pollen analysis, including a field component, a bioinformatics component, using collection data to refine distributional hypotheses, and a lab component at Wake Forest University and Florida Institute of Technology using SEM, Deconvolution Light Microscopy, and automated image analysis, will greatly improve our understanding of both modern species distributional limits and the history of species distributions for a dominant tree genus through the late Pleistocene in the Andes Biodiversity Hotspot. At the cloud forest field station of the Amazon Conservation Association in Peru, the student will work with Dr. Silman, his graduate students, and a Peruvian field crew to collect pollen samples and refine range limits for 11 congeneric species of Weinmannia (Cunonicacae). The student will gain a breadth of experience with international scientists and exposure to diverse topics of study.

• Vegetation and Paleoecology of an Amazon-Andean Elevation Transect
  Awarded $207,874 for the period 3/1/04 to 2/28/05
  Source: NSF

  The eastern flank of the Peruvian Andes supports immense biodiversity. This study will be the first integrated analysis of modern vegetation and paleoecology along an elevational transect of vegetation and lakes, extending from the Amazon lowlands to the treeline. It will perform the first quantitative assessment of tree species diversity and community composition and show how these communities responded to past climatic and land-use changes.

Wayne L. Silver
Multiple Mechanisms of Nasal Chemoreception
Awarded $16,970 for the period 3/1/07 to 2/29/08, Year 5 of 5
Source: NIH

Most nasal cavity sensitivity to chemicals can be attributed to receptor cells in the main olfactory epithelium that rely on the cAMP transduction cascade. Other mechanisms may be found in trigeminal nerves or solitary chemoreceptor cells. In collaboration with researchers at the University of Colorado Health Sciences Center in Denver and Colorado State University in Fort Collins, experiments will explore alternative chemosensory mechanisms using histological, electrophysiological, and behavioral techniques. Results should improve our understanding of how the nasal cavity processes chemosensory information.

• Facilitation of Birch Seedling Establishment in the Caucasus Mountains
  Awarded $8,998 for the period 4/1/07 to 3/31/09
  Source: Civilian Research and Development Foundation (CRDF); Georgian Research and Development Foundation (GRDF)
  
  
  This project extends a CRDF/GRDF grant awarded in 2002 and 2005 to study the mechanisms of high-elevation treeline stability. The Georgian group (Institute of Botany, Georgian Academy of Science, FSU) has expertise in distributional ecology, reproductive biology, and seed germination factors in the birch species under study, while the Wake Forest University team has expertise in evaluating the ecophysiology of seedling survival. They will examine ecological facilitation between Betula litwinowii Doluch and Rhododendron caucasicum Pall, focusing on seedling establishment in the Greater Caucasus mountain range. Stunted B. litwinowii forests typically occur at treeline but can be found at high elevations in association with R. causcasicum. The investigators hypothesize that R. causcasicum facilitates B. liweinoii seedling emergence and establishment at these high elevations through several mechanisms. They will test whether (1) photosynthetic carbon gain speeds growth; (2) low carbon gain and reduced root growth result in a desiccation-induced death later in summer, as oils dry following spring runoff; and/or (3) survival is tightly coupled to infection from ectomycorrhizal soil fungi. The results will provide a strong mechanistic explanation for shifts in the maximum altitude at which the intact forest occurs and the expansion or contraction of subalpine and alpine vegetation zones according to global climate change.

• Conserving the Relic Spruce-fir Forests of the Southern Appalachian Mountains
  Awarded $25,000 for the period 6/6/06 to 12/31/06
  Source: Bipartisan Policy Center

  Fraser fir exists in only six isolated mountain-top populations in North Carolina, southern Virginia, and eastern Tennessee. The dominant tree at elevations above ~1850 m and interspersed with red spruce between 1650 m and 1850 m, it appears to be a relic species that probably diverged from balsam fir 7-8,000 years ago. While once found at much lower elevations throughout the region and as far south and west as Alabama and Mississippi, during a relatively prolonged period of global warming, it survived only at cooler, higher elevations. Over the last several decades, a significant decline in adult populations has been attributed to an introduced insect, the balsam wooly adelgid, but other contributing factors include drought, ice storms, and deposition of atmospheric pollutants. Regional cloud ceilings have been rising for the past thirty years, and species like the fir and spruce that depend on daily cloud cover and cloud-immersion could be replaced by species more adapted to clear-sky conditions. One study reported that current-year Fraser fir seedlings had substantially reduced photosynthetic capacity and low survival when exposed to full sunlight on clear days. Any disappearance of spruce-fir forest would have dire consequences for wood-related industries, recreational use, snowpack accumulation and water supply to storage reservoirs, and global biodiversity.

  Seed supply, germination success, seedling establishment, and subsequent growth beneath new canopy gaps are critical for stand regeneration. Virtually all prior studies on Fraser fir and red spruce seedlings have focused only on the abundance of older, established seedlings without addressing the specific environmental factors influencing the success of young seedlings. In general, studies of adaptive establishment mechanisms in very young conifer seedlings?indeed, on newly emerged seedlings of any species under natural field conditions?are rare. This forest regeneration model (REGEN) makes specific, quantitative comparisons of new fir and spruce seedling growth and survival that can be coupled with current scenarios of global change effects to predict the chances for regeneration and survival of these relic forest communities.

• Sustaining Barrier Island Ecosystems in a Changing Global Environment
  Awarded $14,338 for the period 4/1/06 to 3/31/07
  Source: NSF
  
  Funds support a workshop to consider the sustainability of barrier island ecosystems under current global change scenarios, including the likelihood of continued human disturbance. These unique ecosystems protect all continental shorelines from powerful wave action. An abundance of highly adapted endemic and indigenous species survive in this stressful environment within the ecotonal transition from land to sea, which may be particularly vulnerable to global change.

The workshop will address several crucial questions, including:

1. What is the current status of barrier island ecosystems, including ecological vulnerability and resilience?
2. What will be the impact of global change scenarios that predict continued warming, sea-level rise, and increased frequency of intense oceanic storms?
3. Can these island ecosystems become more stabilized and sustainable by better land management strategies, including a program for insuring the survival and propagation of native plant species?

The workshop will organize an expanded international effort to address the past and future role of coastal barrier islands in ameliorating storm forces from a wide range of perspectives. Strategic recommendations will focus on evaluating the effects of extreme, episodic events, such as hurricanes, on native species; the role of native species in more efficacious land management programs; and the possibility of evaluating remotely sensed changes in barrier island geomorphology and vegetation composition and distribution. A manuscript will be written for a popular scientific journal that reaches a broad audience (e.g., Bioscience, American Scientist, Scientific American).

• Global Change and Natural Stabilization of Barrier Island Sanddune Ecosystems
  Awarded $8,684 for the period 10/1/05 to 06/30/06
  Source: National Oceanic and Atmospheric Administration (NOAA)

Predictions of future global warming include more intense and frequent weather phenomena, such as tornadoes and hurricanes, and rises in sea level. Little is known about the ecological impact on habitats at high risk to episodic disturbance, like sand dunes, at the interface between the terrestrial and marine biomes, and the possibility of increased extinction rates and loss of biodiversity.

This study evaluates the effects of short-term (day-to-day) versus long-term (episodic) stress factors on photosynthetic carbon gain, plant survival, and seed production in five species representing four major categories of plant form and function. Short-term stress factors include daily temperature and water and light limitations, while long-term, episodic stress factors are those associated with overwash events generated by storms and tidal fluctuations. The species under study occur together in a beach sand dune community and represent major categories (herbaceous, grass, and shrub) and metabolic types (C3 versus C4 carbon pathways). One C3 species depends on sexual reproduction and seed production and another on asexual reproduction by clonal ramets; one has dynamic leaf orientation properties during the day. The C4 species is on the US Endangered Species list, and the study will evaluate an anthropogenic stress factor that could compound the effects of episodic storms: off-road vehicles follow a predictable route through the research sites that will be monitored and compared to traffic-free areas.

Despite correlative evidence that transitional ecotones may act as early warning systems for anthropogenic global change, the mechanisms leading to changes in plant distribution patterns and potential loss of biodiversity are largely unknown. This project will provide a more mechanistic basis for evaluating the stability of plant boundary systems in response to global change. Graduate and undergraduate students are an integral part, and results will be broadly disseminated via publication in refereed journals, seminars, presentations at national and international meetings, and a descriptive website designed to communicate effectively with grades K-12 and linked directly to state schools as well as colleges and universities, both nationally and internationally.

• Ecological Facilitation by Rhododendron caucasicum Extends the Betula litwinowii Alpine Treeline, Caucasus Mountains of Georgia
  Awarded $29,212 for the period 8/1/05 to 7/31/07
  Source: NSF

Ecophysiological studies over the past four decades have failed to evaluate influences on population biology, a major drawback in elucidating evolutionary processes. If current projections of climate warming are accurate, a significant portion of the Earth’s biodiversity will disappear during the next century. In particular, alpine tundra ecosystems in temperate and subtropical latitudes may be replaced by the subalpine forest below. Despite these predictions, a unified mechanistic explanation for the upper elevational limits of subalpine forests across the globe is still controversial. Recent studies are developing a more mechanistic interpretation using ecophysiological measurements of seedling establishment away from the forest edge by the two dominant conifers, Abies lasiocarpa (subalpine fir) and Picea engelmannii (Engelmann spruce).

While sunlight exposure and leaf warming during the day can enhance photosynthesis and growth in alpine species, exposure to the accompanying clear, cold skies at night lowers minimum leaf temperatures and severely limits photosynthesis, resulting in inadequate carbon gain to support the root growth necessary to survive the rapidly drying soils of early summer. In addition, the projected increase in cloudcover with global warming increases the diffusion of sunlight. This project will compare the quantitative influences of microsite preference, structural features (leaf to crown), and physiological adjustments on the photoinhibition of photosynthesis (LTP) in the natural environment.

The project uses two new experimental techniques for the first time. It will measure (1) both external and internal fluorescence and (2) the optical properties of diffuse light absorption to gauge their impact on photosynthesis. This approach should lead to a variety of applications for understanding photosynthesis from an entirely new perspective particularly relevant to the predicted increased cloudcover with continued global warming. The project has a strong educational component, including undergraduate and graduate students as well as a local K-12 teacher, and a website will be developed for younger students and accessible to K-12 educators. Finally, the proposed study will provide a more mechanistic model for predicting the future stability of alpine timberlines facing global change. Disappearance of the alpine component of global biodiversity would mean the loss of remarkable genes for withstanding low temperatures and high sunlight levels that might be transferred into agricultural species.

• Ecological Facilitation in the Alpine Treeline Ecotone of Georgia: Implications for Future Global Change
  Awarded $7,000 for the period 1/1/05 to 12/31/07
  Source: US Civilian Research and Demonstration Foundation (CRDF)
  
  
  This investigation is the first comprehensive analysis of the mechanisms dictating alpine treeline stability. It evaluates the fundamental process by which timberlines and treelines migrate either upward into the alpine zone or to lower elevations. The initial study awarded in 2002 brought together research teams from the Institute of Botany, Georgian Academy of Science (FSU), with expertise in distributional ecology, reproductive biology, and seed germination factors in B. litwinowii, and Wake Forest University (USA), with expertise in evaluating the ecophysiology of seedling survival. This second project focuses on the process of ecological facilitation between Betula litwinowii Doluch and Rhodendendron caucasicum Pall. observed during the initial field season in Georgia. Rhododendron caucasicum is one of only a few evergreen, broad- and large-leafed shrub species that can withstand the rigors of this high-altitude environment in the temperate zone. It seems to provide a microclimate that enables B. litwinowii to maximally extend its altitudinal range. Results will provide a strong mechanistic basis for interpreting shifts in the maximum altitude for intact forest and predicting the expansion or contraction of subalpine and alpine vegetation zones in response to global climate changes.

• Global Change and Natural Stabilization of Barrier Island Sand Dune Ecosystem
  Awarded $4,926 for the period 6/1/04 to 5/30/05
  Source: North Carolina Sea Grant

The project will examine sand dune plant communities on North Carolina barrier islands to investigate 3 hypotheses:
1. Episodic storm events have greater impact on annual photosynthetic carbon gain (PCG) than daily stresses, such as temperature, sunlight, water relations, or salt aerosols.
2. Species with favorable life history attributes will survive over species with more favorable PCG, regardless of metabolic or life-form differences, especially during more frequent or intense episodic stress.
3. Certain endangered plants will show the greatest decline in PCG, survival, seed production, and fitness because of episodic storms. Species in high-traffic locations, with off-road vehicle access, will show greater decline in survival and fitness.

• Alpine Tree Stability: Mechanisms of Conifer Tree Seedling Establishment
  Awarded $9,809 for the period 7/1/04 to 7/1/05
  Source: NSF

If current climate warming projections are accurate, a significant portion of the earth’s biodiversity will vanish during the 21st century, and alpine tundra ecosystems in temperate and subtropical latitudes may be replaced by subalpine forest. This study offers a mechanistic explanation of the stability of a transitional zone at the upper elevational limit to tree growth in the south-central Rocky Mountains, as seedlings of the two dominant conifers become established away from the forest edge. Although seedling establishment may be the most selective of all life stages and critical in determining distribution patterns in many species, ecophysiological measurements on newly emerged seedlings in the field are rare. They indicate that atmospheric warming could alter this boundary, leading to a major shift in plant distribution patterns. 

Brian W. Tague
Foundations of Biotechnology at Wake Forest University: New Core Courses in Molecular Genetics and Cellular Biology
Awarded $19,954 for the period 2/1/03 to 1/31/04
Source: North Carolina Biotechnology Center (NCBC)

North Carolina's growing biotechnology workforce needs high-caliber students, trained in the latest concepts and techniques of molecular genetics and cellular biology. To meet this need, the Biology department is reorganizing the core curriculum for biology majors. Two new courses have been designed: Genetics and Molecular Biology and Cell Biology. Coverage of classical genetics, bioinformatics, genomics, central metabolism, and immunology will be expanded, and student-driven investigative laboratories added. In these laboratories, students will learn basic protocols and how to design of experiments. Funds will support new equipment and personnel to introduce technically sophisticated experiments into the undergraduate laboratories.

• REU Supplement to Population Dynamics and Effect of Sex on Natural Yeast Populations
  Awarded $6,000 for the period 6/12/06 to 1/31/07
  Source: NSF
  The adaptive value of sex has not been well established empirically, despite a great deal of theoretical study. While most yeast evolution is conducted in the lab, where conditions can be standardized and readily controlled, several prominent theories of sex propose that environmental variation, either in space or time, is what favors the genetic diversity of sexual offspring. This project compares the fitness of sexual and asexual yeast populations in their natural environment?on and surrounding oak trees. Genes required for mating and recombination are deleted to produce yeast strains that are incapable of sex but otherwise identical to those found naturally at the experimental location, and their fate is then compared to that of their sexual competitors. It also studies the size and genetic diversity of the natural populations, since very little is known about their ecology, population genetics, and population dynamics. Research Experiences for Undergraduates (REU) supplements support student participation