• Evolutionary Genetics of Yeast
• Plant Molecular Genetics
• Evolution of Animal Communication
• Molecular Biology of Protein Synthesis
• Plant Growth and Development
• Neurobiology of the Chemical Senses
• Physiological Plant Ecology
• Animal Form and Function
• Biology of Freshwater Mussels:a Taxon in Peril
• Neuroanatomy: What regulates the structure of the brain? How is brain structure related to behavior?

Refer to individual faculty profiles for more research opportunities.

Evolutionary Genetics of Yeast. Cliff Zeyl's research makes use of the tremendous advances being made in the biology of the budding yeast (Saccharomyces cerevisiae), particularly in the areas of molecular genetics, to construct laboratory test populations, and then to observe their evolution as it occurs. Because yeast populations can undergo up to 16 generations per day, significant evolutionary changes can be observed within several months, under precisely controlled and replicated conditions. For an example of this type of research see his paper in Nature (1998) 388: 465-468.

Here are two examples of the kinds of questions that could be addressed in his lab.    Email Cliff Zeyl for more information.

The roles of chance and historical contingency in adaptation: biologists have often wondered whether evolutionary history would repeat itself given identical starting conditions, or whether every outcome is unique. More precise genetic theories about adaptation also lead to contrasting predictions about the repeatability of evolutionary history. These can be tested by experiments in which cryogenically preserved samples taken from evolving yeast populations over hundreds of generations are revived and used to start parallel evolving populations. Will they repeat the evolutionary changes observed the first time?

Sex and co-operation within genomes: Most genomes contain sequences which appear to be molecular parasites, such as plasmids, transposons, and mobile introns. Over many generations of co-evolution, initially parasitic associations may become commensal or even mutualistic. By breaking up such co-evolving associations, sex may hinder the evolution of co-operation within genomes. Asexual and sexual yeast populations carrying initially harmful plasmids can be used as a model to study these processes.

Plant Molecular Genetics and Development.
Research in the Tague lab focuses on the molecular genetics and development of higher plants.

The C₂H₂ Zinc Finger Protein Genes of Arabidopsis thaliana
Our laboratory has been working on a family of regulatory proteins from Arabidopsis thaliana known as zinc finger proteins (AtZFPs: Arabidopsis thaliana zinc finger proteins). ZFPs have been shown to play crucial regulatory roles in such developmental and morphological pathways as flower development, leaf initiation, lateral shoot initiation, gametogenesis and seed development. Research opportunities include continuing experiments in understanding the function of AtZFP1 and other ZFPs from Arabidopsis by isolating genetic “knock-outs”, analyzing expression using Green Fluorescent Protein and developing transgenic plants.

Cold perception in a model biennial crucifer, Barbarea verna
We are investigating members of the Brassicaceae with developmental or morphological features not found in Arabidopsis thaliana. Our primary focus is an analysis of the signal transduction pathway for flowering in biennials, which flower after induction by cold. Understanding the induction of flowering by cold has important implications for agriculture and horticulture. Research opportunities in this project include a wide array of molecular and physiological approaches to flower induction. In the near future, for example, we will begin construction of genomic and cDNA libraries to aid in the isolation of genes involved in the flower signal transduction pathway. . We will continue to look at the interplay between age, temperature, light and hormones to understand the induction of flowering in this and other biennials.

Interested undergraduates and prospective graduate students should e-mail Brian Tague  for more information. To learn more about Arabidopsis, Barbarea verna, and life in the Tague lab, click here

Bat/Moth Interactions. Arctiid moths deal with echolocating bats in two ways. First, they hear the echolocation cries of bats and avoid bats with a series of evasive maneuvers including loops, spirals, and power dives. Second, they click back at bats. Some researchers suggest that arctiids are jamming the echolocation system of bats and others suggest that they are advertising their unpalatabilty. Using phylogenetic techniques we hope to determine which hypothesis is correct.

Ultrasonic Communication in Tiger Moths. Once moths evolved ears and the ability to produce sound using tymbal organs, it was apparently a simple step to use these structures in their own courtship. But what message do the sounds convey?

Chemical Communication in Tiger Moths. Arctiids are masters of chemical communication. They feed as larvae on plants that contain pyrrolizidine alklaloids and/or cardiac glycosides. These compounds protect them from predators like bats and birds. In some cases males derive their sex pheromones from these defensive compounds. Why?

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Molecular biology of protein synthesis. The ribosomal translation of the genetic code is a fundamental biological process. Cells are composed mostly of protein, and cellular well-being depends on the accurate and efficient production of that biomass. In addition, there are specific mRNA sites in which errors occur at very high frequencies to generate active proteins. For example, a very high frequency frameshift occurs at a specific site in the AIDS virus mRNA. If we could prevent this "programmed frameshift," then the AIDS virus could not grow. We have ongoing projects that explore the molecular mechanisms of programmed frameshifting, translational accuracy, and the evolution of the genetic code. For further information visit Jim Curran’s web site.

DNA molecules as biotech reagents. For many years, antibodies have been used as specific reagents for the detection of pathogens or the quantification of key biological markers of human health. Antigen specificity is the fundamental feature of antibodies that permit these uses. It has recently been shown that synthetic nucleic acids can be created that have binding affinities and specificities as great as those of antibodies. Furthermore, the technologies needed to develop nucleic acid based reagents are much simpler and cheaper than those needed to develop antibody reagents. We exploit these characteristics to develop synthetic DNAs as biotech reagents. For further information visit Jim Curran’s web site.

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Establishment of cellular asymmetry by attachment of an auxin transport protein to the actin cytoskeleton:
One important question that the Muday lab has focused on in recent years is understanding the mechanism by which the auxin efflux carrier stays in only one part of the plasma membrane. These experiments have found that the regulatory protein of the efflux carrier interacts with the actin cytoskeleton that spans the inside of membrane. By forming links with the actin network, the lateral movement of the auxin efflux carrier along the lipid bilayer is apparently restricted. Current experiments in the lab seek to understand whether the cytoskeleton or its association with this protein complex change to allow alterations in either the amount or directionality of auxin movement and on biochemical dissection of all the proteins that form the auxin efflux carrier protein complex.

Examination of the role of auxin transport in development and gravity response:

Additionally, researchers in the Muday lab are more directly exploring the role of auxin transport in plant growth and development. Auxin transport can be altered in plants by use of specific inhibitors that block auxin movements and through the use of plants with lesions in genes that encode auxin transport proteins. The resulting changes in plant growth and development can provide insight into how auxin transport is linked to plant growth and development. These studies have helped strengthen the link between auxin movement and lateral root development and differential growth in response to changes in gravity and light gradients. Current experiments focus on examining the role of auxin transport in plant embryo development and gravity response.

Wayne Silver’s research examines the neurobiology of the chemical senses, including taste, smell, and trigeminal chemoreception (chemesthesis). The lab’s present focus is the characterization of nasal trigeminal chemoreceptors as well as the assessment of the role of these receptors in a number of physiological reflexes. Chemical stimuli entering the nasal cavity stimulate both trigeminal and olfactory receptors. Trigeminal chemoreceptors, usually associated with irritating stimuli, are a class of pain receptors and do not constitute a separate chemical sense. In addition to their role as affectors, signaling the presence of irritating stimuli, these receptors have an effector role, initiating processes which tend to keep the irritating compound from potentially damaging the body. Examples of trigeminal chemoreception include the stinging of ammonia and the burning of horseradish and chili peppers.

A variety of techniques are used including electrophysiological, physiological, and behavioral. The work is done mainly on rats, although other subjects, including humans have been examined. Recently, the research has taken two directions. E-mail Wayne Silver or visit his home page for more information.

Characteristics of Nasal Trigeminal Chemoreceptors.
How do chemical stimuli interact with trigeminal nerve endings? We are examining rat ethmoid nerve (branch of trigeminal innervating the nose) responses to chemical irritants presented to the nasal cavity. By using specific pharmacological agents we can determine what kinds of receptors may be involved in eliciting the response. For example, we recently determined that nicotine is probably stimulating a particular kind of nicotine receptor on nasal trigeminal nerve fibers (Chemical Senses, in press). Further work is necessary to characterize other possible receptors on the trigeminal nerve endings

Effects of Irritants/Odorant on Cerebral Blood Flow. In addition to projecting to the nasal epithelium, trigeminal fibers innervate blood vessels within the cranium. These vessels are the only pain sensitive structures within the cranium and are collectively referred to as the trigeminovascular system. It is now generally believed that stimulation of the trigeminovascular system is responsible for the pain associated with vascular headaches. We are examining the effect of irritants/odorants delivered to the rat nasal cavity on cerebral blood flow and have shown that some odorants can cause increases blood flow as measured by laser Doppler flowmetry (Chemical Senses, in press). This may provide a mechanism to explain odor-induced headaches. Further studies will determine which irritants/odorants and what parameters are necessary to elicit the increased blood flow

Dr. Bill Smith’s broad interests are concerned with how plants have adapted to their respective habitats in order to understand plant evolution and current distribution patterns. His research has been conducted in the deserts of the southwest US, the forest and alpine of the Rocky Mountains, the Australian Outback, and Hawaiian tropical forests. Most of his current projects involve a global change perspective (e.g. elevated CO2, atmospheric warming, air pollution). He is interested in continuing his research in the Rocky Mountains, in addition to initiating new projects in the mountains of the Southern Appalachians and the sand dunes of the Outer Banks. His current interests include the following topics (although Dr. Smith invites students to work on their own areas of interest within the broad realm of physiological ecology):

• Air pollution effects on high elevation tree species
• Plant/leaf form, sunlight interception, CO2 processing, and photosynthesis
• Effects of high elevation on plant gas exchange
• Low temperature and high sunlight inhibition of photosynthesis, plus impacts of frost and dew formation on gas exchange;
• Determination of carbon exchange for different plant communities.

Dr. Smith’s lab combines both field and laboratory studies utilizing portable photosynthesis systems and controlled experiments in growth chambers and the glasshouse. His lab is fully equipped for fieldwork in remote areas such as mountaintops utilizing camping trailers and 4-wheel drive vehicles. Dr. Smith is currently interested in taking on new students to begin work funded by the NSF, NASA, DOE, and other national agencies. Contact Bill Smith at smithwk@wfu.edu and view his web page at www.wfu.edu/~smithwk/smithwk.htm.

Miriam Ashley-Ross’ research focuses on the mechanistic basis of animal behavior, particularly locomotion. Her own research projects use "lower" vertebrates (fish and salamanders), though current graduate students are investigating locomotor performance in groups as diverse as Thoroughbred racehorses, Nazca boobies, and wasps. The unifying research theme of the laboratory is the neural control of locomotion, and we approach this problem using a variety of techniques:

• high-speed video to record the pattern of movement
• electromyography (recording patterns of muscle activity)
• sonomicrometry (recording actual muscle length changes during locomotion)
• in vitro measures of muscle work and power output

Current projects include investigation of the performance characteristics of muscles that differ in their fiber types (but are otherwise similar), and how specialized muscles are "built." For this latter project we are comparing the very fast-contracting dorsal fin muscle of seahorses and pipefish (contract at 20 - 50 Hz against the high resistance of water) to dorsal fin muscles of more typical fish. Graduate students are encouraged to develop projects along their own research interests, but examples of questions that might be addressed in the lab are (1) the mechanics of the escape response in fish with widely varying body forms, and (2) the characteristics of the muscles underlying the “escape response” in armadillos (when startled, these animals leap straight up about 3 feet), as well as the mechanics of the behavior itself. E-mail Miriam Ashley-Ross for further information, or visit the lab web page.

The molluscan Order Unionoida includes some of the most endangered animals in the world. Pollution, stream modification, fisheries pressure and competition from non-indigenous species, combined with the complexity of their life cycles, make freshwater mussels especially vulnerable to local or ultimate extinction. In the US, home to the greatest diversity of mussels on Earth, 70% of the 300 species are listed as threatened or endangered. Ironically, relatively little is known about fundamental aspects of their biology. Dr. Ron Dimock's laboratory (email or visit his lab's web site) is engaged in the following kinds of studies:

Anatomy and physiology of larvae. Using light, fluorescence, and scanning electron microscopy we are studying metamorphosis of larvae (glochidia) to juvenile mussels. This process normally occurs within a cyst on a host fish and has eluded careful study. By using in vitro techniques to induce metamorphosis in the laboratory, we can now follow the progression from larva to juvenile.

Physiology and behavior of juvenile mussels. With large numbers of juveniles available from laboratory culture, basic aspects of the biology of this critical stage in mussel life history can be addressed. We currently are studying the physiological ecology, metabolism and growth of juveniles.

Functional morphology of brood chambers. In contrast to marine bivalves, freshwater mussels retain the developing embryos in specialized areas of their gills. Using video endoscopy and scanning electron microscopy we are compiling comparative data that address functional aspects of the brooding habit.

Immunology of host/larval interactions. In nature glochidia larvae must attach to a suitable host fish to complete their metamorphosis to juveniles. Whether or not fish become immune to this infestation remains poorly understood. The question is important, in part because one approach to the reintroduction of mussels to extirpated populations would utilize glochidia- infected fish.

What regulates the structure of the brain? How is brain structure related to behavior?

The laboratory of Dr. Susan Fahrbach uses insect models to address questions of fundamental interest to all neuroscientists: How do hormones shape the developing nervous system? How does experience alter the brain? Current research in the Fahrbach laboratory focuses on the post-embryonic development of the nervous system, with an emphasis on metamorphosis and the adult stage of life. Important questions currently being investigated ask why nuclear hormone receptors associated with early development are expressed in the bee brain when metamorphosis is complete, how foraging experience increases the volume of the mushroom body neuropil in forager honey bees, and how the circadian clock in the honey bee brain controls behavior. The Fahrbach laboratory is also participating in a 5 year, multi-investigator project funded by the National Science Foundation (http://inquiry.uiuc.edu/cil/out.php?cilid=225) that is using the honey bee to investigate the relationship between nature and nurture by identifying behaviorally relevant patterns of gene expression in the honey bee brain.

Students in the laboratory would initially join a project in progress, but would then be encouraged to develop their own projects using the tools available in the laboratory. Examples of such projects are:

Use of primary cultures of honey bee neurons to determine the factors that control dendritic growth in the adult:
These cell culture studies are designed to identify the hormones and neurotransmitters that promote dendritic growth. The in vitro approach permits the manipulation of gene expression using methods for cell transformation and RNA intrerference.

Mapping the distribution of steroid hormone receptors in the nervous system of the moth, Manduca sexta.
Why are there multiple isoforms of the ecdysteroid receptor (EcR) in the insect nervous system? These neuroanatomical studies are designed to produce detailed maps that can be interpreted in the light of known aspects of neurometamorphosis, including neurogenesis, cell migration, dendritic growth, and establishment of neurotransmitter phenotype.

Effects of cholinergic agonists of honey bee brain structure and behavior.
Stimulation of muscarinic cholinergic structures in the honey bee brain produces growth of brain centers involved in learning and memory and improves the ability of bees to discriminate nestmates from non-nestmates. We are planning both neuroanatomical and behavioral studies to examine in detail the role of cholinergic transmission in honey bee behavioral plasticity.

Identifying the molecular components of the honey bee brain clock.
These studies are designed to identify the cell populations that express clock genes in the honey bee brain. A major goal is to compare the organization of the brain clock of the bee with that of the fruit fly (Drosophila melanogaster) and that of the mammal (the mouse and the human). Is the clock of the bee more like that of the fly or more like that of the human? The answer might surprise you.

Email Susan Fahrbach if you would like to be involved.

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