Faculty Reseach Interests

MAVIS AGBANDJE-MCKENNA (392-5694) - My research interests center around structure function relationships, with the belief that knowledge of structure is essential to understanding the function of biological macromolecules and the numerous array of intricate macromolecular interactions that govern biological processes. The main body of my research is aimed at using a multi-disciplinary approach (structural biology - namely X-ray crystallography and cryo-electron microscopy - in combination with expertise in molecular biology, molecular genetics, biochemistry, histopathology and spectroscopy in collaborating laboratories) to examine events that occur during viral infection. The goal is to elucidate essential structural information that can be applied to the development of treatments of viral diseases that afflict animals and plants, in the form of viral vaccines, foreign antigen delivery vehicles and gene therapy systems.
Email: mckenna@ufl.edu
Website: McKenna lab

JOHN P. ARIS - Cellular Aging Mechanisms. Our laboratory is interested in the cellular basis for aging. There are a number of mechanisms at the cellular level that contribute to the aging process, including, but not limited to: (1) genomic instability; (2) reactive oxygen species (ROS) damage; and (3) impaired DNA repair pathways. Genomic instability includes loss and rearrangement of genetic information in either dividing or non-dividing cells. For example, shortening of telomeres (loss of telomeric repeat sequences) at chromosome ends in dividing cells leads to replicative senescence (failure to divide). In yeast, recombination within the repetitive rDNA sequence give rise to extrachromosomal circular rDNAs that are linked to the aging process. We use yeast as an experimental system because of the ease of using various approaches in biochemistry, cell biology, genetics, and molecular biology. Our goal is to pursue mechanisms that regulate replicative lifespan in yeast cells and extend our studies to other cells types in order to better understand general mechanisms that influence aging at the cellular level.
Email: johnaris@ufl.edu
Website: Aris lab

LINDA BLOOM (392-8708) - Our general research interests are in the dynamic protein-protein and protein-DNA interactions that are required to maintain the structure of DNA and to preserve the genetic integrity of DNA. Our current research is focused in two general areas, DNA replication and DNA repair. We are investigating the activities of individual enzymes required for these processes, as well as the coordination and timing of interactions between proteins and between proteins and DNA. In addition to using traditional biochemical and biophysical approaches to study these systems, we are using novel fluorescence techniques for monitoring these dynamic processes in real time.
Email: lbloom@ufl.edu

MICHAEL R. BUBB, M.D. (273-5346) - Cell motility is relevant to virtually all aspects of human physiology and pathophysiology, functioning critically in carcinogenesis, cardiovascular disease, neurodevelopment, and autoimmunity. Students in our laboratory will learn biophysical and cell biological techniques used to characterize protein-protein and protein-drug interactions. Undergraduate research projects may focus on marine natural products that perturb cell motility, with an emphasis on the development of pharmacological agents that exploit the motile properties of cells to treat human disease. Additional undergraduate projects concern the role of cell motility in memory and learning or in the development of cancer.
Email: bubbmr@medicine.ufl.edu
Website: Bubb lab

JÖRG BUNGERT (392-0121) - Our laboratory is interested in fundamental mechanisms governing the regulation of chromatin structure and gene expression in eukaryotic cells. As a model system, we study the regulation of the human b-globin gene locus, which is active only in red blood cells. The five human b-globin genes are located on chromosome 11 in an order reflecting their expression during development with the embryonic e-globin gene at the 5’ end and the adult b-globin gene at the 3’ end. Developmental stage-specific expression of the genes is mediated by DNA regulatory elements that are located proximal and distal to the genes. One of the most prominent and powerful distal DNA regulatory elements in the b-globin locus is the locus control region (LCR), located from 8 to 22 Kbp upstream of the e-globin gene. The LCR is composed of several units that act together to confer high-level globin gene expression. The LCR harbors both strong enhancer as well as chromatin opening activities. We are using biochemical, molecular, and genetic methods to analyze LCR structure and function. In the biochemical assays, we reconstitute the LCR in vitro and analyze protein-protein and protein-DNA interactions. In the molecular studies we analyze the interaction of transcription complexes and other transcription factors with the globin locus in erythroid cells using in vivo methods. In the genetic studies, we generate transgenic mice with wild-type and mutant globin loci and analyze globin gene expression and chromatin structure to dissect the function of regulatory elements. We also use genetic methods, homologous and site specific recombination techniques, to develop novel procedures for the site-specific integration of globin expression constructs into the mouse genome.
Email: jbungert@college.med.ufl.edu

BRIAN D. CAIN (392-6473) - The proton-translocating ATP synthases are the principal energy-transducing enzymes of most biological organisms. Both the mechanism of protein-facilitated proton movement across the membrane and the processes coupling proton translocation to catalysis are unknown. We are interested in studying these questions using a combination of biochemical and molecular biological approaches. Analysis of site-directed mutations resulting in defective proton translocation allows for the assignment of functional roles to specific amino acid residues in the enzyme.
Email: bcain@biochem.med.ufl.edu

NANCY D. DENSLOW (392-4700 x 5563) - My laboratory works on developing biomarkers at the protein and mRNA level that relate to exposure to environmental contaminants. We use fish as models because they are present in the environments that are most contaminated. We are looking at compounds that behave as estrogen or androgen mimics and that turn on the expression of genes controlled by these hormones at inappropriate times. We are interested in finding out how these compounds adversely affect health and reproduction. We have developed both in vivo assays and cell based assays to measure activity of estrogen receptors and use microarrays and proteomics approaches to identify biomarkers that are relevant to mechanisms by which contaminants exert their deleterious effects. A new direction in the laboratory is to examine the health effects of exposure to nanoparticles.
Email: ndenslow@ufl.edu

BEN M. DUNN (392-3362) - Our laboratory is directed at understanding the interactions that lead to enzyme specificity and catalysis, especially for proteolytic enzymes. In this way, we hope to discover critical interactions contributing to binding and catalysis, and identify points important in selective drug design. Included in the systems that are under study are several members of the aspartic proteinase class of enzymes; the digestive enzymes pepsin and gastricsin, the tissue enzymes cathepsin D and E, and the virally encoded enzyme from the Human Immunodeficiency Virus (HIV), the causative agent for AIDS, as well as other retroviruses. We are also involved in another study dealing with similar enzymes from the malarial parasite, Plasmodium falciparum. We also study some members of the serine proteinase family, such as bacterial subtilisins and a related enzyme from human brain, CLN2, involved in a neurodegenerative condition, classical late-infantile neuronal lipofuscinosis. We use molecular biology, microbiology, protein chemistry, enzymology, x-ray diffraction, and molecular biophysics.
Email: bdunn@college.med.ufl.edu

ARTHUR S. EDISON (392-4535) - My laboratory focuses on the structure-function relationships of small, biologically active neuropeptides. Our primary tools are high-resolution NMR spectroscopy, molecular biology, protein expression, and computer modeling. NMR: Structural studies of FMRFamide-like peptides (FLPs) and other peptides. Students can learn NMR acquisition, data processing, and data analysis on several relatively simple peptides. This work involves the same techniques that are used for complete proteins but on smaller molecules. Molecular Biology: Identification of new FLP receptors. Students can find an invertebrate (e.g., mollusk, nematode, arthropod, etc.), extract RNA, make cDNA, and use PCR to find new FLP receptors. Isolate peptide antibody clones from a phage library. Students can screen a phage library for clones that bind to particular FLP sequences. Once clones are identified, students can use bacterial mutagenesis to optimize the binding of the antibody fragments. Other: Interested students can arrange to work on other ongoing projects. Email: art@ascaris.health.ufl.edu

SUSAN C. FROST (392-3207) - Glucose acts as both a metabolic substrate and a signaling molecule. My laboratory is interested in both aspects of glucose function. As a signaling molecule, we believe that glucose depresses its own flux into cells. This means that in its absence, the activity of the protein that mediates its transport across the plasma membrane is substantially increased. We have hypothesized that the increase in transport activity is related to the synthesis of a novel protein during glucose deprivation. This protein may modulate the activity of the existing transporter....or function as a new transport molecule, itself. We are currently using both biochemical and molecular techniques to identify this protein. We are also interested in protein processing, and particularly that of the insulin receptor, in response to glucose deprivation. Using antibodies to identify the receptor, we have shown that glucose deprivation alters glycosylation of the receptor which prevents its release from the point of synthesis (the endoplasmic reticulum). This is allowing us to model certain human disease states which cause retention of the receptor in the endoplasmic reticulum, preventing its targeting to the plasma membrane which is its functional domain.
Email: sfrost@ufl.edu

SUMING HUANG (273-8199) - My research interests focus on epigenetic regulation of chromatin structure and gene expression. We study the structure and function of chromatin insulator located at the 5’end of chicken b-globin locus. We have identified two kinds of insulator functions mediated by distinct proteins and co-factors, one is CTCF that blocks inappropriate activation of a promoter by a distal enhancer, and the other acts as a chromatin barrier against encroachment of heterochromatin into adjacent euchromatin regions. The second activity relies on binding of the transcription factors USF1/USF2 and its ability to recruit histone modifying enzymes. Currently, we are examining the mechanisms of which USF1 maintains a local environment of active chromatin, both by biochemical and functional analysis of the USF1 containing protein complexes, and by studies of the effects of protein knockdown on the local and long range chromatin structure and histone modification patterns. Another project my laboratory will focus is the regulation of TAL1 oncoprotein activity. Activation of the TAL1 gene is the most frequent gain-of-function mutation in T-cell acute lymphoblastic leukemia (TALL). We will use biochemical and epigenetic approaches to determine: 1) The mechanism underlying the ectopic activation of TAL1 transcription, 2) The mechanism dictating the TAL1 activity in normal and pathological hematopoiesis.
Email: sumingh@ufl.edu

SHALESH KAUSHAL (contact Mark P. Krebs, 392-8561) - An exciting new concept in molecular medicine is that many human diseases may be caused by defects in protein folding. To test this idea, our laboratory studies misfolded proteins associated with inherited eye diseases, particularly retinitis pigmentosa (RP). Many families with RP have mutations in rhodopsin, a protein in the eye that binds vitamin A and detects light. We are actively exploring how misfolded rhodopsin causes RP and developing approaches to treat the disease. In one approach, we add small molecules, such as vitamin A, that bind to the protein and improve its folding in the cell. In another, we stimulate cellular pathways to remove the misfolded protein. We seek talented and motivated students to help with this work. Students can expect to learn PCR, cloning, sequencing, cell tissue culture, protein gel electrophoresis, and UV/visible spectroscopy.
Email: mpkrebs@ufl.edu

WILLIAM R. KEM (392-0669) - My lab investigates naturally occurring toxins, their use as molecular probes of membrane ion channel function and as molecular models for the design of new drugs. Three types of toxins are currently under investigation:(1) heterocyclic compounds from nemertine worms that selectively activate certain brain nicotinic acetylcholine receptors, are being used to design drugs which can enhance cognition (learning and memory) in persons suffering from dementia, (2) peptide toxins which affect voltage-gated sodium or potassium channels in lymphocytes and brain neuronal membranes are being used as models for designing new immunosuppressant drugs, and (3) proteins which lyse cells by forming new membrane ion channels are used to understand how proteins insert into membranes. In addition we are also investigating the chemistry and molecular mechanisms of action of certain plant alkaloids, which block nicotinic acetylcholine receptors in the brain. The lab offers the student opportunities for learning how to purify and characterize peptides, proteins, and heterocyclic molecules, and for learning pharmacological techniques, including radio ligand binding to receptors, 96-well functional assays using cultured cells, isolated muscle and nerve preparations and whole animal assays. Computer modeling is used to visualize the docking of these molecules with their receptors.
Email: Kem@pharmacology.ufl.edu

PHILIP J. LAIPIS (392-6870) - Mitochondrial DNA is a unique genetic entity. We are using DNA cloning/sequencing and pedigree analysis of inbred animals to understand the mechanisms of maternal inheritance of mitochondrial DNA. We are studying mitochondrial segregation after microinjection of mitochondrial into oocytes with the long-term goal of developing a mitochondrial genetic exchange system. A second focus of our research involves cloning the genes for mammalian carbonic anhydrase isozymes and using site-directed mutagenesis to achieve an understanding of the differences in enzyme mechanisms. We are also looking at how regulation of the tissue-specific expression of this gene family occurs.
Email: plaipis@ufl.edu

JOANNA R. LONG (846-1506) - Our laboratory is studying the complex interactions between proteins and cell membranes in order to understand the roles of specific lipids and cholesterol in affecting protein structure, binding, and function. We are especially interested in two classes of proteins: membrane-spanning signal transduction proteins and proteins involved in lipid trafficking and modification. Our studies are currently focused on lung surfactant protein B, a protein critical to proper lung compression and expansion; the ion channel-forming domain of the nicotinic acetylcholine receptor, a major target of anesthetics and neurotoxins; the avb3 integrin receptor, a protein important to cell binding and differentiation; and the amyloid b peptide, the causative agent in Alzheimer ‘s disease. We also are examining the potential for immobilizing these proteins in a functional state on polymers and electronic sensors for biomedical engineering applications. We use protein chemistry, molecular biology, calorimetry, optical spectroscopy, and solid state NMR in our inquiries.
Email: jrlong@mbi.ufl.edu

JIANRONG LU (273-8200) - The major research interest in the laboratory is toward understanding the role of chromatin regulation in mammalian development and cancer. Defects in chromatin structure lead to aberrant gene transcription and genetic instability, which contribute to many developmental defects and cancers. Previously, we performed a genome-wide RNAi screen in cultured Drosophila cells and identified chromatin factors implicated in repression of E2F, a transcription factor critical for cell proliferation and differentiation. We are now extending this study using the mouse models. We focus on two types of chromatin regulators: the mammalian SWR1 chromatin-remodeling complex and MBT domain-containing Polycomb Group (PcG)-like proteins. Currently, we are using mouse genetics to address their function in embryonic development and tumor suppression, and biochemical and molecular approaches to elucidate the mechanisms by which these factors modulate chromatin and transcription.
Email: jrlu@ufl.edu

PETER M. MCGUIRE (392-6853) - Our research interests focus on the regulation of gene expression at the transcriptional level. Presently, recombinant human antibodies and phage display are being used to isolate single chain antibody fragments [scFvs] which bind to molecules that regulate this process. Expression of these antibody fragments in vivo has the potential to affect phenotype transiently and thus provide insight into cell components and processes critical to normal development and homeostasis, or to pathogenesis. Collaborations using these molecules include characterization of scFvs to hormones and to tumor-specific cell antigens, for diagnostic and therapeutic evaluation, as well as development of reagents to examine the cell surface components and genetics of the red tide organism Karenia brevis.
Email: pmcguire@biochem.med.ufl.edu

ROBERT McKENNA (392-5696) - My laboratory focuses on the structure-function relationships of biological macromolecules. Our primary research techniques are X-ray crystallography and three dimensional computer modeling and in collaboration with other research groups, molecular biology, protein and virus expression. The goals of our research is to understanding biological processes at the atomic structure level and identify how the complex amino acid and/or nucleic acid structure of a biological macromolecule is utilized to perform a specific function. We current study various enzymes and correlate their structure to function. Interested students can arrange to work on ongoing or initiate new projects in collaboration with other faculty.
Email: rmckenna@ufl.edu
Website: McKenna lab

JAN S. MOREB (392-9004) - My laboratory interest centers on the significance of aldehyde dehydrogenases in the biology of lung cancer. Lung cancer is the leading cause of cancer-related mortality. In order to impact the curability of lung cancer, we need to better understand the biology of the disease. Aldehyde dehydrogenase class-1A1 (ALDH-1) and class-3A1 (ALDH-3) have been reported to be highly expressed in non-small cell lung cancer. These enzymes are known to be responsible for drug resistance in many cancer types and be involved in carcinogenesis and malignant transformation. Our main working hypothesis is that high levels of these enzymes in lung cancer are related to the evolution of the malignant process and exposure to carcinogens, and may reflect a malignant phenotype with drug resistance against a wide range of anticancer drugs. Our specific aims are to establish the relationship between ALDH-1/ALDH-3 and the pathogenesis of lung cancer, and to determine the relative contribution of each isozyme to drug resistance against 4-hydroperoxycyclophosphamide.
Email: morebjs@medicine.ufl.edu

HARRY S. NICK (392-3303) - Our laboratory's research focuses on understanding how mammalian genes are turned on and off by cell- and tissue- specific mechanisms. We utilize advanced techniques in molecular biology to study molecular mechanisms which control how genes are regulated, by understanding the organization of chromatin structure and studying protein-DNA interactions. We study specific genes which are closely linked to the underlying mechanisms which influence tissue inflammation in the lung, intestine, and brain. Studies are primarily concerned with gene regulation at the following loci: 1) the manganese superoxide dismutases, which serve as intracellular antioxidant regulators; 2) the inducible form of nitric oxide synthase which produces a potent vasodilator and neurotransmitter, nitric oxide; and 3) the cytoplasmic phospholipase A2, an enzyme which generates metabolites involved in promoting inflammation as well as intracellular signaling pathways. Our lab also pursues studies on gene expression following spinal cord injury where we are studying the induction of genes following this type of insult. In addition we have an active program in gene therapy targeting genes that protect cells from damage in models of spinal cord injury and an extensive program in diabetes. There is an immediate opening in our lab for an undergraduate student.
Email: hnick@ufl.edu

THOMAS W. O’BRIEN (392-6878) - Our studies have shown that mammalian mitochondria contain unusual ribosomes that differ structurally and functionally from other ribosomes. These ribosomes are products of two separate genomes, and they appear to be evolving more rapidly than other ribosomes. Among their remarkable features is the presence of several new proteins not found in other ribosomes, including a GTP binding protein implicated in programmed cell death. We are using affinity probes, immunologic, and biochemical approaches to study their organization and unique functional properties. The nuclear genes for all of the mitoribosomal proteins are scattered among different chromosomes, many mapping to disease loci associated with deficiencies in energy metabolism, such as neuropathies, myopathies, developmental and sensorineural disorders and deafness. Other studies address the mechanism of mRNA binding to mitochondrial ribosomes, and the role of specific initiation factors and GTP in the initiation of protein synthesis in this novel translation system.
Email: tobrien@ufl.edu

DANIEL L. PURICH (392-9410) - Microtubules play central roles in cell motility, mitosis, and specialization, and my primary research goal is to understand such processes at the molecular level. Ultimately, every aspect of microtubule action (including self-assembly, coordination with other cellular organelles, and effective regulation) will be related to the unique structural and chemical properties of the microtubule proteins. We seek to identify and to characterize these molecular design properties by borrowing, combining, and extending techniques in biophysics, enzymology, and cell biology with the further intent to provide an integrated molecular and cellular perspective.
Email: dlpurich@ufl.edu

VIJAY S. REDDY, M.D. Ph.D. (392-7346) - Our research is based on cancer immunology focusing on blood stem cell or bone marrow transplantation. We address complications of cancer patients after transplantation and study the immune system in the laboratory to understand and develop new treatments against cancer. Our studies include specialized immune cells called dendritic cells and lymphocytes and inflammatory cytokines from human blood that may have a potential as vaccines to challenge patient's own immune system to fight against cancer. The student will learn about laboratory bench to bedside "translational" basic and clinical research and develop an understanding of the immune system and interaction with cancer.
Email: reddyvs@medicine.ufl.edu

KEITH D. ROBERTSON (392-1810) - The focus of the laboratory is on understanding how epigenetic modifications of the genome, such as DNA methylation and core histone post-translational modifications, regulate normal cellular processes (development & differentiation) and how dysregulation of these modifications leads to human disease. We are particularly interested in how aberrant DNA methylation patterns in the genome contribute to cancer and how DNA methylation may be used a biomarker to detect and diagnose cancer more effectively. Specifically, we use many molecular biology techniques (PCR, RT-PCR, cell culture, recombinant DNA, and expression microarrays) to identify important growth regulatory genes that undergo aberrant DNA methylation-mediated silencing in cancer and, if the gene function is not known, we undertake a variety of assays to try and better understand its role in cancer formation and/or progression.
Email: keithr@ufl.edu
Website: Robertson lab

KATHLEEN T. SHIVERICK (392-3545) - Regulation of Reproductive Function and Fetal Growth - A major area of investigation, funded by the Superfund Program Project Grant and NIH, is studying cultured human placental, uterine and prostate cell lines to characterize the direct effects of cigarette smoke and prototype environment al chemicals on the expression of growth regulatory genes. Our hypothesis is that carcinogens, polychlorinated biphenyls and/or dioxins alter reproductive function by disrupting growth regulatory networks, which are recognized to be essential for differentiation, proliferation, migration and hormone secretion. The growth regulatory systems under study include the cell cycle regulatory proteins (cyclins and their inhibitors), the tumor suppressor gene p53, and the major pro-inflammatory cytokines (ILs-1, -2, -8; TNF-a and interferon). Dose-response relationships are being established for altered expression of specific genes to determine which endpoints are the most sensitive biomarkers of exposure and toxicity. Studies are evaluating whether these environmental chemicals alter gene expression at the level of transcription or mRNA stabilization, as well as at the level of protein products. Gene expression profiling (genomics) and knockout experiments are in progress to identify which cell signalling molecules and pathways mediate the major toxic effects on cell functions. Thus, the dysregulation of cell cycle progression and cytokine gene expression may interfere with normal placental growth and vascular development, which may predispose to low birth weight. Our studies with a number of human uterine and prostate cancer cell lines have found selective deregulation of specific genes important for migration and inflammatory responses. These studies will provide essential information in determining whether environmental contaminants may be linked with uterine endometriosis or infertility in women, as well as prostatic disease in men.
Email: kshiveri@college.med.ufl.edu

DAVID N. SILVERMAN (392-3556) - Our laboratory is involved in research on the basic steps of very fast enzymes. Of particular interest is the large number of carbonic anhydrase isozymes that convert CO2 into HCO3- and a proton as well as the antioxidant enzyme superoxide dismutase; these are among nature’s most rapid catalysts. Using site-directed mutagenesis, this research aims to understand the role of specific amino acids in the rapid catalysis and to relate this information to a functional role for the enzymes in cells. The methods used are mass spectrometry, nuclear magnetic resonance, rapid-mixing kinetics, and computer modeling. Students will be able to use these instrumental methods as applied to problems in enzyme catalysis and inhibition. The design and testing of drugs that inhibit these enzymes are also part of this work.
Email: silvermn@college.med.ufl.edu

W. CLAY SMITH (392-0476) - Research in my lab centers on the molecules involved in phototransduction - the biochemical process by which photons are converted into a neural signal. The phototransduction enzyme cascade is an exquisitely sensitive system, being capable of producing a neural response to a single photon. Our fundamental approach is a combination of molecular biology coupled with biochemistry. Specifically, we create directed mutants of the phototransduction elements and test the heterologously-expressed components in functional assays. Interesting leads are ultimately tested in transgenic frogs to prove that what we find in the test tube is how it really works in the animal. Students in my lab can expect to learn molecular biology techniques (pcr, cloning, DNA sequencing, etc.), protein chromatography, and confocal microscopy.
Email: csmith@eye1.eye.ufl.edu

PETER W. STACPOOLE (392-2321) - Our work centers on the causes and treatment of genetic and acquired disorders of mitochondrial energetics. In particular, we are interested in understanding the molecular, biochemical, and clinical consequences of congenital mutations in nuclear or mitochondrial DNA that give rise to loss of function of critical mitochondrial enzymes involved in substrate utilization and oxidative phosphorylation. We use predominantly human biopsy tissue to investigate the cellular and molecular pathobiology of these diseases and employ recombinant adeno-associated virus technology to develop novel approaches for gene therapy. We have developed investigational drugs for the treatment of inborn errors of mitochondrial energy metabolism and utilize magnetic resonance spectroscopy to elucidate the intra-mitochondrial biochemical consequences of discrete mutations.
Email: stacpool@gcrc.ufl.edu

MARGARET (PEGGY) WALLACE (392-3055) - Our laboratory studies mammalian molecular genetics, including projects to map and clone disease genes, and to find and study mutations. The human genetic disorders currently include neurofibromatosis (tumor syndrome), heart defects, dog hereditary eye conditions, and genetics of pain. Most students will have an independent sub-project to answer a particular question, or will generate data as an integral part of a larger effort. This will involve learning molecular biology techniques such as DNA extraction, PCR, restriction digests, gel electrophoresis, genotyping markers, and possibly some RNA or cell culture/biology work. We prefer students who can be a member of the lab for at least a full calendar year.
Email:peggyw@ufl.edu

THOMAS P. YANG (392-6472) - Our laboratory is interested in two general areas of research: the molecular biology and genetics of the mammalian X chromosome, and transcriptional regulation of gene expression in higher eukaryotes. Three major projects in these areas are currently underway in the laboratory. We are studying the mechanism of mammalian X chromosome inactivation, a process that equalizes the functional dosage of X-linked genes between males and females. Because each female somatic cell carries two X chromosomes while male cells contain only one, each female somatic cell transcriptionally inactivates genes on one of the two X chromosomes. We are studying the molecular mechanisms by which this novel system of differential gene expression is initiated and maintained in female cells. We are also engaged in studies on the molecular mechanisms of genomic imprinting in mammals, the process by which certain mammalian genes are transcribed in a parent-specific manner. Some imprinted genes are expressed only from the chromosome that comes from the mother, and other imprinted genes are expressed only from the chromosome inherited from the father. Our studies are focused on the regulation of imprinted genes in the Prader-Willi/Angelman syndrome region of human chromosome 15. For the third project, we are using the techniques of molecular genetics to localize and map disease genes associated with two X-linked human diseases, a unique from of X-linked arthrogryposis (congenital joint contractures), and an uncharacterized X-linked mental retardation and seizure disorder.
Email: tpyang@ufl.edu