David Lindsey, Chair
Professor of Biology, Rosario Beach Marine Laboratory Director
Ph.D. 1992 University of Texas
- BIOL 142 General Biology
- BIOL 326: Journal Club: Cancer Biology
- BIOL 383 Cell Biology III: Genomics and Regulation
- BIOL 430/530 Molecular Biological Techniques
- BIOL 445 Advanced Microbiology
- Pre-medicine and Biology majors
Professor Lindsey explains his interests as quoted: "The transformation of a fertilized egg to a complex multicellular organism depends on a variety of mechanisms that control cell-cell communication and changes in gene expression. The selective destruction of specific proteins is one of the important mechanisms that control this developmental process. Many proteins are selectively degraded by the ubiquitin-dependent proteolytic pathway. In this pathway, linkage of a protein to ubiquitin targets the protein for degradation by the proteasome. Defects in this pathway have been implicated in a wide range of human disorders including tumor formation and neurodegenerative diseases.
We are interested in understanding the role of ubiquitin-dependent proteolytic pathways in multicellular development. We use the social amoebae Dictyostelium discoideum as a model system. It is a simple and elegant system to study fundamental developmental processes that are used by higher systems including growth-to-differentiation transitions, directed cell movement, cell-type determination, and formation of structures with specific size and shape.
Dictyostelium normally exists as solitary cells that proliferate by cell division while feeding on bacteria in soil and decaying leaves. When stressed by starvation, these amoebae stop dividing and enter a developmental program that results in the formation of a multicellular fruiting body. The cells first aggregate into a mound which then elongates to form a slug that can migrate to a suitable location for fruiting body formation. Cells specified to become stalk cells, the prestalk cells, occupy the tip of the slug; the posterior region of the slug contains mostly prespore cells. Eventually, coordinated cell movements and additional differentiation events result in a fruiting body consisting of a mass of spore cells supported on a column of stalk cells.
We have identified two enzymes that appear to function in ubiquitin-dependent proteolytic pathways and are required for Dictyostelium development: UbpA and RbrA. UbpA is a functional homolog of the yeast Ubp14 and human isopeptidase T, enzymes which appear to function in the disassembly of free ubiquitin chains following their use as tags for protein degradation. It is likely that these enzymes facilitate ubiquitin dependent proteolysis by preventing free ubiquitin chains from competing for substrate binding sites on the proteasome. Control of cellular ubiquitin chain levels by UbpA may provide a mechanism for modulating the rates of protein degradation by the proteasome during changing developmental conditions. We are currently investigating the role of UbpA at the growth-development transition by analyzing defects found in ubpA-deficient cells. Results from this work may elucidate molecular mechanisms that underlie the conversion of stem cells to differentiating cells.
RbrA is a putative ubiquitin ligase that is required for cell-type proportioning and pattern formation. rbrA-deficient cells form slugs that are unable to phototax or develop into fruiting bodies. RbrA is highly similar to ariadne-like ubiquitin ligases, which are members of the RBR family. RBR family members are widespread in eukaryotes and include parkin, a gene implicated in Parkinson's disease. To delineate RbrA-dependent pathways, we are using genetic, molecular, and biochemical approaches to identify proteins that interact with RbrA."
Ph.D. 1987 University of California, Santa Barbara (aquatic and population biology)
- BIOL 143 General Biology
- BIOL 296 Current Topics
- BIOL 316/416 Research in Biology
- BIOL 360 Plant Biology
- BIOL 410 Limnology
- BIOL 465 Ecological Physiology
- BIOL 506 Graduate Seminar
- BIOL 540 Graduate Readings in Biology
- BIOL 458 Marine Biology (Rosario)
- BIOL 460 Marine Ecology (Rosario)
- BIOL 475 Marine Invertebrates (Rosario)
- Pre-medicine and Biology majors
Professor Cowles is intersted in questions that involve animals' survival in the sea. Some projects he is currently involved in include:
- What is causing algal blooms in Lake Crescent, a beautiful hyper-ologitrophic lake in Washington State
- How Hemisquilla californiensis, an active burrow-dwelling stomatopod, survives under low oxygen conditions in its burrow
- The eyes and vision of H. californiensis, and colors it responds to
- Effects of pollution on the gene pools of marine invertebrate species
- How closely related are individuals of the same deep-sea species which are separated by thousands of miles of ocean?
- Swimming energetics and metabolism of a number of deep-sea midwater crustaceans
- Vertical migration
Other research interests include ecological physiology, marine biology, physiology of marine species, both deep-sea and nearshore.
Ph.D. 2013, Washington State University
- BIOL 211/216 Intro to Biological Research I
- BIOL 316 Intro to Biological Research II
- BIOL 326 Journal Club
- BIOL 381 Cell Biology I: Structure and Bioenergetics
- BIOL 400/500 Biocomputing and Bioinformatics
- BIOL 464 Animal Physiology
- Research interests include ecological physiology and behavioral ecology of marine invertebrates, especially cephalopods.
- His current research is focused around the idea that all living things must bring to bear specific physiological adaptations to survive and thrive in the environments in which they find themselves. He is particularly interested in how cephalopods' physiology, which is similar to that of slugs, snails and clams, has enabled this group of marine invertebrates to be active, mobile predators that compete with vertebrates. He is also interested in adaptations, behavioral and physiological to dynamic, changing environments, such as hydrothermal vents.
Ph.D. 2006 Purdue University (Biomedical Engineering)
- BIOL 122 Anatomy and Physiology
- BIOL 316 Intro. to Biological Research II
- BIOL 416 Research in Biology
- Bioengineering majors
- Biotechnology: Upstream processing - DNA methods and analysis, Bioreactor technology; Downstream processing - Protein purification and characterization, Scale-up
Ph.D. 1989 University of Denver
- BIOL 122 Microbiology
- BIOL 382 Cell Biology II: Genetics and Molecular Biology
- BIOL 393 Genetics
- BIOL 466 Immunology
- BIOL 510 Graduate Seminar
- BIOL 525 Ethics Issues in Science
- BIOL 540 Graduate Readings
- Pre-dentistry and Biology majors
Professor Reed's research interests include tumor immunology, hybridoma production, and dietary supplements of immune function.
Ph.D. 1990 University of Colorado, Boulder (Environmental, Population, Organismic Biology)
- BIOL 141 General Biology
- BIOL 250 Biostatistics
- SCDI 441/442 Scientific Diving
- BIOL 405 Natural History of Vertebrates
Professor Nestler's research primarily focuses on the study of sea cucumbers. He is specifically interested in answering the following questions through research:
- "Are sea cucumbers really important? Do they provide any particular function(s) in the marine environment? Who cares if they all get eaten and disappear?"
- "Why do some sea cucumbers lose all of their internal organs in the winter, only to regrow them a month or two later?"