Labs for Environmental Biology
Dr. Luke K. Butler, Avian Biology
Evolutionary ecology of molt dynamics and feather morphology, and response of birds to ecological and human disturbance.
We study the ecology and evolution of molt, the process by which birds replace their old, worn feathers with new, fully functional feathers. Different species, populations, and age classes of birds vary greatly in when, where, how rapidly, and how extensively they molt, but little of that variation is described or understood. We describe molt dynamics and interpret differences among species and populations using contrasts in ecology, behavior, and morphology. In a related line of inquiry, we also study the ecology and morphology of the feathers that cover birds' bodies. Body plumage serves numerous functions but we know little about how different feather functions are served by different feather structures. We are also interested in how birds respond behaviorally and physiologically to environmental disturbance. We work with live birds in the field, and with research specimens in the lab.
Dr. Curt Elderkin, Evolutionary Ecology
Conservation genetics of freshwater mussels
Freshwater mussels (Bivalvia; Unionidae) are the most threatened and endangered family of organisms in the world. Currently 70% of North American taxa are listed at the state or Federal level. Conservation efforts must consist of species specific management, the preservation of freshwater ecosystems where mussels exist, and the conservation of genetic diversity within mussel populations. Currently, our laboratory is studying the genetics of two mussel taxa in Pennsylvania and New Jersey, one species is common and widespread, the other is listed as a federally threatened species. We compare and contrast genetic diversity of co-existing populations to enhance the conservation efforts of the threatened species.
Dr. Donald Lovett, Integrative Physiology
Enzyme regulation and gene activation during osmoregulation in crabs
We study crabs that live in estuaries where the salinity (the amount of salt in the water) varies as the tide flows in and out. Specifically, we study how they osmoregulate -- how they regulate the amount of salt in their blood -- in response to changes in the salinity of the water. We look at how enzymes that function in pumping salt are activated and deactivated, and how changes in gene expression may contribute to changes in enzyme amount or enzyme activity.
Dr. Janet Morrison, Plant Ecology
The ecology of invasive forest plants and plant-pathogen interactions in natural populations
Plants are necessary for most life on Earth, because through photosynthesis they are the base of most food chains. Therefore, the study of how populations and communities of plants function in nature is fundamental to understanding the overall biology of ecosystems and the organisms that inhabit them. In my lab, we are broadly interested in how certain plant species interact with other species -- such as white-tailed deer, fungal pathogens, plant-eating insects, or other plant species -- in ways that strongly influence their success or failure in natural communities. We are particularly interested in studying this for exotic, invasive plant species – those that are not native to our region but are taking over our forests. Our research takes us into lovely local forests and fields for extensive field work, as well as into TCNJ's greenhouse and our lab, where we use molecular techniques to study genetic variability within plant and pathogen populations.
Dr. Keith W. Pecor, Crayfish Ecology
The behavioral and community ecology of native and exotic crayfish
In many lakes and streams, crayfish are keystone species. That is, their impact on the structure and function of the biological community is greater than what might be predicted based on their population sizes alone. Hence, an understanding of crayfish ecology is important for understanding aquatic systems as a whole. In my research lab, we study many aspects of the ecology of crayfish, ranging from dietary habits to the use of chemical stimuli in behavioral interactions. In addition to asking questions about native species, we also consider the ecology of exotic crayfish, i.e., animals that have been introduced into a new area through the actions of humans.
Dr. Matthew Wund, Evolutionary Biology
Evolutionary and developmental responses to novel environments We are interested in how organisms respond to changes in their environment. When a population encounters a novel environment, either as a result of a new colonization event, or because their existing habitat has changed, individuals might either change their own traits or the population as a whole can adapt to the new circumstances. We are particularly interested in how these two very different types of biological responses interact to allow organisms to cope with new challenges. In order to address this issue, we use the threespine stickleback fish as a model. These small fish are remarkable in that the marine population has colonized thousands of freshwater habitats around the northern hemisphere, and they have adapted to numerous conditions in relatively short amounts of time (several years to thousands of years). We are particularly interested in how these marine fish first adapted to novel freshwater environments, and how modern freshwater populations cope with the introductions of novel predators. Our research involves fieldwork in Alaska, as well as laboratory work here at TCNJ.
Labs for the Biology of Model Organisms
Dr. Jeffery T. Erickson, Neurobiology/Physiology
Developmental respiratory neurobiology (model organism: mouse)
To ensure survival, all mammals must begin life outside the womb with the ability to breathe on their own and respond appropriately to external stimuli that require an adaptive change in breathing pattern. The part of the nervous system that controls breathing must therefore be sufficiently developed at the time of birth to support effective breathing behavior. However, the transition to the outside world during birth is relatively sudden and although breathing is initiated almost immediately, it typically takes some time for the breathing pattern of the newborn to become regular and stable. In addition, abnormalities in nervous system development can result in defective breathing behavior after birth and are thought to be the underlying basis for developmental respiratory disorders such as Sudden Infant Death Syndrome (SIDS) and congenital hypoventilation syndrome. My lab is interested in both the genetic and environmental factors that are responsible for the normal development of the respiratory control system, and to the stabilization of breathing behavior after birth. In addition, we are interested in understanding how abnormal prenatal developmental can lead to breathing disorders after birth. We currently employ a multi-level approach to these problems that combines physiological and anatomical techniques, in conjunction with a genetically engineered "knockout" mouse strain, to study the role of the neurochemical serotonin in the development of breathing behavior.
Dr. Tracy Kress, Cell and Molecular Biology and Genetics
Coordination of the steps of gene expression (model organism: yeast)
The major goal of our research is to understand how cells can regulate gene expression to adapt to different environments or situations. Because gene expression is a fundamental cellular process, it can be studied in model organisms such as yeast and give important insight into how the same process functions in humans. Two critical steps in gene expression are 1) the synthesis of RNA from DNA (the RNA serves as a "working copy" of the DNA) and 2) RNA splicing, during which discrete segments of an RNA molecule are pieced together in different ways to encode different types of functional proteins. Misregulation of either process can result in abnormal protein production that may ultimately lead to decreased cell viability or cell death. Indeed, mutations in our genes that lead to imprecise RNA splicing underlie numerous human disorders, including cancer. The accuracy of gene expression depends, in part, on effective coordination of RNA splicing with RNA synthesis. The underlying mechanisms that orchestrate this coordination are poorly defined, but undoubtedly involve specialized proteins that mediate the interaction of RNA molecules with larger protein complexes that synthesize and splice the RNA. Our research involves the combination of genetic, molecular cell biology and biochemical approaches to identify these specialized proteins.
Dr. Sudhir Nayak, Genetics and Bioinformatics
Using the germ line in nematodes to understand the specification of cell fate (Genetics). Developing software to facilitate the analysis of biologically relevant DNA and protein sequences (Bioinformatics).
The genetics focused portion of my laboratory uses the nematode C. elegans as a model system to understand how cell fates (sperm or egg) are specified and executed. More specifically, we use a combination of biochemical, genetic, and molecular approaches to identify and characterize genes involved in the generation of oocytes (eggs). We have also been taking advantage of the tightly regulated nature of oogenesis in C. elegans in development of small molecule inhibitors of cell division that could serve as lead compound in the improvement of anti-cancer therapeutics. The bioinformatics portion of my laboratory develops software to allow for the comparison DNA/protein sequences. Currently, we are characterizing the whole genome protein domain profiles from approximately 140 species in order to identify trends in protein evolution specific to each species.
Dr. Amanda Norvell, Developmental Cell Biology
Post-transcriptional regulation of gene expression during Drosophila oogenesis
My laboratory is interested in understanding how protein expression, both spatially and temporally, is regulated within the cell. As a model system we study Drosophila melanogaster oogenesis, and the regulation of a gene called gurken (grk). The grk gene encodes a signaling molecule that is required for several aspects of proper oocyte development, and females carrying mutations in grk are unable to produce viable offspring. Grk expression must be very tightly controlled, and in particular Grk protein distribution within the oocyte is spatially restricted. The localization of Grk protein is achieved by a two-step process whereby grk mRNA is localized within the oocyte cytoplasm and any unlocalized grk transcripts are translationally repressed, preventing inappropriate Grk protein expression. My laboratory uses a combination of classical genetic techniques, as well as biochemical approaches to define the molecular basis for the regulation of Grk protein accumulation during oogenesis.
Dr. Marcia O'Connell, Developmental Biology
Pattern formation in early embryogenesis in the model organism zebrafish
In my lab we investigate the development of the early fish embryo, and in particular we study some of the earliest events in pattern formation. In other words, we address the questions of how the early embryo is converted from a spherical ball to an organism with three axes of symmetry; a head and tail, a back and front, and a left and right. We study these questions at the molecular level, and so we investigate which genes are required for these important events to take place.
Dr. Leeann Thornton, Plant Biochemistry
Determining how cytochrome P450 enzymes help plants grow and respond to environmental conditions (model organism: Arabidopsis thaliana)
Throughout the life of a plant, growth and development changes in response to external conditions, such as temperature, light, and nutrient availability. External conditions are translated by internal factors, such as hormones, to cause changes in biochemical pathways (i.e. generating new molecules). Cytochrome P450 enzymes are important players in the biochemical pathways of all organisms. My lab aims to determine how a few plant P450 enzymes function during normal plant growth and when stressful environmental conditions occur. We use the model plant Arabidopsis thaliana for genetic studies of P450 enzymes. We also use biochemical techniques to test the function of individual enzymes that have been purified from the plant.
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