Faculty Research Interests

One of the opportunities available to students in Biology at Trinity is a direct involvement in independent research with a faculty member.  Many students do research as seniors and in the summer before their senior year; others initiate research as early as their first or second year at Trinity.
Students with interests in conducting research should talk to faculty members during the semester before initiation of the project; those who are seeking a paid position for the summer must arrange it with faculty in the preceding fall semester or early in the spring semester. If you are contemplating research, discuss it with the faculty member whose programs fit your interests; the research projects of the faculty are summarized below. Also keep in mind that some students engage in research programs in local hospital laboratories under the joint supervision of the Biology Department and the extramural laboratory. Please direct inquiries about these options to the Chair of Biology.
Prof. Daniel Blackburn (LSC 247) - Functional Morphology & Reproduction of Reptiles.  

My research concentrates on the structure, function, and evolution of reproductive specializations associated with viviparity and oviparity in reptiles.  This work draws heavily on microscopic anatomy, and students interested in working with me should gain experience by taking Electron Microscopy (Biol 211) and/or Histophysiology (Biol 206).  These courses and our excellent EM facilities offer wonderful opportunities for Trinity students to learn techniques of great value to biologists.

Two major areas of research activity in 'the Blackburn lab' are:
  1. Morphology and evolution of placentas and fetal membranes:  In viviparous lizards and snakes, embryos develop inside the pregnant female, and are sustained by means of placental organs.  Our research uses light and electron microscopy to analyze the structure, function, and evolution of these placentas, including how they provide oxygen, water, and nutrients to the fetus during gestation.  On a related topic, we also study the morphology of “fetal membranes” in oviparous lizards and snakes.  Fetal membranes are tissues that line the eggshell and provide for the respiratory and nutritional needs of the developing embryos of reptiles and birds.  Data resulting from our work offer insight into important aspects of egg function and evolution.  Further information and resultant publications are available at the following website:  https://commons.trincoll.edu/blackbur/?page_id=13.
  2. Yolk cellularization in reptiles and birds.  The yolk of reptilian and avian eggs must be taken up into cells of the yolk sac and digested before its nutrients can be used to fuel embryonic development.  Our recent research has used electron microscopy to reveal how this process is accomplished in oviparous snakes.  We are expanding our focus to lizards, turtles, and birds to provide insight into the a key event in vertebrate evolution, origins of the terrestrial (amniotic) egg.
Prof. Susan Bush (LSC 336) -- Molecular Plant Physiology
The Bush lab studies the way in which plants respond to environmental stresses. Stresses like drought, heat, or toxic minerals like aluminum in the soil can make it difficult for a plant to grow, and - unlike animals - a plant must survive and reproduce in the same location it was originally planted. Crop plants, like tomato, have been domesticated to carry genes that are important for farming and high yield, but the plants may not carry the gene variants that can help them survive under environmental stresses. Wild South American relatives of tomato and colorful heirloom varieties of domesticated tomatoes harbor naturally occurring genetic diversity, which can make them more tolerant of stressful conditions.
In the Bush lab, we study the physiology, or the growth traits, of tomato plants and the model plant Arabidopsis thaliana under normal conditions and under stressed conditions in the presence of the toxic element aluminum. Students can examine root growth, the effect of stress hormones, and the degree to which stresses impact different plants. We can use microscopy to show the levels of aluminum present in the roots of tomatoes under different conditions. We also study the genes involved in aluminum tolerance, using mutants and different species or varieties of tomato. We can create genetically modified plants carrying more or less tolerant alleles of aluminum-related genes; we can sequence DNA to find new gene variants; we can use bioinformatics to explore global gene expression patterns; and we can use quantitative PCR to examine the copy number of a gene in different varieties of plants. A new project to explore is the types of chemical compounds exuded by tomato roots in the presence of aluminum - what do the roots release to help protect themselves from toxic aluminum? Can we find natural variation in this root exudate response? Students in the Bush lab will work on these types of projects and related ones, to help define the way tomato plants respond to aluminum in their environment.

Prof. Kent Dunlap (LSC 245) - Electrocommunication & Physiology of Electric Fish
I examine environmental and hormonal influences on cell production in the adult brain. In the last few decades, it has become clear that adult mammals produce new cells at low rates in a two brain regions. I examine this phenomenon of neurogenesis in fish, which produce cells all over the brain and at rates 10-100 times greater than mammals. In past research, my students and I have demonstrated that social interaction and adrenal steroid hormones increase the production of brain cells in regions of the brain that regulate social behavior.
More recently, we have examined how predator exposure inhibits the production of cells in brain regions that regulate escape behavior. In future experiments we will also examine changes in brain cell proliferation are related to spatial learning.  Our study animals are freshwater electric fish native to South America. These fish use weak electric discharges to communicate and to locate objects in their surroundings. Their brain has been thoroughly mapped and the behavioral function of certain brain regions is well understood. Thus, they provide an excellent model for examining how new brain cell production may influence the structure and function of the brain.

Prof. Robert Fleming (LSC 238) – Cell- to- Cell Signaling and Developmental Controls
As an organism develops, cells differentiate into specialized types and adopt specific patterns of gene expression. Using molecular and genetic techniques in the fruit fly, my laboratory is attempting to understand the mechanisms that control cell differentiation in embryonic and adult tissues. The focus of our work is on the Serrate gene, which encodes an evolutionarily conserved, trans-membrane protein capable of physically binding to and activating the Notch receptor. This interaction forms the basis of a signaling system that controls the differentiation of various types of cells during development. The Notch signaling system is evolutionarily conserved in multicellular animals and defects in this signaling pathway are linked to numerous developmental defects in humans as well as with many forms of human cancer.
The Notch signaling system is unusual in that the Serrate ligand can work to either activate or inhibit the Notch receptor to control cellular signals. We employ a battery of techniques from genetic selection through in vitro mutagenesis and germ-line microinjection to specifically address structure and function relationships in various regions of protein structure of the Serrate molecule.  Specifically, our studies focus on the identification of regions within the Serrate protein that are used to separately control its activation and inhibition properties.
In addition to the molecular approach of altering the structure of Serrate via the introduction of specific mutations within the protein, we also look for other, previously unidentified genes that help to regulate the Notch signaling system.  We use traditional genetic approaches to find mutations in genes that can modify the outcome of the interactions between the Serrate ligand and the Notch receptor.  These studies are aimed at generating a more complete understanding of how the Notch signaling system functions to control cell fate decisions.
Prof. Lisa-Anne Foster (LSC 236) - Molecular Microbiology and Host-Pathogen Relationships
The human body is colonized with bacteria that help protect us from disease. This "normal flora" also plays a role in regulating how the immune system responds to disease causing organisms and other insults. The lab has focused on studying the composition of the bacterial population colonizing the mucosal surfaces of the upper respiratory tract and the gastrointestinal tract.  
The upper respiratory tract is an important portal of entry to the human body and is heavily colonized with bacteria making this an interesting anatomical location to study.    In this location the protective role of the normal flora is due to its presence interfering with the colonization of the mucosal surface by bacteria capable of causing disease.  The flora at this site has also been found to play a role by regulating the inflammatory response in the tissue.   The lab has investigated the differences in normal flora in between individuals with differing health conditions (asthma) and behaviors (smoking).
The differences in the flora colonizing the GI tract and how that may be associated with various digestive conditions has been well-studied; hence the growth of probiotics to treat various digestive ailments.   It has also been demonstrated that the normal flora colonizing the GI tract have far reaching effects, potentially even impacting behavior and mood.  The lab is currently investigating the differences in the composition of the normal flora colonizing the GI tract of mice used as a model of autism when those mice are fed different diets.  
The lab employs molecular tools extensively in our studies of normal flora. These techniques are transferrable to many areas of research and provide a significant advantage in our studies. The molecular approach to the detection and characterization of bacterial populations does not rely on previous knowledge of what species of bacteria might be present allowing for an unbiased study and therefore provides a more complete examination of the bacterial community colonizing various body sites.

Prof. Claire Fournier (LSC 331) -- Protein Synthesis
I am interested in looking at the products of protein translation, proteins, in an attempt to understand how mRNA molecules are read by ribosomes in eukaryotic cells. In doing so we can seek to understand how cellular processes can be regulated at the level of protein translation. Specifically, can we make “alternative” proteins from the same mRNA message used during normal cellular function. A time when one could imagine the need for an alternative protein would be in times of stress when the cell needs to redirect its attentions away from normal function to survival. In Budding Yeast, and mammalian cells, stressful conditions result in the production of granules that act as hubs for mRNAs and proteins useful in these times of cell distress. With the help of undergraduates, I am interested to mine these granules in search of alternative protein products using protein purification and peptide mass spectrometry.

Prof. Hebe Guardiola-Diaz (LSC 242) - Biochemistry and Molecular Biology of Nuclear Receptors in the Nervous System.
Oligodendrocytes are extraordinary cells that form the myelin sheath that increases the speed of communication between neurons in the brain. In order to produce myelin, oligodendrocytes must make great amounts of lipids and proteins in their endoplasmic reticulum (ER). Therefore, a healthy endoplasmic reticulum is essential for myelin formation and maintenance. Myelin diseases display accumulation of unfolded proteins that may arise, in part, from failure to adapt to ER stress. I am investigating the interaction between ER function and signaling pathways known to be active in oligodendrocytes. I am especially interested in the signaling protein mTOR, which controls protein synthesis in response to hormones, nutrients and energy levels in the cell. These studies will further our understanding of the endogenous mechanisms that make oligodendrocytes resilient and therefore able to establish a robust myelin sheath in dynamic association with its axon.

Prof. Michael O'Donnell (LSC 323) -- Behavioral Ecology of Wildlife in Urbanizing Areas
My research focuses on wild animals in urban, suburban, and developing environments; specifically, how these animals have adapted to these changing habitats. Some examples include: Feeding ecology of the common crow, the use of urban/suburban habitat by gray squirrels and raccoons, and the feeding behavior of urban/suburban gray squirrels. Current student research projects include:
  • Foraging behavior of gray squirrels looks at predation risk and behavioral adaptations, examining whether squirrels that live in a protected urban/suburban area optimally forage for their food. According to optimal foraging theory, squirrels would seek to maximize energy gain while expending the least energy and exposing themselves to the least risk of predation. These field studies include establishing feeding stations, determining food preferences of gray squirrels, and examining alarm (predator avoidance) behavior.  My home page has several student abstracts from this research.

Prof. Amber Pitt (LSC 230) -- Conservation Biology
My interdisciplinary, conservation-driven research focuses on elucidating patterns and causes of biodiversity loss and alteration across spatial and ecological organizational scales. I primarily examine aquatic systems and herpetofauna (i.e., reptiles and amphibians) due to the inherent sensitivity of these ecosystems and taxa to pervasive stressors (e.g., habitat degradation, climate change), and their rapid global decline. Current and recent research has
  1. examined the relative influence of landscape-scale and within-stream habitat variables on hellbender salamander population extirpation and persistence, 
  2. elucidated how small and ephemeral wetlands function ecologically and hydrologically in the Piedmont and Blue Ridge ecoregions of the southern Appalachian Mountains, 
  3. evaluated the effects of forest management techniques (e.g. prescribed fire) on amphibian movement, habitat selection, and behavior, and 
  4. examined long-term changes in river turtle communities and their habitat. All of my research is conducted with the goal of providing conservation practitioners, land managers, and policy makers with necessary information for the effective management and conservation of functional ecosystems and wildlife. 
More information about my research can be found on my website: http://commons.trincoll.edu/apitt/

Prof. Craig Schneider (LSC 223) - Molecular-assisted Taxonomic Studies of the Bermuda Marine Flora
Molecular-assisted morphological taxonomy (MAAT) has recently become a valuable way to assess biodiversity and floristics for a variety of different organisms. Research in my lab focuses on the attached marine flora from the intertidal to deep subtidal waters of the Bermuda islands, and the phytogeographic relationships of Bermuda with the Caribbean and eastern Atlantic islands. We use techniques of morphological analysis along with multi-gene DNA sequencing to analyze marine algae collected from Bermuda (and other tropical locales as comparative sites). Our studies are significantly clarifying our understanding of phylogenetic relationships and distributions of marine flora. They also are helping to establish a new database to help assess effects of climate change on species composition in the islands.
My lab uses DNA sequencing or "barcoding" of nuclear, chloroplast and mitochondrial DNA of hundreds of freshly collected marine specimens, in comparison with information in online databases (GenBank, Barcode of Life Database [BOLD]) as a supplement to traditional morphological investigations with conventional tools and historic literature. Many of the marine species reported for Bermuda in the 1800s were mistakenly identified as European species. Work in my lab has helped to show that a large proportion of these are distinct new species for the western Atlantic Ocean. We now know that several of the ~450 Bermuda species of red, green and brown algae are phenotypically variable, while others have been discovered to be cryptic species residing under the same taxonomic binomial.  Still others, novel species and genera, have been found to be quite distinct and not previously identified or described in the scientific literature. The information gathered in our lab is bringing the Bermuda flora into sharper focus, and is increasing our recognition of the extent of endemism in these distant islands.
Prof. Terri Williams (LSC 232, LSC 239) - Development and Evolution of Arthropod Segmentation. 
One enduring goal of biologists is to understand organismal complexity- a feature unique to each group of animals. Within the crustaceans and insects I study, a key element of complexity is a body plan based on repeated structures, or segments. My research focuses on how evolutionary modifications to the mechanisms that form segments during embryonic development have played a role in the diversification of body plans.
The mechanisms that control segmentation are well known in fruit fly Drosophila, a standard laboratory arthropod species. However, Drosophila is very different from most arthropods in how it forms segments: Drosophila forms its body segments simultaneously, but most arthropods form segments sequentially, adding them one by one from a posterior growth zone. This sequential mode of segmentation is widespread among arthropods, but it is not well understood.
In my lab, we examine the development of small crustaceans (e.g. brine shrimp) and insects (e.g. flour beetles) and try to link the cellular processes that form new segments to the genes that regulate posterior growth. We do this by first characterizing cell dynamics (e.g. cell division and shape change) in the normal segmental growth zone and then comparing this to a growth zone where specific regulatory genes have been knocked down. This research, supported by the National Science Foundation, is a collaborative effort with Dr. Lisa Nagy at the University of Arizona.