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. 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. Kathleen Archer (LSC 344) - The biology of sea slug - chloroplast relationships
One of the most fascinating areas of biology is that of symbiotic mutualisms - where two different species live closely together to the benefit of both. We are interested in an unusual relationship between the marine sea slug Elysia and the algae on which it feeds. Unlike land slugs, marine sea slugs are beautiful creatures - highly ornamented and brightly colored. The species Elysia chlorotica, for example, is an intense, rich, green color, and it turns out this pigmentation comes from chloroplasts ingested while the animal feeds on the alga Vaucheria. The chloroplasts are taken up by cells lining the digestive tract, and there they continue to photosynthesize, providing food for the slug. In fact, if the slugs are given good light they can go without food for many months, relying completely on the chloroplasts for energy. This is a highly unusual twist on symbiosis, as the relationship is not between two different organisms but between an organism and an organelle.
We are interested in how the sea slug can keep chloroplasts alive and functional outside their native algal cells, and whether the slug behavior is adapted to benefit its symbiont. For example, do the sea slugs seek out the optimum light intensities for photosynthesis? Do they move to areas where light wavelengths are best suited for chloroplasts? Do they seek shade when light is too strong? We are also interested in the unique properties of the algal chloroplasts the slugs feed on. The species used by the slugs are well-known for their extremely robust chloroplasts, but know one knows what makes them so tough. How do they avoid getting digested - do they inhibit digestive enzymes, or are they just highly resistant? Do they have physical structures that help them stay intact under such damaging conditions as the slug digestive tract? We anticipate that electron microscopy studies, tests of resistance to digestive enzymes and other treatments will reveal much about what makes this unusual relationship possible.
Prof. Daniel Blackburn (LSC 247) - Functional Morphology & Reproduction of Reptiles.
My research concentrates on the structure, function, and evolution of reproductive specializations in reptiles, particularly features associated with viviparity (live-bearing reproduction) and oviparity (egg- laying reproduction). This work draws heavily on microscopic anatomy, and students interested in working with me ideally should gain experience with electron microscopy before their senior year by taking the half semester course Biology 210 (Scanning EM) and/ or Biology 220 (Transmission EM) before their senior year. These courses and our excellent EM facilities in the LSC and McCook offer wonderful opportunities for Trinity students to learn techniques of immense value to biologists. I sometimes have options for students who wish to focus their attention at the level of light microscopy. Research of several of my recent students has resulted in collaborative research papers, as well as presentations at scientific meetings.
Two major areas of research activity in 'the Blackburn lab' are:
- Placental morphology and evolution of live- bearing reptiles: In viviparous lizards and snakes, embryos develop inside the pregnant female, and are sustained by means of placental organs. My main research interest is in understanding the structure, function, and evolution of these placentas. Our current work is focusing on how anatomical characteristics of the placental membranes of viviparous snakes and lizards enhance provision of oxygen, water, and nutrients to the fetus during gestation. This work involves examination of the cytology and development of the uterus and placental membranes, using light and electron microscopy.
- Development and evolution of fetal membranes in oviparous lizards and snakes: During development, vertebrate eggs are sustained by cellular structures that provide for the respiratory and nutritional needs of the developing embryos. These structures contribute to the placentas of viviparous species. In reptiles and birds, very little is known about the structural composition of these membranes, and how they develop and function. Our current investigations of reproduction in snakes and lizards use light and electron microscopy to study the development and cytology of these membranes. Resultant data offer insight into important aspects of egg function and evolution. Future work will focus on eggshell anatomy (as seen through electron microscopy) and mechanisms of calcium and water uptake.
Prof. Kent Dunlap (LSC 245) - Electrocommunication & Physiology of Electric Fish
I examine the influence of social interaction on the brain structure and communication of electric fish. South American weakly electric fish are nocturnally active and live in muddy waters of the Amazon River basin. They use their electric discharges both for locating objects in the environment and for communicating with each other. These fish have a remarkable ability to generate new cells in the brain during adulthood, at about 100 times the rate of adult mammals. Research by Trinity students showed that this production of new cells is influenced by social interaction. Pairing fish with another fish increases the production of cells in a brain region that controls electrocommunication behavior.
In our present research, we address three main questions: 1) What specific component of social interaction is effective in stimulating changes in brain cell production? 2) Do the new cells that are produced contribute to changes in electrocommunication behavior? 3) How do these newborn cells differentiate into mature cells? This research involves examining the expression of certain molecules in the brain using antibodies and florescent microscopy. In a separate project, students examine electrocommunication behavior between different species of electric fish and conduct experiments to determine the sensory pathways involved in this interspecific electrocommunication. This research involves observing fish as they interact and stimulating fish with artificial electrocommunication signals.
Prof. Robert Fleming (LSC 238) – Cell- to- Cell Signaling and Developmental Controls
As an organism develops, cells differentiate into specialized cell 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 at the same site where another ligand, that of the Delta locus, also binds. During the formation of the adult wing blade, the wing margin is established via Notch activation using both the Serrate and Delta ligands. The Notch system is unique in that its ligands can either activate or inhibit the Notch receptor. Our studies focus on the identification of specific domains within the Serrate ligand that are used to separately control the activation and inhibition properties. In our research, we employ a battery of techniques from genetic selection through in vitro mutagenesis and germ-line microinjection to specifically address structure and function relationships.
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. While there has been significant study of the composition of the bacterial population colonizing the gut, we study the role of the bacterial flora in the upper respiratory tract. The upper respiratory tract is an important portal of entry and is heavily colonized with bacteria. The protective role played by normal bacterial flora whose presence interferes with the colonization by respiratory bacteria capable of causing disease is becoming an area of intense research.
The lab is currently investigating the bacterial communities colonizing different populations to determine if behaviors such as cigarette smoking alter the composition of the microbial communities. We are also interested in determining if health conditions, such as asthma may be exacerbated by differences in the bacterial species colonizing affected individuals. While no definitive cause for asthma has been identified, there is a strong inflammatory component to the disease, suggesting a loss of control of the immune response in the respiratory tract. We are examining the bacterial populations colonizing the upper respiratory tract of children with asthma and those without it, in order to determine if differences in the normal flora are involved in the acute inflammation associated with asthmatic episodes.
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)
Prof. Hebe Guardiola-Diaz (LSC 309) - 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. Joan Morrison (LSC 230) - Conservation Biology
My research program entails studying the population biology, habitat associations, and community structure of birds living in human-impacted landscapes. Questions focus on the population structure of small and isolated populations and the role that spatial variation in habitat and resources plays in determining patterns of reproduction, survival, and movement. Here in Hartford, I am using radiotelemetry to study home range, habitat use, and nesting success of Red-tailed Hawks living in the urban area. My long-term study of the threatened Crested Caracara in Florida is a cooperative effort between cattle ranchers and scientists to understand the biology of this raptor and document land uses compatible with its survival. My collaborators include my colleagues at Virginia Tech
and the US Fish and Wildlife Service
. I have also examined the structure of avian communities in urban parks in Hartford and how these communities change throughout the year. The overall goal of this project is to understand the role these urban green spaces play in the conservation of native birds in Connecticut. Conservation education plays a major role in all my research, and my students regularly interact with people outside the Trinity campus. We regularly conduct mist netting and songbird banding sessions at local secondary schools, and we contribute these data to several nationwide avian monitoring databases
Conservation education plays a major role in all my research. Scientists must improve their communication skills with people outside their academic and peer groups, therefore I require all my students to interact in some way, regarding science or conservation, with people outside the Trinity campus. We frequently conduct banding sessions at local elementary and middle schools.
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
Prof. Craig Schneider (LSC 223) - Molecular-assisted Taxonomic Studies of the Bermuda Marine Flora
Molecular-assisted morphological taxonomy 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 DNA sequencing to analyze marine algae collected from Bermuda and other locales. 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 and 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 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 islands.
Prof. Scott Smedley (LSC 309) - The Chemical Ecology of Insects
As a chemical ecologist, I investigate how organisms use chemicals in their interactions with members of their own and different species. Insects, the most species-rich and ecologically diverse group of animals, are the primary subjects of study for me and my students. Our research focuses on how host plant chemistry influences the behavior and ecology of herbivorous insects and on how insects utilize chemicals as anti-predator defenses. This involves work in both the field (particularly during the summer months when local insects are active) and the laboratory (including projects with animals maintained in culture year-round). Since chemical ecology resides at the interface of biology and chemistry, much of our research effort is in collaboration with colleagues in chemistry.
Various projects are ongoing. These include a study of the underlying physiology and morphology, as well as the adaptive significance of puddling, a behavior in which a male moth (Gluphisia septentrionis) drinks enormous volumes of puddle water (more than 600 times its body mass in a single bout!). This enables the moth to supplement nutrients present at low levels within its food plant and to invest these in its offspring. A second project examines the chemical nature and defensive role of a secretion produced by the immobile, and therefore vulnerable, pupal stage of a beetle (Subcoccinella vigintiquatuorpunctata). Another beetle (Chrysomela knabi) is the subject of an investigation into the adaptive significance of a dramatic developmental change in adult coloration and the relationship of this transformation to the beetle's chemical defenses. In addition to these and other projects that are underway, I am sure that new experimental systems will arise as we make discoveries of Connecticut's insect fauna.
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.