Klingensmith Lab
As of Fall 2005, I'll be an official member of the Klingensmith lab at Duke, in the Department of Cell Biology. The KlingLab is interested in how the mammalian body plan is generated during early pregnancy. We seek to understand the mechanisms that establish and pattern the body axes and organ precursors of the embryo. We are using the unique genetic technologies available in the mouse to study induction, pattern formation, and morphogenesis, particularly of the neural tube and head.

Current Projects:

I am currently studying the relationships between several genes including Chordin, Noggin, Foxa2, Sonic Hedgehog, and Nodal, and BMPs at the level of molecular mechanisms in node. The node appears just prior to gastrulation in the mouse at embryonic day 6.5 and in the third week of human development.

I am also working with Murim Choi on heart development studying the relationships between Chordin, Sonic Hedgehog, Tbx1, BMPs, and FGF8. Mutations in some of these genes lead to a human DiGeorge Syndrome-like phenotype.

Finally, I'm working in collaboration with the David McClay lab on neural tube cell adhesion defects.

Because of the often severe phenotypes associated with homozygous null mutations, and combinatory heterozygous mutations, but not in single heterozygous mutations in these genes, it is possible that single mutations may not cause an external phenotype but may lower the threshold for another insult cause a visible deformity.

First Year Rotations
My first rotation was with Dr. Elwood Linney in the department of Molecular Genetics and Microbiology. This laboratory uses molecular, transgenic, genetic and computer approaches towards studying the regulation of genes during embryonic development with a particular focus on visualizing gene expression in developing zebrafish embryos and young fish. We are using DNA microinjection techniques and pseudotyped retroviral vectors to introduce new genes into the zebrafish genome. Expression of the genes is monitored with fluorescent reporter genes and the images are captured on an confocal microscope and re-constructed using computer rendering techniques. Retroviral vectors are also being used as insertional mutagens coupled with visible screening of changes in gene expression to identify and isolate genes involved in receptor signal transduction pathways. Much of the work focuses on the developing nervous system.My work in the lab was in designing new transgenic lines which will allow better visualization of the developing nervous system and in visualizing subsets of neurons that develop in response to particular stimuli, specifically in creating DNA constructs which would express a membrane-bound GFP in the low-cytoplasm axons of neurons responsive to retinoic acid.

My second rotation was in the lab of Dr. Vann Bennett in the Cell Bio Dept. I worked with a postdoc (Krish Kizhatil), studying Ankyrin and Spectrin proteins in the early developing embryo. The proteins have been studied in a variety of cell types, but they are only known to be involved in polarized cells. Since the cells of the early embryo are undifferentiated and many are unpolarized, we are looking to determine the presence of ankyrins and spectrins. We used fertilized mouse embryos, and mouse ES cells.

My final rotation was in the lab of Dr. John Klingensmith in Cell Biology. I worked with another grad student (Murim Choi) to elucidate the roles of sonic hedgehog (Shh), Tbx1, and Fgf8 in the BMP (bone morphogenetic protein) pathway. We are studying these in the developing heart. Mice mutant for the protein chordin (Chd), a BMP antagonist, show a human DiGeorge Syndrome-like phenotype. I am currently working on developing a thesis project for this lab, to characterize the BMP pathway and Nodal pathway antagonism in the embryonic node. I'll be using molecular biology techniques to study this pathway both in vivo and in vitro. This project will initially be done in collaboration with Tom Sitzman, an MD student in the lab.