The tissues of multicellular organisms are composed of many different cell types, each of which is morphologically and physiologically specialized to perform its particular role within the tissue. But how can this diversity of cellular phenotypes exist, given that each cell in the body has the same genotype? The answer to this question seems to lie in how the information content of the genome is utilized in a given cell. In other words, what makes one cell type different from another is the set of genes that it expresses. This realization has led to the modern field of epigenetics, which attempts to understand how a single genome can be utilized to generate many different cellular phenotypes, and how these phenotypes can be inherited through cell division. This is the research domain in which our group operates.
Our current understanding of the molecular basis of epigenetics suggests that the coordinated action of many factors that act on chromatin, the complex of DNA with histone proteins, serves to selectively activate or silence specific genes in order to give a particular gene expression profile in a given cell type. Although many of the factors at play in the epigenetic system have been identified, how they work together to program and perpetuate the transcriptional output of the genome remains a mystery.
Thus, the main questions that drive our research are:
1) What are the fundamental mechanisms by which chromatin is used to regulate gene transcription and silencing?
2) How do sequence-specific transcription factors and chromatin-based mechanisms cooperate genome-wide to produce the specific gene expression profile that underlies a given specialized cell type?
3) How are multiple differentiation events coordinated to allow the formation of a complex tissue from a pool of stem cells?
To address these questions we use a combination of genomics, genetics, and molecular biology approaches in both the model plant Arabidopsis thaliana as well as in animalcell culture systems. Taking advantage of the virtues of each of these systems provides a powerful set of tools for dissecting the mechanisms of chromatin-based gene regulation and addressing how these mechanisms are employed during development.
In a practical sense, our research program is relevant to understanding diseases, such as cancer, that result from the misregulation of genes and defects in the maintenance of cell identity. In addition, we hope to gain a deeper understanding of how plants build their bodies, which may ultimately help to guide crop plant engineering to improve important attributes.
Excellent research and training opportunities are available in the lab for undergraduates, graduate students, and postdoctoral researchers. Please contact me by phone or email if you are interested in joining our endeavor to understand the fascinating realm of epigenetics and multicellular development.