PhD Defense: Decoding Developmental Epigenetics; Innovation and implementation of single-cell techniques to study epigenetic regulation in embryonic development

Every cell in our body contains the same genetic information, which is encoded in the DNA. This information is used to make the proteins that are responsible for all cellular functions. For this reason, the DNA is often referred to as the blueprint of the cell.

Remarkably, all cells contain the same DNA, even though there are many different cell types with various forms and functions. To achieve this diversity, another layer of information is imposed upon the genetic code that determines which parts of the DNA are switched on or off. This extra layer of information is referred to as the epigenome (from the old Greek word “epi”, meaning “on top of”) and can be encoded in diverse forms, including small chemical modifications of the DNA and the composition of protein complexes around which the DNA is wrapped. All these forms of epigenetic information are regulated by specialized proteins. Disruption of the epigenome is associated with several diseases, including cancer. To study and understand the epigenome, it is important to measure both the interactions of proteins with DNA and which regions of the DNA are active. Ideally, these measurements are taken in single cells so they can be directly related.

In our research, my colleagues and I develop the first technique to simultaneously measure protein-DNA interactions and gene expression (active use of the DNA) from the same single cells. We further extend this technique and apply it to better understand how different cell types emerge during embryonic development.