Hematopoietic stem cell (HSC) transplantation is a curative treatment for many blood cancers and diseases. A better understanding of basic HSC biology has the potential to improve these clinical transplants. Our lab focuses on the tissue microenvironment or “niche” that support HSCs. We use zebrafish and mice as model organisms. The goal of this rotation project is to explore the identity of mesenchymal stromal cells (MSCs) that regulate HSCs and their cell fate decisions. Bone marrow MSCs are highly heterogenous and it is still not clear which cells specifically maintain long term HSC quiescence. Using a combination of genetic tools and live imaging in zebrafish embryos, we will functionally test MSC-derived signals that are required for HSC regulation.