Transcriptional Regulation and Epigenetics

Haematopoietic Stem Cells

The production of blood cells (haemopoiesis) is a complex system, which is tightly controlled. There are several different types of haemopoietic cells and they have different functions; erythrocytes carry oxygen around the body to the tissues, megakaryocytes produce platelets important for wound healing and clotting, and there are several different types of white blood cells (monocytes, lymphocytes, neutrophils, eosinophils, mast cells and basophils) which are involved in the immune response by fighting infection and disease. All of these haemopoietic cells are produced by one single specialist cell called a haemopoietic stem cell (HSC). These can also be formed in vitro from Embryonic Stem cells.

Figure 1. Day 3.75 Embryoid bodies

Using specific growth factors, each single ES cell can be directed to form an embryoid body, which contain cells of many types.

These balls of cells can be disrupted into a single cell population and cultured using growth factors, which only the mesodermal cells respond to, to direct them to form blood cells