Creating cellular diversity through transcription factor competition

Abstract

The development of blood cells has long served as a model system to study the generation of diverse mature cells from multipotent progenitors. The article by Org et al (2015) reveals how transcription factor competition on primed DNA templates may contribute to embryonic blood cell specification during the early stages of mesoderm development. The study not only provides new insights into the functionality of the key haematopoietic transcription factor Scl/Tal1, but also provides a potentially widely applicable framework for transcription factor-mediated cell fate specification.

Figure 1

A model for cell fate diversification during early blood cell development (A) Development of blood cells from early mesoderm. Shown are the lineage relationships between early cardiac, endothelial and blood development, together with haemangioblast and haemogenic endothelial intermediate stages. (B) Model illustrating the generation of diverse cell fates through transcription factor competition on enhancer elements. Enhancers are opened up (primed), which is followed by competitive binding of transcription factors promoting alternative fates. During this process, multipotent cells gradually lose their potential and become increasingly specified to a particular lineage.