[Origin and development of haematopoietic cells]

Area of Science:

• Hematology
• Developmental Biology
• Molecular Biology

Context:

• Increasing interest in hematopoietic stem cell (HSC) biology due to advancements in transplantation for various diseases.
• Need for understanding molecular mechanisms governing the formation and development of hematopoietic tissue.
• Emergence of experimental models, including in vitro embryonic stem (ES) cell differentiation, for HSC research.

Purpose:

• To review recent findings in both in vivo and in vitro hematopoietic stem cell (HSC) studies.
• To elucidate the molecular mechanisms controlling hematopoiesis, with a focus on transcription factors.
• To introduce gene targeting in ES cells as a method for identifying critical genes in hematopoiesis.

Summary:

• Gene disruption in ES cells and the creation of knock-out animals provide insights into gene function, especially for genes lethal in embryonic development.
• This approach, combined with transgenic models, has identified key transcription factors essential for hematopoietic tissue development and differentiation.
• The review covers in vivo and in vitro HSC studies, emphasizing the role of transcription factors in hematopoiesis.

Impact:

• Advances understanding of the fundamental biology of hematopoietic stem cells (HSCs).
• Identifies critical genes and molecular pathways involved in blood formation.
• Provides a foundation for developing novel therapeutic strategies for hematological disorders and improving HSC transplantation outcomes.