Runx1 function in hematopoiesis is required in cells that express Tek

Area of Science:

• Developmental biology
• Hematopoiesis
• Gene regulation

Background:

• Runx1 expression identifies hemogenic endothelium from embryonic days 8.5 to 11.5.
• Runx1 is necessary for forming intra-aortic hematopoietic clusters.

Purpose of the Study:

• To investigate the role of Runx1 in the endothelial to hematopoietic cell transition.
• To determine if Runx1 is required in Tek-positive cells for hematopoiesis.

Main Methods:

• Conditional ablation of the Runx1 gene using Cre-recombinase.
• Cre expression driven by the Tek promoter and enhancer in mouse models.

Main Results:

• Runx1 ablation resulted in embryonic lethality between E12.5 and E13.5.
• The observed phenotype closely resembled that of complete Runx1 deficiency.

Conclusions:

• Runx1 function is critical for establishing definitive hematopoiesis.
• This function is specifically required within Tek-positive cells.