Hematopoietic stem cells

The transcription factor encoded by the stem cell leukemia SCL/tal-1 gene is essential for the embryonic development of hematopoietic stem cells (HSC). In an Advanced Online Publication in Nature, Hanna Mikkola and colleagues describe analysis of mice with a conditional deletion of the SCL/tal-1 gene generated to assess its role in adult hematopoiesis (Nature, DOI:10.1038/nature01345, 19 January 2003).

Mice containing a loxP-flanked SCL/tal-1 allele were bred with the mxCre strain in which Cre expression can be induced by polyI-polyC. Deletion of the SCL/tal-1 gene in adult mice did not affect the differentiation or the maintenance of myeloid or lymphoid lineages. Bone marrow transplantation experiments demonstrated that SCL/tal-1 gene deletion did not affect contribution to all hematopoietic organs.

"Loss of SCL/tal-1 does not seem to impair considerably HSC properties, including engraftment, self-renewal and multipotency. These results suggest that transcription factors required for HSC genesis (such as SCL/tal-1...