Transgenic analysis of the stem cell leukemia +19 stem cell enhancer in adult and embryonic hematopoietic and endothelial cells.
Appropriate transcriptional regulation is critical for the biological functions of many key regulatory genes, including the stem cell leukemia (SCL) gene. As part of a systematic dissection of SCL transcriptional regulation, we have previously identified a 5,245-bp SCL +18/19 enhancer that targeted embryonic endothelium together with embryonic and adult hematopoietic progenitors and stem cells (HSCs). This enhancer is proving to be a powerful tool for manipulating hematopoietic progenitors and stem cells, but the design and interpretation of such transgenic studies require a detailed understanding of enhancer activity in vivo. In this study, we demonstrate that the +18/19 enhancer is active in mast cells, megakaryocytes, and adult endothelium. A 644-bp +19 core enhancer exhibited similar temporal and spatial activity to the 5,245-bp +18/19 fragment both during development and in adult mice. Unlike the +18/19 enhancer, the +19 core enhancer was only active in adult mice when linked to the eukaryotic reporter gene human placental alkaline phosphatase. Activity of a single core enhancer in HSCs, endothelium, mast cells, and megakaryocytes suggests possible overlaps in their respective transcriptional programs. Moreover, activity in a proportion of thymocytes and other SCL-negative cell types suggests the existence of a silencer elsewhere in the SCL locus.
Silberstein
Lev
L
Department of Hematology, Cambridge Institute for Medical Research, Cambridge University, Hills Road, Cambridge CB2 2XY, UK.
Sánchez
María-José
MJ
Socolovsky
Merav
M
Liu
Ying
Y
Hoffman
Gary
G
Kinston
Sarah
S
Piltz
Sandie
S
Bowen
Mark
M
Gambardella
Laure
L
Green
Anthony R
AR
Göttgens
Berthold
B
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D001854:Bone Marrow Cells / Q000166:cytology; D019070:Cell Lineage; D042783:Endothelial Cells / Q000166:cytology / Q000201:enzymology; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D008297:Male; D008407:Mast Cells / Q000166:cytology / Q000201:enzymology; D008533:Megakaryocytes / Q000166:cytology / Q000201:enzymology; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000097:blood / Q000235:genetics
D051792:Basic Helix-Loop-Helix Proteins; D011518:Proto-Oncogene Proteins; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D001616:beta-Galactosidase; C489366:Tal1 protein, mouse