An SCL 3 ' enhancer targets developing endothelium together with embryonic and adult haematopoietic progenitors
- Author(s)
- Sanchez, MJ; Gottgens, B; Sinclair, AM; Stanley, M; Begley, CG; Hunter, S; Green, AR;
- Details
- Publication Year 1999-09,Volume 126,Issue #17,Page 3891-3904
- Journal Title
- DEVELOPMENT
- Publication Type
- Journal Article
- Abstract
- The SCL gene encodes a basic helix-loop-helix transcription factor which is expressed in early haematopoietic progenitors throughout ontogeny and is essential for the normal development of blood and blood vessels. Transgenic studies have characterised spatially distinct 5' enhancers which direct lacZ expression to subdomains of the normal SCL expression pattern, but the same elements failed to produce appropriate haematopoietic expression, We now describe an SCL 3' enhancer with unique properties. It directed lacZ expression in transgenic mice to extra-embryonic mesoderm and subsequently to both endothelial cells and to a subset of blood cells at multiple sites of embryonic haematopoiesis including the yolk sac, para-aortic splanchnopleura and AGM region. The 3' enhancer also targeted expression to haematopoietic progenitors in both foetal liver and adult bone marrow Purified lacZ(+) cells were highly enriched for clonogenic myeloid and erythroid progenitors as well as day-12 spleen colony forming units (CFU-S), Within the total gated population from bone marrow 95% of the myeloid and 90% of the erythroid colony-forming cells were contained in the lacZ(+) fraction, as were 98% of the CFU-S, Activation of the enhancer did not require SCL protein. On the contrary, transgene expression in yolk sacs was markedly increased in an SCL-/- background, suggesting that SCL is subject to negative autoregulation. Alternatively the SCL-/- environment may alter differentiation of extra-embryonic mesoderm and result in an increased number of cells capable of expressing high levels of the transgene. Our data represents the first description of an enhancer that integrates information necessary for expression in developing endothelium and early haematopoietic progenitors at distinct times and sites throughout ontogeny, This enhancer provides a potent tool for the manipulation of haematopoiesis and vasculogenesis in vivo.
- Publisher
- COMPANY OF BIOLOGISTS LTD
- Keywords
- HEMATOPOIETIC STEM-CELLS; TRANSCRIPTION FACTOR GATA-1; PRIMITIVE MYELOID CELLS; YOLK-SAC; MOUSE EMBRYO; PARAAORTIC SPLANCHNOPLEURA; DEFINITIVE HEMATOPOIESIS; TRANSGENIC MICE; PROMOTER REGION; BLOOD-VESSELS
- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 1999-09-01 12:00:00