Sinclair Angus M, Bench Anthony J, Bloor Adrian J C, Li Juan, Göttgens Berthold, Stanley Maureen L, Miller Jane, Piltz Sandie, Hunter Susie, Nacheva Elisabeth P, Sanchez María-José, Green Anthony R
University of Cambridge, Department of Haematology, Cambridge Institute for Medical Research, Hills Road, Cambridge, CB2 2XY, United Kingdom.
Blood. 2002 Jun 1;99(11):3931-8. doi: 10.1182/blood.v99.11.3931.
The stem cell leukemia (SCL) gene encodes a basic helix-loop-helix transcription factor with a critical role in the development of both blood and endothelium. Loss-of-function studies have shown that SCL is essential for the formation of hematopoietic stem cells, for subsequent erythroid development and for yolk sac angiogenesis. SCL exhibits a highly conserved pattern of expression from mammals to teleost fish. Several murine SCL enhancers have been identified, each of which directs reporter gene expression in vivo to a subdomain of the normal SCL expression pattern. However, regulatory elements necessary for SCL expression in erythroid cells remain to be identified and the size of the chromosomal domain needed to support appropriate SCL transcription is unknown. Here we demonstrate that a 130-kilobase (kb) yeast artificial chromosome (YAC) containing the human SCL locus completely rescued the embryonic lethal phenotype of scl(-/-) mice. Rescued YAC(+) scl(-/-) mice were born in appropriate Mendelian ratios, were healthy and fertile, and exhibited no detectable abnormality of yolk sac, fetal liver, or adult hematopoiesis. The human SCL protein can therefore substitute for its murine homologue. In addition, our results demonstrate that the human SCL YAC contains the chromosomal domain necessary to direct expression to the erythroid lineage and to all other tissues in which SCL performs a nonredundant essential function.
干细胞白血病（SCL）基因编码一种基本的螺旋-环-螺旋转录因子，在血液和内皮细胞的发育中起关键作用。功能缺失研究表明，SCL对于造血干细胞的形成、随后的红系发育以及卵黄囊血管生成至关重要。从哺乳动物到硬骨鱼，SCL都呈现出高度保守的表达模式。已鉴定出几种小鼠SCL增强子，每个增强子在体内将报告基因的表达导向正常SCL表达模式的一个亚域。然而，红系细胞中SCL表达所需的调控元件仍有待确定，支持适当SCL转录所需的染色体结构域大小也未知。在此，我们证明包含人类SCL基因座的130千碱基（kb）酵母人工染色体（YAC）完全挽救了scl（-/-）小鼠的胚胎致死表型。获救的YAC（+）scl（-/-）小鼠以适当的孟德尔比例出生，健康且可育，卵黄囊、胎肝或成年造血均未检测到异常。因此，人类SCL蛋白可以替代其小鼠同源物。此外，我们的结果表明，人类SCL YAC包含将表达导向红系谱系以及SCL执行非冗余基本功能的所有其他组织所需的染色体结构域。
