ROLE OF BHLH PROTEIN SCL IN HEMATOPOIETIC DEVELOPMENT

红系细胞发育所需的核调节蛋白质不是 完全定义。在其他发育系统中， 螺旋-环-螺旋（bHLH）家族通常参与指定细胞命运。 bHLH因子被称为SCL（干细胞白血病）（也称为tal- 1/TCL 5）是在红系细胞中发挥重要作用的潜在候选者。 发展在这个项目中，小鼠SCL基因将被灭活， 胚胎干细胞中的基因靶向，以及缺乏的纯合子小鼠 将生成SCL。这些小鼠的表型将是 在整个胚胎发生和成年生活中具有特征（如果可行的话）。在 此外，SCL缺陷纯合的ES细胞将从 单敲除细胞，以评估造血和红系细胞 体外发育如果体外或体内的表型不 在没有SCL的情况下，系统地寻找潜在的 多余的蛋白质将进行，并涉及杂交育种的SCL 具有其它bHLH敲除的杂合子（例如Lyl）。进一步 研究SCL在血细胞发育中的作用， 将与核心B合作分离cDNA克隆， 用于检测正常斑马鱼SCL RNA表达模式 发育，并在异常造血发育所表现出的 无血突变体和其他斑马鱼突变体， 全世界的调查员。通过对小鼠SCL和 斑马鱼，这种蛋白质在红细胞发育中的作用应该是 确立了习

The nuclear regulatory proteins required for erythroid development are not entirely defined. In other developmental systems proteins of the basic helix-loop-helix (bHLH) family are often involved in specifying cell fate. The bHLH factor known as SCL (stem cell leukemia) (also known as tal- 1/TCL5) is a potential candidate for an important role in erythroid development. In this project the murine SCL gene will be inactivated by gene targeting in embryonic stem cells, and mice homozygous for deficiency of SCL will be generated. The phenotype of these mice will be characterized throughout embryogenesis and adult life (if viable). In addition, ES cells homozygous for SCL deficiency will be generated from single knock-out cells in order to assess hematopoietic and erythroid development in vitro. If the phenotypes in vitro or in vivo are not striking in the absence of SCL, a systematic search for potentially redundant proteins will be undertaken, and involve cross-breeding of SCL heterozygotes with other bHLH knock-outs (e.g. Lyl). To further investigate the role of SCL in blood cell development, a zebrafish SCL cDNA clone will be isolated in collaboration with Core B, which will be used to examine the pattern of SCL RNA expression in normal zebrafish development, and in abnormal hematopoietic development exhibited by the bloodless mutant and other zebrafish mutants to be provided from investigators worldwide. Through combined study of SCL in mice and zebrafish the role of this protein in erythroid development should be established.