Searching for the factors concerning hematopoiesis

本研究的目的之一是克隆早期造血相关因子的基因。为此，我们将小鼠胚胎干细胞的体外造血分化诱导方法和信号序列捕获方法（一种选择含有信号肽的分泌蛋白的方法）相结合。从第5天诱导的中胚层细胞集落中构建cDNA文库，其中存在成血管细胞和造血祖细胞。结果，克隆了命名为ESOP-1的cDNA。推导的氨基酸序列为160个氨基酸。人ESOP-1也被克隆，并显示64%的同源性。ESOP-1 cDNA在妊娠7.5天的胚胎中高度表达。该基因在成人和胚胎造血系统中均有表达。免疫组化结果表明，该蛋白在卵黄囊、发育中的神经系统和成体生殖器官中均有表达，并与正常胚胎的表达进行了比较。 ...更多信息 Bcl-X基因在红细胞生成中作用我们利用Bcl-X无效的小鼠胚胎干细胞（ES细胞），并表明，Bcl-X是必不可少的生产胚胎原始红细胞（EryP）和成人定形红细胞（EryD）在其成熟结束。在体内，bcl-x空ES细胞并没有贡献循环EryD在成年嵌合小鼠，所产生的囊胚显微注射的bcl-x空ES细胞。通过在巨噬细胞集落刺激因子缺陷基质细胞系OP 9上体外分化诱导ES细胞产生bcl-x null EryP和EryD，并进行进一步分析。未成熟的EryP和EryD从bcl-x缺失的ES细胞的出现类似于从正常ES细胞。然而，当细胞成熟时，bcl-x null EryP和EryD发生显著的细胞死亡。促红细胞生成素被认为可以防止红系祖细胞的凋亡性细胞死亡，而bcl-x的抗凋亡功能作用于成熟的最后阶段。少

One of the purposes of this study is cloning the genes of the factors that have some roles in early hematopoiesis. For this purpose, we combined the in vitro hematopoietic differentiation induction method from mouse embryonic stem cells and the signal sequence trap method that is a method to select secretory proteins containing signal peptide. cDNA library was constructed from the day 5 induced mesodermal cell colonies in which hemangioblasts and hematopoietic progenitors existed. As a result, cDNA named ESOP-1 was cloned. The deduced amino acid sequence shows 160 amino acids protein. Human ESOP-1 was also cloned and shows 64% homology. ESOP-1 cDNA was highly expressed in embryos at day 7.5 of gestation. This gene was also expressed in both adult and embryonic hematopoietic system. Antibody was produced against this protein and immuno staining revealed that the protein was expressed in yolk sac, developing nervous system and adult genital organs.The other outcome is the analysis of the … More fuction of Bcl-X gene on erythropoiesis. We utilized Bcl-X null mouse embryonic stem cells (ES cells), and showed that Bcl-X is indispensable for the production of both embryonic primitive erythrocytes (EryP) and adult definitive erythrocytes (EryD) at the end of their maturation. In vivo, bcl-x null ES cells did not contribute to circulating EryD in adult chimeric mice that were produced by blastocyst microinjection of the bcl-x null ES cells. bcl-x null EryP and EryD were produced by in vitro differentiation induction of ES cells on a macrophage colony-stimulating factor deficient stromal cell line OP9, and further analysis was carried out. The emergence of immature EryP and EryD from bcl-x null ES cells was similar to that from normal ES cells. However, prominent cell death of bcl-x null EryP and EryD occurred when the cells matured. Erythropoietin is thought to prevent the apoptotic cell death of erythroid progenitor cells, while the anti-apoptotic function of bcl-x acts at the very end of maturation. Less