摘要
ＥＳ细胞（ＥｍｂｒｙｏｎｉｃＳｔｅｍＣｅｌｓ）是来源于小鼠早期胚胎的细胞系，它可以在体外大量培养而不失去其发育的多潜能性。ＥＳ细胞不仅可以用来制作转基因动物，而且能够作为载体进行基因打靶等多种研究。目前，国际上常用的胚胎干细胞系都是来源于１２９小鼠的胚胎。因而，有必要探讨用其它品系小鼠建立ＥＳ系。１９９１年，Ｌｅｄｅｒｍａｎｎ等人首次报道从Ｃ５７ＢＬ／６Ｊ小鼠胚胎中建成了ＥＳ细胞系，但是没有对建立的细胞系进行特性分析。国内柴桂萱等人虽然做了特性分析，但是他们所建细胞系的细胞直径较大，生长速度较慢，不同于常见的ＥＳ细胞系。我们从Ｃ５７ＢＬ／６Ｊ品系小鼠胚胎中共分离了四个ＥＳ细胞系，分别命名为ＣＥ１、ＣＥ２、ＣＥ３、ＣＥ４（Ｆｉｇ．１ａ＆ｂ）。这四个细胞系核型正常率均达到７０％以上。我们检查了ＣＥ２细胞的分化能力，当将ＣＥ２细胞注入同基因型小鼠的皮下后，获得的畸胎瘤（Ｆｉｇ．３）组织切片检查的结果表明：该细胞能够分化成多种组织（Ｆｉｇ．２）。我们也研究了ＥＳ细胞的嵌合能力，用ＩＣＲ小鼠胚胎作为受体胚胎，采用囊胚显微注射法构建嵌合鼠。在幸存的幼鼠中我们获得了来源于ＣＥ２细胞的嵌合鼠（Ｔａｂｌｅ１，Ｆｉｇ．４）。综?
Four embryonic stem (ES) cell lines, designated CE1, CE2, CE3 and CE4, were isolated from C57BL/6J blastocysts. The ratio of normal diploid composition of these cell lines is above 70%. To examine the differentiation potential of the ES cells, the CE2 cells were injected subcutaneously into syngenic mice, and many kinds of differentiated cells were observed on the sections of the teratoma derived from this ES cell line. On the other hand, to test the chimeric ability of the ES cells, the CE2 cells were microinjected into the blastocysts of ICR mice, and a chimera was obtained among living pups. These results show that CE2 ES cells are pluripotent stem cells, which can differentiate into many kinds of cell types, and can be used as a cell system for further research.
