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治疗性克隆的安全性与风险性是阻碍治疗性克隆发展的关键环节之一.由于受到社会伦理问题的限制,人胚胎干细胞的多能性检测只能通过畸胎瘤的方式鉴定,与传统的小鼠生殖系嵌合鉴定方式不同.但是两种多能性检测方式之间的区别还不清楚.本研究利用遗传突变两性小鼠心肌成纤维细胞作为核移植供体细胞,构建核移植胚胎,经过体外培养获得克隆囊胚,建立核移植胚胎干细胞系.对胚胎干细胞系的鉴定结果表明,两性小鼠核移植胚胎干细胞系表达所有小鼠胚胎干细胞系多能性及特异的分子标记,如碱性磷酸酶活性,Oct4,Nanog,SSEA-1等,干细胞注射到免疫缺陷小鼠(SCID)体内能够形成含有三胚层分化附属物的畸胎瘤组织,证明两性小鼠核移植胚胎干细胞系具有多能性.但通过囊胚注射的方式获得的二倍体嵌合小鼠经过交配不能获得生殖系嵌合的小鼠,因而两性小鼠核移植胚胎干细胞系并不具有全能性,说明体内形成三胚层分化附属物的畸胎瘤组织并不能替代传统的生殖系嵌合,提示在人治疗性克隆胚胎干细胞系多能性鉴定中,仍然需要更多、更严格的标准,进而最大程度地降低治疗性克隆临床应用的风险性.
The safety and risk of therapeutic cloning are one of the key steps hindering the development of therapeutic cloning.Because of the restriction of social ethics, the detection of pluripotency of human embryonic stem cells can only be identified by teratoma method, However, the difference between the two pluripotency detection methods is not yet clear.In this study, cardiac myofibroblasts were used as donor cells for nuclear transfer to construct nuclear transfer embryos, The cloned blastocysts were obtained in vitro and the nuclear transfer embryonic stem cell line was established.The identification of ES cell lines showed that the embryonic stem cell lines of allogenic mice expressed the pluripotency and specific molecular markers of all mouse embryonic stem cell lines, The results showed that the injection of stem cells into immunodeficient mice (SCID) could form teratoma tissues containing three germ layer differentiated adjuvants, demonstrating that the nuclear transplanted embryonic stem cell lines of both sexes have more However, diploid chimeric mice obtained by blastocyst injection can not acquire germ-line chimeric mice after mating, Embryonic stem cell lines do not have pluripotency, indicating that the formation of teratoma tissue of the three germ layer differentiation adjuvant in vivo does not replace the traditional germ line chimera, suggesting that in human pluripotent identification of cloned embryonic stem cell lines, More and more stringent standards, thus minimizing the clinical application of therapeutic cloning of the risk.