亲手请教关于嵌合体

zhaoyan1983

另外“囊胚腔内有具有pluripotency的内细胞团（ICM），将iPS注射到囊胚腔里时，iPS和ICM共同发育成为一个成体”，为什么一定要ICM和IPS共同发育，如果IPS在囊胚内独自发育的话，不是更能证明IPS的全能型么？

exin11

学习了，谢谢楼上各位

hjhzhhy

嵌合体一般指，用以指不同遗传性状嵌合或混杂表现的个体或指一个机体身上有两种或两种以上染色体组成不同的细胞系同时存在,彼此能够耐受,不产生排斥反应,相互间处在嵌合状态。嵌合体动物。目前是进行ES或iPS细胞全能型检测的黄金法则，一般通过在早期胚胎或囊胚阶段注射一定数量的检测细胞，移植受体。

sapery279

一般做的嵌合体，是将iPS细胞注入到二倍体的囊胚中，得到的个体是由原来囊胚ICM和iPS共同发育而来的。还有一个黄金标准就是将iPS注到4倍体囊胚中，这样的四倍体囊胚是无法发育成个体的，只能在发育过程中形成胚外组织，也就是说这个个体完全是由iPS细胞发育来的。至于“IPS在囊胚内独自发育的话，不是更能证明IPS的全能型么？”我个人觉得这个在试验上不能做到。即使是iPS细胞与受精卵一模一样，如果没有类似卵裂时的外环境，恐怕是无法正常发育。

jason

有没有高手可以回答一下呢？另外“囊胚腔内有具有pluripotency的内细胞团（ICM），将iPS注射到囊胚腔里时， ...
. i4 S# T3 U1 K0 c/ Fzhaoyan1983 发表于 2010-8-28 13:46

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' r  I! X, C' c! D. ~; y2 ?! [    周琪的nature文章回答的就是你这个问题。利用四倍体嵌合技术能得到完全由ipsc发育而来的成体小鼠。" ?8 d7 I" k5 L( ~5 V% \0 H8 N% g
Zhao, X. Y., W. Li, et al. (2009). "iPS cells produce viable mice through tetraploid complementation." Nature.
5 f( r6 E; A9 J! Q; U        Since the initial description of induced pluripotent stem (iPS) cells created by forced expression of four transcription factors in mouse fibroblasts, the technique has been used to generate embryonic stem (ES)-cell-like pluripotent cells from a variety of cell types in other species, including primates and rat. It has become a popular means to reprogram somatic genomes into an embryonic-like pluripotent state, and a preferred alternative to somatic-cell nuclear transfer and somatic-cell fusion with ES cells. However, iPS cell reprogramming remains slow and inefficient. Notably, no live animals have been produced by the most stringent tetraploid complementation assay, indicative of a failure to create fully pluripotent cells. Here we report the generation of several iPS cell lines that are capable of generating viable, live-born progeny by tetraploid complementation. These iPS cells maintain a pluripotent potential that is very close to ES cells generated from in vivo or nuclear transfer embryos. We demonstrate the practicality of using iPS cells as useful tools for the characterization of cellular reprogramming and developmental potency, and confirm that iPS cells can attain true pluripotency that is similar to that of ES cells.