Chimeric Mouse Production Using High IPSC Of Generation

Embryonic stem (ES) cells have pluripotency to become other types of cells under Specialconditions, which have broad application space on animal models and cell therapy. Because of the Ethicaland moral problem of human beings, the research on ES have to stay in animal level. The occurrence ofinduced pluripotent stem cells (iPSC),let scientists develop an interest on stem cells. Similar to ES cells,iPSC also have totipotency,The emergence of the iPSC overcome the problem of ES cells in the moral, andiPSC provides the advantageous safeguard.for cell therapy and transgenic animal research.There are a lot of methods on inducing iPSC follow the further research, but the efficiency stilllow. Although we have been working to optimize the method, it is not easy to get the iPSC, and thegeneration of iPSC limit its application. Some research suggest that high generation of iPSC can notguarantee their pluripotency, so applications on high generation of iPSC is ignored. In this study, We usedthe40thgeneration of IP2-19to explore their pluripotency through production of chimeric mouse.We used three methods getting different periods of embryo to compare the situation of theirdevelopment to the blastocyst. First we use in vitro fertilization (IVF) to obtain pronucleus stage embryos,which develop in vitro environment, Second through normal mating, we got2-cell embryo and developedthem to the blastocyst in vitro, And the third way we got blastocyst embryo which complete theirdevelopment in the body through rushing out of the embryo. The experiment results showed that: the IVFprovided an average of55.2embryos/4mice which the number is the largest by using the same number ofmice, while the second way produced an average of52.25embryo embryo/4mice, and the third way, wegot3.5thembryos is38.2embryo/4mice through normal mating. normal mating develop to the blastocystis77%±7%, which is higher than IVF (73%±7%). But the number of blastocysts through IVF is higher thanthe second way, And they are all significantly difference compared with the third method.We used manual and pizeo two methods respectively to injected of blastocyst, The blastocoelcollapsed after injection and then reformed. the probability of method ueing pizeo is73.8%higher thanmanual (59.1%).we transplanted these embryo into pseudopregnancy rats,one of them gave birth to eightmice.one of the eight mice is chimeric mice,the others are normal,so its positive is12.5%.mice growth does not appear abnormal. In this study, the high generation of iPSC still keep totipotency similar to the lowgenneration through producting of chimeric mouse, we further excavate the space of iPSC in application.