Research on the in vitro differentiation of embryonic stem cell(ES) is one of the hotspots in the study about developmental biology and cell transplantation therapy. But ethical issues and immune rejection remained to be the reasons which obstruct the progress. Recently, scientists have successfully obtained a kind of phripotent stem cell named induced phripotent stem cells (iPS). Since iPS posses similar properties with ES and can be autologously derived from patients themselves, it is a potential substitute of ES beth in the basic research and clinical application and the above mentioned problems can be avoided. However, iPS must differentiate to specific cells before being used in the clinical therapeutic research. The present article provides a concise summary of current progress on the differentiation ofiPS cell as well as some existing problems.

BACKGROUND:Up to date,inbred embryonic stem cells(ESCs) line mainly derived from 129 mouse strain and C57BL/6 strain,occasionally from BALB/c mouse strain,however,few reports concerning ESCs lines derived from Ch inese Kunmingmouse strain.OBJECTIVE:To isolate and culture mouse ESCs of kunming species,additionally,to identify its biological properties.DESIGN,TIME AND SETTING:The experiment with cells as observed subjects was conducted in the institute of Urology,First Affiliated Hospital of Nanchang University from May 2006 to June 2007.MATERIALS:Blastocysts of Kunmin mice with 3.5 days of embryonic age.METHODS:Inner cell mass from 3.5 days embryonic age were isolated from Kunming species mice,cultured on feeder layers of primary mice embryonic fibroblasts,and then the cells were isolated and subsequently cultured.MAIN OUTCOME MEASURES:Colony growth was observed and determined by alkaline phosphatase (AKP) staining;The expression of stage-specific embryonic antigen (SSEA)-1,and cell specific genes of c-Myc,Nanog,Oct3/4 and Sox2 were measured by immunofluorescence and RT-PCR;finally,the ability of differentiation in vitro and in vivo was identified.RESULTS:The ESCs-like colonies presented typical morphological characteristics of ESCs,which was positive to AKP and SSEA-1,and could express several cell specific genes,such as c-Myc,Nanog,Oct3/4 and Sox2,and differentiate into various cell types in vitro and in vivo.CONCLUSION:An ESCs line is successfully dedved from Kunming mice,which has typical biological characteristics of ESCs.