中文摘要：

目的观察体外培养的人视网膜前体细胞的超微结构特征。方法选取6例5个月人胚胎眼12只，每例取1只眼视网膜行视网膜前体细胞培养后进行透射电子显微镜观察，另一只眼直接行透射电子显微镜观察。结果在胚胎5个月的人视网膜神经上皮层细胞核内出现了大量的异染色质，细胞核呈不规则形。神经上皮层中有少量原始细胞散在分布，细胞核体积大，表面光滑，充满大量的常染色质，核仁明显。体外培养的视网膜前体细胞显示出原始细胞的超微结构特征：有巨大的细胞核，几乎占据整个细胞的体积，细胞浆极少，核仁明显，有大量的常染色质，几乎看不到异染色质。神经球样细胞团内，细胞间紧密贴附，外围细胞体积较大，可见到核分裂相。结论体外培养的人视网膜前体细胞具有原始细胞的超微结构特征。

英文摘要：

Objective To observe the ultrastructural characteristics of human retinal progenitor cells cultured in vitro. Methods Six 5-month-old human fetuses （12 eyes）without eye diseases were selected. Retinal progenitor cells from the retina of one eye of each fetus were cultured in vitro, and observed by transmission electronic microscopy （TEM）; while those from the other eye were directly observed by TEM, Results Abundant heterochromatin were found in the karyon of 5-month embryonic retinal neuroepithelial cells,and the figure of the karyons was irregular, A few scattered initial cells were seen in retinal neuroepithelial layer with large karyon,smooth surface,abundant euchromatin,and distinct nucleolus, The human retinal progenitor cells cultured in vitro had the same uhrastructural characteristics as the initial cells., with huge karyon which almost occupied the whole cell, little cytoplasm, distint nucleolus,abundant euchromatin,and little heterochromatin. The cells clung to each other in the neural globoid cell mass. The size of the outer cells was large,and karyokinesis could be found. Conclusion The cultured human retinal progenitor cells are provided with the same uhrastructure characteristics as the initial cells.