Establishment of canine iPS cells for the study of disease-model dogs

为建立犬iPS细胞，利用EOS载体系统将犬4种重编程因子导入犬胚胎成纤维细胞中，通过GFP的抗药性和荧光检测，筛选出表达内源性Oct3/4基因的克隆。所选克隆的干细胞标记基因呈阳性，并能形成类胚体，这表明诱导出了针对三个胚层中每一层的标记基因。然而，没有观察到畸胎瘤的形成。使用化学定义的培养液，这些克隆在几代中保持未分化状态，但长期培养迫使这些克隆自发分化，因此没有建立与iPS细胞相容的克隆。这些数据表明，犬iPS细胞的适宜培养条件有待进一步研究。

To establish canine iPS cells, canine four reprogramming factor were introduced into canine embryonic fibroblasts with the EOS vector system, which allowed us to select clones with the expression of endogenous Oct3/4 gene by drug-resistance and fluorescence of GFP. Selected clones were positive for stem cell marker genes and able to make embryoid bodies, which showed the induction of marker genes specific for each of three germ layers. Teratoma formation was, however, not observed. Using chemically defined medium, these clones were maintained at undifferentiated state during several passages, but the long term culture forced the spontaneous differentiation of these clones, and therefore no clones with the feature compatible with iPS cells were established. These data indicated that more investigation will be required to find the suitable culture condition for canine iPS cells.