The Axolotl as a system to define the function and evolution of reprogramming activities

非哺乳动物模式生物在机械解剖生物过程和识别基因的基本、保守功能方面至关重要。目前尚不清楚非哺乳动物的OCT4和SOX2同源物是否可以将细胞重编程为多能性。蝾螈是分析OCT4/SOX2驱动重编程保护的理想非哺乳动物模型。AxOCT4可以维持小鼠胚胎干细胞。此外，蝾螈是通过胚胎诱导形成全能性生殖细胞的实验模型。最后，蝾螈进行再生，包括将细胞重新编程到较少的状态。在上一期中，我们发现AxOCT4和AxSOX2可以重编程人类成纤维细胞，使其具有多能性。我们还发现OCT4+SOX2+细胞出现在再生脊髓中，在那里细胞重建功能组织。最后，我们确定了在再生组织和非损伤组织中表达的染色质蛋白可能参与重编程。我们将进一步研究重编程中的AxOCT4、AxSOX2等因素。首先，我们将分离脊髓OCT4+SOX2+细胞，测试其效力，并测试OCT4和我们的染色质因子在这些细胞重编程中的作用。其次，我们将表征从美西螈培养的推定es样细胞。最后，我们将使用转录组分析来比较来自至少三种不同来源的AxOCT4+SOX2+细胞，包括外胚层和再生脊髓，以确定重叠和非重叠的基因集。将这些数据与哺乳动物多能性网络进行比较，将使我们更好地理解完全多能性与部分重编程状态所需的子网络。

Non-mammalian model organisms have been critical in mechanistically dissecting biological processes and identifying the essential, conserved function of genes. It was unknown whether non-mammalian OCT4 and SOX2 orthologs can reprogram cells to pluripotency. The Axolotl is an ideal non-mammalian model to analyze the conservation of OCT4/SOX2 driven reprogramming. AxOCT4 can sustain mouse ES cells. Furthermore the Axolotl is an experimentally accessible model where totipotent germ cells form by embryonic induction. Finally the Axolotl undertakes regeneration that involves reprogramming cells to less committed states.In the last period we showed that AxOCT4 and AxSOX2 can reprogram human fibroblasts to pluripotency. We also showed that OCT4+SOX2+ cells arise in the regenerating spinal cord where cells rebuild functional tissues. Finally, we identified chromatin proteins expressed in regenerating and not wounded tissue likely involved in reprogramming.Here we will further study AxOCT4, AxSOX2 and other factors in reprogramming. First, we will isolate spinal cord OCT4+SOX2+ cells, test their potency, and test the role of OCT4 and our chromatin factors in reprogramming these cells. Second, we will characterize putative ES-like cells cultured from the Axolotl. Finally, we will use transcriptome analysis to compare AxOCT4+SOX2+ cells from atleast three different sources including epiblast and regenerating spinal cord to define the overlapping and non-overlapping gene sets. Comparing this data to the mammalian pluripotency network will refine our understanding of subnetworks required for full pluripotency versus partially reprogrammed states.