Transcriptional profile of mouse nephron progenitor cells

In developing mammalian kidney, nephron progenitor cells (NPC) give rise to all cells in mature nephrons. Expression of the transcription factor Six2 marks NPC in developing mouse kidneys. Within the Six2+ cell population, uncommitted NPC is marked by Cited1 expression. Towards the depletion of NPC in P2, most of the Cited1+ NPC is committed. Therefore, most of the Six2+ cells in kidney represents committed NPC. In order to explore the mechanism of NPC self-renewal and differentiation, hereby we generated transcriptional profiles of uncommitted NPC (Cited1RFP+ cells from kidneys of E16.5 Cited1tagRFP transgenic mice) and committed NPC (Six2GFP+ cells from kidneys of P2 Six2TGC transgenic mice). To obtain transcriptional profile of the target cells, we performed mRNA-Seq of cells purified from transgenic mouse kidneys (Six2TGC, Cited1tagRFP) using FACS.在发育中的哺乳动物肾脏中，肾祖细胞（nephron progenitor cells, NPC）可分化为成熟肾单位内的全部细胞。转录因子Six2的表达可标记发育中小鼠肾脏内的肾祖细胞。在Six2阳性（Six2+）细胞群中，未定向肾祖细胞可通过Cited1的表达进行标记。在出生后第2天（P2）的肾脏中，肾祖细胞已接近耗竭，此时绝大多数Cited1阳性（Cited1+）的肾祖细胞已发生定向分化。因此，该阶段小鼠肾脏内的多数Six2阳性细胞均为已定向的肾祖细胞。为探究肾祖细胞自我更新与分化的调控机制，本研究分别获取了未定向肾祖细胞（来自胚胎期16.5天[E16.5] Cited1tagRFP转基因小鼠肾脏的Cited1RFP阳性细胞）与已定向肾祖细胞（来自出生后第2天[P2] Six2TGC转基因小鼠肾脏的Six2GFP阳性细胞）的转录组表达谱。为获得目标细胞的转录组信息，我们利用荧光激活细胞分选（fluorescence-activated cell sorting, FACS）从上述转基因小鼠（Six2TGC、Cited1tagRFP）的肾脏中纯化目标细胞，并对其开展mRNA测序（mRNA-Seq）。