Mapping of transcription factor binding sites in mouse nephron progenitor cells. Mus musculus

In developing mammalian kidney, nephron progenitor cells (NPC) give rise to all cells in mature nephrons. Several transcription factors, including Six2, Hoxd11, Osr1 and Wt1, are expressed in NPC and are essential for its maintenance and/or specification. In order to understand the regulatory functions of these factors, we mapped binding sites of Six2, Hoxd11 and Osr1 in NPC using a novel transgenic strategy, and of Wt1 in wild-type developing kidney. Overall design: We generated transgenic mice ectopically expressing Six2, hoxd11 or Osr1, driven by an enhancer specifically regulate Six2 expression. In the transgenic mice, each transgenic transcription factor is tag with the FLAG epitope at the 3'-end. To genome-wide map binding sites of Six2, Hoxd11 and Osr1 specifically in mouse nephron progenitor cells, we performed FLAG ChIP using embryonic kidney isolated from these mice. To map Wt1 binding sites in kidney, we independently performed Wt1 ChIP-Seq in wild-type mouse kidneys.