Figure 4.

Impact of lineage-enriched transcription factors on expression of markers genes in Pit-1/Triple cells. Pit-1/Triple cells (5) were transfected with expression constructs encoding each noted transcription factor linked by an IRES to a GFP reporter open reading frame (see “Materials and Methods”). Transfected cells were isolated by GFP FACS and their RNA content was assayed for specific marker gene expression by qRT-PCR. (A) Nupr1. (B) Rxrg. (C) Nr4a2. (D) Pou4f1. In all assays, expression of the recombinant transcription factor was confirmed by targeted qRT-PCR (data not shown). Gene expression was normalized to an internal Gapdh control, and the fold change over empty vector controls was calculated using the ΔΔCt method (see “Materials and Methods”). Gapdh expression levels were stable across all assayed conditions, with no significant changes in Gapdh expression in any of the transfected samples. Error bars indicate 1 SD. n = 5 for all experiments. *P < 0.05, by t test.