Fig. 7.
Knocking down Ctip2 and Nr4a2 in Rsp Satb2-mutant cells prevents their fate transition. a, b The efficiency of shRNAs for Ctip2 and Nr4a2. Ctip2 (a) and Nr4a2 (b) protein are greatly reduced when cotransfected with respective shRNA in HEK293T cells. c–l′ GFP + Cre or GFP + Cre + shRNAs were electroporated into the Rsp of Satb2f/f mice at E14.5 and mice were examined at P3. Satb2 immunofluorescence is absent in GFP+ cells transfected with Cre (c) and Cre + shRNAs (d). e–f′ Ctip2 immunofluorescence in Cre + shRNAs-cotransfected cells is greatly reduced (f, f′) compared with those transfected with Cre only (e, e′). g–h′ In situ hybridization signals for Nr4a2 in Cre + shRNAs-cotransfected cells are greatly reduced (h, h′) compared with those transfected with Cre only (g, g′). To make signals more clearly to compare, mRNA signals were photographed first, and then immunostaining of GFP was performed and imaged again. i–j′ In situ hybridization of FN1 shows that FN1 is ectopically expressed in Cre-transfected cells (i, i′) but absent in Cre + shRNAs-cotransfected cells (j, j′). k–l′ No in situ hybridization signals for Cbln1 are observed in Cre- or Cre + shRNAs-cotransfected cells. n = 3 mice for each group. Scale bars = 25 μm in inserts of d, f′, h′, j′, and l′, and 200 μm in d, f′, h′, j′, and l′. m Proposed model showing the role of Satb2 in determination of Rsp identity during morphogenesis