Figure 7. Non-canonical bone morphogenetic protein (BMP) signaling mediated via Transforming Growth Factor-β activated kinase (TAK) is upregulated in the Müller glia in BMP7 injected murine eyes. Retinal sections from mouse eyes processed 3 and 7 days following injection with either vehicle or BMP7 were co-labeled with antibodies against phospho-TAK1 (green) and Müller glial marker sex determining region Y box 2 (SOX2; red) . The vehicle injected control retinas for 3 and 7 days (D3 and D7 respectively) showed phospho-TAK1 label primarily cells in the ganglion cell layer (GCL), with no phospho-TAK1 labeling in the iner nuclear layer (INL) or outer nuclear layer (ONL). SOX2 (+) reinal astrocytes were observed in the GCL, however very little co-expression was observed with phospho-TAK1 in the vehicle injected retinas. The BMP7-injected retinas did show an increase in phospho-TAK1 expression in the INL, showing a comparatively higher expression in the BMP7-injected retina at 3 days than at 7 days. A subpopulation of the SOX2 (+) in the GCL and INL were co-labeled with phospho-TAK1 in the BMP7 injected retinas (arrows). n=3 different retinas for each immunolabel. Scale Bar A=50 μm applies to all panels.