FIGURE 3 

Dose response (A) and kinetic measurements (B, C) on the array. (A) Percentiles of differentiated neuron-like cells (green) and glial-like cells (red), as a function of spotted Jagged-1 concentration. The higher the concentration of the Notch ligand, the higher or lower the percentage, respectively, of differentiating glial-like and neuron-like cells. Red and green lines represent polynomial fits. Error bars represent standard errors computed using spot replicates on the same array. (B) Differential kinetics of gliogenic responses. Shown are four time points from a time-course experiment conducted in parallel with four arrays that were cultured for 25, 38, 52, and 70 h. Exposure to BMP-4 (orange) and Jagged-1 (red) increased the relative proportions of glia as compared to Ln (black). The BMP-4 response was already at a plateau after 25 h, whereas the response to Jagged-1 stimulation occurred over a significantly longer timescale. (C) Differential kinetics of proliferation. Traces of proliferation index in the same time-course experiment revealed dynamic, spot-dependent differences in proliferation responses. Integration over all four time points revealed that co-exposure to Wnt-3A and Jagged-1 (light blue) or DLL-4 (not shown) led to a significant increase in proliferation.