Table 2. Changes in cell composition in response to RA and EDN3.

	Comparison of mean proportion of immunolabelled cells (p value)
	%peripherin+	%SMA+	%S100β+
RA- vs. RA+ (EDN3-)	17.9 vs. 11.5 (p=0.023)	32.4 vs. 23.4	36.4 vs. 52.7 (p=0.001)
RA- vs. RA+ (EDN3+)	13.7 vs. 7.2 (p=0.022)	27.2 vs. 25.3	19.0 vs. 43.3 (p<0.001)
EDN3- vs. EDN3+ (RA-)	17.9 vs. 13.7	32.4 vs. 27.2	36.4 vs. 19.0 (p<0.001)
EDN3- vs. EDN3+ (RA+)	11.5 vs. 7.2	23.4 vs. 25.3	52.7 vs. 43.3 (p<0.043)
Interaction present?	No	No	No

This table summarizes the effects of RA and EDN3 on the cell composition of ENS precursor cultures after 3 days. Immunoselected cells were cultured in the presence of RA, EDN3, RA with EDN3, or neither compound. When EDN3 was absent, the EDN signaling inhibitor BQ-788 was added to inhibit endogenous EDNRB signaling. The proportion of peripherin, SMA, and S100β immunoreactive cells as a percentage of all cells counted in each condition were compared. A two way ANOVA was employed to identify the contribution of each compound to changes in the proportion of immunolabelled cells. Significant changes are in bold and p values are noted. Data is the summary of nine biological replicates, and ten random microscope fields were counted and summed per condition. Abbreviations: SMA = α-smooth muscle actin; EDN3 = endothelin-3; RA = Retinoic acid;