Figure 2.

SHH Induces Distinct MGE versus FP Ventral Fates under EB and AD Conditions

(A–C) Confocal images show expression of NKX2.1, SOX1, FOXA2 and FOXG1 at day 17 in EB (A) or day 12 in AD (B) differentiated neuroepithelia after SHH patterning. Insets show Hoechst counterstaining of nuclei. Scale bars, 50 μm. Graph (C) shows the percentage of positive cells in (A) and (B). Data are presented as mean ± SEM of three independent experiments. Unpaired two-tailed Student's t test: ^∗∗p < 0.01.

(D and E) mRNA expression of SOX1 (D) and FOXA2 (E) in both EB and AD differentiated neuroepithelia in the presence or absence of SHH exposure. Data are presented as mean ± SEM of three independent experiments. Unpaired two-tailed Student's t test: ^∗∗p < 0.01.

(F) In the presence of SHH exposure, cells differentiated under EB or AD conditions show differential mRNA expression levels of FOXG1, EN1, WNT5A, RAX, and CHL1. Data are presented as mean ± SEM of three independent experiments. Unpaired two-tailed Student's t test: ^∗p < 0.05, ^∗∗p < 0.01.

(G) In EB cells with SHH treatment, neuroprogenitors show high expression of LHX6 and LHX8, but no expression of CTIP2, FOXP2, COUP-TFII, and ZCCHC12. Data are presented as mean ± SEM of three independent experiments. Unpaired two-tailed Student's t test: ^∗∗p < 0.01.

(H) LHX6 and LHX8 are highly expressed in EB but not AD differentiated ventral neuroprogenitors. Data are presented as mean ± SEM of three independent experiments. Unpaired two-tailed Student's t test: ^∗∗p < 0.01.

(I) Confocal images of an E28 human embryo. Human FP cells are positive for SOX2, but negative for either PAX6 or SOX1. Scale bar, 50 μm.

(J) Confocal images of an E9.5 mouse embryo. Mouse FP cells uniformly express FOXA2 and SOX2, but are negative for SOX1. Notochord cells are positive for FOXA2, but lack SOX1 and SOX2 expression. Scale bar, 50 μm.

(K) The FP progenitors generated by SHH exposure under AD conditions are double-positive for FOXA2 and SOX2. Inset shows Hoechst counterstaining of nuclei. Scale bar, 50 μm.

(L) The FP cells specified under AD conditions differentiate into TH⁺ neurons after long-term culture, some of which still retain FOXA2 expression. Scale bar, 50 μm.

(M) FOXA2 and CORIN mRNA is highly induced by SHH exposure under AD conditions, while SPC and TG can hardly be detected. Data are presented as mean ± SEM of three independent experiments. Unpaired two-tailed Student's t test: ^∗∗p < 0.01.

(N) Summary of distinct ventral progenitor fates generated under EB or AD conditions upon SHH treatment.

See also Figure S2.