Fig. 2. FGF2 and BMP2 induce CNS stem cells to neural-crest-like precursor state. (A) RT-PCR analysis of Msx1 expression in passage 1 of medium-density-plated stem cells treated with FGF2 or FGF2 and BMP2 after 3 days. GAPDH expression is shown in reverse-transcribed (+) and non-transcribed (–) samples as loading controls. (B) RT-PCR analysis of Snail1 and Snail2 expression under same conditions over 7 days. GAPDH expression is shown in reverse-transcribed (+) and non-transcribed (–) samples as loading controls. (C) Phase images of FGF2- or FGF2 and BMP2-treated E14.5 rat cortical stem cell cultures at medium density. Notice the initial extension of reticulated processes and cell flattening during BMP2 treatment. (D-G) Comparison of p75^NGFR expression in passage 1 cells plated at clonal density; clones marked after 4 days FGF2 expansion (7.7±1.7 cells/clone) were further expanded ±20 ng/ml BMP2 treatment. By 5 days, p75^NGFR expression is absent in (D) FGF2-expanded cells but prevalent in (E) FGF2 plus BMP2-treated cells. Percent clones containing any (F) p75^NGFR+ cells and total percentage of (G) p75^NGFR+ cells during FGF2 expansion without () or with () BMP2. Graphs show the mean ± s.e.m. (n=3). Bars, 80 µm (C); 40 µm (D,E).