Fig. 2. rs55705857 SNP resides in a brain-specific enhancer.

(A) Schematic of rs55705857 LacZ enhancer reporter construct. (B) Representative whole-mount images of LacZ-stained rs55705857 nonrisk (left) and risk (right) enhancer reporter embryos. Black arrows denote LacZ staining found in both reporter mice, while red arrows indicate LacZ staining only found in risk reporter mice. (C) Summary for enhancer activity of the nonrisk and risk allele. P-value by Fisher-Freeman-Halton exact test. n.s., not significant. (D) Representative immunofluorescent image of a sagittal section of an rs55705857-G risk allele mCherry enhancer reporter embryo at E14.5 stained for mCherry and the radial glial marker Sox2. The pontomedullary hindbrain is shown and arrows depict mCherry/Sox2 double-positive cells. Scale bars, 50 μm. Similar staining patterns were observed in the ventricular zone of the forebrain.