Fig 1: Immunohistochemistry (IHC) and immunofluorescence (IF) analyses of the four candidate VEN markers. (A–P) IF-stain images of the four candidate genes (VAT1L, LYPD1, SULF2, and CHST8). The MAP2 gene is a neuron-specific maker and was used to show cell morphology (A–D), and DAPI was used to show cell nucleus (I–L). The immunoreactivity signals of the four genes are shown in panels E–H, and the merged signals are shown in panels M–P; (Q–T) IHC-stain images of the four candidate genes. Typical VENs with positive IHC-stain are indicated by arrows; (U–X) Comparison of ratios of positive-stain cells between VENs and L5Ps/L3Ps. Three male samples were analyzed (Supplementary Table S1). The black and gray bars are the two adult males, and the red bar is the 1-year-old male. The statistical significance level is labeled as ****(P < 0.0001) (two-tailed t test).