(A and B) Violin plots of candidate entry factor gene expression distributions in NCX-NES and donor-matched NCX single cells (A) or adult NCX (B). Y-axis, log2 transformed RPKM (A) or log2 transformed RPM (B). Proj. neuro., projection neuron; Interneuro., interneuron; Oligo., oligodendrocyte; Endo. cells, endothelial cells.
(C and D) Expression trajectories of AXL (C) and TYRO3 (D) during human neurodevelopment in different brain regions. Y-axis represents gene expression quantified by log2 transformed signal intensities and the X-axis represents the developmental ages quantified by the log10 transformed post-conceptional days. The dash vertical lines indicate the 15 developmental periods as defined by . The trajectory curves are smoothed by lowess function. The shading areas represent mean±SEM. NCX, neocortex; HIP, hippocampus; AMY, amygdala; STR, striatum; MD, mediodorsal nucleus of the thalamus; CBC, cerebellar cortex.
(E, F) Immunostaining showing that NES cells co-express AXL and VIM.
(G) Immunostaining of AXL and VIM in a 16 pcw fetal NCX shows that AXL is predominantly low expressed in the CP (G’), where it is detected mainly in blood vessels. Contrarily, higher expression of AXL is detected in the VZ/SVZ (G”).
(H) Fetal organotypic slices infected with ZIKV are NS1+ in VZ/SVZ RGCs that are also AXL+. Arrows point to AXL+ cells. Arrowheads indicate the presence of ZIKV infection. Asterisks indicate signal blood vessels.
(I) Expression of AXL in the adult NCX is restricted mainly to the astrocyte ribbon, which is also strongly labeled by GFAP, endothelial cells and some astrocyte processes in CP.
MZ, marginal zone; CP, cortical plate; IZ, intermediate zone; SP, subplate; SVZ, subventricular zone; VZ, ventricular zone; LV, lateral ventricle; EL, ependymal layer. Scale bars, 50µm See also .