Fig. 4. Transgenic evaluation of putative cell-type-specific enhancers.
Left column: Cell-type-specific OCRs identified by ATAC-seq and nearby genes: (a) glutamatergic (BDNF), (b) GABAergic (DLX6), and (c) oligodendrocytes (CNDP1). The horizontal gray bars denote OCR assayed in directed transcription via transgenesis. Right: Representative immunofluorescent images showing mCherry (red) expression in 30 µm thick sagittal sections from (a) BDNF and (c) CNPD1 transgenic mice. In (a), specific mCherry expression is identified in Layer V of the cortex and in hippocampus. In (b) representative images of mCherry (red) staining in the cortex of DLX6 transgenic mice (top panel) and double labeling with NeuN (green; bottom panel), showing expression restricted to neurons and scattered in the cortex, similar to the distribution of GABAergic interneurons. In (c) mCherry expression is shown to be restricted to white matter. Four image frames of three independent brain slices per each mouse were analyzed (BDNF enhancer n = 5; DLX6 enhancer n = 6; CNDP1 enhancer n = 4).