Strand-biased hmC and mC profiles in both neurons and glia. (a) The average levels of hmC (left panel) and mC (right panel) for each strand of genes enriched in different brain cell types including neurons, astrocytes and oligodendrocytes (OLs), as well as the house-keeping genes (HKGs). (b) Tet-assisted reduced representation bisulfite sequencing performed in neuron nuclei isolated by FACS using the NeuN antibody (left panel) revealed that hmC is significantly enriched on the sense strands of the neuronal genes expressed at high (3, 4, 5), but not low (1, 2) expression levels (right panel). One-tailed paired Student’s t test. nd, no statistical difference (P >0.05).