Fig. 7

Quantification of the reciprocal localization of UBE3A and DAPI in human neuronal nuclei. To analyze the relationship between UBE3A and DAPI in neuronal nuclei, we used the intensity correlation analysis approach of Li et al. [47]. Analyses are presented as intensity correlation plots: the x value, (channel 1 pixel value–channel 1 mean value) × (channel 2 value–channel 2 mean value), reflect the covariance of both channels, and the y value reflects the intensity of channels 1 or 2. Pixels with values situated left of the x = 0 line do not colocalize or have inversely correlated intensities, whereas pixels situated on the right side colocalize (see diagram in a). Scatterplot in b and c corresponds to the nuclear region of the sections used for illustration in Fig. 6b (Scatterplots are from raw confocal images, while contrast and brightness were adjusted in the micrographs). Panel c shows DAPI with respect to UBE3A, and d shows UBE3A with respect to DAPI. Both plots are skewed toward negative values, implying that UBE3A and DAPI pixel intensity co-varies in opposite directions. d Box and whiskers plot of intensity correlation quotient (ICQ, [47]) from 92 nuclei from layers II–III. ICQ values ~ 0 imply random staining, 0 > ICQ ≥ − 0.5 indicate segregated (negatively correlated) staining, and 0 < ICQ ≤ + 0.5 indicate dependent (positively correlated) staining. We found an average ICQ of − 0.04 ± 0.005, showing that UBE3A and DAPI staining negatively co-vary