Cluster analysis of the time-of-day-dependent SCN proteome.

(A) Hierarchical clustering of the 421 proteins that exhibited statistically significant, time-of-day-dependent expression in the SCN. After z-score normalization of the median value of logarithmized intensities (Log₂) of each protein profile within Euclidean distances against those 421 time-of-day-dependent proteins, they were classified into six different expression clusters (denoted A through F). (B) Expression profile of the six hierarchical clusters, which were statistically different relative to one another. Two dominant clusters, B and E, were mirror images of one another. (C) Distribution of GO biological process terms in the six hierarchical clusters. Three GO biological processes were specifically enriched in cluster E relative to the time-of-day proteome. **p<0.01, ***p<0.001.