To extract additional biological information embedded in the multi-dimensional transcriptome dataset, we performed weighted gene co-expression network analysis29 to identify modules of co-regulated genes. We identified 29 modules associated with distinct spatiotemporal expression patterns and biological processes (Fig. 4a; Supplementary Information 6.7; Supplementary Table 9-11; Supplementary Figs 18-20). Among modules corresponding to specific spatiotemporal patterns, M8 consisted of 24 genes with a common developmental trend that exhibited highest levels in early fetal NCX and HIP (period 3) and then progressively declined with age until infancy (period 9) (Fig. 4b). In contrast, M15 contained 310 genes exhibiting changes in the opposite direction in the NCX, HIP, AMY, and STR (Fig. 4c). Gene ontology (GO) enrichment analysis showed that M8 genes were enriched for GO categories related to neuronal differentiation (Bonferroni-adjusted P=7.7×10-3) and transcription factors (P=5.2×10-3) (Supplementary Information 6.8; Supplementary Table 9).
