Adolescence takes on a most active transcriptomic expression during the mouse cerebrum postnatal development

Cerebrum postnatal development is a complex molecular biological process controlled by multiple genes precisely. To further provide clues to the molecular mechanism about cerebrum development, we investigated the whole transcriptome dynamics of mouse cerebrum in three different developmental stages (infancy, adolescence and adulthood), using high-throughput RNA-seq method. We acquired 44,557,729, 59,257,530, 72,729,636 reads and identified 15,344, 16,048, 15,775 genes expressed in infancy, adolescence and adulthood cerebrum, respectively. We found that gene expression appeared as a first rise-then reduce trend during mouse cerebrum postnatal development and adolescence showed the most active statement at gene expression, in which a large number of regulatory genes and crucial pathways were activated. Transcription factors (TFs) analysis showed the same results, TFs related to neurogenesis differentiation, oligodendrocyte lineage determination and circadian rhythms regulation also displayed a rise-reduce trend after birth. Moreover, our results displayed that many important events occurred during the mouse cerebrum postnatal development. Significantly high expression of Mbp in adolescence and adulthood gave us a hint that brain myelin generated rapidly from adolescence and remained high level until adulthood. The trochaic trend of rhythmic process suggested that adolescence mouse cerebrum had begun to regulate rhythmic movements. Different trends of axon repulsion and attraction from infancy to adolescence indicated that axon repulsion was activated in this period, while axon attraction might be activated in embryonic stages and expressed decreasingly during the whole postnatal development. All these results gave us an insight into the transcriptomic changes of mammalian cerebrum postnatal development.