RESEARCH ARTICLE Protein Expression Profiles Characterize Distinct Features of Mouse Cerebral Cortices at Different Developmental Stages

The proper development of the mammalian cerebral cortex requires precise protein synthe-sis and accurate regulation of protein expression levels. To reveal signatures of protein ex-pression in developing mouse cortices, we here generate proteomic profiles of cortices at embryonic and postnatal stages using tandemmass spectrometry (MS/MS). We found that protein expression profiles are mostly consistent with biological features of the developing cortex. Gene Ontology (GO) and KEGG pathway analyses demonstrate conserved mole-cules that maintain cortical development such as proteins involved in metabolism. GO and KEGG pathway analyses further identify differentially expressed proteins that function at specific stages, for example proteins regulating the cell cycle in the embryonic cortex, and proteins controlling axon guidance in the postnatal cortex, suggesting that distinct protein expression profiles determine biological events in the developing cortex. Furthermore, the STRING network analysis has revealed that many proteins control a single biological event, such as the cell cycle regulation, through cohesive interactions, indicating a complex net-work regulation in the cortex. Our study has identified protein networks that control the corti-cal development and has provided a protein reference for further investigation of protein interactions in the cortex