RNA-Sequencing Analysis Reveals a Regulatory Role for Transcription Factor Fezf2 in the Mature Motor Cortex

Abstract

Forebrain embryonic zinc finger (Fezf2) encodes a transcription factor essential for the specification of layer 5 projection neurons (PNs) in the developing cerebral cortex. As with many developmental transcription factors, Fezf2 continues to be expressed into adulthood, suggesting it remains crucial to the maintenance of neuronal phenotypes. Despite the continued expression, a function has yet to be explored for Fezf2 in the PNs of the developed cortex. Here, we investigated the role of Fezf2 in mature neurons, using lentiviral-mediated delivery of a shRNA to conditionally knockdown the expression of Fezf2 in the mouse primary motor cortex (M1). RNA-sequencing analysis of Fezf2-reduced M1 revealed significant changes to the transcriptome, identifying a regulatory role for Fezf2 in the mature M1. Kyoto Encyclopedia Genes and Genomes (KEGG) pathway analyses of Fezf2-regulated genes indicated a role in neuronal signaling and plasticity, with significant enrichment of neuroactive ligand-receptor interaction, cell adhesion molecules and calcium signaling pathways. Gene Ontology analysis supported a functional role for Fezf2-regulated genes in neuronal transmission and additionally indicated an importance in the regulation of behavior. Using the mammalian phenotype ontology database, we identified a significant overrepresentation of Fezf2-regulated genes associated with specific behavior phenotypes, including associative learning, social interaction, locomotor activation and hyperactivity. These roles were distinct from that of Fezf2-regulated genes identified in development, indicating a dynamic transition in Fezf2 function. Together our findings demonstrate a regulatory role for Fezf2 in the mature brain, with Fezf2-regulated genes having functional roles in sustaining normal neuronal and behavioral phenotypes. These results support the hypothesis that developmental transcription factors are important for maintaining neuron transcriptomes and that disruption of their expression could contribute to the progression of disease phenotypes.

Evolutionarily conserved gene expression patterns for affective disorders revealed using cross-species brain transcriptomic analyses in humans, rats and zebrafish

“…In neurons, both FEZF2 and IKZF1 are important TFs that determine neuroprogenitor cell fate 70 . FEZF2 also promotes neuroplasticity and neuronal signaling that involves neuroactive ligand-receptor interaction, cell adhesion molecules, and calcium signaling pathways 71 , thereby strikingly paralleling our KEGG 56 pathways enrichment findings here (Fig. 2 and Supplementary Tables S4 – S6 and S10 ).…”

Neural Stem Cells Direct Axon Guidance via Their Radial Fiber Scaffold

“…We initiated this study with the aim of identifying genetic targets of FEZF2, a transcription factor necessary for the proper specification of CSNs and CST formation. FEZF2 activates and represses gene expression in the cerebral cortex (Clare et al, 2017;Lodato et al, 2014), including in CSNs in L5. Here, we found that FEZF2 activates the expression of Rnd3, which is cell autonomously required for the proper regulation of axon elongation, dendritic complexity, and spine formation in CSNs.…”

Transcriptome Profiling of Layer 5 Intratelencephalic Projection Neurons From the Mature Mouse Motor Cortex

“…The R package pvclust, which calculates an approximately unbiased (AU) and bootstrap (BP) p -value for each cluster, was used to cluster the highly variable genes (Suzuki and Shimodaira, 2006 ). Heatmap generation was performed as described in Clare et al ( 2017 ).…”