Transcription factor expression defines subclasses of developing projection neurons highly similar to single-cell...

Area of Science:

• Neuroscience
• Developmental Biology
• Genomics

Background:

• The cerebral cortex contains over 50 unique projection neuron types, but the developmental mechanisms generating this diversity are poorly understood.
• Understanding how progenitor cells generate diverse neuron subtypes is crucial for linking cell type to function.

Purpose of the Study:

• To identify transcriptional networks governing neuron cell fate diversification.
• To understand how gene expression and chromatin accessibility change during the development of distinct cortical projection neuron subclasses.

Main Methods:

• Comparative analysis of gene expression and chromatin accessibility in two mouse cortical projection neuron subclasses from embryonic day 13 to postnatal day 5.
• Integration with published single-cell sequencing data.
• Identification of transcription factor binding motifs and long noncoding RNAs.

Main Results:

• Established that layer-defined cell classes contain subtypes and developmental trajectories identified by single-cell sequencing.
• Identified transcription factor groups with subclass-specific regulation and enriched binding motifs.
• Described transcription factor-adjacent long noncoding RNAs defining subclasses and validated the role of Myt1l in balancing subclass ratios.

Conclusions:

• The study supports a model of progressive cell fate restriction driven by inherited transcriptional identities.
• Identified specific molecular players, including transcription factors and lncRNAs, involved in cortical neuron diversification.