Multiplexed CRISPRi reveals a transcriptional switch between KLF activators and repressors in the maturing neocortex.

A transcriptional switch from KLF activators to repressors during early postnatal development regulates neuronal maturation in the mouse neocortex.

• Why it matters: Understanding the transcriptional mechanisms behind postnatal neuronal maturation is crucial because it influences the transition from axon growth to synaptic refinement, which is essential for stable neural circuits.
• What they did: Using a multiplexed CRISPRi knockdown approach, the study identified a shift in KLF family gene expression from activators (Klf6, Klf7) to repressors (Klf9, Klf13) that modulates shared cytoskeletal target genes during early postnatal development.
• The result: This transcriptional switch, buffered by redundancy among KLF paralogs, suggests a conserved regulatory component of neuronal maturation that may underlie the loss of intrinsic axon growth in maturing neurons.