ACTL6a knockout peripheral nerve RNA seq at postnatal day 3

Cells need to integrate chemical and physical signals into transcriptional programs. In the peripheral nerves, axonal caliber selection by specialized Schwann cells, is critical for developmental myelination. However, only mechanisms through which Schwann cells sense chemical signals are well characterized. We identify ACtin-Like protein 6a (ACTL6a), a component of the SWI/SNF chromatin remodeling complex, as critical for axonal caliber recognition and developmental myelination. ACTL6a is expressed in the developing nerve and, when activated by contact with axons or nanofibers of specific caliber, it promotes the eviction of repressive histone marks thereby enhancing the transcriptional program of myelination. Mutant mice with Schwann cells lacking ACTL6a display aberrant recognition of axonal caliber, resulting in defective radial sorting and lower levels of transcripts regulating myelination of developing nerves. We suggest that developing peripheral nerves require an ACTL6a-dependent integration of physical and chemical signals in Schwann cells to release of repressive histone modifications and promote myelination. Overall design: compare RNA seq results from the postnatal day 3 sciatic nerve of wild type and CnpcreActl6a mouse mutant