Runx1 Controls Auditory Sensory Neuron Diversity (CKO)

As the primary sensory neurons of the auditory system, Type I spiral ganglion neurons (SGNs) encode sound stimulus properties critical for the formation of auditory percept in higher brain areas. Their functional heterogeneity is thought to contribute to our ability to hear a wide range of sound intensities and against background noise, but how SGN diversity arises during development is poorly understood. Here we studied the role of the transcription factor Runx1 in establishing SGN heterogeneity in the mouse cochlea by single cell RNA-sequencing. Overall design: Runx1 expression was ablated embryonically in SGNs using mice bearing a floxed Runx1 allele, tdTomato transgene and the bhlhb5-Cre transgene. Cochlear tissues, including spiral ganglia, were harvested from mice of both sexes at P30-P33 and single cell suspensions were created using collagenase and papain for enzymatic dissociation. After fluorescence-activated cell sorting for enrichment of tdTomato+ SGNs, dual-indexed single cell transcriptomic libraries were then created using the 10X Genomics Chromium Single Cell 3' GEM Library and Gel Bead Kit v3. Libraries were sequenced using the NextSeq 500/550 High Output Kit v2.5 (75 Cycles, Illumina).