Single cell sequencing of primary dorsal root ganglia from CAST/Ei or C57BL/6 mouse highlights strain differences in cellular populations.. Mus musculus

Peripheral nerve regeneration after injury is a complex process involving a large number of transcriptional changes. How these changes impact the regenerative outcome is though, poorly understood. Here, we take advantage of the genetically based differences in the peripheral and central regenerative capacity of CAST/Ei and C57BL/6j inbred mice to better understand the molecular bases driving superior regeneration in the CAST/Ei mouse strain. Single cell RNA sequencing highlighted the existence of three populations of cells, one of which expressed genes enriched for mature neuronal function, another one had a gene expression profile enriched for an immature dedifferentiated state while the third one showed an intermediate profile between these two extremes. The immature expression state was observed after injury in both strains but a larger proportion of the CAST/Ei neurons retained an expression pattern consistent with neuronal identity whereas a larger proportion of C57BL/6 neurons acquired an immature gene expression state accompanied by expression of stress markers. This finding suggests that unexpectedly, maintenance of a mature differentiated state in injured neurons increased regenerative success. Overall design: Mouse DRG from two strains (CAST/Ei or C57BL/6) were dissected and processed into single cell suspension. The naive cells were loaded into a fluidigm C1 for cell capture, lysis and cDNA preamplification. IVA (in vitro axotomy) cells were plated for 48h before being resuspended and captured as the naive cells. Overall, 516 individual cells were analyzed.