Ion and contribution to disease. Cell-type particular transcriptome analysis is increasingly recognized as essential for the molecular classification of neuronal populations in the brain and spinal cord (Okaty et al., 2011). Fluorescence activated cell sorting (FACS) and other neuron purification strategies coupled with transcriptional profiling by microarray analysis or RNA sequencing has permitted detailed molecular characterization of discrete populations of mouse forebrain neurons (Sugino et al., 2006), striatal projection neurons (Lobo et al., 2006), serotonergic neurons (Wylie et al., 2010), corticospinal motor neurons (Arlotta et al., 2005), callosal projection neurons (Molyneaux et al., 2009), proprioceptor lineage neurons (Lee et al., 2012), and electrophysiologically distinct neocortical populations (Okaty et al., 2009). These data have uncovered novel molecular insights into neuronal function. Transcriptional profiling technology at the single cell level is transforming our understanding from the organization of tumor cell populations and cellular responses in the immune system (Patel et al., 2014; Shalek et al., 2014), and has begun to become applied to neuronal populations (Citri et al., 2012; Mizeracka et al., 2013). This technology has been proposed as a valuable strategy to begin mapping cell diversity in the mammalian CNS (Wichterle et al., 2013). To start to define the molecular organization in the somatosensory system, we’ve performed cell-type distinct transcriptional profiling of dorsal root ganglion (DRG) neurons at both whole population and single cell levels. Using two reporter mice, SNS-Cre/D-Cysteine Endogenous Metabolite TdTomato and Parv-Cre/TdTomato, together with surface Isolectin B4-FITC staining, we determine 3 important, non-overlapping populations of DRG neurons encompassing practically all C-fibers and lots of A-fibers. SNS-Cre can be a BAC transgenic mouse line expressing Cre beneath the Scn10a (Nav1.8) promoter (Agarwal et al., 2004) which has beenChiu et al. eLife 2014;three:e04660. DOI: 10.7554/eLife.2 ofResearch articleGenomics and evolutionary biology | Neuroscienceshown to encompass DRG and trigeminal ganglia nociceptor lineage neurons, and in conditional gene ablation studies impacts thermosensation, itch, and pain (Liu et al., 2010; Lopes et al., 2012; Lou et al., 2013). A broadly 5993-18-0 Purity utilised Nav1.8-Cre knock-in mouse line also exists (Stirling et al., 2005; Abrahamsen et al., 2008), but differs to some extent in the transgenic SNS-Cre mouse line. We obtain, one example is, that SNS-Cre/TdTomato reporter mice label 82 of total DRG neurons, which is slightly greater than Nav1.8-Cre/TdTomato reporter mice (75 ) (Shields et al., 2012), implying capture of a larger neuronal population. Each the SNS-Cre lineage and Nav1.8-Cre lineage neurons involve a large proportion of C-fibers as well as a smaller population of NF200+ A-fibers (Shields et al., 2012). As anticipated, the majority of TdTomato+ cells (90 ) inside the SNS-Cre/TdTomato line expressed Scn10a transcript encoding Nav1.eight when tested by RNA in situ hybridization (Liu et al., 2010). Our second reporter line applied Parv-Cre, a knock-in strain expressing Ires-Cre under the control of the Parvalbumin promoter, which has been utilised within the study of proprioceptive-lineage (massive NF200+ A-fiber) neuron function (Hippenmeyer et al., 2005; Niu et al., 2013; de Nooij et al., 2013). Lastly we utilised IB4, which labels the surface of non-peptidergic nociceptive neurons (Vulchanova et al., 1998; Stucky et al., 2002; Basbaum et al., 2009). Us.