Expression data from V1 and dI4/dILA spinal interneurons

Spinal inhibitory interneurons play crucial roles in shaping motor output, but the molecular heterogeneity contained within cardinal spinal interneuron populations is unclear. This experiment was designed to identify genes enriched in the Engrailed1 (En1) population of ventral V1 inhibitory interneurons relative to the Ptf1a population of dorsal dI4/dILA interneurons, with the goal of identifying genetic markers for discrete V1 subpopulations. We isolated spinal inhibitory interneurons from either En1-Cre; Rosa.lsl.YFP (V1) or Ptf1a-Cre; Rosa.lsl.YFP (dI4) mice by acutely dissociating e12.5, p0, or p5 spinal cords. YFP-labeled interneurons were isolated by fluorescence activated cell sorting (FACS), followed by RNA extraction, amplification, and analysis on Affymetrix Mouse 430 2.0 arrays. All experiments were performed in triplicate, with the exception of dI4 interneurons isolated from p5 mice, which were performed in duplicate. En1-Cre mice (Kimmel et al., 2000), Ptf1a-Cre mice (Kawaguchi et al., 2002), and Rosa.lsl.YFP mice (Srinivas et al., 2001) have been described previously.