Characterization of PvCre(Arbr); TaumGFP mice. Characterization of PvCre(Arbr); TaumGFP mice. A–C, Immunostaining of P7 PvCre(Arbr); TaumGFP DRG sections with GFP and Pv antibodies. GFP+/Pv− neurons, indicated by white arrows, were found in the limb-level DRGs, such as C6 (A) and L5 (C), but not in non–limb-level DRGs, such as T6 (B). Scale bar, 100 μm. D, Low magnification of a P7 PvCre(Arbr); TaumGFP spinal cord, double-stained with antibodies against GFP and Pv. GFP+/Pv+ fibers innervate the intermediate Clarke's nucleus and ventral horn of the spinal cord. E, High magnification of double-stained PvCre(Arbr);TaumGFP dorsal spinal cord shows boxed area in D. GFP+ fibers also innervate layer III to IV of the dorsal horn, circled with dashed white lines, which are Pv−. This staining pattern is consistent with previous report that Pv is a proprioceptor-specific marker at P7. F–H, Double staining of GFP and S100 in P21 PvCre(Arbr);TaumGFP mice showing that GFP+ fibers innervate mechanosensory end organs in the periphery, including Meissner corpuscles (white arrow) in the dermal papillae of hindpaw footpads (F), Pacinian corpuscles (white arrow) in the interosseous membrane of fibula (G), and longitudinal lanceolate endings (circled by a dashed white ellipse) associated with follicles on back hairy skin (H). I, Triple staining of Pv, Ret, and GFP of E14.5 PvCre(Arbr); TaumGFP DRG sections shows that Cre-mediated recombination begins at this stage, as some Pv+ neurons have now initiated the expression of GFP. Yellow arrows indicate Pv+/Ret+ cells, and white arrows indicate GFP+/Pv+/Ret+ neurons. Scale bar, 50 μm. n = 3 for each age. Jingwen Niu et al. J. Neurosci. 2013;33:17691-17709 ©2013 by Society for Neuroscience