Figure 12.

Neuronal Nrg1 is required for Pacinian, but not Meissner, corpuscle development. A–D, Split^Cre, which drives recombination in RA mechanoreceptors, produced a partial, but significant, decrease in the number of Pacinian corpuscles per leg when combined with a conditional Nrg1 allele at both P7 (data not shown; C) and P21 (A, B, D) (Split^Cre;Nrg1^f/+ controls have 28.13 ± 1.98 corpuscles per leg at P7, Split^Cre;Nrg1^f/− mutants have 14.50 ± 1.92 corpuscles per leg at P7, p = 0.002; Split^Cre;Nrg1^f/+ controls have 30.83 ± 1.01 corpuscles per leg at P21, Split^Cre;Nrg1^f/− mutants have 18.67 ± 3.18 corpuscles per leg at P21; p = 0.02). E, F, Glabrous skin sections from P21 Split^Cre;Nrg1^f/+ controls (E) and Split^Cre;Nrg1^f/− mutants (F) show no obvious change in the appearance or number of Meissner corpuscles in mutants relative to controls. N = 3 animals, 6 legs/glabrous skin samples per genotype. *p < 0.05. **p < 0.01. Error bars indicate SEM. Scale bar, 20 μm.