siRNA knockdown of CWC22 increases DRG neurite outgrowth. (A) Representative images of DRG neurons with scrambled siRNA or CWC22 siRNA. Note the increase in neurite outgrowth. Scale bar: 100 μm. (B) CWC22 siRNA significantly decreased Cwc22 mRNA in adult DRG sensory neurons. *P<0.05, unpaired one-tailed Student's t-test. (C) Neurite outgrowth (total length of candidate neurites). Scrambled: 1195±193 (mean±s.e.m.), siCWC22: 1440±182; n=7, *P=0.044, paired two-tailed Student's t-test. (D) Maximum process length (maximal length over all processes). Scrambled: 383±67, siCWC22: 452±67; n=7, P=0.059, paired two-tailed Student's t-test. (E) Number of processes (number of main neurites sprouting from the cell body). Scrambled: 5.60±0.17, siCWC22: 6.11±0.23; n=7, *P=0.011, paired two-tailed Student's t-test. (F) Number of branches (total branch points). Scrambled: 131±36, siCWC22: 168±44; n=4, P=0.2, paired two-tailed Student's t-test. (G) CWC22 siRNA was associated with a borderline increase in Smn mRNA. Scrambled: 1.03±0.14, siCWC22: 1.89±0.43; n=4, P=0.053, unpaired one-tailed Student's t-test.