Quantifying mRNA Expression in hOPCs

Total RNA was isolated from hOPCs following mitogen withdrawal and real-time RT-PCR performed as described in ref. ^{18 (link)}. Briefly, mRNA was isolated using an E.Z.N.A Total RNA Kit I (Omega Bio-Tek, Norcross, GA) according to the manufacturer’s protocols and complementary DNA prepared (SuperScript III Kit; Invitrogen, Carlsbad, CA). Human-specific primers for SYBR green-based PCR were designed using Primer Express (v1, Applied Biosystems, Foster City, CA). Primer sequences are shown in Supplementary Table 2. Gene expression was calculated by normalizing to glyceraldehyde 3-phosphate dehydrogenase and performing ΔΔCt analysis. Statistical significance was tested on log 2-transformed data using repeated-measures one-way ANOVA followed by Tukey’s post-test.