Total RNA was obtained using Trizol (Life Technologies) following the manufacturer’s instructions. RNA preparations (2 mg) were treated with “Ready-to-go youprime first-strand beads” (GE Healthcare) to generate cDNA. Quantitative real-time PCR was performed using DNA Master SYBR Green I mix (Applied Biosystems). mRNA expression levels were quantified applying the DCt method, DCt ¼ (Ct of gene of interest e Ct of Actin). GFP primers were selected as previously reported [9 (link)]. Other qRT-PCR primer sequences were obtained from the PrimerBank database (http://pga.mgh.harvard.edu/primerbank/).