Global gene expression analysis

Gene expression analysis was conducted on three total RNA samples for each group using SurePrint G3 Mouse GE 8 × 60K Microarrays (Agilent Technologies). These arrays contain over 60-mer probes to examine 39 000 mouse mRNAs and 16 000 lncRNAs. The procedure was basically conducted following the manufacturer's protocol (version 6.5). The scanned image files were converted to TIFF files containing signal values of each probe using Feature Extraction (version 10.7.3.1). The signal values were log 2-transformed and processed to the 75^th percentile normalization.57 Signal averages for each group and the p-value in statistical significance testing (Student's t-test) were obtained. All those showing less than 0.05 for the p-value and “1 (present: gIsPosAndSignif)” for Detection Call in PB-treatment arrays were regarded as up-regulated probe sets. All those showing less than 0.05 for the p-value and “1 (present: gIsPosAndSignif)” for Detection Call in the control arrays were regarded as down-regulated probe sets.