We extracted RNA using the MagMAX-96 Total RNA Isolation Kit (Life Technologies, Grand Island, NY). Total RNA was quantified on a NanoDrop 8000 spectrophotometer (Thermo Fisher Scientific Inc., Rockford, IL) and assessed for quality using the Agilent TapeStation (Agilent Technologies, Inc., Santa Clara, CA). All samples passed quality control measures (RIN > 8). RNA was amplified and biotin-labeled using the Illumina® TotalPrepTM RNA Amplification kit (Ambion, Austin, TX), and aliquots of labeled cRNA were sent to the Yale Center for Genome Analysis (West Haven, CT), where they were hybridized to Illumina® MouseWG-6 v2 Expression BeadChips (Illumina, Inc., San Diego, CA). Each beadchip contains six independent arrays. Samples were counterbalanced to avoid batch effects. The amount of each transcript for each animal was measured by fluorescent intensity after scanning. Microarray data will be deposited in the NCBI Gene Expression Omnibus (GEO) database (http://www.ncbi.nlm.nih.gov/geo/) and described in accordance with MIAME guidelines.
