title: RNA-seq of canis familiaris: elderly adult male prefrontal cortex
design: Total RNA content was extracted from RNAlater-stabilized brain tissue samples using the RNeasy Mini Kit (Qiagen), following the manufacturers protocol. RNA samples were dissolved in RNase-Free Water (AccuGENE Molecular Biology Water (Lonza)) and were stored at80 C until further processing.All further steps from RNA isolation to sequencing were carried out by Omega Bioservices (Norcross, Georgia, USA). RNA integrity number (RIN) numbers were determined by an Agilent 2100 Bioanalyzer, and all samples met the required quality criteria (RIN>7.9). RNAs with poly(A) tail were selected prior to library preparation using the poly(A) capture method. Libraries were then prepared following the Illuminas TruSeq Stranded mRNA library preparation protocol (Illumina).