title: RNA-Seq of primary visual cortex (V1) tissue
design: Tissue samples were collected from 28 individuals representing 13 primate species (n = 1-3 per species). Frozen brain samples from captive adult primates free of known neurological disorders were obtained from various research institutions and zoos. All individuals had been cared for according to Federal and Institutional Animal Care and Use guidelines and died of natural causes. All tissue was collected and stored at -80C with postmortem intervals of less than 8 hours. Each sample was dissected from the cortex of the medial aspect of the occipital pole, surrounding the calcarine sulcus. The thin, striate cortex of V1 was visually identified in each sample. All dissections included the grey matter of V1, extending a small extent into the underlying white matter. Tissue samples were homogenized using a TissueLyser (Qiagen) prior to total RNA extraction using an RNeasy Plus Mini Kit (Qiagen), including a DNase step to remove residual DNA. Total RNA was analyzed for quality using the Agilent Bioanalyzer system (Agilent RNA 6000 Nano kit). Using the NEBNext Poly(A) Magnetic mRNA Isolation Kit (NEB), mRNA was isolated from intact total RNA, and cDNA libraries were made from each sample using the NEBNext RNA Library Prep Kit for Illumina (NEB). Pooled samples were sequenced using the Illumina NextSeq 500 platform to produce 75 base pair reads, yielding a minimum of 20 million reads per sample.