low coverage WGS of human cerebral cortex
NeuN positive or NeuN negative cells were isolated from fresh frozen brain.  Genomic DNA from the cells were amplified using the MDA method described in Evrony et al. Cell 151, 483–496, 2012.  Amplified products were purified with AMPureXP beads and quantified by nanodrop. Amplification quality and contamination were assessed by 1.5% agarose gel electrophoresis of 5%of the product. Samples with no visible product were excluded from library preparation. Four-locus multiplex PCR was performed on all MDA-amplified samples as described in Evrony et al., 2012. Samples with less than three loci amplified were generally excluded.  WGS libraries prepared from 500 ng of DNA with the NEXTflex DNA sequencing kit (Bioo Scientific) were barcoded for multiplexed sequencing on HiSeq 2000 sequencers (Illumina). For low-coverage sequencing, 32 samples were multiplexed into each HiSeq lane for single-end 50 bp runs, obtaining about 5 million pass-filter reads per sample.