Joe Pickrell 'Publishes' Henrietta Lacks’s Genome from Public Data
In his ‘genomes unzipped’ blog, Joe Pickrell provides another perspective on the idiotic politicization surrounding HeLa genome sequencing. He explains that if the reference human genome is publicly available, and if the difference between reference human genome and HeLa line is publicly available based on RNAseq, ChIP-seq and many other large-scale comparative study, any bioinformatician with half-a-brain can reconstruct the genome sequence of Henrietta Lacks. For those who cannot, his blog gave ‘materials and methods’ section explaining how to.
Technical details:
I downloaded sequencing data from the following GEO accessions: SRR227441, SRR227442, SRR227445, SRR227446, SRR227472, SRR227473, SRR227505, SRR227506, SRR227556, SRR227557, SRR350914, SRR350915 SRR568260, SRR568261, SRR577378, SRR577379, SRR577392, SRR577393, SRR577429, SRR577430
These are all ChIP-seq experiments on HeLa cells from the ENCODE project.
I then mapped reads to human hg19 using bwa. To compare to the 1000 Genomes data, I used the genotypes from the Illumina OMNI array. To merge HeLa into these data, I randomly sampled a single sequencing read covering each site on the array (at all sites that had at least a single read covering it) and reported the sequence from that read as the HeLa genotype (calling heterozygotes is moderately annoying, so I didnt try it). In total I genotyped 2095422/2177885 (96%) of sites successfully with this approach. I then ran PCA (using smartpca) on the genotypes from the YRI, ASW, CEU, CHB, and HeLa samples.