By comparing the variants of these genes in the ancient skeletons with those in 60 modern-day Ukrainians, as well as a larger sample of 246 modern genomes from the surrounding region, the team found that the frequency of variants related to lighter skin and hair, as well as blue eyes, increased significantly between the ancient and modern populations.
These additional mutations were identified by comparing the variants in the tumours with the lack of the same in the paired normal tissue samples and following the filtering approach explained in Supplementary Figure 2. In 16 of 20 tumour samples, 37 additional somatic mutations across 32 genes were detected (Supplementary Table 6).
The corresponding SNPs and insertion deletions (indels) were identified by comparing the resulting variant calls to the custom reference genome sequence using the Alpheus software [ 14] with the parameters: variant allele frequency ≥10%%, variant unique reads ≥2 and average base quality score ≥20 in the given accession, and either no variant allele or any allele present in the other accession(s).
The approach we presented here estimates two parameters, the sensitivity and the specificity of variant calls in a next-generation sequencing experiment, by comparing the observed variants with population allele frequency data in a maximum likelihood framework.
In addition, by comparing the sequence variants in the SPRET/Ei Tsc22d3 genomic sequence with sequences in LPS sensitive mouse strains, we found that the variants are unique for the SPRET/Ei strain.
The amount of each V. proteolyticus variant in a sample can be obtained relative to E. coli, e.g. as a ratio, by comparing the V. proteolyticus variant band density with those obtained on the standard curve.
We also performed a conditional independence test between the significant associated variants by comparing the model including both variants and a model including just one of the variant.
We tested this feature by comparing the genetic structural variants identified by Kidd et al. (2008) with variants identified in ESP studies of cancer genomes (Raphael et al., 2008; Volik et al., 2006).
The conservation index (CI) was calculated by comparing the human nucleotide variants with 16 other vertebrates.
The conservation index (CI) was calculated by comparing the human nucleotide variants with the other 16 vertebrates.
