Williamson
02-19-2014, 01:48 PM
Hi Everyone,
BISDNA has produced a spreadsheet which has the results of 2000 men tested there for its Chromo2 test. It is not meant to cover everyone, but just to give a sample of the various haplogroups they're finding.
The file can be downloaded from
https://www.britainsdna.com/download/C2_2000.zip
The first line of the file contains a short description of the results below it:
These are the Chromo2 Y genotypes for 2000 anonymised individuals. Row 2 has the unique identifier for each sample. Row 3 indicates the inferred haplogroup, and row 4 the inferred subtype, as of February 2014. Rows 5 - 14503 are the genotyping results for all 14498 Y SNPs on the Chromo2 chip (NOT including SNPs that were tested by DNA sequencing or Taqman, such as S28 and S21, which were only tested when phylogenetically relevant), including the 258 SNPs that are currently known to be phylogenetically uninformative or have failed (rows 14246-14503). Column 1 gives the SNP name; column 2 indicates the ancestral (negative) genotype, column 3 indicates the derived (positive) genotype for this SNP, called to the Illumina TOP strand. Columns 4 - 2003 are the genotyping results for each of the 2000 samples. While the Y chromosome is a single copy piece of DNA, the Illumina software used to call alleles is designed for autosomal markers which come in two copies. Hence when AA or GG are given, it means A or G, respectively. A small number of markers give apparent heterozygote calls, e.g. AG. The reason they appear to be heterozygous is again because of limitations in the Illumina genotype clustering software, which expects three clusters. If the true ancestral and derived clusters are too close together, it is not possible to force a "homozygous" call for the one variant, hence an AG call is allowed. In a few cases a marker might arise, for example, by the DNA letter A changing to C, then much later in time in someone with the C it changes back to an A again; this is called back-mutation. For SNPs where the back-mutation state defines a subtype, the ANCESTRAL allele defines the subtype, rather than the derived allele, as would normally be the case. Back-mutations are easily spotted when viewing the results of several samples from the same part of the Y tree.
Regards,
Alex
BISDNA has produced a spreadsheet which has the results of 2000 men tested there for its Chromo2 test. It is not meant to cover everyone, but just to give a sample of the various haplogroups they're finding.
The file can be downloaded from
https://www.britainsdna.com/download/C2_2000.zip
The first line of the file contains a short description of the results below it:
These are the Chromo2 Y genotypes for 2000 anonymised individuals. Row 2 has the unique identifier for each sample. Row 3 indicates the inferred haplogroup, and row 4 the inferred subtype, as of February 2014. Rows 5 - 14503 are the genotyping results for all 14498 Y SNPs on the Chromo2 chip (NOT including SNPs that were tested by DNA sequencing or Taqman, such as S28 and S21, which were only tested when phylogenetically relevant), including the 258 SNPs that are currently known to be phylogenetically uninformative or have failed (rows 14246-14503). Column 1 gives the SNP name; column 2 indicates the ancestral (negative) genotype, column 3 indicates the derived (positive) genotype for this SNP, called to the Illumina TOP strand. Columns 4 - 2003 are the genotyping results for each of the 2000 samples. While the Y chromosome is a single copy piece of DNA, the Illumina software used to call alleles is designed for autosomal markers which come in two copies. Hence when AA or GG are given, it means A or G, respectively. A small number of markers give apparent heterozygote calls, e.g. AG. The reason they appear to be heterozygous is again because of limitations in the Illumina genotype clustering software, which expects three clusters. If the true ancestral and derived clusters are too close together, it is not possible to force a "homozygous" call for the one variant, hence an AG call is allowed. In a few cases a marker might arise, for example, by the DNA letter A changing to C, then much later in time in someone with the C it changes back to an A again; this is called back-mutation. For SNPs where the back-mutation state defines a subtype, the ANCESTRAL allele defines the subtype, rather than the derived allele, as would normally be the case. Back-mutations are easily spotted when viewing the results of several samples from the same part of the Y tree.
Regards,
Alex