sábado, 3 de julho de 2010

Genealogy is just a Historical SNP trail

Genealogy is just a SNP trail

Let's compare the SNPs leading to J1b and R1b-P312 as july/2010
http://ytree.ftdna.com/index.php?name=Draft&parent=root

IJK
L15, L16
IJ P123, P124, P125, P126, P127, P129, P130
J 12f2a, 12f2.1, M304, P209, L60, L134
J1 M267, L255
J1b M365

IJK L15, L16
K M9, P128, P131, P132
P 92R7, M45, M74, N12, P27.1, P69, P207, P226, P228, P230, P235, P237, P239, P240, P243, P244, P281, P282, P283, P284, P295
R M207, P224, P227, P229, P232, P280, P285
R M306
R1,P? (ISOGG: R1,P) M173, P231, P233, P234, P236, P238, P241, P242, P245, P286, P294
R1b M343
R1b1 P25_1, P25_2, P25_3
V88
R1b1b P297
R1b1b1 M73
R1b1b2 M269, L265
R1b1b2a L23, L49
L150
(ISOGG: R1b1b2a1) L51
R1b1b2a1 (ISOGG: R1b1b2a1a,R1b1b2a1a) P310, P311, L11, L52, L151
R1b1b2a1b (ISOGG: R1b1b2a1a2) P312

Where are the missing SNPs leading to J1b ?

"A recently published study has used next-gen sequencing technology to resequence two Y chromosomes separated by 13 generations and discovered four single-base differences in 10 Mb DNA, suggesting that the Y chromosome euchromatin accumulates around one mutation per generation. Y-SNPs therefore now offer the best resolution of Y haplotypes and promise to distinguish almost every Y chromosome"

"Investigators have laboriously sought Y-SNPs shared by many individuals and have generally
paid little attention to the more numerous rare or individualspecific SNPs. Since there are around 24 million nucleotides in the euchromatic Y-specific section of the chromosome, there are
plenty of opportunities for SNP variation to occur. Next-gen sequencing technology allows entire Y chromosomes to be sequenced, so this vast potential resource can be accessed. Our
study compared two Y chromosomes from the same family separated by 13 generations [3]. These chromosomes were genotyped with the 67 Y-STRs mentioned above, and showed no
Y-STR differences. But sequencing them revealed four Y-SNP differences (Fig. 1). Detecting this small number of differences presented formidable technical challenges and more than 30,000
false positives had to be eliminated, including eight in vitro mutations that had arisen in the cell lines that formed the source of the DNA that was sequenced rather than in vivo within the
individuals. The four true mutations were confirmed by standard capillary sequencing of blood DNA from the same individuals, and three of the four by their presence in other members of the family".

The hare and the tortoise: One small step for four SNPs, one giant leap for SNP-kind
Yali Xue, Chris Tyler-Smith *
The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK

If there's a new Y DNA SNP per generation approximately, we are going to have a festival of SNPs in the next years. Considering a generation of 30 years, in 900-1000 years of a lineage, we are going to find approx. 30 new Y DNA SNPs, more or less 30 SNPs in each millenium !

The dream of consumption of genetic genealogy ! A complete scan of the Y DNA will reveal the complete genealogy of a person.

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