DMXX
12-20-2012, 07:10 PM
Y-chromosome variation in Tajiks and Iranians
Malyarchuk B, Derenko M, Wozniak M, Grzybowski T.
Link: http://informahealthcare.com/doi/abs/10.3109/03014460.2012.747628
Aim: The purpose of this study was to characterize Y-chromosome diversity in Tajiks from Tajikistan and in Persians and Kurds from Iran.
Method: Y-chromosome haplotypes were identified in 40 Tajiks, 77 Persians and 25 Kurds, using 12 short tandem repeats (STR) and 18 binary markers.
Results: High genetic diversity was observed in the populations studied. Six of 12 haplogroups were common in Persians, Kurds and Tajiks, but only three haplogroups (G-M201, J-12f2 and L-M20) were the most frequent in all populations, comprising together 60% of the Y-chromosomes in the pooled data set. Analysis of genetic distances between Y-STR haplotypes revealed that the Kurds showed a great distance to the Iranian-speaking populations of Iran, Afghanistan and Tajikistan. The presence of Indian-specific haplogroups L-M20, H1-M52 and R2a-M124 in both Tajik samples from Afghanistan and Tajikistan demonstrates an apparent genetic affinity between Tajiks from these two regions.
Conclusions: Despite the marked similarities between Y-chromosome gene pools of Iranian-speaking populations, there are differences between them, defined by many factors, including geographic and linguistic relationships.
http://1.bp.blogspot.com/-pbgP_5AOnms/UL8R8ENDD8I/AAAAAAAAH1I/9w_1e4eSRzI/s1600/iranian_tajik_kurd.png
First impressions;
Sample sizes are a drawback. I tend towards a figure of at least ~50 for cities and ~100 for representative ethnicities or nationalities.
Inadequate Y-STR profiling. The latest papers tend towards at least 17 (e.g. the recent paper on South India (http://www.anthrogenica.com/showthread.php?534-South-Indian-Y-Chromosomes&p=3133#post3133)). Thus, manual haplotype comparisons are made less effective.
Inadequate Y-SNP profiling. One does not need to look into the methodology to anticipate significant markers (such as R1b1a1-M73) when only R1b-M343 is listed.
Due to the small sample sizes, detailed conclusions beyond what current scientific literature has already shown us cannot be made. For instance, we see a west-east frequency gradient between Y-DNA Haplogroups E, G, J & T vs. H, L, Q, R1a1 & R2a.
Haplogroup I makes an appearance once more in the West Iranic-speaking world. Frustratingly, the lack of resolution beyond the M170 marker once more prevents us from learning anything about its' presence there.
The Kurdish results appear the most anomalous (i.e. Y-DNA C, J, R1a1) no doubt confounded by the small sample size. Kurds from Iran were shown to be fairly similar to Azeri Iranians in Grugni et al. (http://vaedhya.blogspot.co.uk/2012/07/interpreting-new-iranian-y-chromosomal.html), who in turn are closest to other Iranians (as per a recent paper from Tabriz, the largest Azeri Iranian city (http://ijb.nigeb.ac.ir/index.php/ijb/article/viewFile/746/319)). One would therefore expect more congruency between the Kurds and Persians here.
Malyarchuk B, Derenko M, Wozniak M, Grzybowski T.
Link: http://informahealthcare.com/doi/abs/10.3109/03014460.2012.747628
Aim: The purpose of this study was to characterize Y-chromosome diversity in Tajiks from Tajikistan and in Persians and Kurds from Iran.
Method: Y-chromosome haplotypes were identified in 40 Tajiks, 77 Persians and 25 Kurds, using 12 short tandem repeats (STR) and 18 binary markers.
Results: High genetic diversity was observed in the populations studied. Six of 12 haplogroups were common in Persians, Kurds and Tajiks, but only three haplogroups (G-M201, J-12f2 and L-M20) were the most frequent in all populations, comprising together 60% of the Y-chromosomes in the pooled data set. Analysis of genetic distances between Y-STR haplotypes revealed that the Kurds showed a great distance to the Iranian-speaking populations of Iran, Afghanistan and Tajikistan. The presence of Indian-specific haplogroups L-M20, H1-M52 and R2a-M124 in both Tajik samples from Afghanistan and Tajikistan demonstrates an apparent genetic affinity between Tajiks from these two regions.
Conclusions: Despite the marked similarities between Y-chromosome gene pools of Iranian-speaking populations, there are differences between them, defined by many factors, including geographic and linguistic relationships.
http://1.bp.blogspot.com/-pbgP_5AOnms/UL8R8ENDD8I/AAAAAAAAH1I/9w_1e4eSRzI/s1600/iranian_tajik_kurd.png
First impressions;
Sample sizes are a drawback. I tend towards a figure of at least ~50 for cities and ~100 for representative ethnicities or nationalities.
Inadequate Y-STR profiling. The latest papers tend towards at least 17 (e.g. the recent paper on South India (http://www.anthrogenica.com/showthread.php?534-South-Indian-Y-Chromosomes&p=3133#post3133)). Thus, manual haplotype comparisons are made less effective.
Inadequate Y-SNP profiling. One does not need to look into the methodology to anticipate significant markers (such as R1b1a1-M73) when only R1b-M343 is listed.
Due to the small sample sizes, detailed conclusions beyond what current scientific literature has already shown us cannot be made. For instance, we see a west-east frequency gradient between Y-DNA Haplogroups E, G, J & T vs. H, L, Q, R1a1 & R2a.
Haplogroup I makes an appearance once more in the West Iranic-speaking world. Frustratingly, the lack of resolution beyond the M170 marker once more prevents us from learning anything about its' presence there.
The Kurdish results appear the most anomalous (i.e. Y-DNA C, J, R1a1) no doubt confounded by the small sample size. Kurds from Iran were shown to be fairly similar to Azeri Iranians in Grugni et al. (http://vaedhya.blogspot.co.uk/2012/07/interpreting-new-iranian-y-chromosomal.html), who in turn are closest to other Iranians (as per a recent paper from Tabriz, the largest Azeri Iranian city (http://ijb.nigeb.ac.ir/index.php/ijb/article/viewFile/746/319)). One would therefore expect more congruency between the Kurds and Persians here.