Youngblood Priest[Formerly The Bass Member # 10328
posted
G. Ferri et al. / Forensic Science International: Genetics Supplement Series 1 (2008) 203–205
Molecular characterisation and population genetics of the DYS458 .2 allelic variant
G. Ferri a,*, C. Robino b, M. Alu` a, D. Luiselli c, S. Tofanelli d, L. Caciagli d, V. Onofri e, S. Pelotti f, C. Di Gaetano g, F. Crobu g, G. Beduschi a, C. Capelli h
Abstract
We recently found a number of intermediate DYS458 alleles, indicated as .2. This allelic variant is distributed in several populations, but currently no information is available regarding the molecular structure and the genealogical correlation of chromosomes with this variant. The molecular characterisation of such allele, its worldwide distribution and the correlated evolutionary history are the subject of the present paper. Molecular and genealogical data are suggestive of a single origin for the .2 variant. Phylogeographic analysis points to either a Middle East or East African origin, but additional data is necessary to clarify this point. Our results suggest that the .2 variants is a stable polymorphism and that it could be used for population studies.
# 2008 Elsevier Ireland Ltd. All rights reserved.
From the full text:
"The molecular organisation of allelic variant was investigated by sequencing a number of different DYS458 .2 alleles from individuals having different geographic origin (Table 1). These variant alleles show an incomplete repeat caused either by a AA insertion or GA deletion in front the third repeat form the last. Initial SNPs analysis identified these chromosomes as derived at the M267 markers, placing them on the J1* cluster. J1 sub lineages were additionally tested (J1a–e) and in all cases the .2 chromosomes resulted ancestral at these additional markers. The DYS458 .2 Y chromosomes were then consequently identified as part of the J1 branch (Fig. 1). The shared molecular structure and the inclusion in the same Y chromosome genealogy branch were considered as supportive to a common origin for the .2 allelic variants."
"Network analysis was conducted as described in Section 2. Fig. 1 shows that two main clusters can be identified: one composed by individuals from the Caucasus (having DYS458*20.2 as modal allele) and a more heterogeneous one containing a well defined North-African clade (DYS458*18.2 modal allele) and other minor clades with European or Ethiopian origin. Only the North-African clade shows a star-like structure, signature of an associated demic expansion. Notably, within each meta population no haplotype structure can be identified except for the Caucasus, due to the rigid apportionment of these populations in groups with different patrilineal descent (data not shown). Some controversies exist about J1 coalescent times [8,9]. However, there is general agreement in recognizing a recent phase of expansion to North Africa that well fit our data: the star-like pattern in the network with Galilee and Palestinian Modal Haplotypes [15] as central nodes."
"The .2 variant shows its frequency peaks in Africa (North and East) and Caucasus. Data from the middle East is scanty and we are currently investigating various populations from this region to gather more information on the distribution in this area (data not shown). The presence in Europe is limited and the occurrences in both US and Asia (India and Malaysia) can be considered as the result of a recent introgression of African and/ or European haplotypes. Given the current set of data it is difficult to establish the ultimate place of origin of such mutation. However, the limited genetic diversity shown by either the Caucasus and North Africa suggest a combination of drift and founder effect (followed by rapid population expansion) in these areas."
The Explorer Member # 14778
posted
So in summation, they are essentially basing their intro-reckoning at this time...
1)on high frequency and sizeable paragroup turnout in East Africa.
2)on ruling out European origin on the one hand, due to the general relative rarity of this haplogroup therein, and on the other hand, ruling North Africa and Caucasus out due to rigid downstream-haplotype allocation to well-defined clades within respective paraphyletic groups. Ps - let's add 'low diversity' to that.
3)on observations 1 & 2 leaving the so-called Middle East out as the alternative origin to East Africa, even though data available to these authors was limited, primarily due to the region's general recognition for frequency peaks for this haplogroup.
Youngblood Priest[Formerly The Bass Member # 10328
posted
I'd like to see more information of the East African specific J1-M267 subclade and how it compares to the Middle Eastern specific subclades because it could be that some J1-M267 in the Middle East, especially in south Arabia, could be of East African origin.
What we do know, which has already been confirmed numerous times, is that J1-M267 in North Africa represents a more recent introgression from so called Arabs, but maybe a small one because founder effect and drift could have elevated its frequency, which would also explain why its far less diverse in North Africa.
akoben Member # 15244
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^ Interesting stuff. I wonder what does this say about some people's theory of whites Jews = Semites?
Djehuti Member # 6698
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^ Nothing since apparently it was only YOU who has ever stated this!
astenb Member # 14524
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I could be mistaken but i believe I have read a Keita study regarding Egyptian Genetics where he also said this could have well be African. At first I dismissed it. I will try and track down the exact quote. Although its Interesting that the Amhara in Ethiopia seem to be "The most Mixed" they also have some of the older lineages such as as P2 and E3. Interesting. Lets say it IS, what would that actually mean?
astenb Member # 14524
posted
G. Ferri et al. / Forensic Science International: Genetics Supplement Series 1 (2008) 203–205
quote:Originally posted by Youngblood Priest[Formerly The Bass:
What we do know, which has already been confirmed numerous times, is that J1-M267 in North Africa represents a more recent introgression from so called Arabs, but maybe a small one because founder effect and drift could have elevated its frequency, which would also explain why its far less diverse in North Africa.
Which is why the authors have ruled out origin in both the North African and the Caucasus populations, even though the lineages in question are part of a paraphyletic ensemble respective to both. The difference here between North Africa and the Caucasus, is that the North African paraphyletic unit displays a star-like arrangement when phylogenetically reconstructed, while -- as it appears from the authors' language -- the Caucasus pharaphyletic unit displays discernable within-paragroup monophyletic relationships not necessarily from a single node, but a few discrete nodes. It appears that the paraphyletic units of the other sampled populations were relatively more phylogenetically scattered at the sub-clade level than the aforementioned two, i.e. showing less discernable within-paragroup monophyletic clustering between the chromosomes.
While in this study, the paraphyetic family of DYS458 .2 chromosomes showed frequency peaks in North African, East African and the Caucasus samples, they differ in their within-paragroup phylogenetic arrangement. The East African pattern is likened to the latter pattern just mentioned, while North African and the Caucasus paraphyletic arrangements are just as mentioned above respectively, showing relatively more discernable within-paragroup [sub-clade] monophyletic relationships. The point of inquiry now, is to see if any potential "Middle Eastern" paraphyletic family of this haplogroup compares with that of the East African family both in terms of frequency peak and loose within-paragroup monophyletic relationships between the chromosomes.
The Explorer Member # 14778
posted
quote:Originally posted by astenb:
Interesting. Lets say it IS, what would that actually mean?
It means that expansions of the common recent ancestral groups of J and K reached their peak in a geographical sphere containing territories on either side of the Red Sea, wherein upon emerging in a group ancestral to those in Ethiopia, [said J1* carriers] either found their way to neighboring regions across the Red Sea via the south Arabian tip close to the Djibouti coast, or trekked down the Nile and used the Sinai corridor. I suppose *if* they had suitable and rugged boats, they could have used any dispersal point along the coasts and crossed the Red Sea.
Youngblood Priest[Formerly The Bass Member # 10328
posted
I still find it more than just probable that some J1-M267 returned to the Middle East from Ethiopia, its just disappointing that geneticists never look into lineages migrating out of Africa except for attributing them to the slave trade. If indeed there was considerable contact between the to[Ethiopia and South Arabia] some J1-M267 most definitely crossed the Red sea back into Arabia.
.Charlie Bass. Member # 10328
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bump
Perahu Member # 18548
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J1 is an Arab haplogroup.
.Charlie Bass. Member # 10328
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quote:Originally posted by Perahu: J1 is an Arab haplogroup.
J1 precedes Arabs you jackass. Jews have it too, so it isn't Arab anyways.
Perahu Member # 18548
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quote:Originally posted by .Charlie Bass.: J1 precedes Arabs you jackass. Jews have it too, so it isn't Arab anyways.
posted ![[Roll Eyes]](rolleyes.gif)
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