Docstoc

Some Aspects of Basques Genetics

Document Sample
Some Aspects of Basques Genetics Powered By Docstoc
					<div class="KonaBody">
        <!--INFOLINKS_ON-->
                <p>The Basques inhabit rugose terrain in the SW extremity
of France and adjacent Spain,which is comprised of seven provinces.These
lands are called Euskal Herria ,the land of the Euskera speakers. It is
their unique,ancient,non-Indo-European,agglutinating language,which
identifies the Basques, who have a high frequency of Rh negative blood
[ca 25%].No linguistic equivalent to their language has been found.The
origin of this tongue is unknown.A proto-type "might" have been
introduced to the Basques lands by people,who predated the influx of
Neolithic agriculturalists,who "may" have spoken an Indo-European
language [speculation].</p>
<p>Preservation of the Basque identity contrasts sharply with the
physical,but not genetic, disappearance of the Neanderthals.The sparse
scatterings of small Neanderthal groups were not able to cope with the
appreciable influxes of Homo sapiens.The Basques were largely
concentrated in a relatively rugged region and large tracts of their land
was not prime acerage.An indigenous core,which was probably assembled
from proximal,warmer,segments of Iberia,after the Younger Dryas,appears
to have had sufficient numbers to found the Basques and assimilate
subsequent newcomers.The original inhabitants included ancient Iberians
and possibly some individuals with Neanderthal genes.Later additions have
diluted the frequencies of the founders,but the new populace managed to
retain a Basque identity.</p>
<p>A Gonz'ales [2006] analyzed 211 Basques samples utilizing the
hypervariable segment of the mtDNA control region and diagnostic RFIP
techniques.The four sequences,which were derived from haplogroup [hg] U8
were completely sequenced.Hg U was one of the earliest genetic
lineages,that was dispersed from the Middle East to western Europe.Sub-hg
U81a,which has a coalescence time of ca 13 +/-5.0Ka,has a 1.0% frequency
in Basques lands.The greatest U8a diversity occurs on the Iberia
Peninsula,which suggests that a few Basques could be descended from the
Gravettians [ibid].The Adaieta cemetery samples contained four ancient
U2e samples,which have not been identified among modern Basques.U2e is
common in the Middle East [A Alzuaide,2007].Analysis of the remains of a
ca 8.5Ka old Basque fisherman from the cost of Hondarribia and Pessia
suggests,that ca 50% of his diet was comprised of marine food [A
Arrizbalagg,2006].</p>
<p>Analysis of 623 Y chromosome samples identified 23 hgs.This study
indicated,that the barrier between the Basques and their immediate
neighbours was minimal.The Iberian populations had a reduced genetic
structure and recent migrations have not totally erased the ancient
Iberian Y chromosome patterns [C Flores,2004].The population of Ireland
has retained a higher indigenous component than the Basques,who were
closer to the European migration routes.</p>
      <!--INFOLINKS_OFF-->

                        <div style="width:300px;float:right;margin:12px
0px 12px 12px">
                   <script type="text/javascript">
          <!--
            AB_pos          = "intext";
            AB_lang         = "en";
            AB_cat_channel = "8695717077, ";
            AB_path        = "http://d21j60o022fwiu.cloudfront.net/";
            document.write(unescape("%3Cscript
src='http://d21j60o022fwiu.cloudfront.net/gads/controller3.js'
type='text/javascript'%3E%3C/script%3E"));
          //-->
          </script>
          <script type="text/javascript">
            google_ad_channel = "7940249670, " + AB_cat_channel +
AB_unit_channel;
            google_language = "en";
            google_ad_region = 'test';
          </script>
          <script type='text/javascript'
src='http://pagead2.googlesyndication.com/pagead/show_ads.js'></script>
        </div>
                             <!--INFOLINKS_ON-->
<p>The mtDNA genetic study by A Alzuaide [2006] provides information
about temporal changes in the Basques female gene pool.The mtDNA of 65
human remains from the ca 550-770 ADE Basque Adaista cemetery were
analysed and compared with a large selection of worldwide haplotypes and
three prehistoric groups of proto-Basques[?] .The unique haplotypes 5,9
and 11 were not present in the Genbank samples or among the world wide
comparison sequences.Haplotypes 7,8,10,12,16 and 17 were deemed to be
uncommon in Europe. The other six haplotypes were widely dispersed
throughout western Europe.This distribution pattern has similarities to
those populations on the Cantabrian fringe [ibid].</p>
<p>Two haplotypes of hg H account for 53% of the Aldaieta samples,which
compares to 62.3% for extant Basques.,and 37-44% at the prehistoric sites
of Rico Ramos,Langar and Sjapl .The percentage of hg H has increased
since prehistoric times in Basques Lands.This differs from hg V,which has
not been identified at the three prehistoric sites and is represented by
a single sample at Aldaieta.The frequency of Hg V ranges from 3-20% among
present day Basques.There were two hg K samples at Adaieta.Present day
Basques have a 3.6% frequency of hg K.This represents a significant
reduction since prehistoric times,when frequencies of hg K varied from
16.7-24.0%.Hg J is generally associated with the introduction of farming
to Europe from the Fertile Cresent.At the three prehistoric sites hg J
averaged 16.4%,which was reduced to 14.7% at Aldaieta.Extant Basques only
have a 2.4% frequency of hg J.The frequency of hgs U5 and U2 have
diminished from 16.7 among the prehistoric specimens to 13.7% among
modern Basques.No hg W samples were identified among the prehistoric or
historic samples,which contrasts with a 1.2% presence among the extant
Basques [ibid].</p>
<p>The pre- and historical Basques received external gene flow,which is
not always reflected to the same extent in extant Basques populations.S
Alonsel [2006] contends that they may not always have been the focus of
major population expansions and might not be best representatives of the
ancient European gene pool.It appears that hg V was introduced to the
Basques at a relatively late date.There are genetic discontinuities
between prehistoric/historic Basques and the extant populations [A
Alzuaide,2006].</p>
<p>C Capelli [2003] reported that the Basques Y chromosome hgs tend to
cluster with those of Ireland [Castlerea],Cornwall, and western Wales
[eg:Haveford West,Llangfini],which can be attributed to the northward
expansion of Iberians from NW coastal communities in Spain after the
Younger Dryas [ca 9700 BCE].The close genetic link between the Basques
and Castlerea,Ireland,infers minimal "retained admixture" from the
expansion of Neolithic male agriculturalists [ibid].</p>
<p>S Oppenheimer [2006] used Y chromosome SRR markers to reconstruct
ancient population movements.Hg R was probably introduced to central
Europe by the Gravettians from the Eastern Russian plains ca 30Ka
ago..Today hg R1b and its 16 descendant lineages have an 86% frequency
among the Basques.Some of these lineages expanded north from Iberia
refugia after the Younger Dryas.The Y chromosome I1b2 followed a northern
Mediterranean coastal route to the west.It contributed 41% to the present
day Sardinian male gene pool,but only 6% to the Basques,who should have
easily assimilated a relatively low percentage of newcomers.There has
been a lower exchange of Y chromosomes between the western Basques and
their neighbours,when compared to the degree of admixture to the
east,where Basques and Aragon share the Ebro valley [M Iriande,
2003].Basques females were less restricted in their choice of partners [M
Brian,2004].Galician G,M, and KM immunoglobian allotype allele
frequencies indicate significantly large statistical variations between
the Galicians and the Basques.The Guipuzean Basques are the most distinct
[R Calderon,2007].</p>
<p>HLA hgs DR3-DQ2.5 and DR7-DO22 are common among the Basques and some
west African populations.A29-Cw16-B44 occurs in west Africa,with a peak
frequency among the Basques and a peak diversity in the Pasiegas
valley.There appears to have been a time lag between the arrival of this
genetic lineage in Iberia and its northward expansion,which could infer a
slow dispersal through Iberia from north Africa prior to the Moor era.It
has an appreciable component in the Pasiegas valley,which could be the
site of recombination.This distinct feature suggests ancient admixture.
There is A29-Cw16 disequilibrium among the Irish [P Deitiker,2008].</p>
<p>Collation of the available genetic data suggest, that the
 inhabitants of the present Basques Lands immediately after the end of
the Younger Dryas ca 9700 BCE are the distant ancestors of the present
day Basques.However subsequent influxes of newcomers over the interim
have diluted and changed the original gene pool.The Basques identity is
essentially determined by their unique language. Future genetic studies
may contribute to solving the Basques enigmas.</p>
<p>Â </p>                <!--INFOLINKS_OFF-->
        </div>

http://www.articlesbase.com/history-articles/some-aspects-of-basques-
genetics-4637709.html

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:5
posted:9/20/2011
language:English
pages:3
mr doen mr doen mr http://bineh.com
About just a nice girl