Y-chromosome polymorphisms and the origins of the European gene pool

Gradients of allele frequencies have long been considered the main genetic characteristic of the European population, but mitochondrial DNA diversity seems to be distributed differently. One Alu insertion (YAP), five tetranucleotide (DYS19, DYS389B, DYS390, DYS391 and DYS393) and one trinucleotide (DYS392) microsatellite loci of the Y chromosome were analysed for geographical patterns in 59 European populations. Spatial correlograms showed clines for most markers, which paralleled the gradients previously observed for two RFLP polymorphisms. Effective separation times between populations were estimated from genetic distances at microsatellite loci. Even after correcting for the possible effects of continuous local gene flow, the most distant Indo-European-speaking populations seem to have separated no more than 7000 years ago. The clinal patterns and the estimated, recent separation times between populations jointly suggest that Y-chromosome diversity in Europe largely reflects a directional demic expansion, which is unlikely to have occurred before the Neolithic period.     

African and Levantine origins of Pakistani YAP+ Y chromosomes.

We surveyed 9 Pakistani subpopulations for variation on the nonrecombining portion of the Y chromosome. The polymorphic systems examined were the Y-chromosome Alu insertion polymorphism (YAP) at DYS287, 5 single nucleotide polymorphisms, and the tetranucleotide microsatellite DYS19. Y chromosomes carrying the YAP element (YAP+) were found in populations from southwestern Pakistan at frequencies ranging from 2% to 8%, whereas northeastern populations appeared to lack YAP+ chromosomes. In contrast to other South Asian populations, several Pakistani subpopulations had a high frequency of the DYS19*B allele, the most frequent allele in West Asian, North African, and European populations. The combination of alleles at all polymorphic sites gave rise to 9 YAP-DYS19 combination haplotypes in Pakistani populations, including YAP+ haplotypes 4-A, 4-B, 5-C, and 5-E. We hypothesize that the geographic distributions of YAP+ haplotypes 4 and 5 trace separate migratory routes to Pakistan: YAP+ haplotype 5 may have entered Pakistan from the Arabian Peninsula by means of migrations across the Gulf of Oman, whereas males possessing YAP+ haplotype 4 may have traveled over land from the Middle East. These inferences are consistent with ethnohistorical data suggesting that Pakistan's ethnic groups have been influenced by migrations from both African and Levantine source populations.     

Polymorphism of Y-chromosomal microsatellites in Russian populations from the northern and southern Russia as exemplified by the populations of Kursk and Arkhangel'sk Oblast

Allelic polymorphisms at five Y-chromosomal microsatellite loci (DYS19, DYS390, DYS391, DYS392, and DYS393) were typed in 87 individuals from male population samples from two geographically isolated regions (Arkhangelsk oblast and Kursk oblast) of the European part of Russia. The populations examined demonstrated substantial differences in the distribution of the DYS392 (P = 0.005) and DYS393 (P = 0.003) alleles. Estimates of genetic relationships between these populations and some other European populations (including Eastern-Slavic) showed that irrespectively of the measure of genetic distance chosen, Arkhangelsk population was closer to the populations belonging to the Finno-Ugric linguistic group (Saami and Estonians) and to the Estonian geographical neighbors, Latvians, while Kursk population was the member of a cluster formed by Eastern-Slavic populations (Russians of Novgorod oblast, Ukrainians, and Belarussians). Phylogenetic analysis of the most frequent haplotypes indicated that these differences between Kursk and Arkhangelsk populations were associated with high prevalence in the latter of major haplotypes characteristic primarily of the Finno-Ugric populations.     

Allele variation of DYS19 and Y-Alu insertion (YAP) polymorphisms in Basques: an insight into the peopling of Europe and the Mediterranean region

Two Y-chromosome DNA polymorphisms, the DYS19 microsatellite and the YAP (at locus DYS287), were tested in males from two autochthonous Basque populations from France and northern Navarre (Spain). The results are compared to those obtained for the same genetic markers in 32 populations from Europe, northern Africa, and western Asia. The high predominance of the DYS19*11 (190-base-pair) allele in Basques indicates that their genetic diversity for microsatellite DYS19 is around half that observed in Europeans, North Africans, and western Asians. The Y-Alu insertion (YAP+) was not detected in the Basque samples. This study attempts to throw some light on the importance of historically recent migratory movements, the main corridors of gene flow, and demographic sizes and their variations in shaping gene frequency patterns in contemporary human populations, particularly in the Mediterranean region. Historical processes may have had more significant effects on the genetic make-up of current human populations than those of prehistoric times.     

Y chromosomal DNA variation and the peopling of Japan.

Four loci mapping to the nonrecombining portion of the Y chromosome were genotyped in Japanese populations from Okinawa, the southernmost island of Japan; Shizuoka and Aomori on the main island of Honshu; and a small sample of Taiwanese. The Y Alu polymorphic (YAP) element is present in 42% of the Japanese and absent in the Taiwanese, confirming the irregular distribution of this polymorphism in Asia. Data from the four loci were used to determine genetic distances among populations, construct Y chromosome haplotypes, and estimate the degree of genetic diversity in each population and on different Y chromosome haplotypes. Evolutionary analysis of Y haplotypes suggests that polymorphisms at the YAP (DYS287) and DXYS5Y loci originated a single time, whereas restriction patterns at the DYS1 locus and microsatellite alleles at the DYS19 locus arose more than once. Genetic distance analysis indicated that the Okinawans are differentiated from Japanese living on Honshu. The data support the hypotheses that modern Japanese populations have resulted from distinctive genetic contributions involving the ancient Jomon people and Yayoi immigrants from Korea or mainland China, with Okinawans experiencing the least amount of admixture with the Yayoi. It is suggested that YAP+ chromosomes migrated to Japan with the Jomon people > 10,000 years ago and that a large infusion of YAP- chromosomes entered Japan with the Yayoi migration starting 2,300 years ago. Different degrees of genetic diversity carried by these two ancient chromosomal lineages may be explained by the different life-styles (hunter-gatherer versus agriculturalist). of the migrant groups, the size of the founding populations, and the antiquities of the founding events.     

Polymorphism of Y-Chromosomal Microsatellites in Russian Populations from the Northern and Southern Russia as Exemplified by the Populations of Kursk and Arkhangelsk Oblast

Allelic polymorphisms at five Y-chromosomal microsatellite loci (DYS19, DYS390, DYS391, DYS392, and DYS393) were typed in 87 individuals from male population samples from two geographically isolated regions (Arkhangelsk oblast and Kursk oblast) of the European part of Russia. The populations examined demonstrated substantial differences in the distribution of the DYS392 (P = 0.005) and DYS393 (P = 0.003) alleles. Estimates of genetic relationships between these populations and some other European populations (including Eastern-Slavic) showed that irrespectively of the measure of genetic distance chosen, Arkhangelsk population was closer to the populations belonging to the Finno-Ugric linguistic group (Saami and Estonians) and to the Estonian geographical neighbors, Latvians, while Kursk population was the member of a cluster formed by Eastern-Slavic populations (Russians of Novgorod oblast, Ukrainians, and Belarussians). Phylogenetic analysis of the most frequent haplotypes indicated that these differences between Kursk and Arkhangelsk populations were associated with high prevalence in the latter of major haplotypes characteristic primarily of the Finno-Ugric populations.__________Translated from Genetika, Vol. 41, No. 8, 2005, pp. 1125–1131.Original Russian Text Copyright © 2005 by Khrunin, Bebyakova, Ivanov, Solodilova, Limborska.     

The Geographic Distribution of Human Y Chromosome Variation

We examined variation on the nonrecombining portion of the human Y chromosome to investigate human evolution during the last 200,000 years. The Y-specific polymorphic sites included the Y Alu insertional polymorphism or ``YAP' element (DYS287), the poly(A) tail associated with the YAP element, three point mutations in close association with the YAP insertion site, an A-G polymorphic transition (DYS271), and a tetranucleotide microsatellite (DYS19). Global variation at the five bi-allelic sites (DYS271, DYS287, and the three point mutations) gave rise to five ``YAP haplotypes' in 60 populations from Africa, Europe, Asia, Australasia, and the New World (n = 1500). Combining the multi-allelic variation at the microsatellite loci (poly(A) tail and DYS19) with the YAP haplotypes resulted in a total of 27 ``combination haplotypes'. All five of the YAP haplotypes and 21 of the 27 combination haplotypes were found in African populations, which had greater haplotype diversity than did populations from other geographical locations. Only subsets of the five YAP haplotypes were found outside of Africa. Patterns of observed variation were compatible with a variety of hypotheses, including multiple human migrations and range expansions.     

广东汉族22个Y-STR基因座遗传多态性及遗传关系分析

调查了广东汉族群体22个 Y-STR基因座的遗传多态性分布情况, 探讨其群体遗传学及法医学应用价值。通过自行建立的两组Y-STR荧光标记复合扩增体系(MultiplexⅠ: DYS505, DYS533, DYS576, DYS588, DYS634, DYS643; MultiplexⅡ: DYS461, DYS481, DYS504, DYS508, DYS607)和应用进口Powerplex Y System (DYS19, DYS389Ⅰ/Ⅱ, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438, DYS439), 对广东汉族216 名无关男性个体进行22 个STR基因座的复合分型, 用ABI310基因分析仪对扩增产物进行检测, 统计22 个Y-STR基因座的群体遗传学参数, 并结合已公开发表的其他12 个群体“扩展单倍型”的数据资料, 分析广东汉族群体遗传距离和聚类关系。3 组复合扩增系统均可成功进行分型, 基因多样性GD值在0.3299(DYS634)~ 0.9425(DYS385); 22 个Y-STR基因座共同构成的单倍型214 种, 单倍型多样性为0.9999。广东汉族和潮汕汉族的遗传距离最近(-0.0030), 与东北汉族的遗传距离最远(0.0195)。22 个Y-STR基因座联合检测具有丰富的遗传多态性, 对建立Y染色体STR数据库, 研究群体遗传学和进行法医学应用有重要意义。     

Sequence diversity of the control region of mitochondrial DNA in Tuscany and its implications for the peopling of Europe

The control region of mitochondrial DNA has been widely studied in various human populations. This paper reports sequence data for hypervariable segments 1 and 2 of the control region from a population from southern Tuscany (Italy). The results confirm the high variability of the control region, with 43 different haplotypes in 49 individuals sampled. The comparison of this set of data with other European populations allows the reconstruction of the population history of Tuscany. Independent approaches, such as the estimation of haplotype diversity, mean pairwise differences, genetic distances and discriminant analysis, place the Tuscan sample in an intermediate position between sequences from culturally or geographically isolated regions of Europe (Sardinia, the Basque Country, Britain) and those from the Middle East. In spite of the remarkable genetic homogeneity in Europe, a degree of variability is shown by local European populations and homogeneity increases with the relative isolation of the population. The pattern of mitochondrial variation in Tuscany indicates the persistence of an ancient European component subsequently enriched by migrational waves, possibly from the Middle East. © 1996 Wiley-Liss, Inc.     

Y-chromosome-specific microsatellite variation in Australian aboriginals

The frequency distributions of 4 highly polymorphic Y-chromosome-specific microsatellites (DYS19, DYS390, DYS391, and DYS392) were determined in 79 unrelated Australian Aboriginal males from the Northern Territory. These results are compared with those observed in worldwide populations at both the locus and the haplotype level. Common alleles in Aboriginals are DYS19*15 (49%), DYS19*14 (28%), DYS390*19 (39%), DYS390*24 (20%), DYS391*10 (72%), DYS392*11 (63%), and DYS392*13 (28%). No evidence of reduced gene diversity was observed for these Y-chromosome alleles. DYS390 exhibits the most complex arrangement, displaying a bimodal distribution composed of common alleles (*22-*26), and rare short alleles (*18-*20), with an intermediate allele (*21) being absent. DYS390*20, previously reported only in Papuans and Samoans, is observed for the first time in Aboriginals. Compared with a recent study of Aboriginals, our sample exhibits considerable diversity in the haplotypes associated with the rare DYS390*19 allele, indicating that this allele is of considerable antiquity, if it arose as a single deletion event. Combining all 4 Y-chromosome-linked microsatellites produced 41 unique haplotypes, which were linked using a median-joining network. This network shows that most (78%) of our Aboriginal haplotypes fall into 2 distinct clusters, which likely represent 2 separate lineages. Seven haplotypes are shared with haplotypes found in a recent study of Aboriginals, and 7 are shared with a Spanish population. The cluster of Aboriginal haplotypes associated with the short DYS390 alleles does not share any haplotypes with the Spanish, indicating that this cluster of haplotypes is unique to Australian Aboriginals. Limited data from 4 worldwide populations used to construct haplotypes based on 3 loci (DYS19, DYS390, DYS392) show that only 4 of these haplotypes are seen in Australian Aboriginals. Shared haplotypes may be the result of admixture and/or recurrent mutation at these loci. Expanding the haplotype analysis to include biallelic markers on the Y chromosome will resolve this issue.     

福建畲族群体17个Y-STR基因座单倍型及遗传关系

应用Y-filerTM试剂盒及基因分型技术,检测152份福建畲族无关男性个体17个Y-STR基因座的多态性分布,计算等位基因频率及单倍型多样性,并结合已公开发表的其他11个群体相应基因座的单倍型资料,分析福建畲族群体遗传距离和聚类关系。福建畲族DYS385a/b基因座检出50种单倍型,其余15个Y-STR基因座分别检出3-11个等位基因,基因多样性GD值在0.4037(DYS391)～0.9725(DYS385a/b);观察到DYS19和DYS390基因座双等位基因和DYS385a/b基因座三等位基因,以及DYS448等部分基因座出现的"off-ladder"等位基因现象。17个Y-STR基因座共同构成的单倍型144种,其中138种单倍型出现1次,5种出现2次,1种出现4次,累计GD值为0.9990。从遗传距离分析发现,福建畲族与浙江汉族之间的遗传距离最近(0.0042),与青海藏族(0.2378)之间的遗传距离相对较远。福建畲族最靠近由台湾群体、浙江汉族、南方汉族等典型南方汉族群体聚成的分支区域。结果表明该17个Y-STR基因座在福建畲族群体中具有丰富的遗传多态性,对建立Y染色体STR数据库,研究群体遗传学和进行法医学应用有重要意义。     

Population Genetics of Y-Chromosome Short Tandem Repeats in Humans

Eight human short tandem repeat polymorphisms (STRs) also known as microsatellites—DYS19, DYS388, DYS390, DYS391, DYS392, DYS393, DYS389I, and DYS389II, mapping in the Y chromosome—were analyzed in two Iberian samples (Basques and Catalans). Allele frequency distributions showed significant differences only for DYS392. Fst and gene diversity index (D) were estimated for the Y STRs. The values obtained are comparable to those of autosomal STR if corrections for the smaller effective population size on the Y chromosome are taken into account. This suggests that Y-chromosome microsatellites might be as useful as their autosomal counterparts to both human population genetics and forensics. Our results also reinforce the hypothesis that selective sweeps in the Y chromosome in recent times are unlikely. Haplotypes combining five of the loci were constructed for 71 individuals, showing 29 different haplotypes. A haplotype tree was constructed, from which an estimate of 7,000 to 60,000 years for the age of the Y-chromosome variation in Iberia was derived, in accordance with previous estimates obtained with mtDNA sequences and nuclear markers. Received: 3 January 1997 / Accepted: 25 April 1997     

Analysis of polymorphism of three human Y-chromosome STR loci: DYS390, DYS392 and DYS393 in the population of northern Poland

The study aimed at development of a multiplex PCR system for amplification of three Y-chromosome STR loci: DYS390, DYS392 and DYS393, and its application in haplotype polymorphism analysis in the population of northern Poland. Due to interactions between originally published primers, a new DYS392 primer pair was proposed. In a population of 158 unrelated males, 28 different haplotypes could be observed, 12 of which were seen only once. The haplotype diversity is 0.805. Distribution of haplotypes of the studied loci is specific to the population of northern Poland and distinguishes it from compared West-European populations. To our knowledge, this is the first report on a Y-STR multiplex system that can be analysed on native polyacrylamide gels.     

Y-chromosome-Specific STR haplotype data on the Rapanui population (Easter Island)

Located in the south Pacific Ocean, Rapanui is one of the most isolated inhabited islands in the world. Cultural and biological data suggest that the initial Rapanui population originated from central Polynesia, although the presence of foreign or exotic genes in the contemporary population, as a result of admixture with Europeans and/or South Americans during the last two centuries, also has to be considered. To estimate the genetic affinities of the Rapanui population with neighboring populations, we analyzed seven microsatellite polymorphisms of the Y chromosome that recently have been indicated as useful in the study of local population structure and recent demographic history. Phylogenetic analysis of Rapanui Y-chromosome haplotypes identified two clusters. The largest cluster contained 60% of all haplotypes and is characterized, in particular, by the presence of the DYS19*16, DYS390*20, and DYS393*14 alleles, a combination found frequently in Western Samoa. The second cluster is characterized by the presence of the DYS19*14, DYS390*24, and DYS393*13 alleles, and these have a relatively high frequency in European and European-derived populations but are either infrequent or absent in native Pacific populations. In addition to the two clusters, one male is of haplogroup Q*, which is indicative of native American ancestry. The genetic structure of the current male population of Rapanui is most likely a product of some genetic contribution from European and South American invaders who mated with the indigenous Polynesian women. However, analysis of Rapanui's relationships with other Pacific and Asian populations indicates that, as in Western Samoa and Samoa, the population has experienced extreme drift and founder events.     

Y chromosome polymorphisms in Native American and Siberian populations: identification of Native American Y chromosome haplotypes

We have initiated a study of ancient male migrations from Siberia to the Americas using Y chromosome polymorphisms. The first polymorphism examined, a C→T transition at nucleotide position 181 of the DYS199 locus, was previously reported only in Native American populations. To investigate the origin of this DYS199 polymorphism, we screened Y chromosomes from a number of Siberian, Asian, and Native American populations for this and other markers. This survey detected the T allele in all five Native American populations studied at an average frequency of 61%, and in two of nine native Siberian populations, the Siberian Eskimo (21%) and the Chukchi (17%). This finding suggested that the DYS199 T allele may have originated in Beringia and was then spread throughout the New World by the founding populations of the major subgroups of modern Native Americans. We further characterized Native American Y chromosome variation by analyzing two additional Y chromosome polymorphisms, the DYS287 Y Alu polymorphic (YAP) element insertion and a YAP-associated A→G transition at DYS271, both commonly found in Africans. We found neither African allele associated with the DYS199 T allele in any of the Native American or native Siberian populations. However, we did find DYS287 YAP+ individuals who harbored the DYS199 C allele in one Native American population, the Mixe, and in one Asian group, the Tibetans. A correlation of these Y chromosome alleles in Native Americans with those of the DYS1 locus, as detected by the p49a/p49f (p49a,f) probes on TaqI-digested genomic DNA, revealed a complete association of DYS1 alleles (p49a,f haplotypes) 13, 18, 66, 67 and 69 with the DYS199 T allele, while DYS1 alleles 8 and 63 were associated with both the DYS199 C and T allele. Received: 18 November 1996 / Accepted: 19 May 1997     

Regional differences among the Finns: a Y-chromosomal perspective

Twenty-two Y-chromosomal markers, consisting of fourteen biallelic markers (YAP/DYS287, M170, M253, P37, M223, 12f2, M9, P43, Tat, 92R7, P36, SRY-1532, M17, P25) and eight STRs (DYS19, DYS385a/b, DYS388, DYS389I/II, DYS390, DYS391, DYS392, DYS393), were analyzed in 536 unrelated Finnish males from eastern and western subpopulations of Finland. The aim of the study was to analyze regional differences in genetic variation within the country, and to analyze the population history of the Finns. Our results gave further support to the existence of a sharp genetic border between eastern and western Finns so far observed exclusively in Y-chromosomal variation. Both biallelic haplogroup and STR haplotype networks showed bifurcated structures, and similar clustering was evident in haplogroup and haplotype frequencies and genetic distances. These results suggest that the western and eastern parts of the country have been subject to partly different population histories, which is also supported by earlier archaeological, historical and genetic data. It seems probable that early migrations from Finno-Ugric sources affected the whole country, whereas subsequent migrations from Scandinavia had an impact mainly on the western parts of the country. The contacts between Finland and neighboring Finno-Ugric, Scandinavian and Baltic regions are evident. However, there is no support for recent migrations from Siberia and Central Europe. Our results emphasize the importance of incorporating Y-chromosomal data to reveal the population substructure which is often left undetected in mitochondrial DNA variation. Early assumptions of the homogeneity of the isolated Finnish population have now proven to be false, which may also have implications for future association studies.     

A study of Y-chromosome microsatellite variation in sub-Saharan Africa: a comparison between F(ST) and R(ST) genetic distances

Seven Y-chromosome microsatellite loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) were analyzed in three populations from sub-Saharan Africa: the Bamileke and Ewondo populations from Cameroon and the Hutu from Rwanda. Complete typing was obtained for 112 individuals, and a total of 53 different haplotypes was observed. The single-locus gene diversity, averaged across populations, ranges from 0.100 for the DYS392 locus to 0.610 for the DYS389I locus. The haplotype diversity ranges from 0.832 (Ewondo) to 0.965 (Hutu), with an intermediate value of 0.918 in the Bamileke. The diversity among Bamileke, Ewondo, Hutu, and other sub-Saharan populations selected from the literature was analyzed using both a classical (F(ST)) and a stepwise-based (R(ST)) genetic distance method. The pattern of interpopulational diversity based on F(ST) was congruent with anthropological knowledge, while that based on R(ST) revealed unexpected and unconvincing population affinities. From a practical point of view, our study indicates that Y-chromosome microsatellite data may provide useful information for analyses of interpopulational diversity among sub-Saharan populations if an adequate number of loci and individuals along with an appropriate genetic distance method are used. On a theoretical ground, we propose that the lesser performance of R(ST) compared to F(ST) could be explained by the important role played by genetic drift in shaping the relationships among examined populations.     

A Comparison of Y-Chromosome Variation in Sardinia and Anatolia Is More Consistent with Cultural Rather than Demic Diffusion of Agriculture

Two alternative models have been proposed to explain the spread of agriculture in Europe during the Neolithic period. The demic diffusion model postulates the spreading of farmers from the Middle East along a Southeast to Northeast axis. Conversely, the cultural diffusion model assumes transmission of agricultural techniques without substantial movements of people. Support for the demic model derives largely from the observation of frequency gradients among some genetic variants, in particular haplogroups defined by single nucleotide polymorphisms (SNPs) in the Y-chromosome. A recent network analysis of the R-M269 Y chromosome lineage has purportedly corroborated Neolithic expansion from Anatolia, the site of diffusion of agriculture. However, the data are still controversial and the analyses so far performed are prone to a number of biases. In the present study we show that the addition of a single marker, DYSA7.2, dramatically changes the shape of the R-M269 network into a topology showing a clear Western-Eastern dichotomy not consistent with a radial diffusion of people from the Middle East. We have also assessed other Y-chromosome haplogroups proposed to be markers of the Neolithic diffusion of farmers and compared their intra-lineage variation—defined by short tandem repeats (STRs)—in Anatolia and in Sardinia, the only Western population where these lineages are present at appreciable frequencies and where there is substantial archaeological and genetic evidence of pre-Neolithic human occupation. The data indicate that Sardinia does not contain a subset of the variability present in Anatolia and that the shared variability between these populations is best explained by an earlier, pre-Neolithic dispersal of haplogroups from a common ancestral gene pool. Overall, these results are consistent with the cultural diffusion and do not support the demic model of agriculture diffusion.     

Y-chromosome-specific microsatellite variation in a population sample from Sardinia (Italy)

The genetic variability at seven Y-chromosomal microsatellite loci was studied among 113 Sardinian males from the regions of Campidano of Cagliari, Nuorese and Gallura. The allelic and haplotypes frequency distributions are compared between our sample and from the available literature data on Mediterranean and European populations. As a result, the Sardinian samples showed a very high allele frequency in the DYS19*17, a rarity in the rest of Europe, probably due to the founder effect. The analysis has shown an intra-population genetic heterogeneity and genetic differentiation from other Mediterranean and European population deal with. The results reported in this work showed that of the Euro-Mediterranean populations, the Corsican of the South seems to have the most genetic affinity with the Sardinians, thereby reaffirming the observations from previous works that had suggested a certain level of genetic similarity.     

DYS19 and DYS390 Y-STR polymorphism in the Iberian Peninsula: a multivariate analysis

Genetic polymorphism of two Y-specific short tandem repeats (DYS19 and DYS390) was investigated in six populations from the Iberian Peninsula (Andalusia, Castilla-La Mancha, Castilla-Leon, Extremadura, Galicia and South East Spain) comprising a total of 895 unrelated and native individuals, and a complete database of DYS19 and DYS390 allele frequency distributions in 34 world-wide populations collected from literature was analysed. DYS19 and DYS390 polymorphism was screened by automated fluorescence analysis of PCR-amplified labelled sample fragments performed with and ABI PRISM 377 Genetic Analyser. The degree of population differentiation was analysed using the STP Test to calculate G Statistic values. Correspondence Analysis based on the allelic frequencies of each locus and combining both was performed using the NTSYS-PC version 1.70 computer package. The diversity of the genetic profiles of gene frequencies suggests an important population heterogeneity in the Iberian Peninsula as a whole (DYS390 being particularly evident), which is corroborated after statistical analyses (G = 139.8457, p = 1.7822 x 10(-14) for DYS19, G = 116.0293, p = 4.6845 x 10(-12) for DYS390). However, multivariate analysis indicates a well defined cluster of the populations of the Central region, and sets them apart from the positions within which peripheral Iberian Peninsula populations are distributed. The Galician population shows trends which bring it closer to the positions throughout which European Atlantic populations are distributed. The results shown by the Central Iberian Peninsula seem to lend support to a model of settlement population stocks which came from the region of Castilla-Leon after the Islam invasions, whereas in the South-East populations the genetic record of Middle Eastern populations is still present, a consequence of the expansion of Islam in Southern Europe in the Middle Ages.