Y-chromosome DNA haplotype XI in Eastern Europe

Haplotype XI frequencies at the Y-chromosome-specific DNA polymorphism (p49-TaqI) were reported in 639 males originating from 13 different geographic locations in Eastern Europe, where haplotype XI represents the major haplotype. The highest frequencies were obtained from Ukraine (44%), Russia (43.9%), and Hungary (40.7%). Percentages of haplotype XI geographic distribution show a gradient of decreasing frequency from these areas of higher percentages toward southeastern and more western countries in Europe.     

North African genes in Iberia studied by Y-chromosome DNA haplotype 5.

The frequency of haplotype 5 at the Y-chromosome-specific DNA polymorphism (p49/TaqI) was reported in a study of 487 males originating from five different geographic locations in Iberia and North Africa. The highest frequency of haplotype 5 (68.9%) was previously observed in Berbers from Morocco, and it has been established that this haplotype is a characteristic Berber haplotype in North Africa. The relative frequencies of haplotype 5 distribution show a geographical gradient of decreasing frequency according to latitude in Iberia: 40.8% in Andalusia, 36.2% in Portugal, 12.1% in Catalonia, and 11.3% in the Basque Country; such a cline of decreasing frequency of haplotype 5 from the south to the north in Iberia clearly establishes a gene flow from North Africa towards Iberia.     

Y-chromosome DNA haplotypes in Jews: comparisons with Lebanese and Palestinians

One Y-specific DNA polymorphism (p49/Taq I) was studied in 54 Lebanese and 69 Palestinian males, and compared with the results found in 693 Jews from three communities (Oriental, Sephardic, and Ashkenazic). Lebanese, Palestinian, and Sephardic Jews seem to be similar in their Y-haplotype patterns, both with regard to the haplotype distributions and the ancestral haplotype VIII frequencies. The haplotype distribution in Oriental Jews is characterized by a significantly higher frequency of haplotype VIII. These results confirm similarities in the Y-haplotype frequencies in Lebanese, Palestinian, and Sephardic Jewish men, three Near-Eastern populations sharing a common geographic origin.     

Y-chromosome DNA haplotypes in north African populations

The frequency distribution of Y-chromosome haplotypes at DNA polymorphism p49/TaqI was studied in a sample of 505 North Africans from Mauritania, Morocco, Algeria, Tunisia, Libya, and Egypt. A particularly high frequency (55.0%) of Y-haplotype 5 (A2, C0, D0, F1, I1) was observed in these populations, with a relative predominance in those of Berber origin. Examination of the relative frequencies of other haplotypes in these populations, mainly haplotype 4 (the "African" haplotype), haplotype 15 (the "European" haplotype), and haplotypes 7 and 8 (the "Near-East" haplotypes), permit useful comparisons with neighboring peoples living in sub-Saharan Africa, Europe, and the Near East.     

Male-mediated introgression of Bos indicus genes into Argentine and Bolivian Creole cattle breeds

The geographic distribution and frequency of Bos taurus and Bos indicus Y chromosome haplotypes amongst Argentine and Bolivian Creole cattle breeds were studied, using cytogenetic and molecular genetic techniques. A complete correspondence between Y chromosome morphology and the haplotype of the Y-linked microsatellite marker INRA 124 was found in all males examined. The taurine and indicine haplotypes were detected in 85.7 and 14.3% of the males studied, respectively, although these frequencies varied amongst the different breeds examined. The geographic distribution of this polymorphism suggests a pattern of zebu introgression in South America. The highest frequencies of the Zebu Y-chromosome are found in Brazilian populations (43-90%), in the eastern part of the continent, while it is absent in the southernmost breeds from Uruguay and Argentina. Bolivian breeds, at the centre of the continent, exhibit intermediate values (17-41%). This east/west and north/south gradient of male Zebu introgression could be explained by historical events and environmental factors.     

Geographic and breed distribution of an Msp I PCR-RFLP in the bovine growth hormone (bGH) gene

Information is presented on the frequency of the Msp I (-) allele in the third intron of the bovine growth hormone gene in a large number of cattle breeds. Consideration of the breed frequencies in relation to their geographic origin shows a low frequency for breeds originating in Northern Europe, moderate frequencies for breeds originating in Eastern Europe or the countries surrounding the Mediterranean basin, and very high frequencies for breeds originating in the Indian subcontinent. Consideration of breed frequencies in relation to breed type, shows low to moderate frequencies for the humpless breeds, high frequencies for the humped breeds. Various explanations for this distribution are discussed, among them the possibility that the Msp I (-) allele originated in the Bos indicus breeds of the Indian subcontinent, from which it diffused through the humpless Bos taurus breeds of Eastern Europe, the Mediterranean basin, eventually reaching Western, Northern Europe, Western Africa in low frequencies.     

Hemogenetic studies of the Cologne political district (North Rhine-Westphalia, Germany)

In two population samples from the administrative area of Cologne, North Rhine-Westphalia, Germany (Eschweiler/Stolberg, B frequencies > 0.0800; Hürtgenwald/Inden/Langerwehe, B frequencies < 0.0800), 26 hemogenetic systems had been studied. The resulting differences of allele and haplotype frequencies, resp., are significant. These differences are interpreted as a result of the migration from North-East Europe to North Rhine-Westphalia in the last 120 years and the selective geographic distribution of the migrants in the industrial and urbanized areas.     

Population distribution of the methionine allele at the PRNP codon 129 polymorphism in Europe and the Middle East

Methionine homozygosity at codon 129 of the prion protein gene is a risk factor for Creutzfeldt-Jakob disease. Knowledge of M129V polymorphism in normal populations may contribute to a better understanding of prion diseases. M129V polymorphism was studied in 2201 normal subjects, originating from 15 populations from Europe and the Middle East. Mean heterozygosity in these populations is 38.9%, and there is some significant geographic heterogeneity between them. A comparison of M129 allele frequencies in these 15 populations to those already published for 8 European countries plus Turkey shows significant correlations with both latitude (r = -0.77) and longitude (r = 0.69). The geographic map of methionine allele frequencies indicates an east-west gradient of decreasing methionine allele values from the Middle East to Western Europe.     

免疫球蛋白同种异型Gm因子在四十个中国人群中的分布

根据免疫球蛋白同种异型Gm因子在维吾尔族、哈萨克族、回族、蒙古族、朝鲜族、藏族、鄂伦春族、壮族、侗族、白族、汉族等40个人群中的分布,计算Gm单倍型频率及遗传距离,提出了“中华民族以北纬30度为界,分南北两大发源地”的假说。     

North African Berber and Arab influences in the western Mediterranean revealed by Y-chromosome DNA haplotypes

We have analyzed Y-chromosome diversity in the western Mediterranean area, examining p49a,f TaqI haplotype V and subhaplotypes Vb (Berber) and Va (Arab). A total of 2,196 unrelated DNA samples, belonging to 22 populations from North Africa and the southern Mediterranean coast of occidental Europe, have been typed. Subhaplotype Vb, predominant in a Berber population of Morocco (63.5%), was also found at high frequencies in southern Portugal (35.9%) and Andalusia (25.4%). The Arab subhaplotype Va, predominant in Algeria (53.9%) and Tunisia (50.6%), was also found at a relatively high frequency in Sicily (23.1%) and Naples (16.4%); its highest frequency in Iberia was in northern Portugal (22.8%) and Andalusia (15.5%). In Iberia there is a gradient of decreasing frequencies in latitude for both subhaplotypes Va and Vb, related to eight centuries of Muslim domination (8th to 15th centuries) in southern Iberia.     

Conditional Hitchhiking of Mitochondrial DNA: Frequency Shifts of Drosophila Melanogaster Mtdna Variants Depend on Nuclear Genetic Background

Tests were performed of the selective neutrality of mitochondrial DNA (mtDNA) variants from geographic populations of Drosophila melanogaster in Argentina (ARG) and Central Africa (CAF). The two populations were completely reproductively compatible. The two distinct mtDNA haplotypes from the two populations were competed in replicate experimental populations on three nuclear genetic backgrounds: homozygous ARG, homozygous CAF, or hybrid ARG/CAF. Mitochondrial haplotype frequencies did not change significantly on either of the two homozygous nuclear backgrounds, and there was no change after experimental perturbation of haplotype frequencies. On the hybrid background, the ARG haplotype frequency increased significantly for the first two generations in all replicate populations but then did not change in subsequent generations. After perturbation, the ARG haplotype frequency increased in only one of four replicates. There is no evidence for selective differences among mtDNA variants in homozygous nuclear contexts or for nuclear-mitochondrial coadaptation. While some ``fitness' difference among mtDNA variants is required to account for the observed frequency shifts, it appears that in these hybrid populations, mtDNA is hitchhiking on fitness variation among hybrid segregating nuclear genes. These results have implications for the use of mtDNA in the study of hybrid zones and gene flow.     

On the origin of the Chinese nation: The distribution of immunoglobulin allotypes in forty Chinese populations

Data from population and family studies show that the human immunoglobulin Gm allotypes prove to be unique genetic markers in studies of human genetics, particularly in the characterization of different race or population determined by the differences in Gm hapolotype composition and its frequency. In this paper, a total of 5,641 individuals from 40 populations were typed for Gma, f, x, b, and g factors. The genetic distances between 13 minorities (Zhuang, Uygur, Dong, Hui, Korean, Kazak, Bai, Tibetan, Mongolian, and Oroqen) and 27 Han populations were computed by Nei's method on the basis of Gm haplotype frequencies and a phylogenetic tree was constructed. The conclusions were (1) The common Gm haplotype are afb, axg, a, and ag. The Gmfb haplotype is observed only in Uygur, Hui, and Kazak. (2) There is a parallel relationship between genetic distance and geographic distance for these populations. (3) The Gmafb haplotype frequency increases sharply from north to south, and there is a concomitant sharp decrease in ag and axg frequencies. (4) A hypothesis was proposed by the author that the origin of the Chinese nation might exist in both the Yellow River and the Yangtze River region and the most likely boundary between the Southern and the Northern Chinese is near the thirty degrees north latitude.     

Y-Haplotype X in the Balkans

A total of 2110 unrelated European male subjects were examined for the p49a,f TaqI Y-haplotype X. The results showed a remarkable mean peak of haplotype X frequencies (46.9%) among subjects from Croatia, and similar elevated frequency values were also found in their counterparts from Slovenia (41.5%), Bosnia (40.3%) and ex-Yugoslavia (36.7%). Frequencies of haplotype X decrease towards west (from 41.5% in Slovenia to less than 1% in northern Italy) and south (23.5% in Albania, 15.9% in Serbia, 7.5% in Greece and 2.1% in Crete), but retain relatively high frequencies in Romania (17.9%) and in Bulgaria (16.1%). Historical and genetic evidence allows us to demonstrate that haplotype X originated in Europe among descendants of men who have been associated with the Gravettian culture. During the Last Glacial Maximum the Western Balkan Peninsula constituted a “refuge” for haplotype X, the starting point of an expansion that spread this haplotype around the neighbouring populations in historical times.     

Divergent haplotypes and human history as revealed in a worldwide survey of X-linked DNA sequence variation

The population genetic history of a 10.1-kbp noncoding region of the human X chromosome was studied using the males of the HGDP-CEPH Human Genome Diversity Panel (672 individuals from 52 populations). The geographic distribution of patterns of variation was roughly consistent with previous studies, with the major exception that 1 highly divergent haplotype (haplotype X, hX) was observed at low frequency in widely scattered non-African populations and not at all observed in sub-Saharan African populations. Microsatellite (short tandem repeat) variation within the sequenced region was low among copies of hX, even though the estimated time of ancestry of hX and other sequences was 1.44 Myr. The estimated age of the common ancestor of all hX copies was 5,230 years (95% consistency index: 2,000-75,480 years). To further address the presence of hX in Africa, additional samples from Chad and Tanzania were screened. Five additional copies of hX were observed, consistent with a history in which hX was present in Africa prior to the migration of modern humans out of Africa and with eastern Africa being the source of non-African modern human populations. Taken together, these features of hX-that it is much older than other haplotypes and uncommon and patchily distributed throughout Africa, Europe, and Asia-present a cautionary tale for interpretations of human history.     

Genetic risk assessment for cardiovascular disease in Azoreans (Portugal): A general population-based study

The identification of clinically validated genetic variants contributing to complex disorders raise the possibility to investigate individuals' risk. In this line of research, the present work aimed to assess the genetic risk for cardiovascular disease (CVD) in Azoreans. Genotyping of 19 SNPs – 9 on 9p21, 5 on LDLR and 5 on USF1 – was performed by TaqMan assays on 170 healthy Azorean individuals. Results demonstrate that the most frequent haplotype in 9p21, with a frequency of 41.4%, is TGGGCGCGC, which harbors all risk alleles. Considering haplotype homozygosity data show that females present higher value of homozygosity for both LDLR (13.5%) and USF1 (15.3%), whereas males present higher value for the 9p21 region (8.2%). Interestingly, genetic profile analysis revealed differences in terms of geographic and gender distribution. The Azorean Central group presented a higher risk for atherosclerosis, 2.7 times higher when compared to the Eastern group, while the Eastern group shows 1.5 times higher risk for dyslipidemias. Moreover, Azorean females demonstrated a 4 times higher risk for dyslipidemias when compared to males, whereas males have an increased risk for atherosclerosis. Although allele frequencies in Azoreans were similar to those reported for the HapMap CEU population, the differences in terms of haplotype and genetic profile distribution must be taken in consideration when assessing genetic risk. Taken together, the data here presented evidence for the need to perform biomedical research and epidemiologic analysis in Azoreans with the aim of developing strategies to CVD prevention, health promotion and population education.     

Genetic position of Andalusians from Huelva in relation to other European and North African populations: a study based on GM and KM allotypes

An understanding of population relationships in the Mediterranean region is crucial to the reconstruction of recent human evolution. Andalusia, the most southern region of Spain, has been continuously and densely occupied since ancient times and has a rich history of contacts with many different Mediterranean populations. Thus, to understand the Mediterranean peopling process, investigators should analyze the population relationships between the Iberian peninsula and northern Africa based on an assessment of genetic diversity that takes Andalusia into consideration. The aim of this study was to address the extent of genetic variation in the Iberian peninsula between its geographic extremes (Huelva and the Basque area) and to explain the intensity of the phylogenetic relationships between Andalusians and other neighboring populations, such as those from North Africa. We present, for the first time, results on allotype markers (GM and KM) of human immunoglobulins in the Andalusian population from Huelva. The most frequent GM haplotypes in Andalusia correspond to those that are also the most common in Europe. A sub-Saharan haplotype was found at a relatively high frequency compared to other Iberian samples, and a North Asian marker did not reach polymorphic frequencies in the study sample. A hierarchical cluster analysis based on the first two principal components (94.1% of the total genetic variance) revealed an interesting geographic structure for the 49 populations selected from the literature. The Huelva sample showed a central position in the multivariate space--despite being geographically located at one of the extremes of the Mediterranean basin--and clustered with most Western European populations. Western Europe and Eastern Europe (the latter group paradoxically including Italy and the major islands of the western Mediterranean) were differentiated. North African populations were grouped in two clusters that did not separate either Arabs and Berbers or their present-day countries. Analysis of immunoglobulin allotype markers shows that gene flow among human populations should generally be interpreted in terms of complex patterns, with the observed frequencies being the consequence of the entire genetic and demographic history of the population. Single historical events rarely determine gene frequencies in large human populations. Analysis of the GM system has shown that the Andalusian population from Huelva, as a result of its complex history, is not simply an outstanding part of the Mediterranean world but rather the genetic center of gravity of that world.     

Immunoglobulin (GM and KM) allotypes in the Sikh population of India

The populations of India are genetically diverse, both within and between geographic regions; immunoglobulin (GM) allotypes provide important information on genetic differences between populations, since the frequencies of combinations of allotypes (termed "haplotypes") vary dramatically among ethnic groups. As part of a project to assess genetic diversity among defined Indian populations, we have examined eight GM allotypes in a sample of 101 unrelated Sikhs who have migrated to Toronto, Canada: Glm(1, 2, 3, 17) and G3m (5, 15, 16, 21). Sikhs are a religious group that arose in the Punjab about 1500 A.D.; most of the original converts are believed to have been middle to upper-middle caste Hindus. Gm allotyping showed that six Gm haplotypes occurred at polymorphic frequencies (greater than 0.01) in Sikhs: Gm3;5, Gm1,17;21, Gm1,2,17;21, Gm1,17;5, Gm1,17;15,16, and Gm1,3;5. These haplotypes have all been previously reported in Indian populations. The frequencies of the first four haplotypes resembled the published frequencies for lower-caste Hindus of NW India more than upper-caste Hindus. However, the last two haplotypes have been found only in upper-caste Hindus. The frequency of one of these, Gm1,17;15,16 was higher in Sikhs (0.09) than has been reported in any Indian population with the exception of Parsis (who are descended from Iranians). We speculate that the high frequency of this haplotype may have been characteristic of some of the Hindu castes in the Punjab from which Sikhs are descended.     

Y-Chromosome Haplotypes in the Greek–Turkish Area

Various populations have contributed to the present-day gene pool in oriental Mediterranean (Aegean Sea) and are well documented for ancient history. The primary objective of the study is to report on the analysis of the paternal component of the variation (Y chromosome haplotypes) in contemporary populations in Greece, Crete, Turkey and Cyprus. A total of 245 males who hailed from five different locations in Turkey, Greece, and the islands of Crete and Cyprus were analyzed for Y-chromosome-specific haplotypes based on p49a,f TaqI polymorphism. The main haplotype observed (21.2%) in the Greek–Turkish area is haplotype VII. The second haplotype in terms of frequency (13.5%) is haplotype VIII, which is characteristic of Semitic populations. The third (11.4%), fourth (6.9%) and fifth (5.7%) haplotypes in frequency are haplotype XI (a typical eastern European haplotype), haplotype V (the North African haplotype) and haplotype XV (the Western European haplotype), respectively. The distribution of haplotype VII is significantly heterogeneous genetically among the five localities studied, with a peak of frequency (43.8%) in Crete. It is proposed that haplotype VII reflects the ancient Minoan civilization. Haplotype VII frequencies actually known are mapped in countries surrounding the Mediterranean Sea.     

A common ancestral origin of the frequent and widespread 2299delG USH2A mutation

Usher syndrome type IIa is an autosomal recessive disorder characterized by mild-to-severe hearing loss and progressive visual loss due to retinitis pigmentosa. The mutation that most commonly causes Usher syndrome type IIa is a 1-bp deletion, described as "2299delG," in the USH2A gene. The mutation has been identified in several patients from northern and southern Europe and from North America, and it has been found in single patients from South America, South Africa, and China. Various studies have reported a range of frequencies (.16-.44) among patients with Usher syndrome, depending on the geographic origin of the patients. The 2299delG mutation may be the one that most frequently causes retinitis pigmentosa in humans. Given the high frequencies and the wide geographic distribution of the mutation, it was of interest to determine whether the mutation resulted from an ancestral mutational event or represented a mutational hotspot in the USH2A gene. Haplotype analysis was performed on DNA samples from 116 unrelated patients with Usher syndrome type IIa; the patients were from 14 countries and represented 148 2299delG alleles. On the basis of six single-nucleotide polymorphisms within the USH2A gene, 12 core haplotypes were observed in a panel of normal chromosomes. However, in our analysis, only one core haplotype was found to be associated with the 2299delG mutation. The data indicate that the widespread geographic distribution of the 2299delG mutation is the result of an ancestral mutation that has spread throughout Europe and into the New World as a result of migration.     

Genetic differentiation of Yemeni people according to rhesus and Gm polymorphisms

For introducing Yemeni population in synthesis of genetic relationships of human populations, analysis of rhesus and Gm polymorphisms have been carried out for a population sample of 210 Yemenites. Rhesus haplotype frequencies were compared to those estimated in an original sample of 171 Tunisians and to available data for other populations. Gm haplotype frequencies were introduced in a wide synthesis of genetic relationships for 67 populations from Africa, Europe, the Near East and India. The genetic profile of Yemeni people would be close to that of a highly diversified ancestral population. The first inhabitants of North Africa, the Berbers and Yemenites have very likely a common origin and were not subject to important genetic drift after their geographic differentiation. While, the divergence between Yemenites and their neighbours of sub-Saharan Africa would have occurred with a founder effect and a long isolation. An important parallelism is observed for the Gm system between genetic and linguistic differentiations.