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.     

Immunoglobulin (Gm) allotypes in a sample of Canadian Ashkenazic Jews

Gm typing on the serum specimens of 507 Ashkenazic Jews (pre-dominantly of Polish-Russian ancestry) from Toronto, Canada has established the presence of haplotypes Gm3;5, Gm1;21, Gm1,2;21, and Gm1,17;5, and the absence of haplotypes Gm1;13,15,16, Gm1;5,6, and Gm1;5,6,24 which have been found in other Jewish peoples. It is suggested that Ashkenazic populations have lower frequencies of haplotype Gm1,17;5 than non-European Jewish populations, and that some eastern European Jewish populations have acquired the Gm1;13,15,16 haplotype through gene flow from Central Asia. Thus Jewish populations show differences in the Gm system; many of the differences may be in the direction of similarities to neighbouring non-Jewish populations.     

Gm haplotype distribution in Amerindians: Relationship with geography and language

A review is made of the Gm haplotype distribution in 60 groups of Eskimos, North, Central and South American Indians, totaling 22,808 individuals. Differences were observed in the shapes of the distribution of Gm*ag and the other markers. Nearly identical values for F_ST and average heterozygosities were obtained in the North+Central/South comparisons. North-South and Southwest/Northeast clinal differences were observed in the Americas using correspondence factorial analysis. The two haplotypes mainly responsible for these differences are Gm*axg and Gm*abOst. When the populations are classified by language groups, besides the recognized differences between Eskimos and Athabaskan (Na-Dene) speakers compared with Amerinds, others are found. For instance, Uto-Aztecan speakers of the United States and Mexico differ in Gm frequencies from the Nuclear Chibchan, Macro-Arawak, and Carib speakers of Central and South America. The notion of a homogeneous Amerind genetic pool does not conform with these and other results. © 1993 Wiley-Liss, Inc.     

Brief communication: immunoglobulin (Gm and Km) allotypes in two populations of Catalonia (Spain)

Serum samples from two populations of Catalonia, Spain, 208 from Olot (Gerona) and 209 from Tortosa (Tarragona), were typed for G1m (1, 2, 3, 17), G3m (5, 10, 11, 13, 14, 15, 16, 26), and Km (1). The Gm patterns of the Catalonian populations are characterized by the presence of four haplotypes, Gm 1,17;21,26 Gm 1,2,17;21,26 Gm 1,3;5,10,11,13,14,26 and Gm 3;5,10,11,13,14,26. The homogeneity for haplotype Gm 1,17;21,26 among our data and other European populations suggests the existence of an isofrequency line which starts from the Mediterranean zone of Iberian Peninsula and continues through the northwestern part of Europe. From this line a decreasing cline towards the south can be observed. For the haplotype Gm 1,2;17,21,26, affinities are observed between Catalonian populations and other populations from central Europe. This confirms the existence of a gradient towards low values from NW to SE. The presence of the typical Mongoloid haplotype Gm 1,3;5,10,11,13,14,26 is discussed in this paper. No significant differences in the frequencies of the Km1 allele were observed among the European populations.     

GM allotypes in Native Americans: evidence for three distinct migrations across the Bering land bridge

We report the results of typings, for immunoglobulin G allotypes, of 5392 Native Americans from ten samples, the typings having been performed over the last 20 years. Four cultural groups are represented: the Pimans-Pima and Papago; the Puebloans-Zuni and Hopi; the Pai-Walapai; and the Athabascans-Apache and Navajo. The haplotype Gm1;21 has the highest frequency in each population while Gm1,2;21 is polymorphic in all except the Hopi. The Mongoloid marker Gm1;11,13 is found primarily in the Athabascans. The Caucasian haplotype Gm3;5,11,13 is found at polymorphic frequencies in several of the populations but its frequency is very low or absent among nonadmixed individuals. Although Nei's standard genetic distance analysis demonstrates genetic similarity at the Gm and Km loci, the heterogeneity that does exist is consistent both with what is known about the prehistory of Native Americans and traditional cultural categories. When the current Gm distributions are analyzed with respect to the three-migration hypothesis, there are three distinct Gm distributions for the postulated migrants: Gm1;21 and Gm1,2;21 for the Paleo-Indians 16,000 to 40,000 years ago; Gm1;21, Gm1,2;21, and Gm1;11,13 for the second wave of Na-Dene hunters 12,000 to 14,000 years ago; and Gm1;21 and Gm1;11,13 for the Eskimo-Aleut migration 9,000 years ago. The Pimans, Puebloans, and the Pai are descendents of the Paleo-Indians while the Apache and Navajo are the contemporary populations related to the Na-Dene. Finally, the Gm distribution in Amerindians is found to be consistent with a hypothesis of one migration of Paleo-Indians to South American, while the most likely homeland for the three ancestral populations is found to be in northeastern Asia.     

Characteristic high- and low-frequency dental traits in sub-Saharan African populations

In an earlier investigation (Irish [1993] Biological Affinities of Late Pleistocene Through Modern African Aboriginal Populations: The Dental Evidence [Ann Arbor: University Microfilms]), biological affinities of 32 sub-Saharan and North African dental samples were estimated using comparative analyses of 36 dental morphological traits. Marked dental homogeneity was revealed among samples within each of the two geographic regions, but significant interregional differences were noted. Assuming dental phenetic expression approximates or is an estimate of genetic variation, the present study of 976 sub-Saharan-affiliated Africans indicates they are not closely related to other world groups; they are characterized by numerous morphologically complex crown and root traits. Turner ([1984] Acta Anthropogenetica 8:23–78; [1985] in R Kirk and E Szathmary (eds.): Out of Asia: Peopling the Americas and the Pacific [Canberra: The Journal of Pacific History], pp. 31–78; [1990] Am. J. Phys. Anthropol. 82:295–318; [1992] Persp. Hum. Biol. 2/Archaeol. Oceania 27:120–127; [1992] in T Akaszawa, K Aoki, and T Kimura (eds.): The Evolution and Dispersal of Modern Humans in Asia [Tokyo: Hokusen-Sha Publishing Co.], pp. 415–438) reports that Northeast Asian/New World sinodonts also have complex teeth relative to Europeans, Southeast Asian sundadonts, Australian/Tasmanians, and Melanesians. However, sinodonty is characterized by UI1 winging, UI1 shoveling, UI1 double shoveling, one-rooted UP1, UM1 enamel extension, M3 agenesis, and three-rooted LM1. Sub-Saharan peoples exhibit very low frequencies of these features. It is proposed that the collection of dental traits which best differentiate sub-Saharan Africans from other worldwide samples includes high frequencies of the Bushman Canine, two-rooted UP1, UM1 Carabelli's trait, three-rooted UM2, LM2 Y-groove pattern, LM1 cusp 7, LP1 Tome's root, two-rooted LM2, UM3 presence, and very low incidences of UI1 double shoveling and UM1 enamel extension. This suite of diagnostic traits is termed the sub-Saharan African dental complex. Am J Phys Anthropol 102:455–467, 1997. © 1997 Wiley-Liss, Inc.     

Population genetic studies of the Philippine Negritos. II. gm and km allotypes of three population groups.

Serum samples of the three tribal Negrito populations in the Philippine Islands (127 from Zambales, 87 from Bataan, and 93 from Agusan) were tested for Glm(1,2,3 and 17), and G3m(5,6,11,13,14,15,16, and 21), and Km(1). The GMpatterm of the Negritos is characterized by three haplotypes, Gm1,17;21, Gm1,2,17;21, and Gm1,3;5,11,13,14, which is also characteristic of Mongoloid-related populations, especially with high incidence of the latter haplotype. They also have the haplotype, Gm1,17;5,13,14, prevalent in Africa, New Guinea, and northern Australia, suggesting an ancient link between the Negritos and the New Guinean-Australian group. Two unusual samples of G3m(15) positive without G3m(16) observed in Zambales Negritos suggest the presence of Gm1,17;5,11,13,14,15 haplotype in the population. This appears to be unique to Zambales Negritos and the first such samples to be found.     

Gm and Km immunoglobulin allotypes in Sicily

The aim of this study was to evaluate the intra- and inter-population variability of the Gm/Km system in the Madonie Mountains, one of the main geographical barriers in north-central Sicily. We analysed 392 samples: 145 from Alia, 128 from Valledolmo, 25 from Cerda and 94 from Palermo. Serum samples were tested for G1m (1,2,3,17), G2m (23), G3m (5,6,10,11,13,14,15,16,21,24,28) and Km (1) allotypes by the standard agglutination-inhibition method. We found the typical genetic patterns of populations in peripheral areas of the Mediterranean basin, with a high frequency of haplotypes Gm5*;3;23 and Gm5*;3;... The frequency of Gm21,28;1,17;... (about 16%) is rather high compared with other southern areas. Of great importance is the presence of the common African haplotype Gm 5*;1,17;..., ranging in frequency from 1.56% at Valledolmo to 5.5% at Alia. The presence of this haplotype suggests past contacts with peoples from North Africa. The introduction of African markers could be due to the Phoenician colonization at the end of the 2nd millennium b.c. or to the more recent Arab conquest (8th–9th centuries a.d.).     

Distribution of Gm and Km allotypes among ten populations of Assam, India

Serum samples from ten endogamous populations of Assam, India-Brahmins, Kalitas, Kaibartas, Muslims, Ahoms, Karbis, Kacharis, Sonowals, Chutiyas, and Rajbanshis-were typed for G1m (1, 2, 3, 17), G3m (5, 10, 11, 13, 14, 15, 16, 21, 26), and Km (1). Among Brahmins, Kalitas, Kaibartas, Muslims, Ahoms, Sonowals, Chutiyas, and Rajbanshis, five different Gm haplotypes were found: Gm1,17;21,26; Gm1,17;10,11,13,15,16; Gm1,2,17;21,26; Gm1,3;5,10,11,13,14,26; and Gm3;5,10,11,13,14,26. Kacharis and Karbis show only four of these haplotypes: Gm3;5,10,11,13,14,26 is absent among them. The intergroup variability in the distribution of these haplotypes is considerable, which can be explained by the ethnohistory of these populations. Genetic distance analysis, in which five Chinese population samples were included, revealed the existence of three main clusters: 1) North and Central Chinese; 2) Kalitas, Kaibartas, Chutiyas, Rajbanshis, Muslims, and Brahmins; and 3) Ahoms, Sonowals, Kacharis, South Chinese, and Karbis. The clusters suggest some genetic relation between these four Assamese populations and South Chinese, which is again understandable considering the ethnohistory of the populations of Northeast India. In the Km system, too, a remarkable variability is seen in distribution of phenotype and allele frequency.     

A private allele ubiquitous in the Americas

The three-wave migration hypothesis of Greenberg et al. has permeated the genetic literature on the peopling of the Americas. Greenberg et al. proposed that Na-Dene, Aleut-Eskimo and Amerind are language phyla which represent separate migrations from Asia to the Americas. We show that a unique allele at autosomal microsatellite locus D9S1120 is present in all sampled North and South American populations, including the Na-Dene and Aleut-Eskimo, and in related Western Beringian groups, at an average frequency of 31.7%. This allele was not observed in any sampled putative Asian source populations or in other worldwide populations. Neither selection nor admixture explains the distribution of this regionally specific marker. The simplest explanation for the ubiquity of this allele across the Americas is that the same founding population contributed a large fraction of ancestry to all modern Native American populations.     

Clan, language, and migration history has shaped genetic diversity in Haida and Tlingit populations from Southeast Alaska

The linguistically distinctive Haida and Tlingit tribes of Southeast Alaska are known for their rich material culture, complex social organization, and elaborate ritual practices. However, much less is known about these tribes from a population genetic perspective. For this reason, we analyzed mtDNA and Y-chromosome variation in Haida and Tlingit populations to elucidate several key issues pertaining to the history of this region. These included the genetic relationships of Haida and Tlingit to other indigenous groups in Alaska and Canada; the relationship between linguistic and genetic data for populations assigned to the Na-Dene linguistic family, specifically, the inclusion of Haida with Athapaskan, Eyak, and Tlingit in the language family; the possible influence of matrilineal clan structure on patterns of genetic variation in Haida and Tlingit populations; and the impact of European entry into the region on the genetic diversity of these indigenous communities. Our analysis indicates that, while sharing a "northern" genetic profile, the Haida and the Tlingit are genetically distinctive from each other. In addition, Tlingit groups themselves differ across their geographic range, in part due to interactions of Tlingit tribes with Athapaskan and Eyak groups to the north. The data also reveal a strong influence of maternal clan identity on mtDNA variation in these groups, as well as the significant influence of non-native males on Y-chromosome diversity. These results yield new details about the histories of the Haida and Tlingit tribes in this region.     

GM and KM allotypes and GM RFLP allogenotypes in Micronesians from Nauru.

Immunoglobulin allotypes of the GM and KM systems were determined in a sample of Micronesian subjects from Nauru. Four GM haplotypes were identified in the sample: GM*1,3 23 5, 10,11,13,14, GM*1,17 23' 21, GM*1,3 23' 5,10,11,13,14, and GM*1,2,17 23' 21, although the last of these may have been introduced by non-Micronesian admixture. The frequency of the KM*1 allele is 0.115 +/- 0.033, which is slightly lower than reported in Micronesians from the Caroline Islands. RFLPs generated by the enzymes Taq I and Pvu II and detected by a Hu gamma 4 probe were related to GM phenotypes. The haplotypes GM*1,3 +/- 23 5,10,11,13,14 were strongly associated with a Taq I 5.0-kb band. The presence and absence of the allotype G2M 23 were marked by a Pvu II 7.0 + 2.0 kb pair and a Pvu II 9.0-kb fragment, respectively. GM*1,17 23' 21 was strongly associated with a Pvu II 5.0 + 2.7 kb pair. The different relationships between GM haplotypes and Hu gamma 4 RFLPs in Micronesians and Caucasians indicate that a universal GM allogenotyping procedure cannot yet be developed; instead, population-specific procedures are necessitated by differences in GM allotype arrangements between populations.     

The genetic position of the autochthonous subpopulation of Northern Navarre (Spain) in relation to other basque subpopulations. A study based on GM and KM immunoglobulin allotypes

GM and KM immunoglobulin (Ig) allotypes were tested in 118 autochthonous Basques from northern Navarre. The results are compared to those obtained for the same genetic markers in 6 other Basque subpopulations, 3 from Spain (Guipúzcoa, Vizcaya, and Alava) and 3 from France: Macaye, Saint-Jean Pied de Port, and Mauleon. The northern Navarrese appear genetically closer to the Alava and Saint-Jean Pied de Port subpopulations. The Basques present 3 GM haplotypes that are uncommon in Caucasian populations, suggesting that they have not been completely isolated either from Asian or African populations. The GM*1,17 23' 10,11,13,15,16 north Asian haplotype was probably the first to be introduced into the Basque area. The GM*1,17 23' 5* haplotype, considered an African genetic marker although also detected in Central Asia, would have reached the Iberian Peninsula through consecutive historic migrations from North Africa. The rare haplotype GM*1,17 23 21,28 results probably from a genetic recombination or crossing-over between the 2 common haplotypes GM*1, 17 23' 21,28 and GM*3 23 5*. It is also found with a low frequency in other neighboring regions and countries; but the possibility of its having been introduced through the main passage connecting western France and Spain during the Roman Empire and Middle Ages cannot be ruled out.     

BamHI-SacI RFLP and Gm analysis of the immunoglobulin IGHG genes in the Northern Selkups (west Siberia): new haplotypes with deletion, duplication and triplication

Gm immunoglobulin allotypes have been studied in 1157 individuals of seven Northern Selkup populations, which account for 80% of the entire population of this west Siberian tribe. This study confirms that the northern Selkup populations are a Caucasoid-Mongoloid hybrid. Restriction fragment length polymorphism (RFLP) analysis of the IGHG genes using double BamHI-SacI digests, performed on 475 DNA samples, allowed us to describe nine new BamHI-SacI haplotypes (BS47 to BS55), eight of them being characterized by IGHG gene deletion or duplication: G1 (BS49) or G4 (BS55) deletion, G4 duplication (BS51), GP-G2-G4 multigene deletion (BS50), duplication (BS48, BS53 and BS54) or triplication (BS52). A new rare Gm haplotype 15,16*;1,17;23 has been found associated with BS52. The BS51 haplotype characterized by a duplicated G4 gene (additional 7.85 kb G4 band identifying a new G4*C5 allele) was always found associated with the Gm 5*;3;23 haplotype. A high RFLP diversity has been observed for the Northern-Mongoloid haplotype Gm 15,16*;1,17;.. which was found (1) with the BS27 haplotype characterized by a 3-exon hinge G3 gene, (2) with two different GP-G2-G4 multigene duplications, BS53 and BS54 haplotypes, which differ by the size of the duplicated G4 genes, and (3) with the BS55 haplotype characterized by a G4 deletion. In the Northern Selkups, haplotypes with duplicated genes were observed at a higher frequency (24%) than haplotypes with deleted genes (6%).     

Phylogenetic relationships of human populations in sub-Saharan Africa

This study utilizes the GM/KM immunoglobulin allotype system to elucidate the phylogenetic relationships of sub-Saharan Africans. The importance of understanding the relatedness of these peoples stems from the sub-Saharan region being the possible birthplace of humans. Haplotype distributions were determined for 19 populations and compared using chi-square analysis. Published data of other sub-Saharan Africans and representative populations worldwide were also added for comparison. Genetic distances between populations were calculated based on haplotype frequencies, and genetic relationships were observed through principal components analysis. Data from the GM/KM system showed a genetic homogeneity of the Bantu populations, with some exceptions, supporting the possibility of a common origin of these peoples. The Malagasy appeared as a divergent population, most likely due to Southeast Asian/Austronesian admixture, as indicated by the presence of the GM*AF B haplotype. The Cape Coloured also showed a divergence, with their genetic structures containing Caucasoid and Khoisan contributions. Finally, the Mbuti Pygmies appeared genetically isolated and had the highest frequency of the GM*A B haplotype out of all studied populations.     

Patterns of Admixture and Population Structure in Native Populations of Northwest North America

The initial contact of European populations with indigenous populations of the Americas produced diverse admixture processes across North, Central, and South America. Recent studies have examined the genetic structure of indigenous populations of Latin America and the Caribbean and their admixed descendants, reporting on the genomic impact of the history of admixture with colonizing populations of European and African ancestry. However, relatively little genomic research has been conducted on admixture in indigenous North American populations. In this study, we analyze genomic data at 475,109 single-nucleotide polymorphisms sampled in indigenous peoples of the Pacific Northwest in British Columbia and Southeast Alaska, populations with a well-documented history of contact with European and Asian traders, fishermen, and contract laborers. We find that the indigenous populations of the Pacific Northwest have higher gene diversity than Latin American indigenous populations. Among the Pacific Northwest populations, interior groups provide more evidence for East Asian admixture, whereas coastal groups have higher levels of European admixture. In contrast with many Latin American indigenous populations, the variance of admixture is high in each of the Pacific Northwest indigenous populations, as expected for recent and ongoing admixture processes. The results reveal some similarities but notable differences between admixture patterns in the Pacific Northwest and those in Latin America, contributing to a more detailed understanding of the genomic consequences of European colonization events throughout the Americas.     

Deletion polymorphism in the human COL1A2 gene: genetic evidence of a non-African population whose descendants spread to all continents

We report the frequencies of a deletion polymorphism at the alpha 2 (1) collagen gene (COL1A2) and argue that this distribution has major implications for understanding the evolution of modern humans immediately after their exodus from sub-Saharan Africa as well as their subsequent spread to all continents. The high frequency of the deletion in non-African populations and its complete absence in sub-Saharan African groups suggest that the deletion event occurred just before or shortly after modern humans left Africa. The deletion probably arose shortly after the African exodus in a group whose descendants were among the ancestors of all contemporary populations, except for sub-Saharan Africans. This, of course, does not imply that there was a single migration out of Africa. The GM immunoglobulin haplotype GM*A,X G displays a similar distribution to that for the COL1A2 deletion, and these 2 polymorphisms suggest that the exodus from Africa may not have been a rapid dispersion to all other regions of the world. Instead, it may have involved a period of time for the savanna-derived gene pool to adapt to novel selective agents, such as bacteria, viruses, and/or environmental xenobiotics found in both animal and plant foods in their new environment. In this context these polymorphisms are indicators of the evolution that occurred before the diaspora of these populations to the current distribution of modern peoples.     

The effect of the interaction of heavy and light chains of IgG on the Gm and Inv antigens

Studies of isolated polypeptide chains, of reconstituted, and of intact IgG show that the antigens present on the Fab fragment, Gm (3), Gm (4), and Inv (1), depend upon the interaction of heavy and light chains for their full antigenic expression, while the antigens of the Fc portion of the heavy chain, Gm (1), Gm (5), Gm (13), and Gm (14), have the same antigenicity in intact IgG, in isolated heavy chains, and in reconstituted IgG. Hybridization experiments using Bence-Jones protein light chains indicate that different homogeneous populations of light chains differ in their ability to restore Gm (3) and Gm (4) antigenicity and that this ability is independent of light-chain antigenic type.The investigations reported in this paper were supported in part by National Institutes of Health Grant GM 07214.Recipient of support from National Institutes of Health Training Grant 2T1 GM 226.     

A global view of the OCA2-HERC2 region and pigmentation

Mutations in the gene OCA2 are responsible for oculocutaneous albinism type 2, but polymorphisms in and around OCA2 have also been associated with normal pigment variation. In Europeans, three haplotypes in the region have been shown to be associated with eye pigmentation and a missense SNP (rs1800407) has been associated with green/hazel eyes (Branicki et al. in Ann Hum Genet 73:160-170, 2009). In addition, a missense mutation (rs1800414) is a candidate for light skin pigmentation in East Asia (Yuasa et al. in Biochem Genet 45:535-542, 2007; Anno et al. in Int J Biol Sci 4, 2008). We have genotyped 3,432 individuals from 72 populations for 21 SNPs in the OCA2-HERC2 region including those previously associated with eye or skin pigmentation. We report that the blue-eye associated alleles at all three haplotypes were found at high frequencies in Europe; however, one is restricted to Europe and surrounding regions, while the other two are found at moderate to high frequencies throughout the world. We also observed that the derived allele of rs1800414 is essentially limited to East Asia where it is found at high frequencies. Long-range haplotype tests provide evidence of selection for the blue-eye allele at the three haplotyped systems but not for the green/hazel eye SNP allele. We also saw evidence of selection at the derived allele of rs1800414 in East Asia. Our data suggest that the haplotype restricted to Europe is the strongest marker for blue eyes globally and add further inferential evidence that the derived allele of rs1800414 is an East Asian skin pigmentation allele.