Genetic heterogeneity among the Negroid and Arab tribes of the Sudan

Genetic distance analysis was carried out among seven tribes of the Sudan comprising three Negroid (Nuba, Fur, and Nilotes) and four Arab tribes (Beja, Gaalin, Hawazma, and Messeria) on the basis of six polymorphic loci (ABO and Rhesus blood groups; haemoglobin and red cell glucose-6-phosphate dehydrogenase; serum haptoglobin and transferrin polymorphisms) controlling 21 alleles and compared with the Arab and Negroid populations in neighbouring countries. The Nuba and Nilotes have been found to have Negroid genetic characteristics, while the Fur are intermediate between the Arabs and Negroids. The Beja and Gaalin tribes have more pronounced Arab genetic characteristics than the Hawazma and Messeria, who have a great deal of Negroid admixture.     

Some blood genetic markers of the Nuba and Hawazma tribes of western Sudan

Two hundred eighty subjects comprising 112 Nuba and 168 Hawazma of the Sudan were tested for the distribution of hemoglobins, eight red cell enzymes, and four serum proteins. The Nuba, the indigenous negroid tribe, had no HbS, HbO-Arab, or GdB(Khartoum) compared to the Hawazma tribe of Negro-Arab descent. The gene frequencies of the above polymorphic systems in the latter were as follows: HbS, 0.13; HbO-Arab, 0.01; GdB(Khartoum), 0.03. The frequency of GdA was higher in the Hawazma than in the Nuba. A high frequency of glucose 6-phosphate dehydrogenase (G6PD) deficiency and HpO was present in both the tribes. Essentially similar gene frequencies of Hp1, TfD, PGDC, pC, and PGM1 were observed in both Nuba and Hawazma. The average heterozygosity at five polymorphic loci was the same (0.23) in both the tribes. The above results agree with the social practice whereby people of mixed Hawazma and Nuba descent are considered members of the Hawazma tribe and confirm that racial admixture between the two groups can be seen as a process of gene flow from the Nuba to the Hawazma, even though the Nuba are the indigenous group, while the Hawazma are the new settlers.     

A study of some genetic characteristics of the Fur and Baggara tribes of the Sudan

The average inbreeding coefficients of the highly consanguineous Fur and Baggara tribes of Western Sudan were 0.04167 and 0.04450, respectively. Two hundred ninety-eight subjects from the two tribes were tested for polymorphism of hemoglobins, seven red cell enzymes, and four serum proteins. The Baggara showed a higher gene frequency of HbS and TfD and lower gene frequency of GdA and PC compared to the Fur. Both tribes showed a low gene frequency of PGM1 and high frequency of G6PD deficiency when compared to other Sudanese tribes. In spite of the high degree of inbreeding, no significant deviation from the Hardy-Weinburg equilibrium was observed in either tribe. The effects of inbreeding seem to be offset by mixing between the two tribes on Gabal Marra Plateau. The flow of the sickle gene from the Baggara into the Fur and other Sudanese tribes is discussed.     

Nonmetric tooth crown traits in the Ami tribe, Taiwan aborigines: comparisons with other east Asian populations.

The frequencies of occurrence of 17 tooth crown traits in the living Ami tribe, which inhabits the east coast of Taiwan, were investigated and compared with other East Asian populations based on Turner's (1987) Mongoloid dental variation theory. Principal coordinate analysis based on Smith's mean measure of divergence using frequencies of the 17 traits suggests that the Ami tribe together with the Yami tribe and the Bunun tribe is included in the sinodont group typical of the Chinese mainland and northeast Asia. In light of these results and the estimated distribution of sinodonty and sundadonty in the past and the present, we speculate that the gene flow from Chinese mainlanders to native sundadonts, who seem to have migrated northward to Taiwan, contributed significantly to the formation of the living Taiwan aboriginal groups, sinodonts. Among the aboriginal tribes of Taiwan, the Ami have characteristics intermediate between those of the Yami and the Bunun. The relative positions of these tribes in East Asian populations suggests that the extent of sinodontification and of genetic isolation is one of the causes of the intertribal variation.     

The spectrum of microsatellite loci on chromosomes 7 and 8 in Taiwan aboriginal populations: a comparative population genetic study

Sixteen microsatellite loci on chromosomes 7 and 8 of Han-Taiwanese and six Taiwan aboriginal populations were systematically analyzed by a high-resolution multiple-fluorescence-based polymerase chain reaction technique. Analysis of allele frequency distribution indicated the genetic divergence among these populations. Several alleles were unique to specific tribes. Only the D8S556 locus deviated from Hardy-Weinberg equilibrium in all tribes. Its F_IS level, as calculated with the Nei method, was also higher and more homozygous than expected. Therefore, with the exception of D8S556, these variable number of tandem repeats (VNTR) loci are suitable genetic markers for forensic and paternal testing. The F_ST level, as the proportion of the total variation among these tribes, ranged from 1.4% at the D7S484 locus to 6.8% at the D7S550 locus. The average F_ST was 3.9%, suggesting that there were substantial variations among these populations. The genetic identity analysis and the genetic distance analysis reached the same conclusions, viz., that the Ami and the Paiwan tribes were genetically close to each other, that the Atayal tribe was relatively unique compared with other tribes, and that the Saisiat tribe was relatively close to the Han-Taiwanese. A dendrogram for these tribes was further constructed by the UPGMA method. These VNTR data not only facilitate forensic and paternity testing, but also provide anthropometric information for further elucidating the relationship of Taiwan populations to the Austronesian family. Received: 12 August 1998 / Accepted: 30 January 1999     

GENETIC DIVERSITY IN THE MATRILINEAL WHALES: MODELS OF CULTURAL HITCHHIKING AND GROUP-SPECIFIC NON-HERITABLE DEMOGRAPHIC VARIATION

Cultural hitchhiking is the process by which cultural selection reduces the diversity of genes that are being transmitted in parallel to selective cultural traits. I use simulation models to investigate cultural hitchhiking in geographically unstructured populations of culturally homogeneous tribes. Substantial reduction of genetic diversity required: a reasonably low mutation rate; that tribes split fairly frequently when they constitute a substantial part of the population; a fairly low migration rate (<∼10 migrants per tribe per generation); only a low rate of cultural evolution (mean culturally determined fitness change >∼0.005%/ generation); and that cultural assimilation from other tribes change the fitness of a tribe less than cultural innovation within it. Cultural hitchhiking tends to increase mean tribe size. Measures of genetic and cultural variation among tribes poorly indicate past cultural hitchhiking. Demographic effects, in which tribal fitness varies but is not heritable, can also reduce a population's genetic diversity if the fitness varies very considerably, or tribal extirpation is added. In such cases populations frequently become extinct. Four species of matrilineal whales have remarkably low mitochondrial DNA diversity. Knowledge of the population and social structure of these species is consistent with the conditions for cultural hitchhiking. However, there remain important information gaps.     

Some blood genetic markers in the Korkus of Central India

A sample of 102 individuals from the Korkus tribe, an Australoid race inhabiting Central India, was studied for the distribution of haemoglobin and ten red cell enzyme types. Polymorphism was observed in G6P dehydrogenase, acid phosphatase, adenylate kinase and glyoxalase I types and in phosphoglucomutase subtypes. The lactate and malate dehydrogenases, glucose phosphate isomerase and superoxide dismutase systems were monomorphic. A single case of HbAS was observed. The Korkus were found to have GdA+; lower frequencies of pa, AK2, GLO1 and PGM2+ were observed in the Korkus in comparison to other related tribes and caste Hindus of the same region.     

Study of blood groups and haemoglobin variants among the Santal tribe in Midnapore District of West Bengal, India

Blood specimens of the Santals in Midnapore District of West Bengal, India were tested for the antigens A, B, C, D, E, c and e, when the incidence of B gene was found to be 26.8%. Another feature of the Santals was the high frequency (74.6%) of CDe chromosome with complete absence of cde. Trace of sickle-cell trait was also noticed among the Santals as is known to occur in some of the aboriginal tribes of the Nilgiri Hills, Uttar Pradesh, Gujarat and Western India. HbS was the only haemoglobin variant detected among them.     

Some blood genetic markers of selected tribes in Western Saudi Arabia

A total of 292 randomly selected subjects belonging to two indigenous Arab tribes (Harbi and Ghamid) and two immigrant tribes (Mograbi and Mowallad), residents in Western Saudi Arabia, have been tested for genetic variants of six blood groups, four serum proteins, and five red cell enzyme systems. The distribution of the polymorphic systems was different between indigenous and immigrant tribes, and the present Arab population shows a considerable degree of admixture from the surrounding countries, in particular Africa.     

Vitamin D Insufficiency in Arabs and South Asians Positively Associates with Polymorphisms in GC and CYP2R1 Genes

Background

A number of genetic studies have reported an association between vitamin D related genes such as group-specific component gene (GC), Cytochrome P450, family 2, subfamily R, polypeptide 1 (CYP2R1) and 7-dehydrocholesterol reductase/nicotinamide-adenine dinucleotide synthetase 1 (DHCR7/NADSYN1) and serum levels of the active form of Vitamin D, 25 (OH) D among African Americans, Caucasians, and Chinese. Little is known about how genetic variations associate with, or contribute to, 25(OH)D levels in Arabs populations.

Methods

Allele frequencies of 18 SNPs derived from CYP2R1, GC, and DHCR7/NADSYN1 genes in 1549 individuals (Arabs, South Asians, and Southeast Asians living in Kuwait) were determined using real time genotyping assays. Serum levels of 25(OH)D were measured using chemiluminescence immunoassay.

Results

GC gene polymorphisms (rs17467825, rs3755967, rs2282679, rs7041 and rs2298850) were found to be associated with 25(OH)D serum levels in Arabs and South Asians. Two of the CYP2R1 SNPs (rs10500804 and rs12794714) and one of GC SNPs (rs1155563) were found to be significantly associated with 25(OH)D serum levels only in people of Arab origin. Across all three ethnicities none of the SNPs of DHCR7/NADSYN1 were associated with serum 25(OH)D levels and none of the 18 SNPs were significantly associated with serum 25(OH)D levels in people from South East Asia.

Conclusion

Our data show for the first time significant association between the GC (rs2282679 and rs7041), CYP2R1 (rs10741657) SNPs and 25(OH)D levels. This supports their roles in vitamin D Insufficiency in Arab and South Asian populations respectively. Interestingly, two of the CYP2R1 SNPs (rs10500804 and rs12794714) and one GC SNP (rs1155563) were found to correlate with vitamin D in Arab population exclusively signifying their importance in this population.     

Genetic variation in Cameroon: Thermostability variants of hemoglobin and of glucose-6-phosphate dehydrogenase

The technique of heat denaturation was used in addition to electrophoresis for the detection of thermostability variants of hemoglobin and glucose-6-phosphate dehydrogenase in an attempt to measure the amount of genetic variability present in villages in the United Republic of Cameroon, Equatorial Africa. A minimum of three to a maximum of 13 thermostability variants were estimated for HbA and HbS, and a minimum of two to a maximum of ten thermostability variants were estimated for GdA, GdB, and GdA —. It is suggested that hemoglobin and glucose-6-phosphate dehydrogenase thermostability variants are genetically determined and that the sites of these variants are at the hemoglobin and glucose-6-phosphate dehydrogenase structural loci. The evidence for the existence of these hidden variants and their importance in the neutralist v. selectionist controversy are discussed.This work was supported in part by National Institutes of Health Grant HL 16005. S. C. B. was an International Telephone and Telegraph International Fellow to Cameroon, was supported by Training Grant NIH-GM 07197, and is currently an Insurance Medical Scientist Scholar. This work is in partial fulfillment of the requirements of the degree of Doctor of Philosophy in Genetics by S. C. B.     

Genetic heterogeneity and population structure of Gond-related tribes in the Vidarbha region of Maharashtra.

Genetic heterogeneity in nine polymorphic loci is observed among Gond-related tribes in the Vidarbha region of Maharashtra. Pardhans, with their high ABO*A2 gene frequency (4.01%), low m gene frequency (57%), high P*1 gene frequency (42.7%), and high HbS trait (31.58%), differ significantly from other tribes. Per locus average heterozygosity among the studied tribes ranged from 36.24% to 40.37%, with Pardhans being more heterozygous. Analysis by FST and the empirical relationship between average allele frequencies and the ratio of within-gene to total gene diversity show that the tribes are isolated and that differentiation among them is at an early stage and approximately in conformity with expected differentiation under genetic drift. However, distances and principal components analysis reveal that Pardhans are far removed from the other tribes and from other central Dravidian tribes. Furthermore, of the various demographic parameters estimated, the high average heterozygosity in Pardhans is significantly correlated with mean marital distance (MMD), regression of MMD on wife's age, and effective population size. There is congruence between genetic and demographic data, showing that Pardhans are distinct. This conforms with Haimendorf's (1979) contention based on cultural traits that Pardhans are Gonds by historical accident and are later migrants to the Gond area from the north. The most significant and practical observation of the present study is that migration from an originally nontribal (Pardhan) to a tribal (Gond) area and admixture lead to severe disease course, differential selection pressure, and hence highly elevated HbS trait frequency.     

云南16个少数民族群体的线粒体DNA多态性研究

利用PCR—RFLP法对傣族、白族、蒙古族、彝族等10个少数民族的16个群体共654人进行了mtDNA编码区多态性分析,共检测到17种单倍群,其中4种为未能确认的单倍群。单倍群频率分布和主成分图共同显示,百越系的3个民族共6个群体有高频的B、F单倍群,聚集在图的下部,表现出鲜明的南方群体特征;蒙古族的2个群体有高频的A、D单倍群,聚在图的上部,具有典型的北方群体特征;氐羌系的5个民族共7个群体全部或绝大多数都兼有南北方高频单倍群,位于图的中间,提示他们同时具有南北方群体的一些母系遗传特征。同一民族不同群体间的单倍群频率分布存在差异,但差异不很大,一般小于不同族源民族间的差异,但不一定都小于同一族源民族间的差异。     

High-resolution Y chromosome haplotypes of Israeli and Palestinian Arabs reveal geographic substructure and substantial overlap with haplotypes of Jews

High-resolution Y chromosome haplotype analysis was performed in 143 paternally unrelated Israeli and Palestinian Moslem Arabs (I&P Arabs) by screening for 11 binary polymorphisms and six microsatellite loci. Two frequent haplotypes were found among the 83 detected: the modal haplotype of the I&P Arabs (approximately 14%) was spread throughout the region, while its one-step microsatellite neighbor, the modal haplotype of the Galilee sample (approximately 8%), was mainly restricted to the north. Geographic substructuring within the Arabs was observed in the highlands of Samaria and Judea. Y chromosome variation in the I&P Arabs was compared to that of Ashkenazi and Sephardic Jews, and to that of North Welsh individuals. At the haplogroup level, defined by the binary polymorphisms only, the Y chromosome distribution in Arabs and Jews was similar but not identical. At the haplotype level, determined by both binary and microsatellite markers, a more detailed pattern was observed. Single-step microsatellite networks of Arab and Jewish haplotypes revealed a common pool for a large portion of Y chromosomes, suggesting a relatively recent common ancestry. The two modal haplotypes in the I&P Arabs were closely related to the most frequent haplotype of Jews (the Cohen modal haplotype). However, the I&P Arab clade that includes the two Arab modal haplotypes (and makes up 32% of Arab chromosomes) is found at only very low frequency among Jews, reflecting divergence and/or admixture from other populations.     

Genetic studies among the sedentes and migrant Oraons of eastern India

A total of 334 Oraons of both sexes from two localities in eastern India were tested for 11 polymorphic and six monomorphic blood genetic markers. The sample comprised 130 sedentes from the Gumla district in Bihar and 204 migrants to the Jalpaiguri district of North Bengal. At the hemoglobin locus one example of HbAS was observed in the Gumla sample, while two cases of HbAS were found in the Jalpaiguri group. The Oraons are a distinct tribe and are characterized by a very low frequency of Hp1, TFC2, and a high frequency of TfD1 and GcIF at the serum protein loci. In the red cell enzyme systems the Oraons have a higher frequency of pa at the acid phosphatase locus and GLO1 at the Glyoxalase I locus. Absence of red cell lactate dehydrogenase and very low HbS and GdB- is also characteristic of the Oraons. A probable new nondeficient slow variant of Gd has been observed in polymorphic frequency in the Oraons of Gumla. There was an excess of homozygotes at the Gc locus. No significant difference in the gene frequency between the two groups of Oraons was observed at any of the loci. Genetic distance estimates using the gene frequency data indicate that the Oraons of the two localities are genetically homogeneous and form one cluster with the Bhils. They are nearer to the Irula and Kurumba tribes of the Nilgiris rather than the other Dravidian tribes, Tamils, or Nayars.     

Genetic study of the population of Tenerife (Canary Islands,Spain): Protein markers and review of classical polymorphisms

Data on six protein polymorphisms (19 alleles) from the human population of Tenerife are presented and discussed along with other classical markers in relation to the origin of the Canarians. Genetic influences from three population groups were considered: the Iberians, and the Berbers and non-Berbers (Arabs) from north Africa. The systems examined show the Tenerife population lies within the limits of variation described for various Iberian groups, with a slight tendency towards the characteristics of north African populations. When blood groups, red cell enzymes and serum protein data were considered, the similarity of the Canary population to Iberians seems strengthened (70% estimated contribution of Iberian peninsula genes to the present-day Canarian pool), while some relation with north African groups is shown. Genetic distances between Canarians and Arabs and Canarians and Berbers are lower than those between the two north African groups, indicating a relative and comparable contribution of each to the present-day gene pool of the Canarian population. The Arab contribution could be attributable to the slaves who were introduced to these islands after the conquest in the 15th century, while the Berber contribution could be the remnants of the extinct aboriginal peoples of the islands (Guanches) or a more recent immigration due to slavery. Genetic data do not allow us to distinguish between these two possibilities. Am. J. Phys. Anthropol. 102:337–349, 1997. © 1997 Wiley-Liss, Inc.     

Microsatellite diversity reveals the interplay of language and geography in shaping genetic differentiation of diverse Proto-Australoid populations of west-central India

Microsatellite diversity was analyzed in four Proto-Australoid tribes, including Indo-European (Marathi)-speaking Katkari, Pawara, Mahadeo-Koli, and Dravidian (Gondi)-speaking groups of Maharashtra, west-central India, to understand their genetic structure and to identify the congruence between language and gene pool. Allele frequency data at 15 short tandem repeat (STR) loci in studied tribes was compared with data of 22 Indo-European- and Dravidian-speaking caste and tribal populations using heterozygosity, allele size variance, analysis of molecular variance (AMOVA), G(ST) estimate, PC plot, and Mantel correlation test. Our results demonstrate that "Gondi" tribes comprising the Madia-Gond, a hunter-gatherer population, and the agriculturist Dheria-Gond harbor lower diversity than "Marathi" tribal groups, which are culturally and genetically distinct. Katkari, a hunter-gatherer tribe, showed greater diversity and the presence of a large number of unique alleles, genetically distinct from all others except the Pawara, supporting their old cultural links. The agriculturist Pawara tribe represents a splinter subgroup of the Bhil tribe and has experienced gene flow. The Mahadeo-Koli, an agriculturally oriented tribe, displayed significant heterozygote deficiency, attributable to the practice of high endogamy. The Proto-Australoid tribal populations were genetically differentiated from castes of similar morphology, suggesting different evolutionary mechanisms operating upon the populations. The populations showed genetic and linguistic similarity, barring a few groups with varied migratory histories. The microsatellite variation clearly demonstrates the interplay of sociocultural factors including linguistic, geographical contiguity, and microevolutionary processes in shaping the genetic diversity of populations in contemporary India. This study supports the ethno-historical relationships of Indian populations.     

Taiwanese aborigines: genetic heterogeneity and paternal contribution to Oceania

In the present study, for the first time, 293 Taiwanese aboriginal males from all nine major tribes (Ami, Atayal, Bunun, Rukai, Paiwan, Saisat, Puyuma, Tsou, Yami) were genotyped with 17 YSTR loci in a attend to reveal migrational patterns connected with the Austronesian expansion. We investigate the paternal genetic relationships of these Taiwanese aborigines to 42 Asia-Pacific reference populations, geographically selected to reflect various locations within the Austronesian domain. The Tsou and Puyuma tribes exhibit the lowest (0.1851) and the highest (0.5453) average total genetic diversity, respectively. Further, the fraction of unique haplotypes is also relatively high in the Puyuma (86.7%) and low in Tsou (33.3%) suggesting different demographic histories. Multidimensional scaling (MDS) and analysis of molecular variance (AMOVA) revealed several notable findings: 1) the Taiwan indigenous populations are highly diverse. In fact, the level of inter-population heterogeneity displayed by the Taiwanese aboriginal populations is close to that exhibited among all 51 Asia-Pacific populations examined; 2) the asymmetrical contribution of the Taiwanese aborigines to the Oceanic groups. Ami, Bunun and Saisiyat tribes exhibit the strongest paternal links to the Solomon and Polynesian island communities, whereas most of the remaining Taiwanese aboriginal groups are more genetically distant to these Oceanic inhabitants; 3) the present YSTR analyses does not reveal a strong paternal affinity of the nine Taiwanese tribes to their continental Asian neighbors. Overall, our current findings suggest that, perhaps, only a few of the tribes were involved in the migration out of Taiwan.     

Ascertaining the role of Taiwan as a source for the Austronesian expansion

Taiwanese aborigines have been deemed the ancestors of Austronesian speakers which are currently distributed throughout two‐thirds of the globe. As such, understanding their genetic distribution and diversity as well as their relationship to mainland Asian groups is important to consolidating the numerous models that have been proposed to explain the dispersal of Austronesian speaking peoples into Oceania. To better understand the role played by the aboriginal Taiwanese in this diaspora, we have analyzed a total of 451 individuals belonging to nine of the tribes currently residing in Taiwan, namely the Ami, Atayal, Bunun, Paiwan, Puyuma, Rukai, Saisiyat, Tsou, and the Yami from Orchid Island off the coast of Taiwan across 15 autosomal short tandem repeat loci. In addition, we have compared the genetic profiles of these tribes to populations from mainland China as well as to collections at key points throughout the Austronesian domain. While our results suggest that Daic populations from Southern China are the likely forefathers of the Taiwanese aborigines, populations within Taiwan show a greater genetic impact on groups at the extremes of the current domain than populations from Indonesia, Mainland, or Southeast Asia lending support to the “Out of Taiwan” hypothesis. We have also observed that specific Taiwanese aboriginal groups (Paiwan, Puyuma, and Saisiyat), and not all tribal populations, have highly influenced genetic distributions of Austronesian populations in the pacific and Madagascar suggesting either an asymmetric migration out of Taiwan or the loss of certain genetic signatures in some of the Taiwanese tribes due to endogamy, isolation, and/or drift. Am J Phys Anthropol 150:551–564, 2013. © 2013 Wiley Periodicals, Inc.     

Failure of linguistic relationships to predict genetic distances between the Waiãpi and other tribes of lower Amazonia

Data on blood group, serum protein, erythrocyte enzyme, and histocompatibility antigen (HLA) traits are presented for the Waiãpi, a Tupispeaking tribe of the Brazilian and French Guianas. Intra- and intertribal comparisons have been made between these data, and previously published data from French Guiana, from another Tupi tribe and from other tribes of neighboring areas, and from the continent as a whole. For this purpose, we have modified the usual measure of genetic distance to obtain a value which is independent of the number of loci being considered. The intertribal genetic distances do not correlate with linguistic affinity. Social differences, which may have affected the rate of drift from the continental mean, correlate better with genetic distances.