Inferring microevolutionary patterns from allele-size frequency distributions of minisatellite loci: a worldwide study of the APOB 3' hypervariable region polymorphism

The availability of numerous population and molecular data makes the apolipoprotein B 3' hypervariable region (APOB 3' HVR) polymorphism ideal for a pilot study of the relationships between the allele-size frequency distributions (referred to as allele-size distributions) of minisatellite loci and the microevolutionary processes underlying their present-day polymorphism in human populations. In this paper, we present a worldwide APOB 3' HVR study, based on published and unpublished data, which refers to 36 populations. We systematically compare APOB 3' HVR within-group diversity (in terms of heterozygosity, number of alleles, and allele-size variance) in numerous human populations, including African, European, Asian, Amerindian, Australomelanesian, and Polynesian groups. Overall, our analyses indicate a greater APOB 3' HVR diversity in Africans than non-Africans. Then, we compare APOB 3' HVR allele-size distributions. The APOB 3' HVR allele-size distribution is found to be quasi-unimodal in Africans and bimodal or nonunimodal in non-African populations. The analysis of the distribution of pairwise comparisons suggests that Africans expanded earlier and/or that their ancestral population was larger than other continental groups. As a final step, we examine APOB 3' HVR interpopulational relationships by using three genetic distances. The F(ST) genetic distance, which assumes genetic drift as being the agent that differentiates populations, provides results that are more congruent with established anthropological knowledge than mutation-based distances (D(SW) and R(ST)). We hypothesize that the ancestral population was characterized by a high heterozygosity, an extended range of allele size, and a quasi-unimodal allele-size distribution centered on allele *37, features persisting in examined African populations. Sampling processes during "out-of-Africa" migrations would be responsible for the decrease in APOB 3' HVR gene diversity and the nonunimodal allele-size distribution observed in non-Africans. Some possible confounding factors are discussed and a prospect of how the hypothesis could be refined and tested is given.     

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.     

Five polymorphisms of the apolipoprotein B gene in healthy Bulgarians

Five APOB polymorphisms (I/D in the promoter region, XbaI [codon 24881, MspI [codon 3611], EcoRI [codon 41541, and 3' VNTRs) were studied in a population sample of 147 healthy normolipemic Bulgarians. For all biallelic loci, the observed genotype distributions do not deviate from Hardy-Weinberg equilibrium. In Bulgaria the insertion allele and the MspI+ allele of APOB presented the highest allelic frequencies (0.793 +/- 0.024 and 0.959 +/- 0.012, respectively) among the European population groups studied so far. The allele frequencies of the other two biallelic polymorphisms (XbaI and EcoRI) found in the Bulgarian population are similar to those previously described in other Caucasian populations. Analysis of the 3' VNTR polymorphism revealed 11 different alleles. Like studies in other Caucasian populations, this study found bimodal allele-size distribution and a high level of heterozygosity. The frequency of allele *31 (0.162 +/- 0.022) among Bulgarians is higher than that of any other European population group studied so far. Genetic distances between Bulgarians and each of six populations from southeastern Europe for which 3' VNTR allele frequencies are available showed an increase in the order: Albanians相似文献   

Apolipoprotein B, apolipoprotein E, and angiotensin-converting enzyme polymorphisms in 2 Italian populations at different risk for coronary artery disease and comparison of allele frequencies among European populations

Polymorphisms at the apolipoprotein B (APOB XbaI, EcoRI, insertion-deletion), apolipoprotein E (APOE), and angiotensin-converting enzyme (ACE) loci are thought to be involved in susceptibility to coronary artery disease (CAD) and myocardial infarction. The aim of this study was to determine whether the allele distribution of the APOB, APOE, and ACE polymorphisms is different in 2 Italian regions with higher (northern Italy) and lower (Sardinia) CAD occurrence. The frequencies of the APOB and APOE alleles that are considered CAD risk factors were higher in northern Italy (APOB X- = 0.655; APOB R- = 0.198; APOB insertion = 0.757; APOE*4 = 0.110) than in Sardinia (APOB X- = 0.568; APOB R- = 0.159; APOB insertion = 0.680; APOE*4 = 0.052), although only APOE allele frequencies differed significantly (p = 0.001). ACE deletion allele frequencies in the 2 geographic areas showed an opposite pattern (northern Italy = 0.658; Sardinia = 0.721). Furthermore, we investigated the impact of APOB and APOE polymorphisms on interindividual variation in total cholesterol level in the 2 Italian samples, which differ in dietary habits. Only APOE phenotypes showed different mean levels of total cholesterol; the association was significant only in northern Italy (p = 0.04), where continental dietary habits and higher mean cholesterol levels prevail. These results support the suggestion that the cholesterol increasing effect of APOE*4 is environmentally mediated. Analysis of allele distributions among European populations, with remarkable differences in CAD prevalence, revealed a constant positive relationship between APOE*4 allele frequency and CAD incidence. The highest frequencies of APOB X- and R- were observed in Finland, where the incidence of CAD is high, and there is a partial agreement between APOB R- frequency and CAD occurrence across Europe, while APOB insertion and ACE deletion alleles are evenly distributed among European populations.     

Ethnic differences in allele distribution for the IL8 and IL1B genes in populations from eastern India

Populations from eastern India have been examined for the allele distribution at polymorphic sites in the IL8 and IL1B genes. Significant differences in allele frequencies between caste and tribal population groups were observed. However, there are no differences in allele frequencies among various subpopulations within caste or tribal groups. We argue that different caste populations from the same geographic location can be pooled for the purpose of population association studies.     

Patterns of social and geographical distribution of transferrin subtype polymorphism in India

Transferrin subtypes have been determined by isoelectric focussing of sera from 536 individuals belonging to 9 South Indian populations: Vaidic Brahmins and Vaysya from Andhra Pradesh; Havik Brahmin, Lingayat and Jenu Kuruba from Karnataka; Namboodri Brahmin, Ezhava and Urali from Kerala; and Kallan from Tamil Nadu. C1 and C2 alleles are present in all the populations, whereas C4 is totally lacking and D1 occurs only in 3 populations. The highest frequency of C1 gene (0.814) is found in Havik Brahmins while C2 shows highest incidence among the tribe Urali. C1 occurs in slightly higher frequencies among the Hindu castes (range 0.724-0.814) than the tribal populations (range 0.698-0.703). C2 is more common in the tribes (range 0.281-0.290) compared to the castes (range 0.186-0.269). Strikingly the C3 allele is absent in all the 3 Brahmin samples but is present in 3 non-Brahmin castes and a tribal population. An examination of all the available data on Tf subtypes in India reveals no clear-cut decreasing north-south gradient in C1 gene as suggested by Walter et al. (1983). Interestingly, however, the same is observed when tribal populations are considered separately. Among the castes, in fact, the opposite trend (increasing north to south) is seen. It is suggested that the basic postulate of Walter et al. (1983) will hold good only among the tribal populations of the country. The data do not fully support the observation of Kamboh and Kirk (1983) that C3 is a specific marker of European (Caucasian) populations.     

Genetic heterogeneity of Apo CII locus in north India

Apolipoprotein CII genotypes were determined in Brahmins, Banias, Jat Sikhs, Khatris, Ramgarhia, Ramdasia and Scheduled Castes of Punjab, North India (n = 930). The Apo CII exhibits three common polymorphic alleles CII*1, CII*2 and CII*3 with pooled frequencies 0.883, 0.114 and 0.003, respectively. CII*3 was absent in Brahmins. Distribution of Apo CII isoforms highlights a considerable variation among different ethnic groups across the world. The average heterozygosity of the Punjabi populations was 0.208. The gene diversity among these population groups was less than 0.1%.     

Genetic variation among four Mexican populations (Huichol, Purepecha, Tarahumara, and Mestizo) revealed by two VNTRs and four STRs

Allele distributions of two polymorphisms with variable number of tandem repeats (VNTR), D1S80 and APOB, and four polymorphisms with short tandem repeats (STR), VWA, TH01, CSF1PO, and HPRTB, were analyzed in three Mexican ethnic groups: Huichol, Purepecha, and Tarahumara. Genotype distribution was in agreement with Hardy-Weinberg expectations for each locus and ethnic group. Heterozygosity (H), power of discrimination, and probability of exclusion were estimated. The three groups presented some distinctive genetic features: (1) a diminished genetic diversity (H = 66.8% to 73.4%) and mean number of alleles by locus (5.8 to 6.3) in comparison with Mexican mestizos (H = 78.3%, 10.5 alleles/locus), and (2) uneven allele distributions as evidenced by "distinctive alleles" with high frequencies, especially in the Tarahumara and the Huichol. Genetic relatedness analysis included data from a previously typed mestizo population, the largest and most widely distributed population in Mexico. Allele distribution differentiation was observed among all four groups, except between mestizo and Purepecha (p > 0.05), which was interpreted as indicating a larger Spanish component in the Purepecha as a result of gene flow effects. Although intrapopulation inbreeding (FIS) was not significant, heterozygote deficiency in the total population (FIT) and divergence among populations (FST) were significant (p < 0.05). Genetic distances displayed a closer relationship among mestizos, Purepechas, and Huichols in relation to Tarahumaras. Correlation between the observed genetic features and the geographic isolation level points to genetic drift as the main cause of differentiation among these Mexican populations.     

Apolipoprotein E and H polymorphisms in Mongolian Buryat: allele frequencies and relationship with plasma lipid levels

A Buryat population consisting of seven tribal groups in eastern Mongolia has been screened to determine the frequency distribution of different apolipoprotein E and H alleles (APOE and APOH, genes) coding for common isoforms and their association with quantitative plasma lipid levels. Allele frequencies at the APOE locus in 125 healthy Buryat aged 17 to 73 years were highest for APOE*3 (0.804), followed by APOE*4 (0.164) and APOE*2 (0.032). The APOH locus had high frequencies of APOH*2 (0.912) and APOH*3 (0.088). APOH*1 was not detected. No significant differences were observed in the overall APOE allele frequencies between the Buryat and the Siberian Evenki, Inuits, and Indians in Asia, or with some European whites. The frequency distribution of the overall APOH alleles of the Buryat was similar to that of the Japanese in Asia. Overall plasma lipid levels of the Buryat (males aged 20 to 73 years, females aged 21 to 64 years) were considerably lower, comparable to those of the Evenki. The APOE*4/E*3 males had significantly high total- and LDL-cholesterol levels compared with the APOE*3/E*3 males (p < 0.025 and p < 0.01, respectively). No significant effects of the APOH genotypes on any of the plasma lipid levels were observed. In particular, our data regarding APOE suggest that the Buryat are genetically close in allele frequencies to the Evenki and Inuits, but differ from them in the association of genotype APOE*4/E*3 with cholesterol levels.     

Brief communication: Allelic and haplotypic structure at the DRD2 locus among five North Indian caste populations

The dopamine D2 receptor (DRD2) gene, with its known human‐specific derived alleles that can facilitate haplotype reconstruction, presents an important locus for anthropological studies. The three sites (TaqIA, TaqIB, and TaqID) of the DRD2 gene are widely studied in various world populations. However, no work has been previously published on DRD2 gene polymorphisms among North Indian populations. Thus, the present study attempts to understand the genetic structure of North Indian upper caste populations using the allele and haplotype frequencies and distribution patterns of the three TaqI sites of the DRD2 gene. Two hundred forty‐six blood samples were collected from five upper caste populations of Himachal Pradesh (Brahmin, Rajput and Jat) and Delhi (Aggarwal and Sindhi), and analysis was performed using standard protocols. All three sites were found to be polymorphic in all five of the studied populations. Uniform allele frequency distribution patterns, low heterozygosity values, the sharing of five common haplotypes, and the absence of two of the eight possible haplotypes observed in this study suggest a genetic proximity among the selected populations. The results also indicate a major genetic contribution from Eurasia to North Indian upper castes, apart from the common genetic unity of Indian populations. The study also demonstrates a greater genetic inflow among North Indian caste populations than is observed among South Indian caste and tribal populations. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Gc subtyping in south Indian tribal and caste populations

Seven tribal (Konda Kammara - 2 samples; Koya Dora - 3 samples; Lambadi) and caste (Madiga) populations from Andhra Pradesh (South India) have been analyzed for the distribution of Gc subtypes. The observed heterogeneity in the distribution of Gc1F, Gc1S and Gc2 alleles was found to be statistically significant. Comparisons are made with North Indian populations as well as with those of other racial affiliation. The anthropological impact of the Gc subtype polymorphism is discussed.     

Apolipoprotein E genotyping among the healthy Kuwaiti population

Apolipoproteins (lipid-free) are lipid-binding proteins that circulate in the plasma of human blood and are responsible for the clearance of lipoproteins. Apolipoprotein E (ApoE) is one of the several classes of this protein family. It acts as a ligand for the low-density lipid (LDL) receptors and is important for the clearance of very low-density lipid (VLDL) and chylomicron remnants. The APOE gene locus is polymorphic, with three major known alleles, APOE*3, *4, and *2. We investigated the distribution of the allele frequency of the APOE gene locus and describe here the genetic variation in four Kuwaiti subpopulations: Arab origin (Arabian peninsula), Arab Bedouin tribes, Iranian origin, and the heterogeneous population. We also describe the use of Spreadex gels in resolving the amplified and digested products of the APOE gene locus. DNA was extracted from whole blood and subjected to PCR and then to RFLP analysis. Allele and genotype frequencies were estimated for the total population and for each subpopulation. Statistical analysis showed no difference in the allele frequencies between the four groups. The frequency of APOE*3 in the Kuwaiti population was highest (88.4%) followed by the frequency of APOE*4 (6.5%) and APOE*2 (5.1%). The genotype and allele frequencies obtained for the Kuwaiti population fell within the reported worldwide distribution for the APOE gene locus. Moreover, the results obtained in this study showed no statistical difference (p > 0.05) between the APOE allele and genotype frequencies between the subgroups for all six genotypes and three alleles, supporting the assumption of admixture in the Kuwaiti population and that the obtained frequencies were in Hardy-Weinberg equilibrium. Finally, we found that the distribution of the APOE alleles in Kuwait differs somewhat from those reported in other Arab populations, suggesting that the Arabs originating from the Arabian peninsula are different from those of Lebanon, Morocco, and Sudan.     

Haptoglobin polymorphism among the tribal groups of southern Gujarat

BACKGROUND:

Gujarat is located at the western most point of the Indian subcontinent. Valsad and Surat districts are part of the ‘tribal belt’of Gujarat and constitute 29.1% of total tribal population of Gujarat. These tribal populations are a rich source of gaining insights in the patterns of genetic diversity and genetico-environmental disorders against the back drop of their ecological, historical and ethnographic aspects.

AIM:

The objectives were to find out a) the genetic diversity among the tribes of Gujarat with reference to haptoglobin (Hp) locus b) the relationship between Hp polymorphism and sickle cell anemia/trait.

MATERIALS AND METHODS:

431 individuals belonging to eight tribal groups were studied for Hp polymorphism using polyacrylamide disc gel electrophoresis (PAGE). Hb*S was screened by dithionate tube turbididy (DTT) test and confirmed using cellulose acetate membrane electrophoresis (CAME).

STATISTICAL ANALYSIS:

Allele frequency was calculated by direct gene counting method. Average heterozygosity and gene diversity were computed using software DISPAN. Analysis of molecular variance (AMOVA) was estimated using software ARLEQUIN version 3.1.

RESULTS AND CONCLUSIONS:

Pattern of allele frequency distribution showed preponderance of Hp² allele in all the eight tribal groups, which is in accordance with its frequency in different populations of Indian subcontinent. Total average heterozygosity (H_T) was found to be low (0.160) but the level of genetic differentiation (G_ST) was found to be moderately high (5.6%). AMOVA analysis indicated least among group variance between west and south Indian populations (-0.04%) indicating the affinities of the tribes of Gujarat with that of Dravidian speaking groups. Analysis of Hp phenotypes among sickle cell anemia/ trait individuals revealed a high frequency of Hp 0-0 phenotype (92.7%) among SS individuals as opposed to only 9.7% among AS individuals, reaffirming the selective advantage of HbAS state in relation to hemolytic disorders.     

Microsatellite variation at 24 STR loci in three endogamous groups of Uttar Pradesh,India

We have studied variation at 24 microsatellite markers among 50 individuals from each of three endogamous groups, Bhargavas, Chaturvedis, and non-Bhargava, non-Chaturvedi Brahmins of Uttar Pradesh, India. The number of alleles at the loci tested varied from 4 to 11, with an average of 6 at each locus. Heterozygosity was found to be quite high at all loci in the three subpopulations. It varied between 0.44 to 0.84 among Bhargavas (average 0.6510), 0.44 to 0.80 among Chaturvedis (average 0.6633 +/-), and 0.42 to 0.85 among Brahmins (average 6.694 +/-). Hardy-Weinberg equilibrium analysis revealed that these populations are under genetic equilibrium at almost all the loci tested. Comparisons of allele frequency between Bhargavas and Chaturvedis showed that they differed significantly at 14 short tandem repeat (STR) markers (p < 0.001), while Chaturvedis and Brahmins differed at 6 (p < 0.05) and Brahmins and Bhargavas at 8 (p < 0.05). Average F(IS) and F(ST) for the 24 STR markers was -0.02 and 0.013, respectively. We used both un-weighted pair group with arithmetic mean and principal components analysis to evaluate genetic distances among the three groups. Our results revealed that although there were differences at particular allele frequencies between Bhargavas vs. Brahmins, Bhargavas vs. Chaturvedis, and Brahmins vs. Chaturvedis, these differences were not statistically significant when combined over all 24 STR markers between Chaturvedis vs. Brahmins and Bhargavas vs. Brahmins. The genetic distance analysis revealed that Bhargavas are slightly apart from the other two populations.     

Haptoglobin polymorphism among fourteen populations of India

Haptoglobin (HP) is a serum protein that has the capability of binding the extracorpuscular haemoglobin released during haemolysis. It plays an important role in protection of haemolytic disease by reducing the oxidative and peroxidative potential at free haemoglobin. The present study was aimed to determine the prevalence of HP polymorphism among different Indian populations, anthropologically belonging to diverse ethnicity. The polymorphism was screened among 642 unrelated individuals belonging to 14 population groups of India including both tribal and non-tribal caste groups from different geographical regions of India with distinct linguistic affiliations. An attempt is also made to understand the distribution of HP polymorphism among the studied populations. The result reveals the HP gene to be polymorphic in all the studied populations. Except the two tribal populations (Thotis of Andhra Pradesh and Patelias of Rajasthan) and one caste population (Rajput of Himachal Pradesh), all the studied populations are found to obey the Hardy-Weinberg equilibrium. The significance of the present study is elucidated with the prevalence of high mutant HP*2 allele frequency in India. Selection could be one of the most plausible explanations for this high HP frequency because of its uniformly high occurrence among all the studied populations.     

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.     

Defective colour vision and taste sensitivity to PTC in the Maharashtrian population

Three caste groups of the Maharashtrian population, namely Brahmin (N=58), Maratha (N=989) and Scheduled caste (N=1073), were studied for defective colour vision and for the ability to taste phenylthiocarbamide (PTC). Comparisons of defective colour vision and PTC taste sensitivity were made with other Maharashtrian populations studied previously by various authors. The incidence of defective colour vision is lowest among the Brahmins (3.44%) and highest in the Scheduled caste people (4.28%). Taste sensitivity to PTC is highest among the Brahmins (72.5%) with a value which is close to the Vednagar Brahmins (73.3%) who show the highest frequency of the ‘T’ gene recorded so far in Maharashtra.     

Patterns of genetic diversity at the nine forensically approved STR loci in the Indian populations

Genetic diversity at the nine short tandem repeat (STR) loci, which are universally approved and widely used for forensic investigations, has been studied among nine Indian populations with diverse ethnic, linguistic, and geographic backgrounds. The nine STR loci were profiled on 902 individuals using fluorescent detection methods on an ABI377 System, with the aid of an Amp-F1 Profiler Plus Kit. The studied populations include two upper castes, Brahmin and Kayastha; a tribe, Garo, from West Bengal; a Hindu caste, Meitei, with historical links to Bengal Brahmins; a migrant group of Muslims; three tribal groups, Naga, Kuki and Hmar, from Manipur in northeast India; and a middle-ranking caste, Golla, who are seminomadic herders from Andhra Pradesh. Gene diversity analysis suggests that the average heterozygosity is uniformly high (>0.8) in the studied populations, with the coefficient of gene differentiation at 0.050 +/- 0.0054. Both neighbor-joining (NJ) and unweighted pair group method with arithmetic mean (UPGMA) trees based on DA distances bring out distinct clusters that are consistent with ethnic, linguistic, and/or geographic backgrounds of the populations. The fit of the Harpending and Ward model of regression of average heterozygosity on the gene frequency centroid is found to be good, and the observed outliers are consistent with the population structure and history of the studied populations. Our study suggests that the nine STR loci, used so far mostly for forensic investigations, can be used fruitfully for microevolutionary studies as well, and for reconstructing the phylogenetic history of human populations, at least at the local level.     

Phylogeography of mitochondrial DNA and Y-chromosome haplogroups reveal asymmetric gene flow in populations of Eastern India

Polymorphisms in mitochondrial (mt) DNA and Y-chromosomes of seven socially and linguistically diverse castes and tribes of Eastern India were examined to determine their genetic relationships, their origin, and the influence of demographic factors on population structure. Samples from the Orissa Brahmin, Karan, Khandayat, Gope, Juang, Saora, and Paroja were analyzed for mtDNA hypervariable sequence (HVS) I and II, eight Y-chromosome short tandem repeats (Y-STRs), and lineage-defining mutations diagnostic for Indian- and Eurasian-specific haplogroups. Our results reveal that haplotype diversity and mean pairwise differences (MPD) was higher in caste groups of the region (>0.998, for both systems) compared to tribes (0.917-0.996 for Y-STRs, and 0.958-0.988 for mtDNA haplotypes). The majority of paternal lineages belong to the R1a1, O2a, and H haplogroups (62.7%), while 73.2% of maternal lineages comprise the Indian-specific M*, M5, M30, and R* mtDNA haplogroups, with a sporadic occurrence of West Eurasian lineages. Our study reveals that Orissa Brahmins (a higher caste population) have a genetic affinity with Indo-European speakers of Eastern Europe, although the Y-chromosome data show that the genetic distances of populations are not correlated to their position in the caste hierarchy. The high frequency of the O2a haplogroup and absence of East Asian-specific mtDNA lineages in the Juang and Saora suggest that a migration of Austro-Asiatic tribes to mainland India was exclusively male-mediated which occurred during the demographic expansion of Neolithic farmers in southern China. The phylogeographic analysis of mtDNA and Y-chromosomes revealed varied ancestral sources for the diverse genetic components of the populations of Eastern India.     

C8A and C8B polymorphisms in Norwegians and Norwegian lapps

C8 inheritance patterns in 364 mother-child pairs formed the basis for evaluation of the existence of silent alleles (null alleles) in the genes determining the two known polymorphic C8 systems. While evidence for such alleles was not found in C8A (alpha-gamma complex), two observations of null allele segregation in C8B (beta chain) indicate a C8BQ*0 allele frequency of about 0.07. Two population samples comprising 150 Lappish and 1,264 non-Lappish Norwegians were examined for phenotype distributions in C8A and C8B. The phenotype distributions were mainly in accordance with the expected Hardy-Weinberg distribution. The results for C8A indicated simple, codominant inheritance of two frequent and several rare alleles. Allele frequencies were similar in the two populations. The C8A B gene frequency in Norwegians was significantly lower than that in FRG and higher than that in Negroes. C8B allele frequencies were also calculated from gene counts in the population material, but with due corrections for the C8BQ*0 frequency observed in the mother-child material.