Genetic aspects of arterial hypertension: the role of Y chromosome and mitochondrial DNA

A study on hybrids from reciprocal crossing of the SHR-SP and the WKY has shown that Y-chromosome and mitochondrial DNA the affect development of the spontaneous hypertension. The Y-chromosome takes part in disorders of baroreceptive sensitivity in phenylnephrine assay associated with hypertension. Although our findings suggest that structural remodelling of peripheral vascular resistance and an increase in noradrenaline-dependent vasocostriction is genetically determined in hypertensive rats, we could not corroborate the role of the Y-chromosome and mitochondrial DNA in the process. A difference was shown between male and female SHR-SP in the level of arterial pressure and in development of the vascular structure changes.     

Genomic diversities and affinities among four endogamous groups of Punjab (India) based on autosomal and mitochondrial DNA polymorphisms

Nineteen insertion/deletion and restriction site polymorphisms on autosomal and mitochondrial genomes and mitochondrial DNA hypervariable segment 1 sequences were used to study genetic diversities and affinities among four endogamous groups of Punjab, India. High values of heterozygosity were noted in all four groups, both in the autosomal and mitochondrial genomes. The coefficient of gene differentiation among the groups, however, was found to be low. Genetic distance and phylogenetic analyses based on these data indicated that inferences on affinities among the populations were different when the two sets of loci (autosomal and mitochondrial) were considered separately. We have interpreted these results on the basis of some known historical data on migrations into this region. The results of this study when compared with the findings of some previous studies indicate that there are regional differences in the patterns of correlation between genomic and sociocultural affinities within India.     

Genetic distances in respect of AB0 blood groups among four castes of Assam,India

Summary An attempt has been made to measure the genetic distances in respect of AB0 blood group genes among four castes, namely, Brahmin, Kalita, Baisya and Kaibarta, in Assam, India. The results reveal that the Kaibarta are distinct from the other three castes, who show no significant differences.

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Zusammenfassung Die genetischen Abst?nde bezüglich der AB0-Blutgruppen wurden zwischen vier Kasten (Brahmin; Kalita; Baisya; Kaibarta) in Assam, Indien, berechnet. Die Kaibarta weichen von den üblichen Kasten signifikant ab; diese zeigen ?hnlichkeiten miteinander.

     

Genetic affinities of the central Indian tribal populations

Background

The central Indian state Madhya Pradesh is often called as ‘heart of India’ and has always been an important region functioning as a trinexus belt for three major language families (Indo-European, Dravidian and Austroasiatic). There are less detailed genetic studies on the populations inhabited in this region. Therefore, this study is an attempt for extensive characterization of genetic ancestries of three tribal populations, namely; Bharia, Bhil and Sahariya, inhabiting this region using haploid and diploid DNA markers.

Methodology/Principal Findings

Mitochondrial DNA analysis showed high diversity, including some of the older sublineages of M haplogroup and prominent R lineages in all the three tribes. Y-chromosomal biallelic markers revealed high frequency of Austroasiatic-specific M95-O2a haplogroup in Bharia and Sahariya, M82-H1a in Bhil and M17-R1a in Bhil and Sahariya. The results obtained by haploid as well as diploid genetic markers revealed strong genetic affinity of Bharia (a Dravidian speaking tribe) with the Austroasiatic (Munda) group. The gene flow from Austroasiatic group is further confirmed by their Y-STRs haplotype sharing analysis, where we determined their founder haplotype from the North Munda speaking tribe, while, autosomal analysis was largely in concordant with the haploid DNA results.

Conclusions/Significance

Bhil exhibited largely Indo-European specific ancestry, while Sahariya and Bharia showed admixed genetic package of Indo-European and Austroasiatic populations. Hence, in a landscape like India, linguistic label doesn''t unequivocally follow the genetic footprints.     

Congruence of genomic and ethnolinguistic affinities among five tribal populations of Madhya Pradesh (India)

The central Indian state of Madhya Pradesh is home to a large number of tribal populations of diverse linguistic and ethnic backgrounds. With a view to examining how well genomic affinities among tribal populations of this state correspond with their ethnic and linguistic affinities, we analysed DNA samples of individuals drawn from five tribes with diverse, but reasonably well-documented, ethnohistorical and linguistic backgrounds. Each DNA sample was scored at 16 biallelic DNA marker loci. On the basis of these data, genomic affinities among these populations were estimated. We have found an extremely good correspondence between the genomic and ethnolinguistic affinities.     

Genetic affinities of AB0 and Rh blood groups among populations of Andhra Pradesh, India: 2. Tribes

Genetic affinities of 21 tribal populations of Andhra Pradesh are reported in terms of genetic distance analysis with regard to AB0 and Rh loci. These tribal populations show a high degree of differentiation in the distribution of AB0 blood groups. Some tribes exhibit the monomorphism for Rh (D) locus. The genetic distance analysis reveals that the 21 tribes included in this study are genetically distant from one another and the genetic clustering pattern correlates with linguistic/ethnic affiliation and geographical propinquity of these tribal populations to a certain extent. The possible reasons for different cluster formations are discussed.     

Python phylogenetics: inference from morphology and mitochondrial DNA

We used nucleotide sequences from four mitochondrial genes and structural features of the mitochondrial control region, combined with a revised, previously published, morphological data set to infer phylogenetic relationships among the pythons. We aimed to determine which of two competing hypotheses of relationships of the genera Aspidites and Python best explains the evolutionary and bioegeographical history of the family. All analyses of the combined data recover a set of relationships in which (1) the genus Python is paraphyletic with the two east Asian species, P. reticulatus and P. timoriensis , as the sister lineage to the seven Australo-Papuan python genera. We support recognition of a distinct genus for the P. reticulatus  +  P. timoriensis clade; (2) the remaining species of the genus Python form a clade which is the sister lineage to the remainder of the family; (3) the genus Aspidites is embedded among the Australo-Papuan genera. The seemingly primitive characteristics of Aspidites may be better interpreted as reversals or specializations that have accompanied a switch to burrowing in this genus. Resolution of the relationships among the Australo-Papuan lineages is weak, possibly because of rapid diversification early in the history of the radiation. We assessed the tempo of the Indo-Australian python radiation using a maximum likelihood framework based on the birth–death process. We find strong support for elevated speciation rates during the period when Australia collided with the proto-Indonesian archipelago. The data support an origin for pythons outside Australia, followed by a radiation into Australia during the mid-Tertiary.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 603–619.     

Neolithic phylogenetic continuity inferred from complete mitochondrial DNA sequences in a tribal population of Southern India

The subsequent human migrations that dispersed out of Africa, both prehistoric and historic and colonization of India by modern humans is unanimous, and phylogeny of major mitochondrial DNA haplogroups have played a key role in assessing the genetic origin of people of India. To address more such events, complete mitogenomes of 113 Melakudiya tribe of Southern India were sequenced and 46 individuals showed the presence of west Eurasian autochthonous haplogroups HV14 and U7. Phylogenetic analysis revealed two novel subclades HV14a1b and HV14a1b1 and sequences representing haplogroup U7 were included under previously described subclade U7a3a1a2* specific to India. Moreover, the present analysis on complete mtDNA reveals addition information of the spread and distribution of west Eurasian haplogroups in southern India, in tracing an unexplored genetic link between Melakudiya tribe with the people of Iranian Plateau, South Caucasus, and Central Asia. Coalescence ages of HV14 and U7a3a1a2* trees in the present study dates?~?16.1?±?4.3 and ~?13.4?±?5.6 kya respectively.     

Fertility and mortality differentials among selected tribal population groups of north-western and eastern India

Selection potential based on differential fertility and mortality has been computed for six tribal groups inhabiting different geo-climatic conditions, namely: Sahariya, Mina and Bhil of the State of Rajasthan, north-western India, and Munda, Santal and Lodha of the State of West Bengal, eastern India. Irrespective of the methodology, the total index of selection was found to be highest among Lodhas (0.668), followed by Sahariyas (0.524), Santals (0.462), Bhils (0.386), Mundas (0.353) and Minas (0.334). Incidentally, Lodha and Sahariya are two of the seventy-four notified primitive tribal groups of India, and these two study populations show the highest index of total selection, mainly because of a higher embryonic and postnatal mortality. The relative contribution of the fertility component to the index of total selection is higher than the corresponding mortality component in all tribal groups. The analysis of postnatal mortality components indicates that childhood mortality constitutes the bulk of postnatal mortality, suggesting that children under 5 years need better health care in these tribal groups.     

广西仫佬族Y染色体和mtDNA的遗传结构分析

文章对我国广西仫佬族91个无关男性个体Y-STR、Y-SNP、mtDNA HVS-Ⅰ和mtDNA-SNP等进行检测分型, 探索仫佬族的分子遗传结构。结果显示：Y染色体单倍群O1a1-P203和O2a1*-M95在仫佬族中为高频单倍群, 利用Y-STR构建的N-J树中仫佬族与侗族聚类, 说明在父系遗传上仫佬族与侗族遗传关系较近; mtDNA中F1a、M*、B4a、B5a等4类单倍群高频出现, 体现出仫佬族在母系遗传方面具有典型的东亚南方群体特征。17个Y-STR位点和mtDNA HVS-Ⅰ具有丰富的遗传多态性, 在群体遗传学和法医学方面具有应用前景。     

Gene pool of ethnic groups of the caucasus: results of integrated study of the Y chromosome and mitochondrial DNA and genome-wide data

Genetic diversity has been analyzed in 22 ethnic groups of the Caucasus on the basis of data on Y-chromosome and mitochondrial DNA (mtDNA) markers, as well as genome-wide data on autosomal single-nucleotide polymorphisms (SNPs). It has been found that the West Asian component is prevailing in all ethnic groups studied except for Nogays. This Near Eastern ancestral component has proved to be characteristic of Caucasian populations and almost entirely absent in their northern neighbors inhabiting the Eastern European Plain. Turkic-speaking populations, except Nogays, did not exhibit an increased proportion of Eastern Eurasian mtDNA or Y-chromosome haplogroups compared to some Abkhaz-Adyghe populations (Adygs and Kabardians). Genome-wide SNP analysis has also shown substantial differences of Nogays from all other Caucasian populations studied. However, the characteristic difference of Nogays from other populations of the Caucasus seems somewhat ambiguous in terms of the R1a1a-M17(M198) and R1b1b1-M73 haplogroups of the Y chromosome. The state of these haplogroups in Turkic-speaking populations of the Caucasus requires further study.     

Genetic structure of native circumpolar populations based on autosomal,mitochondrial, and Y chromosome DNA markers

This study investigates the genetic structure of the present‐day inhabitants of Beringia in order to answer questions concerning their origins and evolution. According to recent studies, the ancestors of Native Americans paused for a time in Beringia, during which they differentiated genetically from other Asians before peopling the New World. Furthermore, the Koryaks of Kamchatka share a “ubiquitous” allele (D9S1120) with Native Americans, indicating they may have descended from the same ancestral Beringian population that gave rise to the New World founders. Our results show that a genetic barrier exists between Kamchatkans (Koryaks and Even) and Bering Island inhabitants (Aleuts, mixed Aleuts, and Russians), based on Analysis of Molecular Variance (AMOVA) and structure analysis of nine autosomal short tandem repeats (STRs). This is supported by mitochondrial DNA evidence, but not by analysis of Y chromosome markers, as recent non‐native male admixture into the region appears to have partially obscured ancient population relationships. Our study indicates that while Aleuts are descended from the original New World founders, the Koryaks are unlikely to represent a Beringian remnant of the ancestral population that gave rise to Native Americans. They are instead, like the Even, more recent arrivals to Kamchatka from interior Siberia, and the “ubiquitous” allele in Koryaks may result from recent gene flow from Chukotka. Genbank accession numbers for mtDNA sequences: GQ922935‐GQ922973. Am J Phys Anthropol 143:62–74, 2010. © 2010 Wiley‐Liss, Inc.     

Genetic diversity in an Andean population from Peru and regional migration patterns of Amerindians in South America: data from Y chromosome and mitochondrial DNA

The genetic variability of a Quechua-speaking Andean population from Peru was examined on the basis of four Y chromosome markers and restriction sites that define the Amerindian mitochondrial DNA (mtDNA) haplogroups. Forty-nine out of 52 (90.4%) individuals had mtDNA which belonged to one of the four common Amerindian haplogroups, with 54% of the samples belonging to haplogroup B. Among 25 males, 12 had an Amerindian Y chromosome, which exists as four haplotypes defined on the basis of the DYS287, DYS199, DYS392 and DYS19 markers, three of which are shared by Amazonian Amerindians. Thus, there is a clear directionality of marriages, with an estimated genetic admixture with non-Amerindians that is 9 times lower for mtDNA than for Y chromosome DNA. The comparison of mtDNA of Andean Amerindians with that of people from other regions of South America in a total of 1,086 individuals demonstrates a geographical pattern, with a decreasing frequency of A and C haplotypes and increasing frequency of the D haplotype from the north of the Amazon River to the south of the Amazon River, reaching the lowest and the highest frequencies, respectively, in the more southern populations of Chile and Argentina. Conversely, the highest and lowest frequencies of the haplogroup B are found, respectively, in the Andean and the North Amazon regions, and it is absent from some southern populations, suggesting that haplotypes A, C and D, and haplotype B may have been dispersed by two different migratory routes within the continent.     

Genetic distances among the five tribal populations of Andhra, Pradesh, South India.

In this paper, data on genetic distances among five tribal populations ae given. Among the five tribes, Koya Dora, Raj Gond and Naikpod are autochthonous populations of the Deccan plateau whereas the other two groups, Pardhan and Lambadi are migrants. Kova Doras were sampled from five distant localities. Genetic markers typed are: A1A2B0, Rho(D) blood group systems glucose-6-phosphate dehydrogenase deficiency, transferrin, haptoglobin, groupspecific component, haemoglobin, colour-vision deficiency and tastability to P. T. C. Using frequency data for the above nine genetic loci, genetic distances between the five endogamous tribes, and between the five groups of Koya Dora are calculated by adopting the statistical method of Edwards (1971). While genetic distances between Koya Dora, Raj Gond and Lambadi are minimal, the genetic distance between Pardhans and other tribal groups is maximum. Naikpods occupy an intermediate position. The closeness of Lambadi with Koya Dora and RAJ Gond can be regarded as coincidental. Interestingly, the differences in the genetic distance values between five Koya Dora groups are as great as the differences between the five endogamous tribal populations tested for the same loci. Genetic affinities of these tribal populations are discussed in relation to their ethnic origin migration and geographical isolation.     

Genetic variation in South Indian castes: evidence from Y-chromosome, mitochondrial, and autosomal polymorphisms

Background

Major population movements, social structure, and caste endogamy have influenced the genetic structure of Indian populations. An understanding of these influences is increasingly important as gene mapping and case-control studies are initiated in South Indian populations.

Results

We report new data on 155 individuals from four Tamil caste populations of South India and perform comparative analyses with caste populations from the neighboring state of Andhra Pradesh. Genetic differentiation among Tamil castes is low (R_ST = 0.96% for 45 autosomal short tandem repeat (STR) markers), reflecting a largely common origin. Nonetheless, caste- and continent-specific patterns are evident. For 32 lineage-defining Y-chromosome SNPs, Tamil castes show higher affinity to Europeans than to eastern Asians, and genetic distance estimates to the Europeans are ordered by caste rank. For 32 lineage-defining mitochondrial SNPs and hypervariable sequence (HVS) 1, Tamil castes have higher affinity to eastern Asians than to Europeans. For 45 autosomal STRs, upper and middle rank castes show higher affinity to Europeans than do lower rank castes from either Tamil Nadu or Andhra Pradesh. Local between-caste variation (Tamil Nadu R_ST = 0.96%, Andhra Pradesh R_ST = 0.77%) exceeds the estimate of variation between these geographically separated groups (R_ST = 0.12%). Low, but statistically significant, correlations between caste rank distance and genetic distance are demonstrated for Tamil castes using Y-chromosome, mtDNA, and autosomal data.

Conclusion

Genetic data from Y-chromosome, mtDNA, and autosomal STRs are in accord with historical accounts of northwest to southeast population movements in India. The influence of ancient and historical population movements and caste social structure can be detected and replicated in South Indian caste populations from two different geographic regions.     

Fertility and mortality differentials among the tribal population groups of Bastar District, Madhya Pradesh, India

The authors examine fertility and mortality differentials and their impact on health care and natural selection potentials among tribal populations in rural India. Data are from the Bastar District and concern 366 mothers who have completed their reproductive life span.     

Genetic drift of marker Y chromosome del(Y)(q12) in Khanty from the lower Ob river

Summary A cytogenetic study of Khanty from the lower Ob river in West Siberia has detected a high frequency of the Y chromosome heterochromatin subtotal deletion—del(Y) (q12). This morphologically identical deletion was found in 32 of 154 males examined (20.8%). The carriers had 10 different surnames. Taking into account the small size, isolation by distance, and historical pecularities of the surname formation of the population, it has been concluded that the high frequency of the del(Y)(q12) results from the genetic drift of the marker chromosome.     

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.