logo
    Mitochondrial and Y-chromosome diversity of the Tharus (Nepal): a reservoir of genetic variation
    74
    Citation
    88
    Reference
    10
    Related Paper
    Citation Trend
    Abstract:
    Central Asia and the Indian subcontinent represent an area considered as a source and a reservoir for human genetic diversity, with many markers taking root here, most of which are the ancestral state of eastern and western haplogroups, while others are local. Between these two regions, Terai (Nepal) is a pivotal passageway allowing, in different times, multiple population interactions, although because of its highly malarial environment, it was scarcely inhabited until a few decades ago, when malaria was eradicated. One of the oldest and the largest indigenous people of Terai is represented by the malaria resistant Tharus, whose gene pool could still retain traces of ancient complex interactions. Until now, however, investigations on their genetic structure have been scarce mainly identifying East Asian signatures.High-resolution analyses of mitochondrial-DNA (including 34 complete sequences) and Y-chromosome (67 SNPs and 12 STRs) variations carried out in 173 Tharus (two groups from Central and one from Eastern Terai), and 104 Indians (Hindus from Terai and New Delhi and tribals from Andhra Pradesh) allowed the identification of three principal components: East Asian, West Eurasian and Indian, the last including both local and inter-regional sub-components, at least for the Y chromosome.Although remarkable quantitative and qualitative differences appear among the various population groups and also between sexes within the same group, many mitochondrial-DNA and Y-chromosome lineages are shared or derived from ancient Indian haplogroups, thus revealing a deep shared ancestry between Tharus and Indians. Interestingly, the local Y-chromosome Indian component observed in the Andhra-Pradesh tribals is present in all Tharu groups, whereas the inter-regional component strongly prevails in the two Hindu samples and other Nepalese populations.The complete sequencing of mtDNAs from unresolved haplogroups also provided informative markers that greatly improved the mtDNA phylogeny and allowed the identification of ancient relationships between Tharus and Malaysia, the Andaman Islands and Japan as well as between India and North and East Africa. Overall, this study gives a paradigmatic example of the importance of genetic isolates in revealing variants not easily detectable in the general population.
    Keywords:
    Haplogroup
    Two major Ovis aries mitochondrial DNA (mtDNA) haplogroups have been described in independent studies. HinfI RFLP data of mitochondrial genomes from a large sample set (n = 239) indicated an ancient mutation which differentiates between the two mtDNA types. A completely determined sheep mtDNA sequence was used to assign this mutation to the COI gene and to develop a PCR based assay discriminating between the two phylogenetic branches. The haplogroup specificity of the mutation was further investigated in 26 randomly selected individuals. The animals were unequivocally assigned to their respective groups on the basis of the developed test and their complete control region sequences. The assay provides a rapid and economic means of discriminating between both major domestic sheep mtDNAs.
    Haplogroup
    Ovis
    mtDNA control region
    Sequence (biology)
    Abstract Huntington's disease (HD) is caused by an increase in the number of CAG triplet repeats in exon 1 of the Huntingtin ( HTT ) gene. Expansions that contain more than 39 repeats predispose to disease. Some specific genetic elements (SNPs), and the haplotypes they create (haplogroups A, B, and C), located at the HTT locus seem to impact CAG repeat instability, and thus the prevalence of disease across different ethnic groups. We describe the haplotype structure in HD patients from India, using previously described informative SNPs at the HTT locus. We found that 27.8% of the HD patients are associated with high-risk haplotype variants (A1 and A2) and identified new variants within haplogroup A2 and C in HD patients. However, the representative control populations (1000 Genome South Asian and Genome Asia India) showed a complete absence of haplogroup A1. The major haplogroup in both HD and control populations was A4. The distribution of haplogroups A, B, and C among Indian HD patients suggested a mixture of genetic influences from European, East Asian and African populations. Also, a new variant of Hap.15 was identified in the Hap.01-Hap.16 haplotype classification. Additionally, we propose a new haplotype classification specifically for HD patients in India. The novel HTT haplotypes (HT-1 to HT-7) classification exhibited significant heterogeneity in HD patients. The observed variation may be attributed to population heterogeneity or multiple ancestral origins.
    Haplogroup
    We have obtained mitochondrial DNA (mtDNA) sequences from Karl Wilhelm Naundorff’s hair, who pretended to be the son of King Louis XVI (1754-1793) and Queen Marie-Antoinette (1755-1793). Authenticity of the hair is established by optic and electronic microscopy. Sequences of hypervariable regions of the mitochondrial DNA (extracted from two different hairs) show five mutations : 16298C ; 72C, 152C, 195C and 263G ; the corresponding mtDNA haplogroup is the sub-haplogroup HVO. Consequently, Naundorff cannot be excluded to be considered as being Louis XVII on the basis of mtDNA sequence of his humerus (as affirmed in Jehaes et al., 1998). Comparisons of mtDNA sequences between mtDNA extracted from Naundorff’s hair reported here and those (Jehaes et al., 2001) of the living Anna of Roumania (of Habsburg descent) shows that both correspond to mtDNA haplogroups of the general HV cluster.
    Haplogroup
    Hypervariable region
    Sequence (biology)
    Citations (4)
    Abstract Mitochondrial DNA analysis of 31 unrelated Shuswap speakers from a previously poorly sampled region of North America revealed two individuals with haplogroups rarely found in the Americas, C4c and C1d. Comparison of the complete genomes of the two individuals with others found in the literature confirms that C4c is a founding haplotype and gives insight into the evolution of the C1d haplotype. This study demonstrates the importance of collecting and analyzing data from Native North Americans when addressing hypotheses about the peopling of the Americas. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.
    Haplogroup
    Citations (46)
    The genetic diversity and relationships of dog haplogroups were studied by analyzing the HV1 region of mitochondrial DNA. Previous studies have found six distinct haplogroups (A, B, C, D, E, and F) in dogs. Haplogroups A, B, and C were widely distributed, while haplogroups D, E, F were rare and distributed in restricted regions. In this study, HV1 sequences from global dog populations were collected, categorized into haplotypes, and used to construct haplotype networks. The results showed that haplogroup A was the most prevalent, comprising approximately 72.34% of dogs worldwide. Haplogroups A, B, and C together accounted for around 97.40% of the global dog population. Haplogroups D, E, and F were rare, constituting less than 3% of the dog population. Haplogroups E and F made up only about 1-2%. Number of haplotypes in haplogroups D, E, and F were little, sgesting that these haplotypes were introduced into the canine population more recently with limited time for significant mutations. Analysis of haplotype networks showed that haplotypes A were introduced into the dog populations in the early stage of dog domestication. Haplotype Eharbouring dogs were genetically close to wolves, suggesting a recent introduction of haplogroup E. Similarly, haplogroup F exhibited a narrow distribution primarily in Japanese dogs, with haplotype F3 identified as the founder haplotype likely introduced from a few wolves carrying the F3 haplotype.Through the analysis of the haplotype network and assessment of the betweenness value, this study has identified important haplotypes contributing significantly to the dog population. These analyses offer valuable insights into the identification of founder haplotypes involved in the formation of dog breeds worldwide, serving as a valuable reference for breed development and genetic studies.
    Haplogroup
    To estimate the maternal effects of dog breeds using mitochondrial DNA(mtDNA) haplotypes in the dogs with several clinical disorders, 600 base pairs of mtDNA D-loop region were amplified from 365 dogs and were determined for mtDNA sequences. The diversity of the 600-bp sequences was classified into 64 haplotypes, including 46 newly discovered haplotypes, and the haplotypes were grouped into four clusters I to IV. Lineage analysis using the mtDNA haplotype indicated that each dog breed genetically comprises one or a few mtDNA haplotypes. When the relationship between genetic background and occurrences of clinical diseases was estimated, canine lineage analysis using mtDNA haplotype revealed that the disorders distributed in the dominant mtDNA haplotypes of each dog breed, but no disorder closely associated with mtDNA haplotypes was detected.
    Lineage (genetic)
    mtDNA control region
    Citations (14)
    Mitochondrial DNA (mtDNA) haplogroups affect the clinical expression of Leber hereditary optic neuropathy, age-related macular degeneration, and other diseases. The objective of this study is to investigate whether an mtDNA background is associated with myopia.Blood DNA was obtained from 192 college students, including 96 individuals with moderate-to-high myopia and 96 controls without myopia. All the subjects were from a well-known isolated population living in the Chaoshan area of east Guangdong Province and speaking one of the four major dialects in southern China. The mtDNA haplogroups in the 192 subjects were determined by sequencing the mtDNA control region and partial coding regions as well as by analysis of restriction fragment length polymorphisms. Each mtDNA was classified according to the updated version of the Eastern Asian haplogroup system.Sixteen mtDNA haplogroups were recognized in the 192 subjects. The overall matrilineal structures of the samples with and without myopia were similar and had genetic imprints showing their ethno-origin. There was no statistical difference in frequencies of haplogroup distribution between subjects with and without myopia (chi(2) test, p=0.556).We failed to identify clues that suggest an involvement of mtDNA background in the predisposition to myopia.
    Haplogroup
    Citations (67)
    Circulating cell-free mitochondrial DNA (ccf-mtDNA) acts as a damage-associated molecular pattern molecule and may be cargo within extracellular vesicles (EVs). ccf-mtDNA and select mitochondrial DNA (mtDNA) haplogroups are associated with cardiovascular disease. We hypothesized that ccf-mtDNA and plasma EV mtDNA would be associated with hypertension, sex, self-identified race, and mtDNA haplogroup ancestry. Participants were normotensive (n = 107) and hypertensive (n = 108) African American and White adults from the Healthy Aging in Neighborhoods of Diversity across the Life Span study. ccf-mtDNA levels were higher in African American participants compared with White participants in both plasma and EVs, but ccf-mtDNA levels were not related to hypertension. EV mtDNA levels were highest in African American participants with African mtDNA haplogroup. Circulating inflammatory protein levels were altered with mtDNA haplogroup, race, and EV mtDNA. Our findings highlight that race is a social construct and that ancestry is crucial when examining health and biomarker differences between groups.
    Haplogroup