34 research outputs found

    Analysis of Y chromosome STR haplotypes in the European part of Russia reveals high diversities but non-significant genetic distances between populations

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    A total of 17 Y-specific STR loci were studied in 12 districts of the European part of Russia aiming to ascertain the amount of substructure required for the construction of a representative regional database. All groups exhibited high haplotype diversities but low inter-population variance as measured by an analysis of molecular variance. However, when Western Russia is taken as a whole, the genetic distances to the neighbouring populations were significant. Whereas gradual change in the Y chromosome pool exists between Russia and the Slavic-speaking populations to the West, remarkable discontinuities were observed with neighbouring populations in the East, North and South

    A Worldwide Survey of Human Male Demographic History Based on Y-SNP and Y-STR Data from the HGDP–CEPH Populations

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    We have investigated human male demographic history using 590 males from 51 populations in the Human Genome Diversity Project - Centre d’Étude du Polymorphisme Humain worldwide panel, typed with 37 Y-chromosomal Single Nucleotide Polymorphisms and 65 Y-chromosomal Short Tandem Repeats and analyzed with the program Bayesian Analysis of Trees With Internal Node Generation. The general patterns we observe show a gradient from the oldest population time to the most recent common ancestors (TMRCAs) and expansion times together with the largest effective population sizes in Africa, to the youngest times and smallest effective population sizes in the Americas. These parameters are significantly negatively correlated with distance from East Africa, and the patterns are consistent with most other studies of human variation and history. In contrast, growth rate showed a weaker correlation in the opposite direction. Y-lineage diversity and TMRCA also decrease with distance from East Africa, supporting a model of expansion with serial founder events starting from this source. A number of individual populations diverge from these general patterns, including previously documented examples such as recent expansions of the Yoruba in Africa, Basques in Europe, and Yakut in Northern Asia. However, some unexpected demographic histories were also found, including low growth rates in the Hazara and Kalash from Pakistan and recent expansion of the Mozabites in North Africa

    Mitochondrial DNA Haplogroup Analysis Reveals no Association between the Common Genetic Lineages and Prostate Cancer in the Korean Population

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    Mitochondrial DNA (mtDNA) variation has recently been suggested to have an association with various cancers, including prostate cancer risk, in human populations. Since mtDNA is haploid and lacks recombination, specific mutations in the mtDNA genome associated with human diseases arise and remain in particular genetic backgrounds referred to as haplogroups. To assess the possible contribution of mtDNA haplogroup-specific mutations to the occurrence of prostate cancer, we have therefore performed a population-based study of a prostate cancer cases and corresponding controls from the Korean population. No statistically significant difference in the distribution of mtDNA haplogroup frequencies was observed between the case and control groups of Koreans. Thus, our data imply that specific mtDNA mutations/lineages did not appear to have a significant effect on a predisposition to prostate cancer in the Korean population, although larger sample sizes are necessary to validate our results

    Multiplexed SNP Typing of Ancient DNA Clarifies the Origin of Andaman mtDNA Haplogroups amongst South Asian Tribal Populations

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    The issue of errors in genetic data sets is of growing concern, particularly in population genetics where whole genome mtDNA sequence data is coming under increased scrutiny. Multiplexed PCR reactions, combined with SNP typing, are currently under-exploited in this context, but have the potential to genotype whole populations rapidly and accurately, significantly reducing the amount of errors appearing in published data sets. To show the sensitivity of this technique for screening mtDNA genomic sequence data, 20 historic samples of the enigmatic Andaman Islanders and 12 modern samples from three Indian tribal populations (Chenchu, Lambadi and Lodha) were genotyped for 20 coding region sites after provisional haplogroup assignment with control region sequences. The genotype data from the historic samples significantly revise the topologies for the Andaman M31 and M32 mtDNA lineages by rectifying conflicts in published data sets. The new Indian data extend the distribution of the M31a lineage to South Asia, challenging previous interpretations of mtDNA phylogeography. This genetic connection between the ancestors of the Andamanese and South Asian tribal groups ∼30 kya has important implications for the debate concerning migration routes and settlement patterns of humans leaving Africa during the late Pleistocene, and indicates the need for more detailed genotyping strategies. The methodology serves as a low-cost, high-throughput model for the production and authentication of data from modern or ancient DNA, and demonstrates the value of museum collections as important records of human genetic diversity

    Evolutionary History of Hunter-Gatherer Marriage Practices

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    Background: The universality of marriage in human societies around the world suggests a deep evolutionary history of institutionalized pair-bonding that stems back at least to early modern humans. However, marriage practices vary considerably from culture to culture, ranging from strict prescriptions and arranged marriages in some societies to mostly unregulated courtship in others, presence to absence of brideservice and brideprice, and polyandrous to polygynous unions. The ancestral state of early human marriage is not well known given the lack of conclusive archaeological evidence. Methodology: Comparative phylogenetic analyses using data from contemporary hunter-gatherers around the world may allow for the reconstruction of ancestral human cultural traits. We attempt to reconstruct ancestral marriage practices using hunter-gatherer phylogenies based on mitochondrial DNA sequences. Results: Arranged marriages are inferred to go back at least to first modern human migrations out of Africa. Reconstructions are equivocal on whether or not earlier human marriages were arranged because several African hunter-gatherers have courtship marriages. Phylogenetic reconstructions suggest that marriages in early ancestral human societies probably had low levels of polygyny (low reproductive skew) and reciprocal exchanges between the families of marital partners (i.e., brideservice or brideprice). Discussion: Phylogenetic results suggest a deep history of regulated exchange of mates and resources among lineages tha

    Annotated mitochondrial genome with Nanopore R9 signal for <i>Nippostrongylus brasiliensis</i>

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    Nippostrongylus brasiliensis, a nematode parasite of rodents, has a parasitic life cycle that is an extremely useful model for the study of human hookworm infection, particularly in regards to the induced immune response. The current reference genome for this parasite is highly fragmented with minimal annotation, but new advances in long-read sequencing suggest that a more complete and annotated assembly should be an achievable goal. We de-novo assembled a single contig mitochondrial genome from N. brasiliensis using MinION R9 nanopore data. The assembly was error-corrected using existing Illumina HiSeq reads, and annotated in full (i.e. gene boundary definitions without substantial gaps) by comparing with annotated genomes from similar parasite relatives. The mitochondrial genome has also been annotated with a preliminary electrical consensus sequence, using raw signal data generated from a Nanopore R9 flow cell

    A study on the efficiency of current methods of breeding and testing for wheat improvement in the Western Cape Province

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    Thesis (PhD (Agric)) -- University of Stellenbosch, 1977.Full text to be digitised and attached to bibliographic record

    n Genetiese studie met Suid-Afrikaanse lusern (Medicago sativa L.)

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    Verhandeling (M. Sc. Landbou) -- Universiteit van Stellenbosch, 1965.Full text to be digitised and attached to bibliographic record
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