29 research outputs found

    Mosaic maternal ancestry in the Great Lakes region of East Africa

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    The Great Lakes lie within a region of East Africa with very high human genetic diversity, home of many ethno-linguistic groups usually assumed to be the product of a small number of major dispersals. However, our knowledge of these dispersals relies primarily on the inferences of historical, linguistics and oral traditions, with attempts to match up the archaeological evidence where possible. This is an obvious area to which archaeogenetics can contribute, yet Uganda, at the heart of these developments, has not been studied for mitochondrial DNA (mtDNA) variation. Here, we compare mtDNA lineages at this putative genetic crossroads across 409 representatives of the major language groups: Bantu speakers and Eastern and Western Nilotic speakers. We show that Uganda harbours one of the highest mtDNA diversities within and between linguistic groups, with the various groups significantly differentiated from each other. Despite an inferred linguistic origin in South Sudan, the data from the two Nilotic-speaking groups point to a much more complex history, involving not only possible dispersals from Sudan and the Horn but also large-scale assimilation of autochthonous lineages within East Africa and even Uganda itself. The Eastern Nilotic group also carries signals characteristic of West-Central Africa, primarily due to Bantu influence, whereas a much stronger signal in the Western Nilotic group suggests direct West-Central African ancestry. Bantu speakers share lineages with both Nilotic groups, and also harbour East African lineages not found in Western Nilotic speakers, likely due to assimilating indigenous populations since arriving in the region ~3000 years ago

    60,000 years of interactions between Central and Eastern Africa documented by major African mitochondrial haplogroup L2

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    Mitochondrial DNA (mtDNA) haplogroup L2 originated in Western Africa but is nowadays spread across the entire continent. L2 movements were previously postulated to be related to the Bantu expansion, but L2 expansions eastwards probably occurred much earlier. By reconstructing the phylogeny of L2 (44 new complete sequences) we provide insights on the complex net of within-African migrations in the last 60 thousand years (ka). Results show that lineages in Southern Africa cluster with Western/Central African lineages at a recent time scale, whereas, eastern lineages seem to be substantially more ancient. Three moments of expansion from a Central African source are associated to L2: (1) one migration at 70-50 ka into Eastern or Southern Africa, (2) postglacial movements (15-10 ka) into Eastern Africa; and (3) the southward Bantu Expansion in the last 5 ka. The complementary population and L0a phylogeography analyses indicate no strong evidence of mtDNA gene flow between eastern and southern populations during the later movement, suggesting low admixture between Eastern African populations and the Bantu migrants. This implies that, at least in the early stages, the Bantu expansion was mainly a demic diffusion with little incorporation of local populations.This research received support from the European project “A European Initial Training Network on the History, Archaeology, and New Genetics of the Trans-Atlantic Slave Trade (EUROTAST)” (EU project: 290344). PSo is supported by FCT (the Portuguese Foundation for Science and Technology), European Social Fund, Programa Operacional Potencial Humano and the FCT Investigator Programme (IF/01641/2013). IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT. This work is funded by FEDER funds through the Operational Programme for Competitiveness FactorsCOMPETE and National Funds through FCT, under the project “PEst-C/SAU/LA0003/2013”. FCT/MEC supports CBMA through Portuguese funds (PIDDAC) - PEst-OE/BIA/UI4050/2014. NORTE-07-0162FEDER-00018 (Contributos para o reforço da capacidade do IPATIMUP enquanto actor do sistema regional de inovação) and NORTE-07-0162-FEDER-000067 (Reforço e consolidação da capacidade infraestrutural do IPATIMUP para o sistema regional de inovação), both supported by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), through FEDER funds under the Quadro de Referência Estratégico Nacional (QREN)

    Effectiveness and cost-effectiveness of transmural collaborative care with consultation letter (TCCCL) and duloxetine for major depressive disorder (MDD) and (sub)chronic pain in collaboration with primary care: design of a randomized placebo-controlled multi-Centre trial: TCC:PAINDIP

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    __Abstract__ Background: The comorbidity of pain and depression is associated with high disease burden for patients in terms of disability, wellbeing, and use of medical care. Patients with major and minor depression often present themselves with pain to a general practitioner and recognition of depression in such cases is low, but evolving. Also, physical symptoms, including pain, in major depressive disorder, predict a poorer response to treatment. A multi-faceted, patient-tailored treatment programme, like collaborative care, is promising. However, treatment of chronic pain conditions in depressive patients has, so far, received limited attention in research. Cost effectiveness of an integrated approach of pain in depressed patients has not been studied. This article describes the aims and design of a study to evaluate effects and costs of collaborative care with the antidepressant duloxetine for patients with pain symptoms and a depressive disorder, compared to collaborative care with placebo and compared to duloxetine alone

    A substantial prehistoric European ancestry amongst Ashkenazi maternal lineages

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    The origins of Ashkenazi Jews remain highly controversial. Like Judaism, mitochondrial DNA is passed along the maternal line. Its variation in the Ashkenazim is highly distinctive, with four major and numerous minor founders. However, due to their rarity in the general population, these founders have been difficult to trace to a source. Here we show that all four major founders, ~40% of Ashkenazi mtDNA variation, have ancestry in prehistoric Europe, rather than the Near East or Caucasus. Furthermore, most of the remaining minor founders share a similar deep European ancestry. Thus the great majority of Ashkenazi maternal lineages were not brought from the Levant, as commonly supposed, nor recruited in the Caucasus, as sometimes suggested, but assimilated within Europe. These results point to a significant role for the conversion of women in the formation of Ashkenazi communities, and provide the foundation for a detailed reconstruction of Ashkenazi genealogical history

    Mitogenomes from Two Uncommon Haplogroups Mark Late Glacial/Postglacial Expansions from the Near East and Neolithic Dispersals within Europe

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    The current human mitochondrial (mtDNA) phylogeny does not equally represent all human populations but is biased in favour of representatives originally from north and central Europe. This especially affects the phylogeny of some uncommon West Eurasian haplogroups, including I and W, whose southern European and Near Eastern components are very poorly represented, suggesting that extensive hidden phylogenetic substructure remains to be uncovered. This study expanded and re-analysed the available datasets of I and W complete mtDNA genomes, reaching a comprehensive 419 mitogenomes, and searched for precise correlations between the ages and geographical distributions of their numerous newly identified subclades with events of human dispersal which contributed to the genetic formation of modern Europeans. Our results showed that haplogroups I (within N1a1b) and W originated in the Near East during the Last Glacial Maximum or pre-warming period (the period of gradual warming between the end of the LGM, ~19 ky ago, and the beginning of the first main warming phase, ~15 ky ago) and, like the much more common haplogroups J and T, may have been involved in Late Glacial expansions starting from the Near East. Thus our data contribute to a better definition of the Late and postglacial re-peopling of Europe, providing further evidence for the scenario that major population expansions started after the Last Glacial Maximum but before Neolithic times, but also evidencing traces of diffusion events in several I and W subclades dating to the European Neolithic and restricted to Europe

    Linking transpiration reduction to rhizosphere salinity using a 3D coupled soil-plant model

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    Soil salinity can cause salt plant stress by reducing plant transpiration and yield due to very low osmotic potentials in the soil. For predicting this reduction, we present a simulation study to (i) identify a suitable functional form of the transpiration reduction function and (ii) to explain the different shapes of empirically observed reduction functions. Methods We used high resolution simulations with a model that couples 3D water flow and salt transport in the soil towards individual roots with flow in the root system. Results The simulations demonstrated that the local total water potential at the soil-root interface, i.e. the sum of the matric and osmotic potentials, is for a given root system, uniquely and piecewise linearly related to the transpiration rate. Using bulk total water potentials, i.e. spatially and temporally averaged potentials in the soil around roots, sigmoid relations were obtained. Unlike for the local potentials, the sigmoid relations were non-unique functions of the total bulk potential but depended on the contribution of the bulk osmotic potential. Conclusions To a large extent, Transpiration reduction is controlled by water potentials at the soil-root interface. Since spatial gradients in water potentials around roots are different for osmotic and matric potentials, depending on the root density and on soil hydraulic properties, transpiration reduction functions in terms of bulk water potentials cannot be transferred to other conditions, i.e. soil type, salt content, root density, beyond the conditions for which they were derived. Such a transfer could be achieved by downscaling to the soilroot interface using simulations with a high resolution process model
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