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Serradell JM, Lorenzo-Salazar JM, Flores C, Lao O, Comas D. Modelling the demographic history of human North African genomes points to a recent soft split divergence between populations. Genome Biol 2024; 25:201. [PMID: 39080715 PMCID: PMC11290046 DOI: 10.1186/s13059-024-03341-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 07/22/2024] [Indexed: 08/02/2024] Open
Abstract
BACKGROUND North African human populations present a complex demographic scenario due to the presence of an autochthonous genetic component and population substructure, plus extensive gene flow from the Middle East, Europe, and sub-Saharan Africa. RESULTS We conducted a comprehensive analysis of 364 genomes to construct detailed demographic models for the North African region, encompassing its two primary ethnic groups, the Arab and Amazigh populations. This was achieved through an Approximate Bayesian Computation with Deep Learning (ABC-DL) framework and a novel algorithm called Genetic Programming for Population Genetics (GP4PG). This innovative approach enabled us to effectively model intricate demographic scenarios, utilizing a subset of 16 whole genomes at > 30X coverage. The demographic model suggested by GP4PG exhibited a closer alignment with the observed data compared to the ABC-DL model. Both point to a back-to-Africa origin of North African individuals and a close relationship with Eurasian populations. Results support different origins for Amazigh and Arab populations, with Amazigh populations originating back in Epipaleolithic times, while GP4PG supports Arabization as the main source of Middle Eastern ancestry. The GP4PG model includes population substructure in surrounding populations (sub-Saharan Africa and Middle East) with continuous decaying gene flow after population split. Contrary to ABC-DL, the best GP4PG model does not require pulses of admixture from surrounding populations into North Africa pointing to soft splits as drivers of divergence in North Africa. CONCLUSIONS We have built a demographic model on North Africa that points to a back-to-Africa expansion and a differential origin between Arab and Amazigh populations.
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Affiliation(s)
- Jose M Serradell
- Departament de Medicina i Ciències de la Vida, Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Carrer del Doctor Aiguader 88, Barcelona, 08003, Spain
| | - Jose M Lorenzo-Salazar
- Genomics Division, Instituto Tecnológico y de Energías Renovables (ITER), Granadilla de Abona s/n, Santa Cruz de Tenerife, 38600, Spain
| | - Carlos Flores
- Genomics Division, Instituto Tecnológico y de Energías Renovables (ITER), Granadilla de Abona s/n, Santa Cruz de Tenerife, 38600, Spain
- Plataforma Genómica de Alto Rendimiento para el Estudio de la Biodiversidad, Instituto de Productos Naturales y Agrobiología (IPNA), Consejo Superior de Investigaciones Científicas, San Cristóbal de La Laguna, Santa Cruz de Tenerife, 38206, Spain
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Carretera del Rosario 145, Santa Cruz de Tenerife, 38010, Spain
- CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Av. de Monforte de Lemos, 3-5, Madrid, 28029, Spain
- Facultad de Ciencias de la Salud, Universidad Fernando de Pessoa Canarias, Calle de La Juventud S/N, Santa María de Guía, Las Palmas de Gran Canaria, 35450, Spain
| | - Oscar Lao
- Departament de Medicina i Ciències de la Vida, Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Carrer del Doctor Aiguader 88, Barcelona, 08003, Spain.
| | - David Comas
- Departament de Medicina i Ciències de la Vida, Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Carrer del Doctor Aiguader 88, Barcelona, 08003, Spain.
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Pathak AK, Simonian H, Ibrahim IAA, Hrechdakian P, Behar DM, Ayub Q, Arsanov P, Metspalu E, Yepiskoposyan L, Rootsi S, Endicott P, Villems R, Sahakyan H. Human Y chromosome haplogroup L1-M22 traces Neolithic expansion in West Asia and supports the Elamite and Dravidian connection. iScience 2024; 27:110016. [PMID: 38883810 PMCID: PMC11177204 DOI: 10.1016/j.isci.2024.110016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/06/2024] [Accepted: 05/14/2024] [Indexed: 06/18/2024] Open
Abstract
West and South Asian populations profoundly influenced Eurasian genetic and cultural diversity. We investigate the genetic history of the Y chromosome haplogroup L1-M22, which, while prevalent in these regions, lacks in-depth study. Robust Bayesian analyses of 165 high-coverage Y chromosomes favor a West Asian origin for L1-M22 ∼20.6 thousand years ago (kya). Moreover, this haplogroup parallels the genome-wide genetic ancestry of hunter-gatherers from the Iranian Plateau and the Caucasus. We characterized two L1-M22 harboring population groups during the Early Holocene. One expanded with the West Asian Neolithic transition. The other moved to South Asia ∼8-6 kya but showed no expansion. This group likely participated in the spread of Dravidian languages. These South Asian L1-M22 lineages expanded ∼4-3 kya, coinciding with the Steppe ancestry introduction. Our findings advance the current understanding of Eurasian historical dynamics, emphasizing L1-M22's West Asian origin, associated population movements, and possible linguistic impacts.
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Affiliation(s)
- Ajai Kumar Pathak
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010 Tartu, Estonia
- Department of Human Genetics, KU Leuven, 3000 Leuven, Belgium
| | - Hovann Simonian
- Armenian DNA Project at Family Tree DNA, Houston, TX 77008, USA
| | - Ibrahim Abdel Aziz Ibrahim
- Department of Pharmacology and Toxicology, Faculty of Medicine, Umm Al-Qura University, Makkah 21955, Saudi Arabia
| | | | - Doron M Behar
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010 Tartu, Estonia
| | - Qasim Ayub
- Monash University Malaysia Genomics Platform, School of Science, Monash University, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia
| | - Pakhrudin Arsanov
- Chechen-Noahcho DNA Project at Family Tree DNA, Kostanay 110008, Kazakhstan
| | - Ene Metspalu
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010 Tartu, Estonia
| | - Levon Yepiskoposyan
- Laboratory of Evolutionary Genomics, Institute of Molecular Biology of National Academy of Sciences of the Republic of Armenia, Yerevan 0014, Armenia
| | - Siiri Rootsi
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010 Tartu, Estonia
| | - Phillip Endicott
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010 Tartu, Estonia
- Department of Archaeology and Anthropology, Bournemouth University, Fern Barrow, Poole, Dorset BH12 5BB, UK
- Department of Linguistics, University of Hawai'i at Mānoa, Honolulu, Hawai'i 96822, USA
- DFG Center for Advanced Studies, University of Tübingen, 72074 Tübingen, Germany
| | - Richard Villems
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010 Tartu, Estonia
| | - Hovhannes Sahakyan
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010 Tartu, Estonia
- Laboratory of Evolutionary Genomics, Institute of Molecular Biology of National Academy of Sciences of the Republic of Armenia, Yerevan 0014, Armenia
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Vilà-Valls L, Abdeli A, Lucas-Sánchez M, Bekada A, Calafell F, Benhassine T, Comas D. Understanding the genomic heterogeneity of North African Imazighen: from broad to microgeographical perspectives. Sci Rep 2024; 14:9979. [PMID: 38693301 PMCID: PMC11063056 DOI: 10.1038/s41598-024-60568-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024] Open
Abstract
The strategic location of North Africa has led to cultural and demographic shifts, shaping its genetic structure. Historical migrations brought different genetic components that are evident in present-day North African genomes, along with autochthonous components. The Imazighen (plural of Amazigh) are believed to be the descendants of autochthonous North Africans and speak various Amazigh languages, which belong to the Afro-Asiatic language family. However, the arrival of different human groups, especially during the Arab conquest, caused cultural and linguistic changes in local populations, increasing their heterogeneity. We aim to characterize the genetic structure of the region, using the largest Amazigh dataset to date and other reference samples. Our findings indicate microgeographical genetic heterogeneity among Amazigh populations, modeled by various admixture waves and different effective population sizes. A first admixture wave is detected group-wide around the twelfth century, whereas a second wave appears in some Amazigh groups around the nineteenth century. These events involved populations with higher genetic ancestry from south of the Sahara compared to the current North Africans. A plausible explanation would be the historical trans-Saharan slave trade, which lasted from the Roman times to the nineteenth century. Furthermore, our investigation shows that assortative mating in North Africa has been rare.
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Affiliation(s)
- Laura Vilà-Valls
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Amine Abdeli
- Laboratoire de Biologie Cellulaire et Moléculaire, Faculté Des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene, Alger, Algeria
| | - Marcel Lucas-Sánchez
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Asmahan Bekada
- Département de Biotechnologie, Faculté des Sciences de la Nature et de la Vie, Université Oran 1 (Ahmad Ben Bella), Oran, Algeria
| | - Francesc Calafell
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Traki Benhassine
- Laboratoire de Biologie Cellulaire et Moléculaire, Faculté Des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene, Alger, Algeria
| | - David Comas
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain.
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Lucas-Sánchez M, Abdeli A, Bekada A, Calafell F, Benhassine T, Comas D. The Impact of Recent Demography on Functional Genetic Variation in North African Human Groups. Mol Biol Evol 2024; 41:msad283. [PMID: 38152862 PMCID: PMC10783648 DOI: 10.1093/molbev/msad283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 11/22/2023] [Accepted: 12/19/2023] [Indexed: 12/29/2023] Open
Abstract
The strategic location of North Africa has made the region the core of a wide range of human demographic events, including migrations, bottlenecks, and admixture processes. This has led to a complex and heterogeneous genetic and cultural landscape, which remains poorly studied compared to other world regions. Whole-exome sequencing is particularly relevant to determine the effects of these demographic events on current-day North Africans' genomes, since it allows to focus on those parts of the genome that are more likely to have direct biomedical consequences. Whole-exome sequencing can also be used to assess the effect of recent demography in functional genetic variation and the efficacy of natural selection, a long-lasting debate. In the present work, we use newly generated whole-exome sequencing and genome-wide array genotypes to investigate the effect of demography in functional variation in 7 North African populations, considering both cultural and demographic differences and with a special focus on Amazigh (plur. Imazighen) groups. We detect genetic differences among populations related to their degree of isolation and the presence of bottlenecks in their recent history. We find differences in the functional part of the genome that suggest a relaxation of purifying selection in the more isolated groups, allowing for an increase of putatively damaging variation. Our results also show a shift in mutational load coinciding with major demographic events in the region and reveal differences within and between cultural and geographic groups.
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Affiliation(s)
- Marcel Lucas-Sánchez
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Amine Abdeli
- Faculté des Sciences Biologiques, Laboratoire de Biologie Cellulaire et Moléculaire, Université des Sciences et de la Technologie Houari Boumediene, Alger, Algeria
| | - Asmahan Bekada
- Département de Biotechnologie, Faculté des Sciences de la Nature et de la Vie, Université Oran 1 (Ahmad Ben Bella), Oran, Algeria
| | - Francesc Calafell
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Traki Benhassine
- Faculté des Sciences Biologiques, Laboratoire de Biologie Cellulaire et Moléculaire, Université des Sciences et de la Technologie Houari Boumediene, Alger, Algeria
| | - David Comas
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
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Fähnrich A, Stephan I, Hirose M, Haarich F, Awadelkareem MA, Ibrahim S, Busch H, Wohlers I. North and East African mitochondrial genetic variation needs further characterization towards precision medicine. J Adv Res 2023; 54:59-76. [PMID: 36736695 PMCID: PMC10703728 DOI: 10.1016/j.jare.2023.01.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/16/2023] [Accepted: 01/26/2023] [Indexed: 02/05/2023] Open
Abstract
INTRODUCTION Mitochondria are maternally inherited cell organelles with their own genome, and perform various functions in eukaryotic cells such as energy production and cellular homeostasis. Due to their inheritance and manifold biological roles in health and disease, mitochondrial genetics serves a dual purpose of tracing the history as well as disease susceptibility of human populations across the globe. This work requires a comprehensive catalogue of commonly observed genetic variations in the mitochondrial DNAs for all regions throughout the world. So far, however, certain regions, such as North and East Africa have been understudied. OBJECTIVES To address this shortcoming, we have created the most comprehensive quality-controlled North and East African mitochondrial data set to date and use it for characterizing mitochondrial genetic variation in this region. METHODS We compiled 11 published cohorts with novel data for mitochondrial genomes from 159 Sudanese individuals. We combined these 641 mitochondrial sequences with sequences from the 1000 Genomes (n = 2504) and the Human Genome Diversity Project (n = 828) and used the tool haplocheck for extensive quality control and detection of in-sample contamination, as well as Nanopore long read sequencing for haplogroup validation of 18 samples. RESULTS Using a subset of high-coverage mitochondrial sequences, we predict 15 potentially novel haplogroups in North and East African subjects and observe likely phylogenetic deviations from the established PhyloTree reference for haplogroups L0a1 and L2a1. CONCLUSION Our findings demonstrate common hitherto unexplored variants in mitochondrial genomes of North and East Africa that lead to novel phylogenetic relationships between haplogroups present in these regions. These observations call for further in-depth population genetic studies in that region to enable the prospective use of mitochondrial genetic variation for precision medicine.
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Affiliation(s)
- Anke Fähnrich
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Isabel Stephan
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Misa Hirose
- Genetics Division, Lübeck Institute of Experimental Dermatology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Franziska Haarich
- Institute for Cardiogenetics, University of Lübeck, DZHK (German Research Centre for Cardiovascular Research), Partner Site Hamburg/Lübeck/Kiel, and University Heart Center, Lübeck, Lübeck, Germany
| | - Mosab Ali Awadelkareem
- Faculty of Medical Laboratory Sciences, Al-Neelain University, Khartoum, Sudan; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Saleh Ibrahim
- Genetics Division, Lübeck Institute of Experimental Dermatology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany; Khalifa University, Abu Dhabi, United Arab Emirates
| | - Hauke Busch
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany; University Cancer Center Schleswig-Holstein, University Hospital of Schleswig-Holstein, Campus Lübeck, 23538 Lübeck, Germany
| | - Inken Wohlers
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany; Biomedical Data Science, Research Center Borstel, 23845 Borstel, Germany.
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Serrano JG, Ordóñez AC, Santana J, Sánchez-Cañadillas E, Arnay M, Rodríguez-Rodríguez A, Morales J, Velasco-Vázquez J, Alberto-Barroso V, Delgado-Darias T, de Mercadal MCC, Hernández JC, Moreno-Benítez MA, Pais J, Ringbauer H, Sikora M, McColl H, Pino-Yanes M, Ferrer MH, Bustamante CD, Fregel R. The genomic history of the indigenous people of the Canary Islands. Nat Commun 2023; 14:4641. [PMID: 37582830 PMCID: PMC10427657 DOI: 10.1038/s41467-023-40198-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 07/17/2023] [Indexed: 08/17/2023] Open
Abstract
The indigenous population of the Canary Islands, which colonized the archipelago around the 3rd century CE, provides both a window into the past of North Africa and a unique model to explore the effects of insularity. We generate genome-wide data from 40 individuals from the seven islands, dated between the 3rd-16rd centuries CE. Along with components already present in Moroccan Neolithic populations, the Canarian natives show signatures related to Bronze Age expansions in Eurasia and trans-Saharan migrations. The lack of gene flow between islands and constant or decreasing effective population sizes suggest that populations were isolated. While some island populations maintained relatively high genetic diversity, with the only detected bottleneck coinciding with the colonization time, other islands with fewer natural resources show the effects of insularity and isolation. Finally, consistent genetic differentiation between eastern and western islands points to a more complex colonization process than previously thought.
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Affiliation(s)
- Javier G Serrano
- Evolution, Paleogenomics and Population Genetics Group, Department of Biochemistry, Microbiology, Cell Biology and Genetics, Universidad de La Laguna, San Cristóbal de La Laguna, Santa Cruz de Tenerife, Spain
| | - Alejandra C Ordóñez
- Tarha Group, Department of Historical Sciences, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Jonathan Santana
- Tarha Group, Department of Historical Sciences, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Elías Sánchez-Cañadillas
- Tarha Group, Department of Historical Sciences, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Matilde Arnay
- Bioanthropology: Paleopathology, Diet and Nutrition in Ancient Populations Group, Department of Prehistory, Anthropology and Ancient History, Universidad de La Laguna, San Cristóbal de La Laguna, Santa Cruz de Tenerife, Spain
| | - Amelia Rodríguez-Rodríguez
- Tarha Group, Department of Historical Sciences, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Jacob Morales
- Tarha Group, Department of Historical Sciences, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Las Palmas, Spain
| | - Javier Velasco-Vázquez
- Servicio de Patrimonio Histórico, Cabildo de Gran Canaria, Las Palmas de Gran Canaria, Las Palmas, Spain
| | | | | | | | - Juan Carlos Hernández
- Museo Arqueológico de La Gomera, San Sebastián de La Gomera, Santa Cruz de Tenerife, Spain
| | | | - Jorge Pais
- Museo Arqueológico Benahoarita, Los Llanos de Aridane, Santa Cruz de Tenerife, Spain
| | - Harald Ringbauer
- Department of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Martin Sikora
- Lundbeck Foundation GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - Hugh McColl
- Lundbeck Foundation GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - Maria Pino-Yanes
- Genomics and Health Group, Department of Biochemistry, Microbiology, Cell Biology and Genetics, Universidad de La Laguna, San Cristóbal de La Laguna, Santa Cruz de Tenerife, Spain
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Mariano Hernández Ferrer
- Molecular Genetics and Biodiversity Group, Department of Biochemistry, Microbiology, Cell Biology and Genetics, Universidad de La Laguna, San Cristóbal de La Laguna, Santa Cruz de Tenerife, Spain
| | | | - Rosa Fregel
- Evolution, Paleogenomics and Population Genetics Group, Department of Biochemistry, Microbiology, Cell Biology and Genetics, Universidad de La Laguna, San Cristóbal de La Laguna, Santa Cruz de Tenerife, Spain.
- Department of Genetics, Stanford University, Stanford, CA, USA.
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Aizpurua-Iraola J, Abdeli A, Benhassine T, Calafell F, Comas D. Whole mitogenomes reveal that NW Africa has acted both as a source and a destination for multiple human movements. Sci Rep 2023; 13:10395. [PMID: 37369751 DOI: 10.1038/s41598-023-37549-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/23/2023] [Indexed: 06/29/2023] Open
Abstract
Despite being enclosed between the Mediterranean Sea and the Sahara Desert, North Africa has been the scenario of multiple human migrations that have shaped the genetic structure of its present-day populations. Despite its richness, North Africa remains underrepresented in genomic studies. To overcome this, we have sequenced and analyzed 264 mitogenomes from the Algerian Chaoui-speaking Imazighen (a.k.a. Berbers) living in the Aurès region. The maternal genetic composition of the Aurès is similar to Arab populations in the region, dominated by West Eurasian lineages with a moderate presence of M1/U6 North African and L sub-Saharan lineages. When focusing on the time and geographic origin of the North African specific clades within the non-autochthonous haplogroups, different geographical neighboring regions contributed to the North African maternal gene pool during time periods that could be attributed to previously suggested admixture events in the region, since Paleolithic times to recent historical movements such as the Arabization. We have also observed the role of North Africa as a source of geneflow mainly in Southern European regions since Neolithic times. Finally, the present work constitutes an effort to increase the representation of North African populations in genetic databases, which is key to understand their history.
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Affiliation(s)
- Julen Aizpurua-Iraola
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Amine Abdeli
- Laboratorie de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene, Alger, Algeria
| | - Traki Benhassine
- Laboratorie de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene, Alger, Algeria
| | - Francesc Calafell
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - David Comas
- Departament de Medicina i Ciències de la Vida, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain.
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Caro-Consuegra R, Lucas-Sánchez M, Comas D, Bosch E. Identifying signatures of positive selection in human populations from North Africa. Sci Rep 2023; 13:8166. [PMID: 37210386 DOI: 10.1038/s41598-023-35312-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 05/16/2023] [Indexed: 05/22/2023] Open
Abstract
Because of its location, North Africa (NA) has witnessed continuous demographic movements with an impact on the genomes of present-day human populations. Genomic data describe a complex scenario with varying proportions of at least four main ancestry components: Maghrebi, Middle Eastern-, European-, and West-and-East-African-like. However, the footprint of positive selection in NA has not been studied. Here, we compile genome-wide genotyping data from 190 North Africans and individuals from surrounding populations, investigate for signatures of positive selection using allele frequencies and linkage disequilibrium-based methods and infer ancestry proportions to discern adaptive admixture from post-admixture selection events. Our results show private candidate genes for selection in NA involved in insulin processing (KIF5A), immune function (KIF5A, IL1RN, TLR3), and haemoglobin phenotypes (BCL11A). We also detect signatures of positive selection related to skin pigmentation (SLC24A5, KITLG), and immunity function (IL1R1, CD44, JAK1) shared with European populations and candidate genes associated with haemoglobin phenotypes (HPSE2, HBE1, HBG2), other immune-related (DOCK2) traits, and insulin processing (GLIS3) traits shared with West and East African populations. Finally, the SLC8A1 gene, which codifies for a sodium-calcium exchanger, was the only candidate identified under post-admixture selection in Western NA.
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Affiliation(s)
- Rocio Caro-Consuegra
- Institut de Biologia Evolutiva (UPF-CSIC), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003, Barcelona, Spain
| | - Marcel Lucas-Sánchez
- Institut de Biologia Evolutiva (UPF-CSIC), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003, Barcelona, Spain
| | - David Comas
- Institut de Biologia Evolutiva (UPF-CSIC), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003, Barcelona, Spain
| | - Elena Bosch
- Institut de Biologia Evolutiva (UPF-CSIC), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, 08003, Barcelona, Spain.
- Centro de Investigación Biomédica en Red de Salud Mental, Instituto de Salud Carlos III, 28029, Madrid, Spain.
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Cheffi K, El Khair A, Dahbi N, Talbi J, Hilali A, El Ossmani H. Genetic analysis based on 15 autosomal short tandem repeats (STRs) in the Chaouia population, western center Morocco, and genetic relationships with worldwide populations. Mol Genet Genomics 2023; 298:931-941. [PMID: 37162566 DOI: 10.1007/s00438-023-02028-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 04/29/2023] [Indexed: 05/11/2023]
Abstract
The complex demographic history of human populations in North Africa has resulted in a high degree of genetic heterogeneity across the region. However, little is known about the pattern of these genetic variations in its current populations. The present study provides new data on the genetic background of Chaouia, an Arabic-speaking North African population in the western center of Morocco. A random sample of 150 unrelated healthy individuals from Chaouia was assessed using the AmpFLSTR Identifiler kit. The most polymorphic markers were D21S11 and D18S51, with 23 and 22 alleles, respectively. After Bonferroni's correction, two loci (TH01 and D18S51) deviated from Hardy-Weinberg equilibrium. The phylogeny analysis separated North African populations into northeastern and northwestern groups. The Chaouia population was clustered with northwestern Africans. It was the closest to the Berbers of Azrou. The Chaouia shared close genetic affinities with populations from North Africa, the Middle East, and Europe, particularly Iberians, and to a lesser extent with sub-Saharan populations. The pattern of genetic admixture varied across North African populations without a clear correlation between their geographic (northeastern or northwestern) or linguistic identities (Arab or Berber), however, genetic heterogeneity among Berbers was observed. These findings suggest that the diversity observed in North African populations extends geographical and linguistic boundaries. It is further linked to each population's unique and complex demographic history. Human North African population genetics seems to present an intriguing landscape for future studies in the region and its surrounding populations to trace the origins of the genetic heterogeneity observed in these populations.
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Affiliation(s)
- Khadija Cheffi
- Hassan First University of Settat, Higher Institute of Health Sciences, Laboratory of Health Sciences and Technologies, Settat, Morocco.
| | - Abderrazak El Khair
- Hassan First University of Settat, Higher Institute of Health Sciences, Laboratory of Health Sciences and Technologies, Settat, Morocco
| | - Noura Dahbi
- Hassan First University of Settat, Higher Institute of Health Sciences, Laboratory of Health Sciences and Technologies, Settat, Morocco
| | - Jalal Talbi
- General Directorate of National Security, National Laboratory of the Scientific and Technical Police, Casablanca, Morocco
| | - Abderraouf Hilali
- Hassan First University of Settat, Higher Institute of Health Sciences, Laboratory of Health Sciences and Technologies, Settat, Morocco
| | - Hicham El Ossmani
- Institut de Criminalistique de la Gendarmerie Royale, Rabat, Morocco
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10
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Pfennig A, Petersen LN, Kachambwa P, Lachance J. Evolutionary Genetics and Admixture in African Populations. Genome Biol Evol 2023; 15:evad054. [PMID: 36987563 PMCID: PMC10118306 DOI: 10.1093/gbe/evad054] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/15/2023] [Accepted: 03/22/2023] [Indexed: 03/30/2023] Open
Abstract
As the ancestral homeland of our species, Africa contains elevated levels of genetic diversity and substantial population structure. Importantly, African genomes are heterogeneous: They contain mixtures of multiple ancestries, each of which have experienced different evolutionary histories. In this review, we view population genetics through the lens of admixture, highlighting how multiple demographic events have shaped African genomes. Each of these historical vignettes paints a recurring picture of population divergence followed by secondary contact. First, we give a brief overview of genetic variation in Africa and examine deep population structure within Africa, including the evidence of ancient introgression from archaic "ghost" populations. Second, we describe the genetic legacies of admixture events that have occurred during the past 10,000 years. This includes gene flow between different click-speaking Khoe-San populations, the stepwise spread of pastoralism from eastern to southern Africa, multiple migrations of Bantu speakers across the continent, as well as admixture from the Middle East and Europe into the Sahel region and North Africa. Furthermore, the genomic signatures of more recent admixture can be found in the Cape Peninsula and throughout the African diaspora. Third, we highlight how natural selection has shaped patterns of genetic variation across the continent, noting that gene flow provides a potent source of adaptive variation and that selective pressures vary across Africa. Finally, we explore the biomedical implications of population structure in Africa on health and disease and call for more ethically conducted studies of genetic variation in Africa.
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Affiliation(s)
- Aaron Pfennig
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | | | | | - Joseph Lachance
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
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11
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Fan S, Spence JP, Feng Y, Hansen MEB, Terhorst J, Beltrame MH, Ranciaro A, Hirbo J, Beggs W, Thomas N, Nyambo T, Mpoloka SW, Mokone GG, Njamnshi A, Folkunang C, Meskel DW, Belay G, Song YS, Tishkoff SA. Whole-genome sequencing reveals a complex African population demographic history and signatures of local adaptation. Cell 2023; 186:923-939.e14. [PMID: 36868214 PMCID: PMC10568978 DOI: 10.1016/j.cell.2023.01.042] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 10/16/2022] [Accepted: 01/30/2023] [Indexed: 03/05/2023]
Abstract
We conduct high coverage (>30×) whole-genome sequencing of 180 individuals from 12 indigenous African populations. We identify millions of unreported variants, many predicted to be functionally important. We observe that the ancestors of southern African San and central African rainforest hunter-gatherers (RHG) diverged from other populations >200 kya and maintained a large effective population size. We observe evidence for ancient population structure in Africa and for multiple introgression events from "ghost" populations with highly diverged genetic lineages. Although currently geographically isolated, we observe evidence for gene flow between eastern and southern Khoesan-speaking hunter-gatherer populations lasting until ∼12 kya. We identify signatures of local adaptation for traits related to skin color, immune response, height, and metabolic processes. We identify a positively selected variant in the lightly pigmented San that influences pigmentation in vitro by regulating the enhancer activity and gene expression of PDPK1.
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Affiliation(s)
- Shaohua Fan
- State Key Laboratory of Genetic Engineering, Human Phenome Institute, Zhangjiang Fudan International Innovation Center, School of Life Science, Fudan University, Shanghai, 200438, China; Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jeffrey P Spence
- Department of Genetics, School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Yuanqing Feng
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew E B Hansen
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jonathan Terhorst
- Department of Statistics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Marcia H Beltrame
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alessia Ranciaro
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jibril Hirbo
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William Beggs
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Neil Thomas
- Computer Science Division, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Thomas Nyambo
- Department of Biochemistry, Kampala International University in Tanzania, P.O. Box 9790, Dar es Salaam, Tanzania
| | - Sununguko Wata Mpoloka
- Department of Biological Sciences, Faculty of Science, University of Botswana Gaborone, Private Bag UB 0022, Gaborone, Botswana
| | - Gaonyadiwe George Mokone
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana Gaborone, Private Bag UB 0022, Gaborone, Botswana
| | - Alfred Njamnshi
- Department of Neurology, Central Hospital Yaoundé; Brain Research Africa Initiative (BRAIN), Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Charles Folkunang
- Department of Pharmacotoxicology and Pharmacokinetics, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Dawit Wolde Meskel
- Department of Microbial Cellular and Molecular Biology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Gurja Belay
- Department of Microbial Cellular and Molecular Biology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Yun S Song
- Computer Science Division, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Statistics, University of California, Berkeley, Berkeley, CA 94720, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Sarah A Tishkoff
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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12
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Lucas-Sánchez M, Fadhlaoui-Zid K, Comas D. The genomic analysis of current-day North African populations reveals the existence of trans-Saharan migrations with different origins and dates. Hum Genet 2023; 142:305-320. [PMID: 36441222 PMCID: PMC9918576 DOI: 10.1007/s00439-022-02503-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/28/2022] [Indexed: 11/29/2022]
Abstract
The Sahara Desert has acted as a barrier to human gene-flow between the northern and central parts of Africa since its aridification. Nonetheless, some contacts between both sides of the desert have occurred throughout history, mainly driven by commercial activity. Part of this was the infamous trans-Saharan slave trade, which forcedly brought peoples from south of the Sahara to North Africa from Roman times until the nineteenth century. Although historical records exist, the genetic aspects of these trans-Saharan migrations have not been deeply studied. In the present study, we assess the genetic influence of trans-Saharan migrations in current-day North Africa and characterize its amount, geographical origin, and dates. We confirm the heterogeneous and generally low-frequency presence of genomic segments of sub-Saharan origin in present-day North Africans acquired in recent historical times, and we show evidence of at least two admixture events: one dated around the thirteenth-fourteenth centuries CE between North Africans and a Western-sub-Saharan-like source similar to current-day Senegambian populations, and another one dated around the seventeenth century CE involving Tunisians and an Eastern-sub-Saharan-like source related to current-day south-Sudan and Kenyan populations. Time and location coincide with the peak of trans-Saharan slave-trade activity between Western African empires and North African powers, and are also concordant with the possibility of continuous recent south-to-north gene-flow. These findings confirm the trans-Saharan human genetic contacts, providing new and precise evidence about its possible dates and geographical origins, which are pivotal to understanding the genomic composition of an underrepresented region such as North Africa.
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Affiliation(s)
- Marcel Lucas-Sánchez
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Barcelona, Spain
| | - Karima Fadhlaoui-Zid
- Laboratory of Genetics, Immunology, and Human Pathologies, Faculty of Science of Tunis, University of Tunis El Manar, Tunis, Tunisia ,College of Science, Department of Biology, Taibah University, Al Madinah Al Monawarah, Saudi Arabia
| | - David Comas
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Departament de Medicina i Ciències de la Vida, Universitat Pompeu Fabra, Barcelona, Spain.
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13
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Developing CIRdb as a catalog of natural genetic variation in the Canary Islanders. Sci Rep 2022; 12:16132. [PMID: 36168029 PMCID: PMC9514705 DOI: 10.1038/s41598-022-20442-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 09/13/2022] [Indexed: 11/29/2022] Open
Abstract
The current inhabitants of the Canary Islands have a unique genetic makeup in the European diversity landscape due to the existence of African footprints from recent admixture events, especially of North African components (> 20%). The underrepresentation of non-Europeans in genetic studies and the sizable North African ancestry, which is nearly absent from all existing catalogs of worldwide genetic diversity, justify the need to develop CIRdb, a population-specific reference catalog of natural genetic variation in the Canary Islanders. Based on array genotyping of the selected unrelated donors and comparisons against available datasets from European, sub-Saharan, and North African populations, we illustrate the intermediate genetic differentiation of Canary Islanders between Europeans and North Africans and the existence of within-population differences that are likely driven by genetic isolation. Here we describe the overall design and the methods that are being implemented to further develop CIRdb. This resource will help to strengthen the implementation of Precision Medicine in this population by contributing to increase the diversity in genetic studies. Among others, this will translate into improved ability to fine map disease genes and simplify the identification of causal variants and estimate the prevalence of unattended Mendelian diseases.
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14
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Font-Porterias N, García-Fernández C, Aizpurua-Iraola J, Comas D, Torrents D, de Cid R, Calafell F. Sequence diversity of the uniparentally transmitted portions of the genome in the resident population of Catalonia. Forensic Sci Int Genet 2022; 61:102783. [DOI: 10.1016/j.fsigen.2022.102783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/30/2022]
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15
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Hernandez-Beeftink T, Marcelino-Rodríguez I, Guillen-Guio B, Rodríguez-Pérez H, Lorenzo-Salazar JM, Corrales A, Díaz-de Usera A, González-Montelongo R, Domínguez D, Espinosa E, Villar J, Flores C. Admixture Mapping of Sepsis in European Individuals With African Ancestries. Front Med (Lausanne) 2022; 9:754440. [PMID: 35345767 PMCID: PMC8957104 DOI: 10.3389/fmed.2022.754440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 01/24/2022] [Indexed: 11/30/2022] Open
Abstract
Sepsis is a severe systemic inflammatory response to infections that is accompanied by organ dysfunction. Although the ancestral genetic background is a relevant factor for sepsis susceptibility, there is a lack of studies using the genetic singularities of a recently admixed population to identify loci involved in sepsis susceptibility. Here we aimed to discover new sepsis loci by completing the first admixture mapping study of sepsis in Canary Islanders, leveraging their distinctive genetic makeup as a mixture of Europeans and African ancestries. We used a case-control approach and inferred local ancestry blocks from genome-wide data from 113,414 polymorphisms genotyped in 343 patients with sepsis and 410 unrelated controls, all ascertained for grandparental origin in the Canary Islands (Spain). Deviations in local ancestries between cases and controls were tested using logistic regressions, followed by fine-mapping analyses based on imputed genotypes, in silico functional assessments, and gene expression analysis centered on the region of interest. The admixture mapping analysis detected that local European ancestry in a locus spanning 1.2 megabases of chromosome 8p23.1 was associated with sepsis (lowest p = 1.37 × 10−4; Odds Ratio [OR] = 0.51; 95%CI = 0.40–0.66). Fine-mapping studies prioritized the variant rs13249564 within intron 1 of MFHAS1 gene associated with sepsis (p = 9.94 × 10−4; OR = 0.65; 95%CI = 0.50–0.84). Functional and gene expression analyses focused on 8p23.1 allowed us to identify alternative genes with possible biological plausibility such as defensins, which are well-known effector molecules of innate immunity. By completing the first admixture mapping study of sepsis, our results revealed a new genetic locus (8p23.1) harboring a number of genes with plausible implications in sepsis susceptibility.
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Affiliation(s)
- Tamara Hernandez-Beeftink
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,Research Unit, Hospital Universitario de Gran Canaria Dr. Negrín, Las Palmas de Gran Canaria, Spain
| | - Itahisa Marcelino-Rodríguez
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Beatriz Guillen-Guio
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Héctor Rodríguez-Pérez
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Jose M Lorenzo-Salazar
- Genomics Division, Instituto Tecnológico y de Energías Renovables (ITER), Santa Cruz de Tenerife, Spain
| | - Almudena Corrales
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Ana Díaz-de Usera
- Genomics Division, Instituto Tecnológico y de Energías Renovables (ITER), Santa Cruz de Tenerife, Spain
| | | | - David Domínguez
- Department of Anesthesiology, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Elena Espinosa
- Department of Anesthesiology, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Jesús Villar
- Research Unit, Hospital Universitario de Gran Canaria Dr. Negrín, Las Palmas de Gran Canaria, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Carlos Flores
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,Genomics Division, Instituto Tecnológico y de Energías Renovables (ITER), Santa Cruz de Tenerife, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
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16
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Mestiri S, Boussetta S, Pakstis AJ, El Kamel S, Ben Ammar El Gaaied A, Kidd KK, Cherni L. New Insight into the human genetic diversity in North African populations by genotyping of SNPs in DRD3, CSMD1 and NRG1 genes. Mol Genet Genomic Med 2022; 10:e1871. [PMID: 35128830 PMCID: PMC8922960 DOI: 10.1002/mgg3.1871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/02/2021] [Accepted: 01/04/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND The single nucleotide polymorphisms (SNPs) of the dopamine D3 receptor (DRD3), the CUB and sushi multiple domains 1 (CSMD1) and the neuregulin 1 (NRG1) genes were used to study the genetic diversity and affinity among North African populations and to examine their genetic relationships in worldwide populations. METHODS The rs3773678, rs3732783 and rs6280 SNPs of the DRD3 gene located on chromosome 3, the rs10108270 SNP of the CSMD1 gene and the rs383632, rs385396 and rs1462906 SNPs of the NRG1 gene located on chromosome 8 were analysed in 366 individuals from seven North African populations (Libya, Kairouan, Mehdia, Sousse, Kesra, Smar and Kerkennah). RESULTS The low values of FST indicated that only 0.27%-1.65% of the genetic variability was due to the differences between the populations. The Kairouan population has the lowest average heterozygosity among the North African populations. Haplotypes composed of the ancestral alleles ACC and ACAT were more frequent in the Kairouan population than in other North African populations. The PCA and the haplotypic analysis showed that the genetic structure of populations in North Africa was closer to that of Europeans, Admixed Americans, South Asians and East Asians. However, analysis of the rs3732783 and rs6280 SNPs revealed that the CT microhaplotype was specific to the North African population. CONCLUSIONS The Kairouan population exhibited a relatively low rate of genetic variability. The North African population has undergone significant gene flow but also evolutionary forces that have made it genetically distinct from other populations.
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Affiliation(s)
- Souhir Mestiri
- Laboratory of Genetics, Biodiversity and Bioresource Valorization (LR11ES41)University of MonastirMonastirTunisia
- Higher Institute of Biotechnology of MonastirMonastir UniversityMonastirTunisia
| | - Sami Boussetta
- Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of TunisUniversity of Tunis El ManarTunisTunisia
| | - Andrew J. Pakstis
- Department of GeneticsYale University School of MedicineNew HavenConnecticutUSA
| | - Sarra El Kamel
- Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of TunisUniversity of Tunis El ManarTunisTunisia
| | - Amel Ben Ammar El Gaaied
- Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of TunisUniversity of Tunis El ManarTunisTunisia
| | - Kenneth K. Kidd
- Department of GeneticsYale University School of MedicineNew HavenConnecticutUSA
| | - Lotfi Cherni
- Higher Institute of Biotechnology of MonastirMonastir UniversityMonastirTunisia
- Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of TunisUniversity of Tunis El ManarTunisTunisia
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17
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Whole-exome analysis in Tunisian Imazighen and Arabs shows the impact of demography in functional variation. Sci Rep 2021; 11:21125. [PMID: 34702931 PMCID: PMC8548440 DOI: 10.1038/s41598-021-00576-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/14/2021] [Indexed: 11/08/2022] Open
Abstract
Human populations are genetically affected by their demographic history, which shapes the distribution of their functional genomic variation. However, the genetic impact of recent demography is debated. This issue has been studied in different populations, but never in North Africans, despite their relevant cultural and demographic diversity. In this study we address the question by analyzing new whole-exome sequences from two culturally different Tunisian populations, an isolated Amazigh population and a close non-isolated Arab-speaking population, focusing on the distribution of functional variation. Both populations present clear differences in their variant frequency distribution, in general and for putatively damaging variation. This suggests a relevant effect in the Amazigh population of genetic isolation, drift, and inbreeding, pointing to relaxed purifying selection. We also discover the enrichment in Imazighen of variation associated to specific diseases or phenotypic traits, but the scarce genetic and biomedical data in the region limits further interpretation. Our results show the genomic impact of recent demography and reveal a clear genetic differentiation probably related to culture. These findings highlight the importance of considering cultural and demographic heterogeneity within North Africa when defining population groups, and the need for more data to improve knowledge on the region's health and disease landscape.
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18
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Breton G, Johansson ACV, Sjödin P, Schlebusch CM, Jakobsson M. Comparison of sequencing data processing pipelines and application to underrepresented African human populations. BMC Bioinformatics 2021; 22:488. [PMID: 34627144 PMCID: PMC8502359 DOI: 10.1186/s12859-021-04407-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 09/27/2021] [Indexed: 11/10/2022] Open
Abstract
Background Population genetic studies of humans make increasing use of high-throughput sequencing in order to capture diversity in an unbiased way. There is an abundance of sequencing technologies, bioinformatic tools and the available genomes are increasing in number. Studies have evaluated and compared some of these technologies and tools, such as the Genome Analysis Toolkit (GATK) and its “Best Practices” bioinformatic pipelines. However, studies often focus on a few genomes of Eurasian origin in order to detect technical issues. We instead surveyed the use of the GATK tools and established a pipeline for processing high coverage full genomes from a diverse set of populations, including Sub-Saharan African groups, in order to reveal challenges from human diversity and stratification. Results We surveyed 29 studies using high-throughput sequencing data, and compared their strategies for data pre-processing and variant calling. We found that processing of data is very variable across studies and that the GATK “Best Practices” are seldom followed strictly. We then compared three versions of a GATK pipeline, differing in the inclusion of an indel realignment step and with a modification of the base quality score recalibration step. We applied the pipelines on a diverse set of 28 individuals. We compared the pipelines in terms of count of called variants and overlap of the callsets. We found that the pipelines resulted in similar callsets, in particular after callset filtering. We also ran one of the pipelines on a larger dataset of 179 individuals. We noted that including more individuals at the joint genotyping step resulted in different counts of variants. At the individual level, we observed that the average genome coverage was correlated to the number of variants called. Conclusions We conclude that applying the GATK “Best Practices” pipeline, including their recommended reference datasets, to underrepresented populations does not lead to a decrease in the number of called variants compared to alternative pipelines. We recommend to aim for coverage of > 30X if identifying most variants is important, and to work with large sample sizes at the variant calling stage, also for underrepresented individuals and populations. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-021-04407-x.
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Affiliation(s)
- Gwenna Breton
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18C, 752 36, Uppsala, Sweden.
| | - Anna C V Johansson
- Department of Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Husargatan 3, 752 37, Uppsala, Sweden
| | - Per Sjödin
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18C, 752 36, Uppsala, Sweden
| | - Carina M Schlebusch
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18C, 752 36, Uppsala, Sweden.,Palaeo-Research Institute, University of Johannesburg, P.O. Box 524, Auckland Park, 2006, South Africa.,Science for Life Laboratory, Uppsala, Sweden
| | - Mattias Jakobsson
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18C, 752 36, Uppsala, Sweden. .,Palaeo-Research Institute, University of Johannesburg, P.O. Box 524, Auckland Park, 2006, South Africa. .,Science for Life Laboratory, Uppsala, Sweden.
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19
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Mestiri S, Boussetta S, Pakstis AJ, Elkamel S, Elgaaied ABA, Kidd KK, Cherni L. Genetic diversity of the North African population revealed by the typing of SNPs in the DRD2/ANKK1 genomic region. Gene 2021; 777:145466. [PMID: 33524518 DOI: 10.1016/j.gene.2021.145466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 01/11/2021] [Accepted: 01/22/2021] [Indexed: 10/22/2022]
Abstract
The dopamine - related genes, like dopamine D2 receptor (DRD2) gene and ankyrin repeat and kinase domain containing 1 (ANKK1) gene are implicated in neurological functions. Some polymorphisms of the DRD2/ANKK1 locus (TaqIA, TaqIB, TaqID) have been used to study genetic diversity and the evolution of human populations. The present investigation aims to assess the genetic diversity in seven North African populations in order to explore their genetic structure and to compare them to others worldwide populations studied for the same locus. Nine single nucleotide polymorphisms (SNPs) from the DRD2/ANKK1 locus (rs1800497 TaqIA, rs2242592, rs1124492, rs6277, rs6275, rs1079727, rs2002453, rs2234690 and rs1079597 TaqIB) were typed in 366 individuals from seven North African populations: six from Tunisia (Sousse, Smar, Kesra, Kairouan, Mehdia and Kerkennah) and one from Libya. The allelic frequencies of rs2002453 and rs2234690 were higher in the Smar population than in the other North African populations. More, the Smar population showed the lowest average heterozygosity (0.313). The principal component analysis (PCA) showed that the Smar population was clearly separated from others. Furthermore, linkage disequilibrium analysis shown a high linkage disequilibrium in the North African population and essentially in Smar population. Comparison with other world populations has shown that the heterozygosity of North African population was very close to that of the African and European populations. The PCA and the haplotypic analysis suggested the presence of an important Eurasian genetic component for the North African population. These results suggested that the Smar population was isolated from the others North Africans ones by its peculiar genetic structure because of isolation, endogamy and genetic drift. On the other hand, the North African population is characterized by a multi ancestral gene pool from Eurasia and sub-Saharan Africa due to human migration since prehistoric times.
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Affiliation(s)
- Souhir Mestiri
- Laboratory of Genetics, Biodiversity and Bioresource Valorization (LR11ES41), University of Monastir, Monastir 5000, Tunisia; Higher Institute of Biotechnology of Monastir, Monastir University, 5000 Monastir, Tunisia.
| | - Sami Boussetta
- Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of Tunis, University of Tunis El Manar, 2092 Tunis, Tunisia.
| | - Andrew J Pakstis
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Sarra Elkamel
- Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of Tunis, University of Tunis El Manar, 2092 Tunis, Tunisia.
| | - Amel Ben Ammar Elgaaied
- Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of Tunis, University of Tunis El Manar, 2092 Tunis, Tunisia
| | - Kenneth K Kidd
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Lotfi Cherni
- Higher Institute of Biotechnology of Monastir, Monastir University, 5000 Monastir, Tunisia; Laboratory of Genetics, Immunology and Human Pathologies, Faculty of Sciences of Tunis, University of Tunis El Manar, 2092 Tunis, Tunisia.
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20
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Lucas-Sánchez M, Serradell JM, Comas D. Population history of North Africa based on modern and ancient genomes. Hum Mol Genet 2020; 30:R17-R23. [PMID: 33284971 DOI: 10.1093/hmg/ddaa261] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 01/09/2023] Open
Abstract
Compared with the rest of the African continent, North Africa has provided limited genomic data. Nonetheless, the genetic data available show a complex demographic scenario characterized by extensive admixture and drift. Despite the continuous gene flow from the Middle East, Europe and sub-Saharan Africa, an autochthonous genetic component that dates back to pre-Holocene times is still present in North African groups. The comparison of ancient and modern genomes has evidenced a genetic continuity in the region since Epipaleolithic times. Later population movements, especially the gene flow from the Middle East associated with the Neolithic, have diluted the genetic autochthonous component, creating an east to west gradient. Recent historical movements, such as the Arabization, have also contributed to the genetic landscape observed currently in North Africa and have culturally transformed the region. Genome analyses have not shown evidence of a clear correlation between cultural and genetic diversity in North Africa, as there is no genetic pattern of differentiation between Tamazight (i.e. Berber) and Arab speakers as a whole. Besides the gene flow received from neighboring areas, the analysis of North African genomes has shown that the region has also acted as a source of gene flow since ancient times. As a result of the genetic uniqueness of North African groups and the lack of available data, there is an urgent need for the study of genetic variation in the region and its implications in health and disease.
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Affiliation(s)
- Marcel Lucas-Sánchez
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - Jose M Serradell
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - David Comas
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, 08003 Barcelona, Spain
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21
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Bianco E, Laval G, Font-Porterias N, García-Fernández C, Dobon B, Sabido-Vera R, Sukarova Stefanovska E, Kučinskas V, Makukh H, Pamjav H, Quintana-Murci L, Netea MG, Bertranpetit J, Calafell F, Comas D. Recent Common Origin, Reduced Population Size, and Marked Admixture Have Shaped European Roma Genomes. Mol Biol Evol 2020; 37:3175-3187. [PMID: 32589725 DOI: 10.1093/molbev/msaa156] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Roma Diaspora-traditionally known as Gypsies-remains among the least explored population migratory events in historical times. It involved the migration of Roma ancestors out-of-India through the plateaus of Western Asia ultimately reaching Europe. The demographic effects of the Diaspora-bottlenecks, endogamy, and gene flow-might have left marked molecular traces in the Roma genomes. Here, we analyze the whole-genome sequence of 46 Roma individuals pertaining to four migrant groups in six European countries. Our analyses revealed a strong, early founder effect followed by a drastic reduction of ∼44% in effective population size. The Roma common ancestors split from the Punjabi population, from Northwest India, some generations before the Diaspora started, <2,000 years ago. The initial bottleneck and subsequent endogamy are revealed by the occurrence of extensive runs of homozygosity and identity-by-descent segments in all Roma populations. Furthermore, we provide evidence of gene flow from Armenian and Anatolian groups in present-day Roma, although the primary contribution to Roma gene pool comes from non-Roma Europeans, which accounts for >50% of their genomes. The linguistic and historical differentiation of Roma in migrant groups is confirmed by the differential proportion, but not a differential source, of European admixture in the Roma groups, which shows a westward cline. In the present study, we found that despite the strong admixture Roma had in their diaspora, the signature of the initial bottleneck and the subsequent endogamy is still present in Roma genomes.
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Affiliation(s)
- Erica Bianco
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Guillaume Laval
- Human Evolutionary Genetics Unit, Department of Genomes and Genetics, UMR 2000, CNRS, Institut Pasteur, Paris, France
| | - Neus Font-Porterias
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Carla García-Fernández
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Begoña Dobon
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Rubén Sabido-Vera
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Emilija Sukarova Stefanovska
- Research Center for Genetic Engineering and Biotechnology "Georgi D. Efremov", Macedonian Academy of Science and Arts, Skopje, Macedonia
| | - Vaidutis Kučinskas
- Department of Human and Medical Genetics, Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Halyna Makukh
- Institute of Hereditary Pathology of the Ukrainian Academy of Medical Sciences, Lviv, Ukraine
| | - Horolma Pamjav
- Department of Reference Sample Analysis, Institute of Forensic Genetics, Hungarian Institute for Forensic Sciences, Budapest, Hungary
| | - Lluis Quintana-Murci
- Human Evolutionary Genetics Unit, Department of Genomes and Genetics, UMR 2000, CNRS, Institut Pasteur, Paris, France.,Chair Human Genomics and Evolution, Collège de France, Paris, France
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.,Department for Genomics & Immunoregulation, Life and Medical Sciences 12 Institute (LIMES), University of Bonn, Bonn, Germany
| | - Jaume Bertranpetit
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - Francesc Calafell
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
| | - David Comas
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (CSIC-UPF), Universitat Pompeu Fabra, Barcelona, Spain
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22
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Wohlers I, Künstner A, Munz M, Olbrich M, Fähnrich A, Calonga-Solís V, Ma C, Hirose M, El-Mosallamy S, Salama M, Busch H, Ibrahim S. An integrated personal and population-based Egyptian genome reference. Nat Commun 2020; 11:4719. [PMID: 32948767 PMCID: PMC7501257 DOI: 10.1038/s41467-020-17964-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 07/24/2020] [Indexed: 02/05/2023] Open
Abstract
A small number of de novo assembled human genomes have been reported to date, and few have been complemented with population-based genetic variation, which is particularly important for North Africa, a region underrepresented in current genome-wide references. Here, we combine long- and short-read whole-genome sequencing data with recent assembly approaches into a de novo assembly of an Egyptian genome. The assembly demonstrates well-balanced quality metrics and is complemented with variant phasing via linked reads into haploblocks, which we associate with gene expression changes in blood. To construct an Egyptian genome reference, we identify genome-wide genetic variation within a cohort of 110 Egyptian individuals. We show that differences in allele frequencies and linkage disequilibrium between Egyptians and Europeans may compromise the transferability of European ancestry-based genetic disease risk and polygenic scores, substantiating the need for multi-ethnic genome references. Thus, the Egyptian genome reference will be a valuable resource for precision medicine.
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Affiliation(s)
- Inken Wohlers
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Axel Künstner
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Matthias Munz
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Michael Olbrich
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Anke Fähnrich
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Verónica Calonga-Solís
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
- Department of Genetics, Federal University of Paraná (UFPR), Centro Politécnico, Jardim das Américas, 81531-990, Curitiba, Brazil
| | - Caixia Ma
- Novogene (UK) Company Limited, 25 Cambridge Science Park, Milton Road, CB4 0FW, Cambridge, UK
| | - Misa Hirose
- Genetics Division, Lübeck Institute of Experimental Dermatology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Shaaban El-Mosallamy
- Medical Experimental Research Center (MERC), Mansoura University, Elgomhouria St., Dakahlia Governorate, 35516, Mansoura, Egypt
| | - Mohamed Salama
- Medical Experimental Research Center (MERC), Mansoura University, Elgomhouria St., Dakahlia Governorate, 35516, Mansoura, Egypt
- Institute of Global Health and Human Ecology, The American University in Cairo, AUC avenue, 11835, Cairo, Egypt
| | - Hauke Busch
- Medical Systems Biology Division, Lübeck Institute of Experimental Dermatology and Institute for Cardiogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
| | - Saleh Ibrahim
- Genetics Division, Lübeck Institute of Experimental Dermatology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
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23
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Anagnostou P, Dominici V, Battaggia C, Boukhchim N, Ben Nasr J, Boussoffara R, Cancellieri E, Marnaoui M, Marzouki M, Bel Haj Brahim H, Bou Rass M, di Lernia S, Destro Bisol G. Berbers and Arabs: Tracing the genetic diversity and history of Southern Tunisia through genome wide analysis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 173:697-708. [PMID: 32936953 DOI: 10.1002/ajpa.24139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 06/11/2020] [Accepted: 08/02/2020] [Indexed: 01/09/2023]
Abstract
OBJECTIVES Tunisia has been a crossroads for people from Africa, Europe, and the Middle East since prehistoric times. At present, it is inhabited by two main ethnic groups, Arabs and Berbers, and several minorities. This study aims to advance knowledge regarding their genetic structure using new population samplings and a genome-wide approach. MATERIALS AND METHODS We investigated genomic variation, estimated ancestry components and dated admixture events in three Berber and two Arab populations from Southern Tunisia, mining a dataset including Middle Eastern, sub-Saharan, and European populations. RESULTS Differences in the proportion of North African, Arabian, and European ancestries and the varying impact of admixture and isolation determined significant heterogeneity in the genetic structure of Southern Tunisian populations. Admixture time estimates show a multilayer pattern of admixture events, involving both ethno-linguistic groups, which started around the mid XI century and lasted for nearly five centuries. DISCUSSION Our study provides evidence that the relationships between genetic and cultural diversity of old and new inhabitants of North Africa in southern Tunisia follow different patterns. The Berbers seem to have preserved a significant part of their common genomic heritage despite Islamization, Arab cultural influence, and linguistic diversity. Compared to Morocco and Algeria, southern Tunisian Arabs have retained a higher level of Arabian ancestry. This is more evident in the semi-nomad R'Baya, who have kept their original Bedouin lifestyle, than in the population from Douz, who have undergone multiple events of stratification and admixture.
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Affiliation(s)
- Paolo Anagnostou
- Dipartimento di Biologia Ambientale, Università di Roma "La Sapienza", Italy.,Istituto Italiano di Antropologia, Italy
| | - Valentina Dominici
- Dipartimento di Biologia Ambientale, Università di Roma "La Sapienza", Italy
| | - Cinzia Battaggia
- Dipartimento di Biologia Ambientale, Università di Roma "La Sapienza", Italy
| | - Nouri Boukhchim
- Faculté des Lettres et Sciences Humaines, Université de Kairouan, Kairouan, Tunisia.,Laboratoire LMAIM, LR99ES01, Université de Tunis, Tunisia
| | - Jaâfar Ben Nasr
- Département d'Archéologie (FLSHK), LR 13 ES 11/ UR 16 ES 01, Université de Kairouan, Tunisia
| | | | | | - Marwa Marnaoui
- Dipartimento di Scienze dell'Antichità, Università di Roma "La Sapienza", Italy
| | - Meriem Marzouki
- Higher institute of fine arts, Department of Space Design, University of Sousse, Sousse, Tunisia
| | | | | | - Savino di Lernia
- Dipartimento di Scienze dell'Antichità, Università di Roma "La Sapienza", Italy.,GAES, University of Witwatersrand, Johannesburg, South Africa
| | - Giovanni Destro Bisol
- Dipartimento di Biologia Ambientale, Università di Roma "La Sapienza", Italy.,Istituto Italiano di Antropologia, Italy
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