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Pfennig A, Lachance J. The evolutionary fate of Neanderthal DNA in 30,780 admixed genomes with recent African-like ancestry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.25.605203. [PMID: 39091830 PMCID: PMC11291122 DOI: 10.1101/2024.07.25.605203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Following introgression, Neanderthal DNA was initially purged from non-African genomes, but the evolutionary fate of remaining introgressed DNA has not been explored yet. To fill this gap, we analyzed 30,780 admixed genomes with African-like ancestry from the All of Us research program, in which Neanderthal alleles encountered novel genetic backgrounds during the last 15 generations. Observed amounts of Neanderthal DNA approximately match expectations based on ancestry proportions, suggesting neutral evolution. Nevertheless, we identified genomic regions that have significantly less or more Neanderthal ancestry than expected and are associated with spermatogenesis, innate immunity, and other biological processes. We also identified three novel introgression desert-like regions in recently admixed genomes, whose genetic features are compatible with hybrid incompatibilities and intrinsic negative selection. Overall, we find that much of the remaining Neanderthal DNA in human genomes is not under strong selection, and complex evolutionary dynamics have shaped introgression landscapes in our species.
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Affiliation(s)
- Aaron Pfennig
- School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr, Atlanta, 30332, GA, USA
| | - Joseph Lachance
- School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr, Atlanta, 30332, GA, USA
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Li L, Comi TJ, Bierman RF, Akey JM. Recurrent gene flow between Neanderthals and modern humans over the past 200,000 years. Science 2024; 385:eadi1768. [PMID: 38991054 DOI: 10.1126/science.adi1768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 05/14/2024] [Indexed: 07/13/2024]
Abstract
Although it is well known that the ancestors of modern humans and Neanderthals admixed, the effects of gene flow on the Neanderthal genome are not well understood. We develop methods to estimate the amount of human-introgressed sequences in Neanderthals and apply it to whole-genome sequence data from 2000 modern humans and three Neanderthals. We estimate that Neanderthals have 2.5 to 3.7% human ancestry, and we leverage human-introgressed sequences in Neanderthals to revise estimates of Neanderthal ancestry in modern humans, show that Neanderthal population sizes were significantly smaller than previously estimated, and identify two distinct waves of modern human gene flow into Neanderthals. Our data provide insights into the genetic legacy of recurrent gene flow between modern humans and Neanderthals.
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Affiliation(s)
- Liming Li
- Department of Medical Genetics and Developmental Biology, School of Medicine, The Key Laboratory of Developmental Genes and Human Diseases, Ministry of Education, Southeast University, Nanjing 210009, China
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Troy J Comi
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Rob F Bierman
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Joshua M Akey
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
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Tellini N, De Chiara M, Mozzachiodi S, Tattini L, Vischioni C, Naumova ES, Warringer J, Bergström A, Liti G. Ancient and recent origins of shared polymorphisms in yeast. Nat Ecol Evol 2024; 8:761-776. [PMID: 38472432 DOI: 10.1038/s41559-024-02352-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 01/30/2024] [Indexed: 03/14/2024]
Abstract
Shared genetic polymorphisms between populations and species can be ascribed to ancestral variation or to more recent gene flow. Here, we mapped shared polymorphisms in Saccharomyces cerevisiae and its sister species Saccharomyces paradoxus, which diverged 4-6 million years ago. We used a dense map of single-nucleotide diagnostic markers (mean distance 15.6 base pairs) in 1,673 sequenced S. cerevisiae isolates to catalogue 3,852 sequence blocks (≥5 consecutive markers) introgressed from S. paradoxus, with most being recent and clade-specific. The highly diverged wild Chinese S. cerevisiae lineages were depleted of introgressed blocks but retained an excess of individual ancestral polymorphisms derived from incomplete lineage sorting, perhaps due to less dramatic population bottlenecks. In the non-Chinese S. cerevisiae lineages, we inferred major hybridization events and detected cases of overlapping introgressed blocks across distinct clades due to either shared histories or convergent evolution. We experimentally engineered, in otherwise isogenic backgrounds, the introgressed PAD1-FDC1 gene pair that independently arose in two S. cerevisiae clades and revealed that it increases resistance against diverse antifungal drugs. Overall, our study retraces the histories of divergence and secondary contacts across S. cerevisiae and S. paradoxus populations and unveils a functional outcome.
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Affiliation(s)
- Nicolò Tellini
- CNRS, INSERM, IRCAN, Côte d'Azur University, Nice, France
| | | | | | | | | | - Elena S Naumova
- Kurchatov Complex for Genetic Research (GosNIIgenetika), National Research Center 'Kurchatov Institute', Moscow, Russia
| | - Jonas Warringer
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Anders Bergström
- Ancient Genomics Laboratory, The Francis Crick Institute, London, UK
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Gianni Liti
- CNRS, INSERM, IRCAN, Côte d'Azur University, Nice, France.
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Janivara R, Hazra U, Pfennig A, Harlemon M, Kim MS, Eaaswarkhanth M, Chen WC, Ogunbiyi A, Kachambwa P, Petersen LN, Jalloh M, Mensah JE, Adjei AA, Adusei B, Joffe M, Gueye SM, Aisuodionoe-Shadrach OI, Fernandez PW, Rohan TE, Andrews C, Rebbeck TR, Adebiyi AO, Agalliu I, Lachance J. Uncovering the genetic architecture and evolutionary roots of androgenetic alopecia in African men. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.12.575396. [PMID: 38293167 PMCID: PMC10827056 DOI: 10.1101/2024.01.12.575396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Androgenetic alopecia is a highly heritable trait. However, much of our understanding about the genetics of male pattern baldness comes from individuals of European descent. Here, we examined a novel dataset comprising 2,136 men from Ghana, Nigeria, Senegal, and South Africa that were genotyped using a custom array. We first tested how genetic predictions of baldness generalize from Europe to Africa, finding that polygenic scores from European GWAS yielded AUC statistics that ranged from 0.513 to 0.546, indicating that genetic predictions of baldness in African populations performed notably worse than in European populations. Subsequently, we conducted the first African GWAS of androgenetic alopecia, focusing on self-reported baldness patterns at age 45. After correcting for present age, population structure, and study site, we identified 266 moderately significant associations, 51 of which were independent (p-value < 10-5, r2 < 0.2). Most baldness associations were autosomal, and the X chromosomes does not appear to have a large impact on baldness in African men. Finally, we examined the evolutionary causes of continental differences in genetic architecture. Although Neanderthal alleles have previously been associated with skin and hair phenotypes, we did not find evidence that European-ascertained baldness hits were enriched for signatures of ancient introgression. Most loci that are associated with androgenetic alopecia are evolving neutrally. However, multiple baldness-associated SNPs near the EDA2R and AR genes have large allele frequency differences between continents. Collectively, our findings illustrate how evolutionary history contributes to the limited portability of genetic predictions across ancestries.
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Affiliation(s)
- Rohini Janivara
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Ujani Hazra
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Aaron Pfennig
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Maxine Harlemon
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Department of Biology, Morgan State University, Baltimore, Maryland, USA
| | - Michelle S Kim
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Department of Human Genetics University of Michigan, Ann Arbor, Michigan, USA
| | | | - Wenlong C Chen
- Strengthening Oncology Services Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- National Cancer Registry, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg, South Africa
| | | | - Paidamoyo Kachambwa
- Centre for Proteomic and Genomic Research, Cape Town, South Africa
- Mediclinic Precise Southern Africa, Cape Town, South Africa
| | - Lindsay N Petersen
- Centre for Proteomic and Genomic Research, Cape Town, South Africa
- Mediclinic Precise Southern Africa, Cape Town, South Africa
| | - Mohamed Jalloh
- Université Cheikh Anta Diop de Dakar, Dakar, Senegal
- Université Iba Der Thiam de Thiès, Thiès, Senegal
| | - James E Mensah
- Korle-Bu Teaching Hospital and University of Ghana Medical School, Accra, Ghana
| | - Andrew A Adjei
- Department of Pathology, University of Ghana Medical School, Accra, Ghana
| | | | - Maureen Joffe
- Strengthening Oncology Services Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Oseremen I Aisuodionoe-Shadrach
- College of Health Sciences, University of Abuja, University of Abuja Teaching Hospital and Cancer Science Centre, Abuja, Nigeria
| | - Pedro W Fernandez
- Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Thomas E Rohan
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York, USA
| | | | - Timothy R Rebbeck
- Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | | | - Ilir Agalliu
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Joseph Lachance
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
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