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Kyriazis CC, Serieys LE, Bishop JM, Drouilly M, Viljoen S, Wayne RK, Lohmueller KE. The influence of gene flow on population viability in an isolated urban caracal population. Mol Ecol 2024; 33:e17346. [PMID: 38581173 PMCID: PMC11035096 DOI: 10.1111/mec.17346] [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: 07/20/2023] [Revised: 01/23/2024] [Accepted: 03/26/2024] [Indexed: 04/08/2024]
Abstract
Wildlife populations are becoming increasingly fragmented by anthropogenic development. Small and isolated populations often face an elevated risk of extinction, in part due to inbreeding depression. Here, we examine the genomic consequences of urbanization in a caracal (Caracal caracal) population that has become isolated in the Cape Peninsula region of the City of Cape Town, South Africa, and is thought to number ~50 individuals. We document low levels of migration into the population over the past ~75 years, with an estimated rate of 1.3 effective migrants per generation. As a consequence of this isolation and small population size, levels of inbreeding are elevated in the contemporary Cape Peninsula population (mean FROH = 0.20). Inbreeding primarily manifests as long runs of homozygosity >10 Mb, consistent with the effects of isolation due to the rapid recent growth of Cape Town. To explore how reduced migration and elevated inbreeding may impact future population dynamics, we parameterized an eco-evolutionary simulation model. We find that if migration rates do not change in the future, the population is expected to decline, though with a low projected risk of extinction. However, if migration rates decline or anthropogenic mortality rates increase, the potential risk of extinction is greatly elevated. To avert a population decline, we suggest that translocating migrants into the Cape Peninsula to initiate a genetic rescue may be warranted in the near future. Our analysis highlights the utility of genomic datasets coupled with computational simulation models for investigating the influence of gene flow on population viability.
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Affiliation(s)
- Christopher C. Kyriazis
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA
| | - Laurel E.K. Serieys
- Panthera, 8 W 40th St, 18th Floor, New York, NY 10018, USA
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa
| | - Jacqueline M. Bishop
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa
| | - Marine Drouilly
- Panthera, 8 W 40th St, 18th Floor, New York, NY 10018, USA
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa
- Centre for Social Science Research, University of Cape Town, Rondebosch, 7701, South Africa
| | - Storme Viljoen
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa
| | - Robert K. Wayne
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA
| | - Kirk E. Lohmueller
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA
- Interdepartmental Program in Bioinformatics, University of California, Los Angeles, CA 90095, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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2
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Steux C, Szpiech ZA. The Maintenance of Deleterious Variation in Wild Chinese Rhesus Macaques. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.04.560901. [PMID: 38712222 PMCID: PMC11071285 DOI: 10.1101/2023.10.04.560901] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Understanding how deleterious variation is shaped and maintained in natural populations is important in conservation and evolutionary biology, as decreased fitness caused by these deleterious mutations can potentially lead to an increase in extinction risk. It is known that demographic processes can influence these patterns. For example, population bottlenecks and inbreeding increase the probability of inheriting identical-by-descent haplotypes from a recent common ancestor, creating long tracts of homozygous genotypes called runs of homozygosity (ROH), which have been associated with an accumulation of mildly deleterious homozygotes. Counter intuitively, positive selection can also maintain deleterious variants in a population through genetic hitchhiking. Here we analyze the whole genomes of 79 wild Chinese rhesus macaques across five subspecies and characterize patterns of deleterious variation with respect to ROH and signals of recent positive selection. We show that the fraction of homozygotes occurring in long ROH is significantly higher for deleterious homozygotes than tolerated ones, whereas this trend is not observed for short and medium ROH. This confirms that inbreeding, by generating these long tracts of homozygosity, is the main driver of the high burden of homozygous deleterious alleles in wild macaque populations. Furthermore, we show evidence that homozygous LOF variants are being purged. Next, we identify 7 deleterious variants at high frequency in regions putatively under selection near genes involved with olfaction and other processes. Our results shed light on how evolutionary processes can shape the distribution of deleterious variation in wild non-human primates.
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Affiliation(s)
- Camille Steux
- Department of Biology, Pennsylvania State University, USA
- Centre de Recherche sur la Biodiversité et l’Environnement (CRBE), Université de Toulouse, CNRS, IRD, Toulouse INP, Université Toulouse 3 – Paul Sabatier (UT3), Toulouse, France
- Département de Biologie, École Normale Supérieure, PSL Université Paris, Paris, France
| | - Zachary A. Szpiech
- Department of Biology, Pennsylvania State University, USA
- Institute for Computational and Data Sciences, Pennsylvania State University, USA
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3
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Lawson DJ, Howard-McCombe J, Beaumont M, Senn H. How admixed captive breeding populations could be rescued using local ancestry information. Mol Ecol 2024:e17349. [PMID: 38634332 DOI: 10.1111/mec.17349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/21/2023] [Accepted: 02/26/2024] [Indexed: 04/19/2024]
Abstract
This paper asks the question: can genomic information be used to recover a species that is already on the pathway to extinction due to genetic swamping from a related and more numerous population? We show that a breeding strategy in a captive breeding program can use whole genome sequencing to identify and remove segments of DNA introgressed through hybridisation. The proposed policy uses a generalized measure of kinship or heterozygosity accounting for local ancestry, that is, whether a specific genetic location was inherited from the target of conservation. We then show that optimizing these measures would minimize undesired ancestry while also controlling kinship and/or heterozygosity, in a simulated breeding population. The process is applied to real data representing the hybridized Scottish wildcat breeding population, with the result that it should be possible to breed out domestic cat ancestry. The ability to reverse introgression is a powerful tool brought about through the combination of sequencing with computational advances in ancestry estimation. Since it works best when applied early in the process, important decisions need to be made about which genetically distinct populations should benefit from it and which should be left to reform into a single population.
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Affiliation(s)
- Daniel J Lawson
- Institute of Statistical Sciences, School of Mathematics, University of Bristol, Bristol, UK
| | - Jo Howard-McCombe
- RZSS WildGenes Laboratory, Conservation Department, Royal Zoological Society of Scotland, Edinburgh, UK
| | - Mark Beaumont
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Helen Senn
- RZSS WildGenes Laboratory, Conservation Department, Royal Zoological Society of Scotland, Edinburgh, UK
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4
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Bozkurt-Yozgatli T, Pehlivan D, Gibbs RA, Sezerman U, Posey JE, Lupski JR, Coban-Akdemir Z. Multilocus pathogenic variants contribute to intrafamilial clinical heterogeneity: a retrospective study of sibling pairs with neurodevelopmental disorders. BMC Med Genomics 2024; 17:85. [PMID: 38622594 PMCID: PMC11020671 DOI: 10.1186/s12920-024-01852-4] [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: 01/04/2024] [Accepted: 03/27/2024] [Indexed: 04/17/2024] Open
Abstract
BACKGROUND Multilocus pathogenic variants (MPVs) are genetic changes that affect multiple gene loci or regions of the genome, collectively leading to multiple molecular diagnoses. MPVs may also contribute to intrafamilial phenotypic variability between affected individuals within a nuclear family. In this study, we aim to gain further insights into the influence of MPVs on a disease manifestation in individual research subjects and explore the complexities of the human genome within a familial context. METHODS We conducted a systematic reanalysis of exome sequencing data and runs of homozygosity (ROH) regions of 47 sibling pairs previously diagnosed with various neurodevelopmental disorders (NDD). RESULTS We found siblings with MPVs driven by long ROH regions in 8.5% of families (4/47). The patients with MPVs exhibited significantly higher FROH values (p-value = 1.4e-2) and larger total ROH length (p-value = 1.8e-2). Long ROH regions mainly contribute to this pattern; the siblings with MPVs have a larger total size of long ROH regions than their siblings in all families (p-value = 6.9e-3). Whereas the short ROH regions in the siblings with MPVs are lower in total size compared to their sibling pairs with single locus pathogenic variants (p-value = 0.029), and there are no statistically significant differences in medium ROH regions between sibling pairs (p-value = 0.52). CONCLUSION This study sheds light on the significance of considering MPVs in families with affected sibling pairs and the role of ROH as an adjuvant tool in explaining clinical variability within families. Identifying individuals carrying MPVs may have implications for disease management, identification of possible disease risks to different family members, genetic counseling and exploring personalized treatment approaches.
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Affiliation(s)
- Tugce Bozkurt-Yozgatli
- Department of Biostatistics and Bioinformatics, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Davut Pehlivan
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
- Texas Children's Hospital, Houston, TX, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Ugur Sezerman
- Department of Biostatistics and Bioinformatics, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
- Department of Biostatistics and Medical Informatics, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - James R Lupski
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
- Texas Children's Hospital, Houston, TX, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA.
| | - Zeynep Coban-Akdemir
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
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5
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Carter RC, Yang Z, Akkaya-Hocagil T, Jacobson SW, Jacobson JL, Dodge NC, Hoyme HE, Zeisel SH, Meintjes EM, Kizil C, Tosto G. Genetic admixture predictors of fetal alcohol spectrum disorders (FASD) in the South African Cape Coloured population. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.03.31.24305130. [PMID: 38633769 PMCID: PMC11023663 DOI: 10.1101/2024.03.31.24305130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Ancestrally admixed populations are underrepresented in genetic studies of complex diseases, which are still dominated by European-descent populations. This is relevant not only from a representation standpoint but also because of admixed populations' unique features, including being enriched for rare variants, for which effect sizes are disproportionately larger than common polymorphisms. Furthermore, results from these populations may be generalizable to other populations. The South African Cape Coloured (SACC) population is genetically admixed, with one of the highest prevalences of fetal alcohol spectrum disorders (FASD) worldwide. We profiled its admixture and examined associations between ancestry profiles and FASD outcomes using two longitudinal birth cohorts ( N =308 mothers, 280 children) designed to examine effects of prenatal alcohol exposure on development. Participants were genotyped via MEGA-ex array to capture common and rare variants. Rare variants were overrepresented in our SACC cohorts, with numerous polymorphisms being monomorphic in other reference populations (e.g., ∼30,000 and ∼221,000 variants in gnomAD European and Asian populations, respectively). The cohorts showed global African (51%; Bantu and San); European (26%; Northern/Western); South Asian (18%); and East Asian (5%; largely Southern regions) ancestries. The cohorts exhibited high rates of homozygosity (6%), with regions of homozygosity harboring more deleterious variants when lying within African local-ancestry genomic segments. Both maternal and child ancestry profiles were associated with FASD risk and altered severity of prenatal alcohol exposure-related cognitive deficits in the child. Our findings indicate that the SACC population may be a valuable asset to identify novel disease-associated genetic loci for FASD and other diseases.
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Leon-Apodaca AV, Kumar M, Del Castillo A, Conroy GC, Lamont RW, Ogbourne S, Cairns KM, Borburgh L, Behrendorff L, Subramanian S, Szpiech ZA. Genomic consequences of isolation and inbreeding in an island dingo population. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.15.557950. [PMID: 37745583 PMCID: PMC10516007 DOI: 10.1101/2023.09.15.557950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Dingoes come from an ancient canid lineage that originated in East Asia around 8000-11,000 years BP. As Australia's largest terrestrial predator, dingoes play an important ecological role. A small, protected population exists on a world heritage listed offshore island, K'gari (formerly Fraser Island). Concern regarding the persistence of dingoes on K'gari has risen due to their low genetic diversity and elevated inbreeding levels. However, whole-genome sequencing data is lacking from this population. Here, we include five new whole-genome sequences of K'gari dingoes. We analyze a total of 18 whole genome sequences of dingoes sampled from mainland Australia and K'gari to assess the genomic consequences of their demographic histories. Long (>1 Mb) runs of homozygosity (ROH) - indicators of inbreeding - are elevated in all sampled dingoes. However, K'gari dingoes showed significantly higher levels of very long ROH (>5 Mb), providing genomic evidence for small population size, isolation, inbreeding, and a strong founder effect. Our results suggest that, despite current levels of inbreeding, the K'gari population is purging strongly deleterious mutations, which, in the absence of further reductions in population size, may facilitate the persistence of small populations despite low genetic diversity and isolation. However, there may be little to no purging of mildly deleterious alleles, which may have important long-term consequences, and should be considered by conservation and management programs. SIGNIFICANCE A long-standing question in conservation genetics is whether long-term isolation and elevated levels of inbreeding always leads to inevitable population extinction. Here we conduct the first-ever whole-genome analysis of a population of dingoes living in long-term isolation on an island off the coast of Australia (K'gari). We show that these animals are beset by very low genetic diversity, likely the result of extensive inbreeding, and an elevated number of deleterious homozygotes. However, our results suggest that these dingoes are likely purging highly deleterious alleles, which may have allowed them to persist long term despite their extremely small population (<200 individuals).
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7
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Swinford NA, Prall SP, Gopalan S, Williams CM, Sheehama J, Scelza BA, Henn BM. Increased homozygosity due to endogamy results in fitness consequences in a human population. Proc Natl Acad Sci U S A 2023; 120:e2309552120. [PMID: 37847737 PMCID: PMC10614605 DOI: 10.1073/pnas.2309552120] [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: 06/08/2023] [Accepted: 09/18/2023] [Indexed: 10/19/2023] Open
Abstract
Recessive alleles have been shown to directly affect both human Mendelian disease phenotypes and complex traits. Pedigree studies also suggest that consanguinity results in increased childhood mortality and adverse health phenotypes, presumably through penetrance of recessive mutations. Here, we test whether the accumulation of homozygous, recessive alleles decreases reproductive success in a human population. We address this question among the Namibian Himba, an endogamous agro-pastoralist population, who until very recently practiced natural fertility. Using a sample of 681 individuals, we show that Himba exhibit elevated levels of "inbreeding," calculated as the fraction of the genome in runs of homozygosity (FROH). Many individuals contain multiple long segments of ROH in their genomes, indicating that their parents had high kinship coefficients. However, we do not find evidence that this is explained by first-cousin consanguinity, despite a reported social preference for cross-cousin marriages. Rather, we show that elevated haplotype sharing in the Himba is due to a bottleneck, likely in the past 60 generations. We test whether increased recessive mutation load results in observed fitness consequences by assessing the effect of FROH on completed fertility in a cohort of postreproductive women (n = 69). We find that higher FROH is significantly associated with lower fertility. Our data suggest a multilocus genetic effect on fitness driven by the expression of deleterious recessive alleles, especially those in long ROH. However, these effects are not the result of consanguinity but rather elevated background identity by descent.
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Affiliation(s)
- N. A. Swinford
- Department of Anthropology, University of California Davis, Davis, CA95616
| | - S. P. Prall
- Department of Anthropology, University of Missouri, Columbia, MO65211
| | - S. Gopalan
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
| | - C. M. Williams
- Center for Computational Molecular Biology, Brown University, Providence, RI02912
| | - J. Sheehama
- Department of Human, Biological and Translational Medical Sciences, School of Medicine University of Namibia, Oshakati10005, Namibia
| | - B. A. Scelza
- Department of Anthropology, University of California Los Angeles, Los Angeles, CA90095
| | - B. M. Henn
- Department of Anthropology, University of California Davis, Davis, CA95616
- Center for Population Biology, University of California Davis, Davis, CA95616
- Genome Center, University of California Davis, Davis, CA95616
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Caggiano C, Boudaie A, Shemirani R, Mefford J, Petter E, Chiu A, Ercelen D, He R, Tward D, Paul KC, Chang TS, Pasaniuc B, Kenny EE, Shortt JA, Gignoux CR, Balliu B, Arboleda VA, Belbin G, Zaitlen N. Disease risk and healthcare utilization among ancestrally diverse groups in the Los Angeles region. Nat Med 2023; 29:1845-1856. [PMID: 37464048 PMCID: PMC11121511 DOI: 10.1038/s41591-023-02425-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 05/30/2023] [Indexed: 07/20/2023]
Abstract
An individual's disease risk is affected by the populations that they belong to, due to shared genetics and environmental factors. The study of fine-scale populations in clinical care is important for identifying and reducing health disparities and for developing personalized interventions. To assess patterns of clinical diagnoses and healthcare utilization by fine-scale populations, we leveraged genetic data and electronic medical records from 35,968 patients as part of the UCLA ATLAS Community Health Initiative. We defined clusters of individuals using identity by descent, a form of genetic relatedness that utilizes shared genomic segments arising due to a common ancestor. In total, we identified 376 clusters, including clusters with patients of Afro-Caribbean, Puerto Rican, Lebanese Christian, Iranian Jewish and Gujarati ancestry. Our analysis uncovered 1,218 significant associations between disease diagnoses and clusters and 124 significant associations with specialty visits. We also examined the distribution of pathogenic alleles and found 189 significant alleles at elevated frequency in particular clusters, including many that are not regularly included in population screening efforts. Overall, this work progresses the understanding of health in understudied communities and can provide the foundation for further study into health inequities.
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Affiliation(s)
- Christa Caggiano
- Interdepartmental Program in Bioinformatics, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA, USA
| | | | - Ruhollah Shemirani
- Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Joel Mefford
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ella Petter
- Department of Computer Science, University of California, Los Angeles, Los Angeles, CA, USA
| | - Alec Chiu
- Interdepartmental Program in Bioinformatics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Defne Ercelen
- Computational and Systems Biology Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA, USA
| | - Rosemary He
- Department of Computer Science, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Daniel Tward
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kimberly C Paul
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Timothy S Chang
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Bogdan Pasaniuc
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Institute of Precision Health, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Eimear E Kenny
- Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jonathan A Shortt
- Colorado Center for Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Division of Bioinformatics and Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Christopher R Gignoux
- Colorado Center for Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Division of Bioinformatics and Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Brunilda Balliu
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Valerie A Arboleda
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Gillian Belbin
- Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Noah Zaitlen
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA, USA.
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9
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Wood AW, Szpiech ZA, Lovette IJ, Smith BT, Toews DPL. Genomes of the extinct Bachman's warbler show high divergence and no evidence of admixture with other extant Vermivora warblers. Curr Biol 2023:S0960-9822(23)00690-5. [PMID: 37329885 DOI: 10.1016/j.cub.2023.05.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/25/2023] [Accepted: 05/25/2023] [Indexed: 06/19/2023]
Abstract
Bachman's warbler1 (Vermivora bachmanii)-last sighted in 1988-is one of the only North American passerines to recently go extinct.2,3,4 Given extensive ongoing hybridization of its two extant congeners-the blue-winged warbler (V. cyanoptera) and golden-winged warbler (V. chrysoptera)5,6,7,8-and shared patterns of plumage variation between Bachman's warbler and hybrids between those extant species, it has been suggested that Bachman's warbler might have also had a component of hybrid ancestry. Here, we use historic DNA (hDNA) and whole genomes of Bachman's warblers collected at the turn of the 20th century to address this. We combine these data with the two extant Vermivora species to examine patterns of population differentiation, inbreeding, and gene flow. In contrast to the admixture hypothesis, the genomic evidence is consistent with V. bachmanii having been a highly divergent, reproductively isolated species, with no evidence of introgression. We show that these three species have similar levels of runs of homozygosity (ROH), consistent with effects of a small long-term effective population size or population bottlenecks, with one V. bachmanii outlier showing numerous long ROH and a FROH greater than 5%. We also found-using population branch statistic estimates-previously undocumented evidence of lineage-specific evolution in V. chrysoptera near a pigmentation gene candidate, CORIN, which is a known modifier of ASIP, which is in turn involved in melanic throat and mask coloration in this family of birds. Together, these genomic results also highlight how natural history collections are such invaluable repositories of information about extant and extinct species.
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Affiliation(s)
- Andrew W Wood
- Department of Biology, Pennsylvania State University, 619 Mueller Laboratory, University Park, State College, PA 16802, USA
| | - Zachary A Szpiech
- Department of Biology, Pennsylvania State University, 619 Mueller Laboratory, University Park, State College, PA 16802, USA; Institute for Computational and Data Sciences, Pennsylvania State University, University Park, State College, PA 16802, USA
| | - Irby J Lovette
- Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, Cornell University, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA
| | - Brian Tilston Smith
- Department of Ornithology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA
| | - David P L Toews
- Department of Biology, Pennsylvania State University, 619 Mueller Laboratory, University Park, State College, PA 16802, USA.
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10
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Kyriazis CC, Beichman AC, Brzeski KE, Hoy SR, Peterson RO, Vucetich JA, Vucetich LM, Lohmueller KE, Wayne RK. Genomic Underpinnings of Population Persistence in Isle Royale Moose. Mol Biol Evol 2023; 40:7024794. [PMID: 36729989 PMCID: PMC9927576 DOI: 10.1093/molbev/msad021] [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: 05/20/2022] [Revised: 01/20/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023] Open
Abstract
Island ecosystems provide natural laboratories to assess the impacts of isolation on population persistence. However, most studies of persistence have focused on a single species, without comparisons to other organisms they interact with in the ecosystem. The case study of moose and gray wolves on Isle Royale allows for a direct contrast of genetic variation in isolated populations that have experienced dramatically differing population trajectories over the past decade. Whereas the Isle Royale wolf population recently declined nearly to extinction due to severe inbreeding depression, the moose population has thrived and continues to persist, despite having low genetic diversity and being isolated for ∼120 years. Here, we examine the patterns of genomic variation underlying the continued persistence of the Isle Royale moose population. We document high levels of inbreeding in the population, roughly as high as the wolf population at the time of its decline. However, inbreeding in the moose population manifests in the form of intermediate-length runs of homozygosity suggestive of historical inbreeding and purging, contrasting with the long runs of homozygosity observed in the smaller wolf population. Using simulations, we confirm that substantial purging has likely occurred in the moose population. However, we also document notable increases in genetic load, which could eventually threaten population viability over the long term. Overall, our results demonstrate a complex relationship between inbreeding, genetic diversity, and population viability that highlights the use of genomic datasets and computational simulation tools for understanding the factors enabling persistence in isolated populations.
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Affiliation(s)
| | | | - Kristin E Brzeski
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI
| | - Sarah R Hoy
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI
| | - Rolf O Peterson
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI
| | - John A Vucetich
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI
| | - Leah M Vucetich
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI
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11
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Belkadi A, Thareja G, Abbaszadeh F, Badii R, Fauman E, Albagha OM, Suhre K. Identification of PCSK9-like human gene knockouts using metabolomics, proteomics, and whole-genome sequencing in a consanguineous population. CELL GENOMICS 2022; 3:100218. [PMID: 36777185 PMCID: PMC9903797 DOI: 10.1016/j.xgen.2022.100218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 07/16/2022] [Accepted: 10/25/2022] [Indexed: 11/17/2022]
Abstract
Natural human knockouts of genes associated with desirable outcomes, such as PCSK9 with low levels of LDL-cholesterol, can lead to the discovery of new drug targets and treatments. Rare loss-of-function variants are more likely to be found in the homozygous state in consanguineous populations, and deep molecular phenotyping of blood samples from homozygous carriers can help to discriminate between silent and functional variants. Here, we combined whole-genome sequencing with proteomics and metabolomics for 2,935 individuals from the Qatar Biobank (QBB) to evaluate the power of this approach for finding genes of clinical and pharmaceutical interest. As proof-of-concept, we identified a homozygous carrier of a very rare PCSK9 variant with extremely low circulating PCSK9 levels and low LDL. Our study demonstrates that the chances of finding such variants are about 168 times higher in QBB compared with GnomAD and emphasizes the potential of consanguineous populations for drug discovery.
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Affiliation(s)
- Aziz Belkadi
- Bioinformatics Core, Weill Cornell Medicine-Qatar, Education City, Doha 24144, Qatar,Department of Biophysics and Physiology, Weill Cornell Medicine, New York, NY, USA
| | - Gaurav Thareja
- Bioinformatics Core, Weill Cornell Medicine-Qatar, Education City, Doha 24144, Qatar,Department of Biophysics and Physiology, Weill Cornell Medicine, New York, NY, USA
| | | | | | | | - Omar M.E. Albagha
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar,Centre for Genomic and Experimental Medicine, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | | | - Karsten Suhre
- Bioinformatics Core, Weill Cornell Medicine-Qatar, Education City, Doha 24144, Qatar,Department of Biophysics and Physiology, Weill Cornell Medicine, New York, NY, USA,Corresponding author
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12
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Nadachowska‐Brzyska K, Konczal M, Babik W. Navigating the temporal continuum of effective population size. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13740] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | | | - Wieslaw Babik
- Jagiellonian University in Kraków Faculty of Biology Institute of Environmental Sciences Kraków Poland
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13
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Foster Y, Dutoit L, Grosser S, Dussex N, Foster BJ, Dodds KG, Brauning R, Van Stijn T, Robertson F, McEwan JC, Jacobs JME, Robertson BC. Genomic signatures of inbreeding in a critically endangered parrot, the kākāpō. G3 (BETHESDA, MD.) 2021; 11:jkab307. [PMID: 34542587 PMCID: PMC8527487 DOI: 10.1093/g3journal/jkab307] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/23/2021] [Indexed: 02/06/2023]
Abstract
Events of inbreeding are inevitable in critically endangered species. Reduced population sizes and unique life-history traits can increase the severity of inbreeding, leading to declines in fitness and increased risk of extinction. Here, we investigate levels of inbreeding in a critically endangered flightless parrot, the kākāpō (Strigops habroptilus), wherein a highly inbred island population and one individual from the mainland of New Zealand founded the entire extant population. Genotyping-by-sequencing (GBS), and a genotype calling approach using a chromosome-level genome assembly, identified a filtered set of 12,241 single-nucleotide polymorphisms (SNPs) among 161 kākāpō, which together encompass the total genetic potential of the extant population. Multiple molecular-based estimates of inbreeding were compared, including genome-wide estimates of heterozygosity (FH), the diagonal elements of a genomic-relatedness matrix (FGRM), and runs of homozygosity (RoH, FRoH). In addition, we compared levels of inbreeding in chicks from a recent breeding season to examine if inbreeding is associated with offspring survival. The density of SNPs generated with GBS was sufficient to identify chromosomes that were largely homozygous with RoH distributed in similar patterns to other inbred species. Measures of inbreeding were largely correlated and differed significantly between descendants of the two founding populations. However, neither inbreeding nor ancestry was found to be associated with reduced survivorship in chicks, owing to unexpected mortality in chicks exhibiting low levels of inbreeding. Our study highlights important considerations for estimating inbreeding in critically endangered species, such as the impacts of small population sizes and admixture between diverse lineages.
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Affiliation(s)
- Yasmin Foster
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
| | - Ludovic Dutoit
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
| | - Stefanie Grosser
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
| | - Nicolas Dussex
- Centre for Palaeogenetics, SE-106 91 Stockholm, Sweden
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, SE-104 05 Stockholm, Sweden
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Brodie J Foster
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
| | - Ken G Dodds
- AgResearch Invermay Agricultural Centre, Mosgiel 9053, New Zealand
| | - Rudiger Brauning
- AgResearch Invermay Agricultural Centre, Mosgiel 9053, New Zealand
| | - Tracey Van Stijn
- AgResearch Invermay Agricultural Centre, Mosgiel 9053, New Zealand
| | - Fiona Robertson
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
| | - John C McEwan
- AgResearch Invermay Agricultural Centre, Mosgiel 9053, New Zealand
| | | | - Bruce C Robertson
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
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14
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Parental relatedness through time revealed by runs of homozygosity in ancient DNA. Nat Commun 2021; 12:5425. [PMID: 34521843 PMCID: PMC8440622 DOI: 10.1038/s41467-021-25289-w] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 07/21/2021] [Indexed: 02/08/2023] Open
Abstract
Parental relatedness of present-day humans varies substantially across the globe, but little is known about the past. Here we analyze ancient DNA, leveraging that parental relatedness leaves genomic traces in the form of runs of homozygosity. We present an approach to identify such runs in low-coverage ancient DNA data aided by haplotype information from a modern phased reference panel. Simulation and experiments show that this method robustly detects runs of homozygosity longer than 4 centimorgan for ancient individuals with at least 0.3 × coverage. Analyzing genomic data from 1,785 ancient humans who lived in the last 45,000 years, we detect low rates of first cousin or closer unions across most ancient populations. Moreover, we find a marked decay in background parental relatedness co-occurring with or shortly after the advent of sedentary agriculture. We observe this signal, likely linked to increasing local population sizes, across several geographic transects worldwide.
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15
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Sumreddee P, Hay EH, Toghiani S, Roberts A, Aggrey SE, Rekaya R. Grid search approach to discriminate between old and recent inbreeding using phenotypic, pedigree and genomic information. BMC Genomics 2021; 22:538. [PMID: 34256689 PMCID: PMC8278650 DOI: 10.1186/s12864-021-07872-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 07/05/2021] [Indexed: 12/02/2022] Open
Abstract
Background Although inbreeding caused by the mating of animals related through a recent common ancestor is expected to have more harmful effects on phenotypes than ancient inbreeding (old inbreeding), estimating these effects requires a clear definition of recent (new) and ancient (old) inbreeding. Several methods have been proposed to classify inbreeding using pedigree and genomic data. Unfortunately, these methods are largely based on heuristic criteria such as the number of generations from a common ancestor or length of runs of homozygosity (ROH) segments. To mitigate these deficiencies, this study aimed to develop a method to classify pedigree and genomic inbreeding into recent and ancient classes based on a grid search algorithm driven by the assumption that new inbreeding tends to have a more pronounced detrimental effect on traits. The proposed method was tested using a cattle population characterized by a deep pedigree. Results Effects of recent and ancient inbreeding were assessed on four growth traits (birth, weaning and yearling weights and average daily gain). Thresholds to classify inbreeding into recent and ancient classes were trait-specific and varied across traits and sources of information. Using pedigree information, inbreeding generated in the last 10 to 11 generations was considered as recent. When genomic information (ROH) was used, thresholds ranged between four to seven generations, indicating, in part, the ability of ROH segments to characterize the harmful effects of inbreeding in shorter periods of time. Nevertheless, using the proposed classification method, the discrimination between new and old inbreeding was less robust when ROH segments were used compared to pedigree. Using several model comparison criteria, the proposed approach was generally better than existing methods. Recent inbreeding appeared to be more harmful across the growth traits analyzed. However, both new and old inbreeding were found to be associated with decreased yearling weight and average daily gain. Conclusions The proposed method provided a more objective quantitative approach for the classification of inbreeding. The proposed method detected a clear divergence in the effects of old and recent inbreeding using pedigree data and it was superior to existing methods for all analyzed traits. Using ROH data, the discrimination between old and recent inbreeding was less clear and the proposed method was superior to existing approaches for two out of the four analyzed traits. Deleterious effects of recent inbreeding were detected sooner (fewer generations) using genomic information than pedigree. Difference in the results using genomic and pedigree information could be due to the dissimilarity in the number of generations to a common ancestor. Additionally, the uncertainty associated with the identification of ROH segments and associated inbreeding could have an effect on the results. Potential biases in the estimation of inbreeding effects may occur when new and old inbreeding are discriminated based on arbitrary thresholds. To minimize the impact of inbreeding, mating designs should take the different inbreeding origins into consideration. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07872-z.
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Affiliation(s)
- Pattarapol Sumreddee
- Department of Animal and Dairy Science, The University of Georgia, Athens, GA, 30602, USA
| | - El Hamidi Hay
- USDA Agricultural Research Service, Fort Keogh Livestock and Range Research Laboratory, Miles City, MT, 59301, USA.
| | - Sajjad Toghiani
- USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD, 20705, USA
| | - Andrew Roberts
- USDA Agricultural Research Service, Fort Keogh Livestock and Range Research Laboratory, Miles City, MT, 59301, USA
| | - Samuel E Aggrey
- Department of Poultry Science, The University of Georgia, Athens, GA, 30602, USA.,Institute of Bioinformatics, The University of Georgia, Athens, GA, 30602, USA
| | - Romdhane Rekaya
- Department of Animal and Dairy Science, The University of Georgia, Athens, GA, 30602, USA.,Institute of Bioinformatics, The University of Georgia, Athens, GA, 30602, USA.,Department of Statistics, The University of Georgia, Athens, GA, 30602, USA
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16
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Stoffel MA, Johnston SE, Pilkington JG, Pemberton JM. Mutation load decreases with haplotype age in wild Soay sheep. Evol Lett 2021; 5:187-195. [PMID: 34136268 PMCID: PMC8190445 DOI: 10.1002/evl3.229] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/06/2021] [Accepted: 04/13/2021] [Indexed: 01/01/2023] Open
Abstract
Runs of homozygosity (ROH) are pervasive in diploid genomes and expose the effects of deleterious recessive mutations, but how exactly these regions contribute to variation in fitness remains unclear. Here, we combined empirical analyses and simulations to explore the deleterious effects of ROH with varying genetic map lengths in wild Soay sheep. Using a long-term dataset of 4879 individuals genotyped at 417K SNPs, we found that inbreeding depression increases with ROH length. A 1% genomic increase in long ROH (>12.5 cM) reduced the odds of first-year survival by 12.4% compared to only 7.7% for medium ROH (1.56-12.5 cM), whereas short ROH (<1.56 cM) had no effect on survival. We show by forward genetic simulations that this is predicted: compared to shorter ROH, long ROH will have higher densities of deleterious alleles, with larger average effects on fitness and lower population frequencies. Taken together, our results are consistent with the idea that the mutation load decreases in older haplotypes underlying shorter ROH, where purifying selection has had more time to purge deleterious mutations. Finally, our study demonstrates that strong inbreeding depression can persist despite ongoing purging in a historically small population.
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Affiliation(s)
- Martin A. Stoffel
- School of Biological Sciences, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
| | - Susan E. Johnston
- School of Biological Sciences, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
| | - Jill G. Pilkington
- School of Biological Sciences, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
| | - Josephine M. Pemberton
- School of Biological Sciences, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
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17
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Peng Q, Ehlers CL. Long tracks of homozygosity predict the severity of alcohol use disorders in an American Indian population. Mol Psychiatry 2021; 26:2200-2211. [PMID: 33398086 PMCID: PMC8254832 DOI: 10.1038/s41380-020-00989-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 11/30/2020] [Accepted: 12/07/2020] [Indexed: 11/20/2022]
Abstract
Runs of homozygosity (ROH) arise when an individual inherits two copies of the same haplotype segment. While ROH are ubiquitous across human populations, Native populations-with shared parental ancestry arising from isolation and endogamy-can carry a substantial enrichment for ROH. We have been investigating genetic and environmental risk factors for alcohol use disorders (AUD) in a group of American Indians (AI) who have higher rates of AUD than the general U. S. population. Here we explore whether ROH might be associated with incidence and severity of AUD in this admixed AI population (n = 742) that live on geographically contiguous reservations, using low-coverage whole genome sequences. We have found that the genomic regions in the ROH that were identified in this population had significantly elevated American Indian heritage compared with the rest of the genome. Increased ROH abundance and ROH burden are likely risk factors for AUD severity in this AI population, especially in those diagnosed with severe and moderate AUD. The association between ROH and AUD was mostly driven by ROH of moderate lengths between 1 and 2 Mb. An ROH island on chromosome 1p32.3 and a rare ROH pool on chromosome 3p12.3 were found to be significantly associated with AUD severity. They contain genes involved in lipid metabolism, oxidative stress and inflammatory responses; and OSBPL9 was found to reside on the consensus part of the ROH island. These data demonstrate that ROH are associated with risk for AUD severity in this AI population.
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Affiliation(s)
- Qian Peng
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, USA.
| | - Cindy L Ehlers
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, USA.
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18
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Stoffel MA, Johnston SE, Pilkington JG, Pemberton JM. Genetic architecture and lifetime dynamics of inbreeding depression in a wild mammal. Nat Commun 2021; 12:2972. [PMID: 34016997 PMCID: PMC8138023 DOI: 10.1038/s41467-021-23222-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 03/29/2021] [Indexed: 02/03/2023] Open
Abstract
Inbreeding depression is ubiquitous, but we still know little about its genetic architecture and precise effects in wild populations. Here, we combine long-term life-history data with 417 K imputed SNP genotypes for 5952 wild Soay sheep to explore inbreeding depression on a key fitness component, annual survival. Inbreeding manifests in long runs of homozygosity (ROH), which make up nearly half of the genome in the most inbred individuals. The ROH landscape varies widely across the genome, with islands where up to 87% and deserts where only 4% of individuals have ROH. The fitness consequences of inbreeding are severe; a 10% increase in individual inbreeding FROH is associated with a 60% reduction in the odds of survival in lambs, though inbreeding depression decreases with age. Finally, a genome-wide association scan on ROH shows that many loci with small effects and five loci with larger effects contribute to inbreeding depression in survival.
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Affiliation(s)
- M A Stoffel
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
| | - S E Johnston
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - J G Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - J M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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19
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Abstract
Dogs and humans have coexisted together for thousands of years, but it was not until the Victorian Era that humans practiced selective breeding to produce the modern standards we see today. Strong artificial selection during the breed formation period has simplified the genetic architecture of complex traits and caused an enrichment of identity-by-descent (IBD) segments in the dog genome. This study demonstrates the value of IBD segments and utilizes them to infer the recent demography of canids, predict case-control status for complex traits, locate regions of the genome potentially linked to inbreeding depression, and to identify understudied breeds where there is potential to discover new disease-associated variants. Domestic dogs have experienced population bottlenecks, recent inbreeding, and strong artificial selection. These processes have simplified the genetic architecture of complex traits, allowed deleterious variation to persist, and increased both identity-by-descent (IBD) segments and runs of homozygosity (ROH). As such, dogs provide an excellent model for examining how these evolutionary processes influence disease. We assembled a dataset containing 4,414 breed dogs, 327 village dogs, and 380 wolves genotyped at 117,288 markers and data for clinical and morphological phenotypes. Breed dogs have an enrichment of IBD and ROH, relative to both village dogs and wolves, and we use these patterns to show that breed dogs have experienced differing severities of bottlenecks in their recent past. We then found that ROH burden is associated with phenotypes in breed dogs, such as lymphoma. We next test the prediction that breeds with greater ROH have more disease alleles reported in the Online Mendelian Inheritance in Animals (OMIA). Surprisingly, the number of causal variants identified correlates with the popularity of that breed rather than the ROH or IBD burden, suggesting an ascertainment bias in OMIA. Lastly, we use the distribution of ROH across the genome to identify genes with depletions of ROH as potential hotspots for inbreeding depression and find multiple exons where ROH are never observed. Our results suggest that inbreeding has played a large role in shaping genetic and phenotypic variation in dogs and that future work on understudied breeds may reveal new disease-causing variation.
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20
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Font-Porterias N, Caro-Consuegra R, Lucas-Sánchez M, Lopez M, Giménez A, Carballo-Mesa A, Bosch E, Calafell F, Quintana-Murci L, Comas D. The Counteracting Effects of Demography on Functional Genomic Variation: The Roma Paradigm. Mol Biol Evol 2021; 38:2804-2817. [PMID: 33713133 PMCID: PMC8233508 DOI: 10.1093/molbev/msab070] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Demographic history plays a major role in shaping the distribution of genomic variation. Yet the interaction between different demographic forces and their effects in the genomes is not fully resolved in human populations. Here, we focus on the Roma population, the largest transnational ethnic minority in Europe. They have a South Asian origin and their demographic history is characterized by recent dispersals, multiple founder events, and extensive gene flow from non-Roma groups. Through the analyses of new high-coverage whole exome sequences and genome-wide array data for 89 Iberian Roma individuals together with forward simulations, we show that founder effects have reduced their genetic diversity and proportion of rare variants, gene flow has counteracted the increase in mutational load, runs of homozygosity show ancestry-specific patterns of accumulation of deleterious homozygotes, and selection signals primarily derive from preadmixture adaptation in the Roma population sources. The present study shows how two demographic forces, bottlenecks and admixture, act in opposite directions and have long-term balancing effects on the Roma genomes. Understanding how demography and gene flow shape the genome of an admixed population provides an opportunity to elucidate how genomic variation is modeled in human populations.
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Affiliation(s)
- Neus Font-Porterias
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Barcelona, Spain
| | - Rocio Caro-Consuegra
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Barcelona, Spain
| | - Marcel Lucas-Sánchez
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Barcelona, Spain
| | - Marie Lopez
- Human Evolutionary Genetics Unit, Institut Pasteur, UMR2000, CNRS, Paris, France
| | - Aaron Giménez
- Facultat de Sociologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | | | - Elena Bosch
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Reus, Spain
| | - Francesc Calafell
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Barcelona, Spain
| | - Lluís Quintana-Murci
- Human Evolutionary Genetics Unit, Institut Pasteur, UMR2000, CNRS, Paris, France.,Human Genomics and Evolution, Collège de France, Paris, France
| | - David Comas
- Departament de Ciències Experimentals i de la Salut, Institut de Biologia Evolutiva (UPF-CSIC), Universitat Pompeu Fabra, Barcelona, Spain
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21
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Kyriazis CC, Wayne RK, Lohmueller KE. Strongly deleterious mutations are a primary determinant of extinction risk due to inbreeding depression. Evol Lett 2021; 5:33-47. [PMID: 33552534 PMCID: PMC7857301 DOI: 10.1002/evl3.209] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 11/10/2020] [Accepted: 11/21/2020] [Indexed: 11/08/2022] Open
Abstract
Human-driven habitat fragmentation and loss have led to a proliferation of small and isolated plant and animal populations with high risk of extinction. One of the main threats to extinction in these populations is inbreeding depression, which is primarily caused by recessive deleterious mutations becoming homozygous due to inbreeding. The typical approach for managing these populations is to maintain high genetic diversity, increasingly by translocating individuals from large populations to initiate a "genetic rescue." However, the limitations of this approach have recently been highlighted by the demise of the gray wolf population on Isle Royale, which declined to the brink of extinction soon after the arrival of a migrant from the large mainland wolf population. Here, we use a novel population genetic simulation framework to investigate the role of genetic diversity, deleterious variation, and demographic history in mediating extinction risk due to inbreeding depression in small populations. We show that, under realistic models of dominance, large populations harbor high levels of recessive strongly deleterious variation due to these mutations being hidden from selection in the heterozygous state. As a result, when large populations contract, they experience a substantially elevated risk of extinction after these strongly deleterious mutations are exposed by inbreeding. Moreover, we demonstrate that, although genetic rescue is broadly effective as a means to reduce extinction risk, its effectiveness can be greatly increased by drawing migrants from small or moderate-sized source populations rather than large source populations due to smaller populations harboring lower levels of recessive strongly deleterious variation. Our findings challenge the traditional conservation paradigm that focuses on maximizing genetic diversity in small populations in favor of a view that emphasizes minimizing strongly deleterious variation. These insights have important implications for managing small and isolated populations in the increasingly fragmented landscape of the Anthropocene.
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Affiliation(s)
- Christopher C. Kyriazis
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCalifornia90095
| | - Robert K. Wayne
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCalifornia90095
| | - Kirk E. Lohmueller
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaLos AngelesCalifornia90095
- Interdepartmental Program in BioinformaticsUniversity of CaliforniaLos AngelesCalifornia90095
- Department of Human Genetics, David Geffen School of MedicineUniversity of CaliforniaLos AngelesCalifornia90095
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22
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Sole-Navais P, Bacelis J, Helgeland Ø, Modzelewska D, Vaudel M, Flatley C, Andreassen O, Njølstad PR, Muglia LJ, Johansson S, Zhang G, Jacobsson B. Autozygosity mapping and time-to-spontaneous delivery in Norwegian parent-offspring trios. Hum Mol Genet 2020; 29:3845-3858. [PMID: 33291140 PMCID: PMC7861013 DOI: 10.1093/hmg/ddaa255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/21/2020] [Accepted: 11/24/2020] [Indexed: 11/18/2022] Open
Abstract
Parental genetic relatedness may lead to adverse health and fitness outcomes in the offspring. However, the degree to which it affects human delivery timing is unknown. We use genotype data from ≃25 000 parent-offspring trios from the Norwegian Mother, Father and Child Cohort Study to optimize runs of homozygosity (ROH) calling by maximizing the correlation between parental genetic relatedness and offspring ROHs. We then estimate the effect of maternal, paternal and fetal autozygosity and that of autozygosity mapping (common segments and gene burden test) on the timing of spontaneous onset of delivery. The correlation between offspring ROH using a variety of parameters and parental genetic relatedness ranged between −0.2 and 0.6, revealing the importance of the minimum number of genetic variants included in an ROH and the use of genetic distance. The optimized compared to predefined parameters showed a ≃45% higher correlation between parental genetic relatedness and offspring ROH. We found no evidence of an effect of maternal, paternal nor fetal overall autozygosity on spontaneous delivery timing. Yet, through autozygosity mapping, we identified three maternal loci TBC1D1, SIGLECs and EDN1 gene regions reducing the median time-to-spontaneous onset of delivery by ≃2–5% (P-value < 2.3 × 10−6). We also found suggestive evidence of a fetal locus at 3q22.2, near the RYK gene region (P-value = 2.0 × 10−6). Autozygosity mapping may provide new insights on the genetic determinants of delivery timing beyond traditional genome-wide association studies, but particular and rigorous attention should be given to ROH calling parameter selection.
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Affiliation(s)
- Pol Sole-Navais
- Department of Obstetrics and Gynecology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 41685, Sweden
| | - Jonas Bacelis
- Department of Obstetrics and Gynecology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 41685, Sweden
| | - Øyvind Helgeland
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, 5020 Bergen, Norway.,Division of Health Data and Digitalization, Department of Genetics and Bioinformatics, Norwegian Institute of Public Health, Oslo 0213, Norway
| | - Dominika Modzelewska
- Department of Obstetrics and Gynecology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 41685, Sweden
| | - Marc Vaudel
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, 5020 Bergen, Norway.,Department of Pediatrics and Adolescents, Haukeland University Hospital, Bergen 5021, Norway
| | - Christopher Flatley
- Division of Health Data and Digitalization, Department of Genetics and Bioinformatics, Norwegian Institute of Public Health, Oslo 0213, Norway
| | - Ole Andreassen
- NORMENT, University of Oslo, Oslo 0450, Norway.,Division of Mental Health and Addiction, Oslo University Hospital, Oslo 0450, Norway.,Department of Psychiatry, University of California San Diego, San Diego, CA 92093, USA
| | - Pål R Njølstad
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, 5020 Bergen, Norway.,Department of Pediatrics and Adolescents, Haukeland University Hospital, Bergen 5021, Norway
| | - Louis J Muglia
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.,Division of Human Genetics, The Center for Prevention of Preterm Birth, Perinatal Institute, March of Dimes Prematurity Research Center Ohio Collaborative, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45267, USA
| | - Stefan Johansson
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, 5020 Bergen, Norway.,Center for Medical Genetics, Haukeland University Hospital, Bergen 5021, Norway
| | - Ge Zhang
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.,Division of Human Genetics, The Center for Prevention of Preterm Birth, Perinatal Institute, March of Dimes Prematurity Research Center Ohio Collaborative, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45267, USA
| | - Bo Jacobsson
- Department of Obstetrics and Gynecology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 41685, Sweden.,Division of Health Data and Digitalization, Department of Genetics and Bioinformatics, Norwegian Institute of Public Health, Oslo 0213, Norway.,Department of Obstetrics and Gynecology, Sahlgrenska University Hospital, Gothenburg 41685, Sweden
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23
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Salvianolic Acid B in Microemulsion Formulation Provided Sufficient Hydration for Dry Skin and Ameliorated the Severity of Imiquimod-Induced Psoriasis-Like Dermatitis in Mice. Pharmaceutics 2020; 12:pharmaceutics12050457. [PMID: 32429542 PMCID: PMC7284938 DOI: 10.3390/pharmaceutics12050457] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 12/19/2022] Open
Abstract
Psoriasis is a chronic inflammatory skin disorder with a pathogenesis involving the interleukin-23/interleukin-17 axis. Salvianolic acid B exerts several pharmacological effects, such as antioxidation, anti-inflammation, and antitumor effects. The anti-psoriatic effects of salvianolic acid B have not been reported. In this study, we aimed to determine the optimum vehicle for salvianolic acid B, investigate its therapeutic effect on psoriatic-like skin conditions, and explore its underlying mechanisms of action. BALB/c mice were administered topical imiquimod to induce psoriasis-like skin and were then randomly assigned to control, vehicle control, salvianolic acid B in vehicles, and 0.25% desoximetasone ointment treatment groups. Barrier function, cytokine expression, histology assessment, and disease severity were evaluated. The results showed that salvianolic acid B-containing microemulsion alleviated disease severity, reduced acanthosis, and inhibited interleukin-23/interleukin-17 (IL-23/IL-17) cytokines, epidermal proliferation, and increased skin hydration. Our study suggests that salvianolic acid B represents a possible new therapeutic drug for the treatment of psoriasis. In addition, such formulation could obtain high therapeutic efficacy in addition to providing sufficient hydration for dry skin.
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24
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Lerario AM, Mohan DR, Montenegro LR, Funari MFDA, Nishi MY, Narcizo ADM, Benedetti AFF, Oba-Shinjo SM, Vitorino AJ, dos Santos RASX, Jorge AADL, Onuchic LF, Marie SKN, Mendonca BB. SELAdb: A database of exonic variants in a Brazilian population referred to a quaternary medical center in São Paulo. Clinics (Sao Paulo) 2020; 75:e1913. [PMID: 32785571 PMCID: PMC7410354 DOI: 10.6061/clinics/2020/e1913] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 06/30/2020] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES High-throughput sequencing of genomes, exomes, and disease-focused gene panels is becoming increasingly common for molecular diagnostics. However, identifying a single clinically relevant pathogenic variant among thousands of genetic polymorphisms is a challenging task. Publicly available genomic databases are useful resources to filter out common genetic variants present in the population and enable the identification of each disease-causing variant. Based on our experience applying these technologies at Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP), São Paulo, Brazil, we recognized that the Brazilian population is not adequately represented in widely available genomic databases. METHODS Here, we took advantage of our 5-year experience as a high-throughput sequencing core facility focused on individuals with putative genetic disorders to build a genomic database that may serve as a more accurate reference for our patient population: SELAdb. RESULTS/CONCLUSIONS Currently, our database comprises a final cohort of 523 unrelated individuals, including patients or family members managed by different clinics of HCFMUSP. We compared SELAdb with other publicly available genomic databases and demonstrated that this population is very heterogeneous, largely resembling Latin American individuals of mixed origin, rather than individuals of pure European ancestry. Interestingly, exclusively through SELAdb, we identified a spectrum of known and potentially novel pathogenic variants in genes associated with highly penetrant Mendelian disorders, illustrating that pathogenic variants circulating in the Brazilian population that is treated in our clinics are underrepresented in other population databases. SELAdb is freely available for public consultation at: http://intranet.fm.usp.br/sela.
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Affiliation(s)
- Antonio Marcondes Lerario
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Michigan, Ann Arbor, MI, USA
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Dipika R. Mohan
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI, USA
- Doctoral Program in Cancer Biology, University of Michigan, Ann Arbor, MI, USA
| | - Luciana Ribeiro Montenegro
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Mariana Ferreira de Assis Funari
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Mirian Yumie Nishi
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Amanda de Moraes Narcizo
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Anna Flavia Figueredo Benedetti
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Sueli Mieko Oba-Shinjo
- Laboratorio de Biologia Molecular e Celular, LIM/15, Departamento de Neurologia, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Aurélio José Vitorino
- Laboratorio de Informatica Medica - LIM/01, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | | | - Alexander Augusto de Lima Jorge
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Luiz Fernando Onuchic
- Disciplina de Medicina Molecular, Departamento de Clinica Medica, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Disciplina de Nefrologia, Departamento de Clinica Medica, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Suely Kazue Nagahashi Marie
- Laboratorio de Biologia Molecular e Celular, LIM/15, Departamento de Neurologia, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Berenice Bilharinho Mendonca
- Disciplina de Endocrinologia e Metabologia, Departamento de Clinica Medica, LIM/42, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
- Laboratorio de Sequenciamento em Larga Escala (SELA), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR
- *Corresponding author. E-mail:
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