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Cuello HA, Sinha S, Verhagen AL, Varki N, Varki A, Ghosh P. Human-specific elimination of epithelial Siglec-XII suppresses the risk of inflammation-driven colorectal cancers. JCI Insight 2024; 9:e181539. [PMID: 38990656 PMCID: PMC11343606 DOI: 10.1172/jci.insight.181539] [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: 04/03/2024] [Accepted: 07/03/2024] [Indexed: 07/13/2024] Open
Abstract
Carcinomas are common in humans but rare among closely related "great apes." Plausible explanations, including human-specific genomic alterations affecting the biology of sialic acids, are proposed, but causality remains unproven. Here, an integrated evolutionary genetics-phenome-transcriptome approach studied the role of SIGLEC12 gene (encoding Siglec-XII) in epithelial transformation and cancer. Exogenous expression of the protein in cell lines and genetically engineered mice recapitulated approximately 30% of the human population in whom the protein is expressed in a form that cannot bind ligand because of a fixed, homozygous, human-universal missense mutation. Siglec-XII-null cells/mice recapitulated the remaining approximately 70% of the human population in whom an additional polymorphic frameshift mutation eliminates the entire protein. Siglec-XII expression drove several pro-oncogenic phenotypes in cell lines and increased tumor burden in mice challenged with chemical carcinogen and inflammation. Transcriptomic studies yielded a 29-gene signature of Siglec-XII-positive disease and when used as a computational tool for navigating human data sets, pinpointed with surprising precision that SIGLEC12 expression (model) recapitulates a very specific type of colorectal carcinomas (disease) that is associated with mismatch-repair defects and inflammation, disproportionately affects European Americans, and carries a favorable prognosis. They revealed a hitherto-unknown evolutionary genetic mechanism for an ethnic/environmental predisposition of carcinogenesis.
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Affiliation(s)
- Hector A. Cuello
- Department of Cellular & Molecular Medicine
- Glycobiology Research and Training Center
| | | | - Andrea L. Verhagen
- Department of Cellular & Molecular Medicine
- Glycobiology Research and Training Center
| | - Nissi Varki
- Glycobiology Research and Training Center
- Department of Pathology
| | - Ajit Varki
- Department of Cellular & Molecular Medicine
- Glycobiology Research and Training Center
- Department of Medicine
- Center for Academic Research and Training in Anthropogeny
| | - Pradipta Ghosh
- Department of Cellular & Molecular Medicine
- Department of Medicine
- Moores Comprehensive Cancer Center, and
- HUMANOID Center of Research Excellence (CoRE), University of California, San Diego, La Jolla, California, USA
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2
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Ogbodo AK, Mustafov D, Arora M, Lambrou GI, Braoudaki M, Siddiqui SS. Analysis of SIGLEC12 expression, immunomodulation and prognostic value in renal cancer using multiomic databases. Heliyon 2024; 10:e24286. [PMID: 38268823 PMCID: PMC10803920 DOI: 10.1016/j.heliyon.2024.e24286] [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: 06/04/2023] [Revised: 11/30/2023] [Accepted: 01/05/2024] [Indexed: 01/26/2024] Open
Abstract
Siglecs belong to a family of immune regulatory receptors predominantly found on hematopoietic cells. They interact with Sia, resulting in the activation or inhibition of the immune response. Previous reports have suggested that the SIGLEC12 gene, which encodes the Siglec-XII protein, is expressed in the epithelial tissues and upregulated in carcinomas. However, studies deciphering the role of Siglec-XII in renal cancer (RC) are still unavailable, and here we provide insights on this question. We conducted expression analysis using the Human Protein Atlas and UALCAN databases. The impact of SIGLEC12 on RC prognosis was determined using the KM plotter, and an assessment of immune infiltration with SIGLEC12 was performed using the TIMER database. GSEA was conducted to identify the pathways affected by SIGLEC12. Finally, using GeneMania, we identified Siglec-XII interacting proteins. Our findings indicated that macrophages express SIGLEC12 in the kidney. Furthermore, we hypothesize that Siglec-XII expression might be involved in the increase of primary RC, but this effect may not be dependent on the age of the patient. In the tumour microenvironment, oncogenic pathways appeared to be upregulated by SIGLEC12. Similarly, our analysis suggested that SIGLEC12-related kidney renal papillary cell carcinomas may be more suitable for targeted immunotherapy, such as CTLA-4 and PD-1/PD-L1 inhibitors. These preliminary results suggested that high expression of SIGLEC12 is associated with poor prognosis for RC. Future studies to assess its clinical utility are necessitated.
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Affiliation(s)
- Amobichukwu K. Ogbodo
- School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield AL10 9AB, United Kingdom
- #Current Address: Nuffield Department of Population Health, University of Oxford, Richard Doll Building, Old Road Campus, Oxford OX3 7LF, United Kingdom
| | - Denis Mustafov
- School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield AL10 9AB, United Kingdom
- College of Health, Medicine, and Life Science, Brunel University London UB8 3PH, United Kingdom
| | - Mohit Arora
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi 110029, India
| | - George I. Lambrou
- Choremeio Research Laboratory, First Department of Paediatrics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece, Thivon & Levadeias 8, 11527, Goudi, Athens, Greece
- University Research Institute of Maternal and Child Health & Precision Medicine, National and Kapodistrian University of Athens, Thivon & Levadeias 8, 11527 Athens, Greece
| | - Maria Braoudaki
- School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield AL10 9AB, United Kingdom
| | - Shoib S. Siddiqui
- School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield AL10 9AB, United Kingdom
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Clark JSC, Podsiadło K, Sobalska-Kwapis M, Marciniak B, Rydzewska K, Ciechanowicz A, van de Wetering T, Strapagiel D. rs67047829 genotypes of ERV3-1/ZNF117 are associated with lower body mass index in the Polish population. Sci Rep 2023; 13:17118. [PMID: 37816715 PMCID: PMC10564729 DOI: 10.1038/s41598-023-43323-3] [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: 04/20/2023] [Accepted: 09/22/2023] [Indexed: 10/12/2023] Open
Abstract
There is now substantial evidence that zinc-finger proteins are implicated in adiposity. Aims were to datamine for high-frequency (near-neutral selection) pretermination-codon (PTC) single-nucleotide polymorphisms (SNPs; n = 141) from a database with > 550,000 variants and analyze possible association with body mass index in a large Polish sample (n = 5757). BMI was regressed (males/females together or separately) against genetic models. Regression for rs67047829 uncovered an interaction-independent association with BMI with both sexes together: mean ± standard deviation, kg/m2: [G];[G], 25.4 ± 4.59 (n = 3650); [G](;)[A], 25.0 ± 4.28 (n = 731); [A];[A], 23.4 ± 3.60 (n = 44); additive model adjusted for age and sex: p = 4.08 × 10-5; beta: - 0.0458, 95% confidence interval (CI) - 0.0732 : - 0.0183; surviving Bonferroni correction; for males: [G];[G], 24.8 ± 4.94 (n = 1878); [G](;)[A], 24.2 ± 4.31 (n = 386); [A];[A], 22.4 ± 3.69 (n = 23); p = 4.20 × 10-4; beta: - 0.0573, CI - 0.0947 : - 0.0199. For average-height males the difference between [G];[G] and [A];[A] genotypes would correspond to ~ 6 kg, suggesting considerable protection against increased BMI. rs67047829 gives a pretermination codon in ERV3-1 which shares an exonic region and possibly promoter with ZNF117, previously associated with adiposity and type-2 diabetes. As this result occurs in a near-neutral Mendelian setting, a drug targetting ERV3-1/ZNF117 might potentially provide considerable benefits with minimal side-effects. This result needs to be replicated, followed by analyses of splice-variant mRNAs and protein expression.
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Affiliation(s)
- Jeremy S C Clark
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111, Szczecin, Zachodniopomorskie, Poland.
| | - Konrad Podsiadło
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111, Szczecin, Zachodniopomorskie, Poland
| | - Marta Sobalska-Kwapis
- Biobank Lab, Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Łodż, 90-237, Łódż, Poland
| | - Błażej Marciniak
- Biobank Lab, Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Łodż, 90-237, Łódż, Poland
| | - Kamila Rydzewska
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111, Szczecin, Zachodniopomorskie, Poland
| | - Andrzej Ciechanowicz
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111, Szczecin, Zachodniopomorskie, Poland
| | - Thierry van de Wetering
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111, Szczecin, Zachodniopomorskie, Poland
| | - Dominik Strapagiel
- Biobank Lab, Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Łodż, 90-237, Łódż, Poland
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Sung C, An J, Lee S, Park J, Lee KS, Kim IH, Han JY, Park YH, Kim JH, Kang EJ, Hong MH, Kim TY, Lee JC, Lee JL, Yoon S, Choi CM, Lee DH, Yoo C, Kim SW, Jeong JH, Seo S, Kim SY, Kong SY, Choi JK, Park SR. Integrative analysis of risk factors for immune-related adverse events of checkpoint blockade therapy in cancer. NATURE CANCER 2023; 4:844-859. [PMID: 37308678 DOI: 10.1038/s43018-023-00572-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 05/05/2023] [Indexed: 06/14/2023]
Abstract
Immune-related adverse events (irAEs) induced by checkpoint inhibitors involve a multitude of different risk factors. Here, to interrogate the multifaceted underlying mechanisms, we compiled germline exomes and blood transcriptomes with clinical data, before and after checkpoint inhibitor treatment, from 672 patients with cancer. Overall, irAE samples showed a substantially lower contribution of neutrophils in terms of baseline and on-therapy cell counts and gene expression markers related to neutrophil function. Allelic variation of HLA-B correlated with overall irAE risk. Analysis of germline coding variants identified a nonsense mutation in an immunoglobulin superfamily protein, TMEM162. In our cohort and the Cancer Genome Atlas (TCGA) data, TMEM162 alteration was associated with higher peripheral and tumor-infiltrating B cell counts and suppression of regulatory T cells in response to therapy. We developed machine learning models for irAE prediction, validated using additional data from 169 patients. Our results provide valuable insights into risk factors of irAE and their clinical utility.
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Affiliation(s)
- Changhwan Sung
- Department of Bio and Brain Engineering, KAIST, Daejeon, Republic of Korea
- Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jinhyeon An
- Department of Bio and Brain Engineering, KAIST, Daejeon, Republic of Korea
| | - Soohyeon Lee
- Division of Oncology-Hematology, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jaesoon Park
- Department of Bio and Brain Engineering, KAIST, Daejeon, Republic of Korea
| | - Kang Seon Lee
- Department of Bio and Brain Engineering, KAIST, Daejeon, Republic of Korea
| | - Il-Hwan Kim
- Department of Oncology, Haeundae Paik Hospital, Cancer Center, Inje University College of Medicine, Busan, Republic of Korea
| | - Ji-Youn Han
- Center for Lung Cancer, National Cancer Center, Goyang, Republic of Korea
| | - Yeon Hee Park
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jee Hyun Kim
- Division of Hematology and Medical Oncology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Eun Joo Kang
- Division of Oncology, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Republic of Korea
| | - Min Hee Hong
- Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Tae-Yong Kim
- Division of Hematology and Medical Oncology, Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jae Cheol Lee
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jae Lyun Lee
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Shinkyo Yoon
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Chang-Min Choi
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Dae Ho Lee
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Changhoon Yoo
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang-We Kim
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jae Ho Jeong
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Seyoung Seo
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sun Young Kim
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sun-Young Kong
- Targeted Therapy Branch, Research Institute, National Cancer Center, Goyang, Republic of Korea
- Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Republic of Korea
- Department of Laboratory Medicine, Hospital, National Cancer Center, Goyang, Republic of Korea
| | - Jung Kyoon Choi
- Department of Bio and Brain Engineering, KAIST, Daejeon, Republic of Korea.
- Penta Medix Co., Ltd., Seongnam, Republic of Korea.
| | - Sook Ryun Park
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
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5
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Zhang H, Xie Y. Novel start codons introduce novel coding sequences in the human genomes. Sci Rep 2023; 13:8141. [PMID: 37208378 DOI: 10.1038/s41598-023-34770-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 05/07/2023] [Indexed: 05/21/2023] Open
Abstract
Start-gain mutations can introduce novel start codons and generate novel coding sequences that may affect the function of genes. In this study, we systematically investigated the novel start codons that were either polymorphic or fixed in the human genomes. 829 polymorphic start-gain SNVs were identified in the human populations, and the novel start codons introduced by these SNVs have significantly higher activity in translation initiation. Some of these start-gain SNVs were reported to be associated with phenotypes and diseases in previous studies. By comparative genomic analysis, we found 26 human-specific start codons that were fixed after the divergence between the human and chimpanzee, and high-level translation initiation activity was observed on them. The negative selection signal was detected in the novel coding sequences introduced by these human-specific start codons, indicating the important function of these novel coding sequences.
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Affiliation(s)
- He Zhang
- Quantitative Biomedical Research Center, Department of Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Yang Xie
- Quantitative Biomedical Research Center, Department of Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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6
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Angata T, Varki A. Discovery, classification, evolution and diversity of Siglecs. Mol Aspects Med 2023; 90:101117. [PMID: 35989204 PMCID: PMC9905256 DOI: 10.1016/j.mam.2022.101117] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 08/03/2022] [Accepted: 08/06/2022] [Indexed: 02/08/2023]
Abstract
Immunoglobulin (Ig) superfamily proteins play diverse roles in vertebrates, including regulation of cellular responses by sensing endogenous or exogenous ligands. Siglecs are a family of glycan-recognizing proteins belonging to the Ig superfamily (i.e., I-type lectins). Siglecs are expressed on various leukocyte types and are involved in diverse aspects of immunity, including the regulation of inflammatory responses, leukocyte proliferation, host-microbe interaction, and cancer immunity. Sialoadhesin/Siglec-1, CD22/Siglec-2, and myelin-associated glycoprotein/Siglec-4 were among the first to be characterized as members of the Siglec family, and along with Siglec-15, they are relatively well-conserved among tetrapods. Conversely, CD33/Siglec-3-related Siglecs (CD33rSiglecs, so named as they show high sequence similarity with CD33/Siglec-3) are encoded in a gene cluster with many interspecies variations and even intraspecies variations within some lineages such as humans. The rapid evolution of CD33rSiglecs expressed on leukocytes involved in innate immunity likely reflects the selective pressure by pathogens that interact and possibly exploit these Siglecs. Human Siglecs have several additional unique and/or polymorphic properties as compared with closely related great apes, changes possibly related to the loss of the sialic acid Neu5Gc, another distinctly human event in sialobiology. Multiple changes in human CD33rSiglecs compared to great apes include many examples of human-specific expression in non-immune cells, coinciding with human-specific diseases involving such cell types. Some Siglec gene polymorphisms have dual consequences-beneficial in a situation but detrimental in another. The association of human Siglec gene polymorphisms with several infectious and non-infectious diseases likely reflects the ongoing competition between the host and microbial pathogens.
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Affiliation(s)
- Takashi Angata
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
| | - Ajit Varki
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, USA.
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Adaptive Evolution of the OAS Gene Family Provides New Insights into the Antiviral Ability of Laurasiatherian Mammals. Animals (Basel) 2023; 13:ani13020209. [PMID: 36670749 PMCID: PMC9854896 DOI: 10.3390/ani13020209] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/31/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023] Open
Abstract
Many mammals risk damage from virus invasion due to frequent environmental changes. The oligoadenylate synthesis (OAS) gene family, which is an important component of the immune system, provides an essential response to the antiviral activities of interferons by regulating immune signal pathways. However, little is known about the evolutionary characteristics of OASs in Laurasiatherian mammals. Here, we examined the evolution of the OAS genes in 64 mammals to explore the accompanying molecular mechanisms of the antiviral ability of Laurasiatherian mammals living in different environments. We found that OAS2 and OAS3 were found to be pseudogenes in Odontoceti species. This may be related to the fact that they live in water. Some Antilopinae, Caprinae, and Cervidae species lacked the OASL gene, which may be related to their habitats being at higher altitudes. The OASs had a high number of positive selection sites in Cetartiodactyla, which drove the expression of strong antiviral ability. The OAS gene family evolved in Laurasiatherian mammals at different rates and was highly correlated with the species' antiviral ability. The gene evolution rate in Cetartiodactyla was significantly higher than that in the other orders. Compared to other species of the Carnivora family, the higher selection pressure on the OAS gene and the absence of positive selection sites in Canidae may be responsible for its weak resistance to rabies virus. The OAS gene family was relatively conserved during evolution. Conserved genes are able to provide better maintenance of gene function. The rate of gene evolution and the number of positively selected sites combine to influence the resistance of a species to viruses. The positive selection sites demonstrate the adaptive evolution of the OAS gene family to the environment. Adaptive evolution combined with conserved gene function improves resistance to viruses. Our findings offer insights into the molecular and functional evolution of the antiviral ability of Laurasian mammals.
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Potapova NA. Nonsense Mutations in Eukaryotes. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:400-412. [PMID: 35790376 DOI: 10.1134/s0006297922050029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/14/2022] [Accepted: 03/22/2022] [Indexed: 06/15/2023]
Abstract
Nonsense mutations are a type of mutations which results in a premature termination codon occurrence. In general, these mutations have been considered to be among the most harmful ones which lead to premature protein translation termination and result in shortened nonfunctional polypeptide. However, there is evidence that not all nonsense mutations are harmful as well as some molecular mechanisms exist which allow to avoid pathogenic effects of these mutations. This review addresses relevant information on nonsense mutations in eukaryotic genomes, characteristics of these mutations, and different molecular mechanisms preventing or mitigating harmful effects thereof.
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Affiliation(s)
- Nadezhda A Potapova
- Kharkevich Institute for Information Transmission Problems (IITP), Russian Academy of Sciences, Moscow, 127051, Russia.
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Zhao J, Li Z, Puri R, Liu K, Nunez I, Chen L, Zheng S. Molecular profiling of individual FDA-approved clinical drugs identifies modulators of nonsense-mediated mRNA decay. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 27:304-318. [PMID: 35024243 PMCID: PMC8718828 DOI: 10.1016/j.omtn.2021.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 12/07/2021] [Indexed: 12/12/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) degrades transcripts with premature stop codons. Given the prevalence of nonsense single nucleotide polymorphisms (SNPs) in the general population, it is urgent to catalog the effects of clinically approved drugs on NMD activity: any interference could alter the expression of nonsense SNPs, inadvertently inducing adverse effects. This risk is higher for patients with disease-causing nonsense mutations or an illness linked to dysregulated nonsense transcripts. On the other hand, hundreds of disorders are affected by cellular NMD efficiency and may benefit from NMD-modulatory drugs. Here, we profiled individual FDA-approved drugs for their impact on cellular NMD efficiency using a sensitive method that directly probes multiple endogenous NMD targets for a robust readout of NMD modulation. We found most FDA-approved drugs cause unremarkable effects on NMD, while many elicit clear transcriptional responses. Besides several potential mild NMD modulators, the anticancer drug homoharringtonine (HHT or omacetaxine mepesuccinate) consistently upregulates various endogenous NMD substrates in a dose-dependent manner in multiple cell types. We further showed translation inhibition mediates HHT's NMD effect. In summary, many FDA drugs induce transcriptional changes, and a few impact global NMD, and direct measurement of endogenous NMD substrate expression is robust to monitor cellular NMD.
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Affiliation(s)
- Jingrong Zhao
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Zhelin Li
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Ruchira Puri
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Kelvin Liu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Israel Nunez
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
| | - Liang Chen
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Sika Zheng
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 91709, USA
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10
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Wahyudi F, Aghakhanian F, Rahman S, Teo YY, Szpak M, Dhaliwal J, Ayub Q. Prioritising positively selected variants in whole-genome sequencing data using FineMAV. BMC Bioinformatics 2021; 22:604. [PMID: 34922440 PMCID: PMC8684245 DOI: 10.1186/s12859-021-04506-9] [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: 09/16/2021] [Accepted: 11/30/2021] [Indexed: 11/17/2022] Open
Abstract
Background In population genomics, polymorphisms that are highly differentiated between geographically separated populations are often suggestive of Darwinian positive selection. Genomic scans have highlighted several such regions in African and non-African populations, but only a handful of these have functional data that clearly associates candidate variations driving the selection process. Fine-Mapping of Adaptive Variation (FineMAV) was developed to address this in a high-throughput manner using population based whole-genome sequences generated by the 1000 Genomes Project. It pinpoints positively selected genetic variants in sequencing data by prioritizing high frequency, population-specific and functional derived alleles. Results We developed a stand-alone software that implements the FineMAV statistic. To graphically visualise the FineMAV scores, it outputs the statistics as bigWig files, which is a common file format supported by many genome browsers. It is available as a command-line and graphical user interface. The software was tested by replicating the FineMAV scores obtained using 1000 Genomes Project African, European, East and South Asian populations and subsequently applied to whole-genome sequencing datasets from Singapore and China to highlight population specific variants that can be subsequently modelled. The software tool is publicly available at https://github.com/fadilla-wahyudi/finemav. Conclusions The software tool described here determines genome-wide FineMAV scores, using low or high-coverage whole-genome sequencing datasets, that can be used to prioritize a list of population specific, highly differentiated candidate variants for in vitro or in vivo functional screens. The tool displays these scores on the human genome browsers for easy visualisation, annotation and comparison between different genomic regions in worldwide human populations. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-021-04506-9.
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Affiliation(s)
- Fadilla Wahyudi
- School of Science, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Farhang Aghakhanian
- Monash University Malaysia Genomics Facility, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia.,Genes and Human Disease Research Program, Oklahoma Medical Research Foundation,, Oklahoma City, OK, 73104, USA
| | - Sadequr Rahman
- School of Science, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia.,Tropical Medicine and Biology Multidisciplinary Platform, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Yik-Ying Teo
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Michał Szpak
- European Bioinformatics Institute, Hinxton, CB10 1SA, UK.,Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
| | - Jasbir Dhaliwal
- School of Information Technology, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia.
| | - Qasim Ayub
- School of Science, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia. .,Monash University Malaysia Genomics Facility, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia. .,Tropical Medicine and Biology Multidisciplinary Platform, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia.
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11
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Szpak M, Collins SC, Li Y, Liu X, Ayub Q, Fischer MC, Vancollie VE, Lelliott CJ, Xue Y, Yalcin B, Yang H, Tyler-Smith C. A Positively Selected MAGEE2 LoF Allele Is Associated with Sexual Dimorphism in Human Brain Size and Shows Similar Phenotypes in Magee2 Null Mice. Mol Biol Evol 2021; 38:5655-5663. [PMID: 34464968 PMCID: PMC8662591 DOI: 10.1093/molbev/msab243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A nonsense allele at rs1343879 in human MAGEE2 on chromosome X has previously been reported as a strong candidate for positive selection in East Asia. This premature stop codon causing ∼80% protein truncation is characterized by a striking geographical pattern of high population differentiation: common in Asia and the Americas (up to 84% in the 1000 Genomes Project East Asians) but rare elsewhere. Here, we generated a Magee2 mouse knockout mimicking the human loss-of-function mutation to study its functional consequences. The Magee2 null mice did not exhibit gross abnormalities apart from enlarged brain structures (13% increased total brain area, P = 0.0022) in hemizygous males. The area of the granular retrosplenial cortex responsible for memory, navigation, and spatial information processing was the most severely affected, exhibiting an enlargement of 34% (P = 3.4×10-6). The brain size in homozygous females showed the opposite trend of reduced brain size, although this did not reach statistical significance. With these insights, we performed human association analyses between brain size measurements and rs1343879 genotypes in 141 Chinese volunteers with brain MRI scans, replicating the sexual dimorphism seen in the knockout mouse model. The derived stop gain allele was significantly associated with a larger volume of gray matter in males (P = 0.00094), and smaller volumes of gray (P = 0.00021) and white (P = 0.0015) matter in females. It is unclear whether or not the observed neuroanatomical phenotypes affect behavior or cognition, but it might have been the driving force underlying the positive selection in humans.
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Affiliation(s)
- Michał Szpak
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Stephan C Collins
- Inserm UMR1231, Genetics of Developmental Disorders Laboratory, University of Bourgogne Franche-Comté, Dijon, France.,IGBMC, UMR7104, Illkirch, Inserm, France
| | - Yan Li
- BGI-Shenzhen, Shenzhen, China
| | - Xiao Liu
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
| | - Qasim Ayub
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom.,Monash University Malaysia Genomics Facility, School of Science, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | | | | | | | - Yali Xue
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
| | - Binnaz Yalcin
- Inserm UMR1231, Genetics of Developmental Disorders Laboratory, University of Bourgogne Franche-Comté, Dijon, France.,IGBMC, UMR7104, Illkirch, Inserm, France
| | | | - Chris Tyler-Smith
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
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12
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Durward-Akhurst SA, Schaefer RJ, Grantham B, Carey WK, Mickelson JR, McCue ME. Genetic Variation and the Distribution of Variant Types in the Horse. Front Genet 2021; 12:758366. [PMID: 34925451 PMCID: PMC8676274 DOI: 10.3389/fgene.2021.758366] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/10/2021] [Indexed: 11/13/2022] Open
Abstract
Genetic variation is a key contributor to health and disease. Understanding the link between an individual's genotype and the corresponding phenotype is a major goal of medical genetics. Whole genome sequencing (WGS) within and across populations enables highly efficient variant discovery and elucidation of the molecular nature of virtually all genetic variation. Here, we report the largest catalog of genetic variation for the horse, a species of importance as a model for human athletic and performance related traits, using WGS of 534 horses. We show the extent of agreement between two commonly used variant callers. In data from ten target breeds that represent major breed clusters in the domestic horse, we demonstrate the distribution of variants, their allele frequencies across breeds, and identify variants that are unique to a single breed. We investigate variants with no homozygotes that may be potential embryonic lethal variants, as well as variants present in all individuals that likely represent regions of the genome with errors, poor annotation or where the reference genome carries a variant. Finally, we show regions of the genome that have higher or lower levels of genetic variation compared to the genome average. This catalog can be used for variant prioritization for important equine diseases and traits, and to provide key information about regions of the genome where the assembly and/or annotation need to be improved.
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Affiliation(s)
- S. A. Durward-Akhurst
- Department of Veterinary Population Medicine, University of Minnesota, Minneapolis, MN, United States
| | - R. J. Schaefer
- Department of Veterinary Population Medicine, University of Minnesota, Minneapolis, MN, United States
| | - B. Grantham
- Interval Bio LLC, Mountain View, CA, United States
| | - W. K. Carey
- Interval Bio LLC, Mountain View, CA, United States
| | - J. R. Mickelson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Minneapolis, MN, United States
| | - M. E. McCue
- Department of Veterinary Population Medicine, University of Minnesota, Minneapolis, MN, United States
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13
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Siddiqui SS, Vaill M, Varki A. Ongoing selection for a uniquely human null allele of SIGLEC12 in world-wide populations may protect against the risk of advanced carcinomas. FASEB Bioadv 2021; 3:278-279. [PMID: 33842853 PMCID: PMC8019254 DOI: 10.1096/fba.2021-00036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 03/12/2021] [Indexed: 11/11/2022] Open
Affiliation(s)
- Shoib S. Siddiqui
- Departments of Medicine and Cellular and Molecular MedicineGlycobiology Research and Training Center, and Center for Academic Research and Training in AnthropogenyUniversity of CaliforniaSan DiegoCAUSA
- Present address:
School of Life and Medical SciencesUniversity of HertfordshireHatfieldUK
| | - Michael Vaill
- Departments of Medicine and Cellular and Molecular MedicineGlycobiology Research and Training Center, and Center for Academic Research and Training in AnthropogenyUniversity of CaliforniaSan DiegoCAUSA
| | - Ajit Varki
- Departments of Medicine and Cellular and Molecular MedicineGlycobiology Research and Training Center, and Center for Academic Research and Training in AnthropogenyUniversity of CaliforniaSan DiegoCAUSA
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14
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Romdhane L, Mezzi N, Dallali H, Messaoud O, Shan J, Fakhro KA, Kefi R, Chouchane L, Abdelhak S. A map of copy number variations in the Tunisian population: a valuable tool for medical genomics in North Africa. NPJ Genom Med 2021; 6:3. [PMID: 33420067 PMCID: PMC7794582 DOI: 10.1038/s41525-020-00166-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 11/18/2020] [Indexed: 11/24/2022] Open
Abstract
Copy number variation (CNV) is considered as the most frequent type of structural variation in the human genome. Some CNVs can act on human phenotype diversity, encompassing rare Mendelian diseases and genomic disorders. The North African populations remain underrepresented in public genetic databases in terms of single-nucleotide variants as well as for larger genomic mutations. In this study, we present the first CNV map for a North African population using the Affymetrix Genome-Wide SNP (single-nucleotide polymorphism) array 6.0 array genotyping intensity data to call CNVs in 102 Tunisian healthy individuals. Two softwares, PennCNV and Birdsuite, were used to call CNVs in order to provide reliable data. Subsequent bioinformatic analyses were performed to explore their features and patterns. The CNV map of the Tunisian population includes 1083 CNVs spanning 61.443 Mb of the genome. The CNV length ranged from 1.017 kb to 2.074 Mb with an average of 56.734 kb. Deletions represent 57.43% of the identified CNVs, while duplications and the mixed loci are less represented. One hundred and three genes disrupted by CNVs are reported to cause 155 Mendelian diseases/phenotypes. Drug response genes were also reported to be affected by CNVs. Data on genes overlapped by deletions and duplications segments and the sequence properties in and around them also provided insights into the functional and health impacts of CNVs. These findings represent valuable clues to genetic diversity and personalized medicine in the Tunisian population as well as in the ethnically similar populations from North Africa.
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Affiliation(s)
- Lilia Romdhane
- Biomedical Genomics and Oncogenetics Laboratory (LR16IPT05), Institut Pasteur de Tunis, Tunis, Tunisia.
- Department of Biology, Faculty of Science of Bizerte, Jarzouna, Tunisia.
| | - Nessrine Mezzi
- Biomedical Genomics and Oncogenetics Laboratory (LR16IPT05), Institut Pasteur de Tunis, Tunis, Tunisia
| | - Hamza Dallali
- Biomedical Genomics and Oncogenetics Laboratory (LR16IPT05), Institut Pasteur de Tunis, Tunis, Tunisia
| | - Olfa Messaoud
- Biomedical Genomics and Oncogenetics Laboratory (LR16IPT05), Institut Pasteur de Tunis, Tunis, Tunisia
| | - Jingxuan Shan
- Department of Genetic Medicine, Weill Cornell Medicine, New York, NY, USA
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
- Genetic Intelligence Laboratory, Weill Cornell Medicine in Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Khalid A Fakhro
- Department of Genetic Medicine, Weill Cornell Medical College in Qatar, Doha, Qatar
- Department of Human Genetics, Sidra Medicine, Doha, Qatar
| | - Rym Kefi
- Biomedical Genomics and Oncogenetics Laboratory (LR16IPT05), Institut Pasteur de Tunis, Tunis, Tunisia
| | - Lotfi Chouchane
- Department of Genetic Medicine, Weill Cornell Medicine, New York, NY, USA
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
- Genetic Intelligence Laboratory, Weill Cornell Medicine in Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Sonia Abdelhak
- Biomedical Genomics and Oncogenetics Laboratory (LR16IPT05), Institut Pasteur de Tunis, Tunis, Tunisia
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15
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Siddiqui SS, Vaill M, Do R, Khan N, Verhagen AL, Zhang W, Lenz HJ, Johnson-Pais TL, Leach RJ, Fraser G, Wang C, Feng GS, Varki N, Varki A. Human-specific polymorphic pseudogenization of SIGLEC12 protects against advanced cancer progression. FASEB Bioadv 2020; 3:69-82. [PMID: 33615152 PMCID: PMC7876704 DOI: 10.1096/fba.2020-00092] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 12/22/2022] Open
Abstract
Compared with our closest living evolutionary cousins, humans appear unusually prone to develop carcinomas (cancers arising from epithelia). The SIGLEC12 gene, which encodes the Siglec-XII protein expressed on epithelial cells, has several uniquely human features: a fixed homozygous missense mutation inactivating its natural ligand recognition property; a polymorphic frameshift mutation eliminating full-length protein expression in ~60%-70% of worldwide human populations; and, genomic features suggesting a negative selective sweep favoring the pseudogene state. Despite the loss of canonical sialic acid binding, Siglec-XII still recruits Shp2 and accelerates tumor growth in a mouse model. We hypothesized that dysfunctional Siglec-XII facilitates human carcinoma progression, correlating with known tumorigenic signatures of Shp2-dependent cancers. Immunohistochemistry was used to detect Siglec-XII expression on tissue microarrays. PC-3 prostate cancer cells were transfected with Siglec-XII and transcription of genes enriched with Siglec-XII was determined. Genomic SIGLEC12 status was determined for four different cancer cohorts. Finally, a dot blot analysis of human urinary epithelial cells was established to determine the Siglec-XII expressors versus non-expressors. Forced expression in a SIGLEC12 null carcinoma cell line enriched transcription of genes associated with cancer progression. While Siglec-XII was detected as expected in ~30%-40% of normal epithelia, ~80% of advanced carcinomas showed strong expression. Notably, >80% of late-stage colorectal cancers had a functional SIGLEC12 allele, correlating with overall increased mortality. Thus, advanced carcinomas are much more likely to occur in individuals whose genomes have an intact SIGLEC12 gene, likely because the encoded Siglec-XII protein recruits Shp2-related oncogenic pathways. The finding has prognostic, diagnostic, and therapeutic implications.
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Affiliation(s)
- Shoib S Siddiqui
- Departments of Medicine, Cellular and Molecular Medicine, and Pathology, Glycobiology Research and Training Cente and Center for Academic Research and Training in Anthropogeny University of California San Diego CA USA.,Present address: Department of Biotechnology American University of Ras Al Khaimah (AURAK American University of Ras Al Khaimah Road Al Burairat Area Ras Al Khaimah UAE
| | - Michael Vaill
- Departments of Medicine, Cellular and Molecular Medicine, and Pathology, Glycobiology Research and Training Cente and Center for Academic Research and Training in Anthropogeny University of California San Diego CA USA
| | - Raymond Do
- Departments of Medicine, Cellular and Molecular Medicine, and Pathology, Glycobiology Research and Training Cente and Center for Academic Research and Training in Anthropogeny University of California San Diego CA USA
| | - Naazneen Khan
- Departments of Medicine, Cellular and Molecular Medicine, and Pathology, Glycobiology Research and Training Cente and Center for Academic Research and Training in Anthropogeny University of California San Diego CA USA
| | - Andrea L Verhagen
- Departments of Medicine, Cellular and Molecular Medicine, and Pathology, Glycobiology Research and Training Cente and Center for Academic Research and Training in Anthropogeny University of California San Diego CA USA
| | - Wu Zhang
- University of Southern California Norris Comprehensive Cancer Center Los Angeles CA USA
| | - Heinz-Josef Lenz
- University of Southern California Norris Comprehensive Cancer Center Los Angeles CA USA
| | | | - Robin J Leach
- Department of Urology University of TX Health Science Center San Antonio TX USA.,Departments of Cell Systems and Anatomy University of TX Health Science Center San Antonio TX USA
| | - Gary Fraser
- School of Public Health Loma Linda University Loma Linda CA USA
| | - Charles Wang
- School of Public Health Loma Linda University Loma Linda CA USA
| | - Gen-Sheng Feng
- Departments of Medicine, Cellular and Molecular Medicine, and Pathology, Glycobiology Research and Training Cente and Center for Academic Research and Training in Anthropogeny University of California San Diego CA USA
| | - Nissi Varki
- Departments of Medicine, Cellular and Molecular Medicine, and Pathology, Glycobiology Research and Training Cente and Center for Academic Research and Training in Anthropogeny University of California San Diego CA USA
| | - Ajit Varki
- Departments of Medicine, Cellular and Molecular Medicine, and Pathology, Glycobiology Research and Training Cente and Center for Academic Research and Training in Anthropogeny University of California San Diego CA USA
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16
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Xu YC, Guo YL. Less Is More, Natural Loss-of-Function Mutation Is a Strategy for Adaptation. PLANT COMMUNICATIONS 2020; 1:100103. [PMID: 33367264 PMCID: PMC7743898 DOI: 10.1016/j.xplc.2020.100103] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/08/2020] [Accepted: 08/12/2020] [Indexed: 05/12/2023]
Abstract
Gene gain and loss are crucial factors that shape the evolutionary success of diverse organisms. In the past two decades, more attention has been paid to the significance of gene gain through gene duplication or de novo genes. However, gene loss through natural loss-of-function (LoF) mutations, which is prevalent in the genomes of diverse organisms, has been largely ignored. With the development of sequencing techniques, many genomes have been sequenced across diverse species and can be used to study the evolutionary patterns of gene loss. In this review, we summarize recent advances in research on various aspects of LoF mutations, including their identification, evolutionary dynamics in natural populations, and functional effects. In particular, we discuss how LoF mutations can provide insights into the minimum gene set (or the essential gene set) of an organism. Furthermore, we emphasize their potential impact on adaptation. At the genome level, although most LoF mutations are neutral or deleterious, at least some of them are under positive selection and may contribute to biodiversity and adaptation. Overall, we highlight the importance of natural LoF mutations as a robust framework for understanding biological questions in general.
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Affiliation(s)
- Yong-Chao Xu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ya-Long Guo
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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17
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Gao XL, Tian WJ, Liu B, Wu J, Xie W, Shen Q. High-mobility group nucleosomal binding domain 2 protects against microcephaly by maintaining global chromatin accessibility during corticogenesis. J Biol Chem 2019; 295:468-480. [PMID: 31699896 DOI: 10.1074/jbc.ra119.010616] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/30/2019] [Indexed: 11/06/2022] Open
Abstract
The surface area of the human cerebral cortex undergoes dramatic expansion during late fetal development, leading to cortical folding, an evolutionary feature not present in rodents. Microcephaly is a neurodevelopmental disorder defined by an abnormally small brain, and many gene mutations have been found to be associated with primary microcephaly. However, mouse models generated by ablating primary microcephaly-associated genes often fail to recapitulate the severe loss of cortical surface area observed in individuals with this pathology. Here, we show that a mouse model with deficient expression of high-mobility group nucleosomal binding domain 2 (HMGN2) manifests microcephaly with reduced cortical surface area and almost normal radial corticogenesis, with a pattern of incomplete penetrance. We revealed that altered cleavage plane and mitotic delay of ventricular radial glia may explain the rising ratio of intermediate progenitor cells to radial glia and the displacement of neural progenitor cells in microcephalic mutant mice. These led to decreased self-renewal of the radial glia and reduction in lateral expansion. Furthermore, we found that HMGN2 protected corticogenesis by maintaining global chromatin accessibility mainly at promoter regions, thereby ensuring the correct regulation of the transcriptome. Our findings underscore the importance of the regulation of chromatin structure in cortical development and highlight a mouse model with critical insights into the etiology of microcephaly.
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Affiliation(s)
- Xue-Ling Gao
- School of Life Sciences, Peking University, Beijing 100871, China; Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Tongji Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200065, China; Frontier Science Center for Stem Cell Research, Ministry of Education, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Wen-Jia Tian
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Tongji Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200065, China; Frontier Science Center for Stem Cell Research, Ministry of Education, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China; Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Bofeng Liu
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China; Center for Stem Cell Biology and Regenerative Medicine, MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jingyi Wu
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China; Center for Stem Cell Biology and Regenerative Medicine, MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Xie
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China; Center for Stem Cell Biology and Regenerative Medicine, MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qin Shen
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Tongji Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200065, China; Frontier Science Center for Stem Cell Research, Ministry of Education, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China; Tongji University Brain and Spinal Cord Clinical Research Center, Shanghai 200092, China.
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18
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Abouelhoda M, Faquih T, El-Kalioby M, Alkuraya FS. Revisiting the morbid genome of Mendelian disorders. Genome Biol 2016; 17:235. [PMID: 27884173 PMCID: PMC5123336 DOI: 10.1186/s13059-016-1102-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 11/08/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The pathogenicity of many Mendelian variants has been challenged by large-scale sequencing efforts. However, many rare and benign "disease mutations" are difficult to analyze due to their rarity. The Saudi Arabian variome is enriched for homozygosity due to inbreeding, a key advantage that can be exploited for the critical examination of previously published variants. RESULTS We collated all "disease-related mutations" listed in the Human Gene Mutation Database (HGMD) and ClinVar, including "variants of uncertain significance" (VOUS). We find that the use of public databases including 1000 Genomes, ExAC, and Kaviar can reclassify many of these variants as likely benign. Our Saudi Human Genome Program (SHGP) can reclassify many variants that are rare in public databases. Furthermore, SGPD allows us to observe many previously reported variants in the homozygous state and our extensive phenotyping of participants makes it possible to demonstrate the lack of phenotype for these variants, thus challenging their pathogenicity despite their rarity. We also find that 18 VOUS BRCA1 and BRCA2 variants that are listed in BRCA Exchange are present at least once in the homozygous state in patients who lack features of Fanconi anemia. Reassuringly, we could reciprocally demonstrate that none of those labeled as "pathogenic" were observed in the homozygous statue in individuals who lack Fanconi phenotype in our database. CONCLUSION Our study shows the importance of revisiting disease-related databases using public resources as well as of population-specific resources to improve the specificity of the morbid genome of Mendelian diseases in humans.
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Affiliation(s)
- Mohamed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
- Saudi Human Genome Program, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia.
| | - Tariq Faquih
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Saudi Human Genome Program, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
| | - Mohamed El-Kalioby
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Saudi Human Genome Program, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
- Saudi Human Genome Program, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia.
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
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19
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Ma Q, Wu M, Pei W, Wang X, Zhai H, Wang W, Li X, Zhang J, Yu J, Yu S. RNA-Seq-Mediated Transcriptome Analysis of a Fiberless Mutant Cotton and Its Possible Origin Based on SNP Markers. PLoS One 2016; 11:e0151994. [PMID: 26990639 PMCID: PMC4798417 DOI: 10.1371/journal.pone.0151994] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/07/2016] [Indexed: 01/01/2023] Open
Abstract
As the longest known single-celled trichomes, cotton (Gossypium L.) fibers constitute a classic model system to investigate cell initiation and elongation. In this study, we used a high-throughput transcriptome sequencing technology to identify fiber-initiation-related single nucleotide polymorphism (SNP) markers and differentially expressed genes (DEGs) between the wild-type (WT) Upland cotton (G. hirsutum) Xuzhou 142 and its natural fuzzless-lintless mutant Xuzhou 142 fl. Approximately 700 million high-quality cDNA reads representing over 58 Gb of sequences were obtained, resulting in the identification of 28,610 SNPs--of which 17,479 were novel--from 13,960 expressed genes. Of these SNPs, 50% of SNPs in fl were identical to those of G. barbadense, which suggests the likely origin of the fl mutant from an interspecific hybridization between Xuzhou 142 and an unknown G. barbadense genotype. Of all detected SNPs, 15,555, 12,750, and 305 were classified as non-synonymous, synonymous, and pre-terminated ones, respectively. Moreover, 1,352 insertion/deletion polymorphisms (InDels) were also detected. A total of 865 DEGs were identified between the WT and fl in ovules at -3 and 0 days post-anthesis, with 302 candidate SNPs selected from these DEGs for validation by a high-resolution melting analysis and Sanger sequencing in seven cotton genotypes. The number of genotypic pairwise polymorphisms varied from 43 to 302, indicating that the identified SNPs are reliable. These SNPs should serve as good resources for breeding and genetic studies in cotton.
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Affiliation(s)
- Qifeng Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China
| | - Man Wu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China
| | - Wenfeng Pei
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China
| | - Xiaoyan Wang
- College of Biology and Food Technology, Anyang Institute of Technology, Anyang, China
| | - Honghong Zhai
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China
| | - Wenkui Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China
| | - Xingli Li
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China
| | - Jinfa Zhang
- Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - Jiwen Yu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China
| | - Shuxun Yu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China
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20
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Fujikura K. Premature termination codons in modern human genomes. Sci Rep 2016; 6:22468. [PMID: 26932450 PMCID: PMC4773809 DOI: 10.1038/srep22468] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 01/14/2016] [Indexed: 12/16/2022] Open
Abstract
The considerable range of genetic variation in human populations may partly reflect distinctive processes of adaptation to variable environmental conditions. However, the adaptive genomic signatures remain to be completely elucidated. This research explores candidate loci under selection at the population level by characterizing recently arisen premature termination codons (PTCs), some of which indicate a human knockout. From a total of 7595 participants from two population exome projects, 246 PTCs were found where natural selection has resulted in new alleles with a high frequency (from 1% to 96%) of derived alleles and various levels of population differentiation (FST = 0.00139–0.626). The PTC genes formed protein and regulatory networks limited to 15 biological processes or gene families, of which seven categories were previously unreported. PTC mutations have a strong tendency to be introduced into members of the same gene family, even during modern human evolution, although the exact nature of the selection is not fully known. The findings here suggest the ongoing evolutionary plasticity of modern humans at the genetic level and also partly provide insights into common human knockouts.
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Affiliation(s)
- Kohei Fujikura
- Kobe University School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
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21
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A catalog of hemizygous variation in 127 22q11 deletion patients. Hum Genome Var 2016; 3:15065. [PMID: 27274857 PMCID: PMC4892188 DOI: 10.1038/hgv.2015.65] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/30/2015] [Accepted: 11/02/2015] [Indexed: 02/06/2023] Open
Abstract
The 22q11.2 deletion syndrome is the most common microdeletion disorder, with wide phenotypic variability. To investigate variation within the non-deleted allele we performed targeted resequencing of the 22q11.2 region for 127 patients, identifying multiple deletion sizes, including two deletions with atypical breakpoints. We cataloged ~12,000 hemizygous variant positions, of which 84% were previously annotated. Within the coding regions 95 non-synonymous variants, three stop gains, and two frameshift insertions were identified, some of which we speculate could contribute to atypical phenotypes. We also catalog tolerability of 22q11 gene mutations based on related autosomal recessive disorders in man, embryonic lethality in mice, cross-species conservation and observations that some genes harbor more or less variants than expected. This extensive catalog of hemizygous variants will serve as a blueprint for future experiments to correlate 22q11DS variation with phenotype.
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Liu T, Lin K. The distribution pattern of genetic variation in the transcript isoforms of the alternatively spliced protein-coding genes in the human genome. MOLECULAR BIOSYSTEMS 2016; 11:1378-88. [PMID: 25820936 DOI: 10.1039/c5mb00132c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
By enabling the transcription of multiple isoforms from the same gene locus, alternative-splicing mechanisms greatly expand the diversity of the human transcriptome and proteome. Currently, the alternatively spliced transcripts from each protein-coding gene locus in the human genome can be classified as either principal or non-principal isoforms, providing that they differ with respect to cross-species conservation or biological features. By mapping the variants from the 1000 Genomes Project onto the coding region of each isoform, an interesting pattern of the genetic variation distributions of the coding regions for these two types of transcript isoforms was revealed on a whole-genome scale: compared with the principal isoform-specific coding regions, the non-principal isoform-specific coding regions are significantly enriched in amino acid-changing variants, particularly those that have a strong impact on protein function and have higher derived allele frequencies, suggesting that non-principal isoform-specific substitutions are less likely to be related to phenotype changes or disease. The results herein can help us better understand the potential consequences of alternatively spliced products from a population perspective.
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Affiliation(s)
- Ting Liu
- College of Life Sciences, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing, 100875, P. R. China.
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Fakhro KA, Yousri NA, Rodriguez-Flores JL, Robay A, Staudt MR, Agosto-Perez F, Salit J, Malek JA, Suhre K, Jayyousi A, Zirie M, Stadler D, Mezey JG, Crystal RG. Copy number variations in the genome of the Qatari population. BMC Genomics 2015; 16:834. [PMID: 26490036 PMCID: PMC4618522 DOI: 10.1186/s12864-015-1991-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 10/06/2015] [Indexed: 12/25/2022] Open
Abstract
Background The populations of the Arabian Peninsula remain the least represented in public genetic databases, both in terms of single nucleotide variants and of larger genomic mutations. We present the first high-resolution copy number variation (CNV) map for a Gulf Arab population, using a hybrid approach that integrates array genotyping intensity data and next-generation sequencing reads to call CNVs in the Qatari population. Methods CNVs were detected in 97 unrelated Qatari individuals by running two calling algorithms on each of two primary datasets: high-resolution genotyping (Illumina Omni 2.5M) and high depth whole-genome sequencing (Illumina PE 100bp). The four call-sets were integrated to identify high confidence CNV regions, which were subsequently annotated for putative functional effect and compared to public databases of CNVs in other populations. The availability of genome sequence was leveraged to identify tagging SNPs in high LD with common deletions in this population, enabling their imputation from genotyping experiments in the future. Results Genotyping intensities and genome sequencing data from 97 Qataris were analyzed with four different algorithms and integrated to discover 16,660 high confidence CNV regions (CNVRs) in the total population, affecting ~28 Mb in the median Qatari genome. Up to 40 % of all CNVs affected genes, including novel CNVs affecting Mendelian disease genes, segregating at different frequencies in the 3 major Qatari subpopulations, including those with Bedouin, Persian/South Asian, and African ancestry. Consistent with high consanguinity levels in the Bedouin subpopulation, we found an increased burden for homozygous deletions in this group. In comparison to known CNVs in the comprehensive Database of Genomic Variants, we found that 5 % of all CNVRs in Qataris were completely novel, with an enrichment of CNVs affecting several known chromosomal disorder loci and genes known to regulate sugar metabolism and type 2 diabetes in the Qatari cohort. Finally, we leveraged the availability of genome sequence to find suitable tagging SNPs for common deletions in this population. Conclusion We combine four independently generated datasets from 97 individuals to study CNVs for the first time at high-resolution in a Gulf Arab population. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1991-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Khalid A Fakhro
- Department of Genetic Medicine, Weill Cornell Medical College in Qatar, Doha, Qatar. .,Division of Translational Medicine, Sidra Medical Research Centre, Doha, Qatar.
| | - Noha A Yousri
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Doha, Qatar. .,Computer and Systems Engineering, Alexandria University, Alexandria, Egypt.
| | - Juan L Rodriguez-Flores
- Department of Genetic Medicine, Weill Cornell Medical College, 1300 York Avenue, Box 164, New York, NY, 10065, USA.
| | - Amal Robay
- Department of Genetic Medicine, Weill Cornell Medical College in Qatar, Doha, Qatar.
| | - Michelle R Staudt
- Department of Genetic Medicine, Weill Cornell Medical College, 1300 York Avenue, Box 164, New York, NY, 10065, USA.
| | - Francisco Agosto-Perez
- Department of Genetic Medicine, Weill Cornell Medical College, 1300 York Avenue, Box 164, New York, NY, 10065, USA.
| | - Jacqueline Salit
- Department of Genetic Medicine, Weill Cornell Medical College, 1300 York Avenue, Box 164, New York, NY, 10065, USA.
| | - Joel A Malek
- Department of Genetic Medicine, Weill Cornell Medical College in Qatar, Doha, Qatar.
| | - Karsten Suhre
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Doha, Qatar.
| | - Amin Jayyousi
- Department of Medicine, Hamad Medical Corporation, Doha, Qatar.
| | - Mahmoud Zirie
- Department of Medicine, Hamad Medical Corporation, Doha, Qatar.
| | - Dora Stadler
- Department of Medicine, Weill Cornell Medical College in Qatar, Doha, Qatar.
| | - Jason G Mezey
- Computer and Systems Engineering, Alexandria University, Alexandria, Egypt. .,Department Biological Statistics and Computational Biology, Cornell University, Ithaca, NY, USA.
| | - Ronald G Crystal
- Department of Genetic Medicine, Weill Cornell Medical College in Qatar, Doha, Qatar. .,Department of Genetic Medicine, Weill Cornell Medical College, 1300 York Avenue, Box 164, New York, NY, 10065, USA.
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Fujikura K. Multiple loss-of-function variants of taste receptors in modern humans. Sci Rep 2015; 5:12349. [PMID: 26307445 PMCID: PMC4549710 DOI: 10.1038/srep12349] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 06/26/2015] [Indexed: 12/20/2022] Open
Abstract
Despite recent advances in the knowledge of interindividual taste differences, the underlying genetic backgrounds have remained to be fully elucidated. Much of the taste variation among different mammalian species can be explained by pseudogenization of taste receptors. Here I investigated whether the most recent disruptions of taste receptor genes segregate with their intact forms in modern humans by analyzing 14 ethnically diverse populations. The results revealed an unprecedented prevalence of 25 segregating loss-of-function (LoF) taste receptor variants, identifying one of the most pronounced cases of functional population diversity in the human genome. LoF variant frequency in taste receptors (2.10%) was considerably higher than the overall LoF frequency in human genome (0.16%). In particular, molecular evolutionary rates of candidate sour (14.7%) and bitter (1.8%) receptors were far higher in humans than those of sweet (0.02%), salty (0.05%), and umami (0.17%) receptors compared with other carnivorous mammals, although not all of the taste receptors were identified. Many LoF variants are population-specific, some of which arose even after population differentiation, not before divergence of the modern and archaic human. I conclude that modern humans might have been losing some sour and bitter receptor genes because of high-frequency LoF variants.
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Affiliation(s)
- Kohei Fujikura
- Kobe University School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
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25
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Marco A. Selection Against Maternal microRNA Target Sites in Maternal Transcripts. G3 (BETHESDA, MD.) 2015; 5:2199-207. [PMID: 26306531 PMCID: PMC4593001 DOI: 10.1534/g3.115.019497] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/19/2015] [Indexed: 12/20/2022]
Abstract
In animals, before the zygotic genome is expressed, the egg already contains gene products deposited by the mother. These maternal products are crucial during the initial steps of development. In Drosophila melanogaster, a large number of maternal products are found in the oocyte, some of which are indispensable. Many of these products are RNA molecules, such as gene transcripts and ribosomal RNAs. Recently, microRNAs (small RNA gene regulators) have been detected early during development and are important in these initial steps. The presence of some microRNAs in unfertilized eggs has been reported, but whether they have a functional impact in the egg or early embryo has not being explored. I have extracted and sequenced small RNAs from Drosophila unfertilized eggs. The unfertilized egg is rich in small RNAs and contains multiple microRNA products. Maternal microRNAs often are encoded within the intron of maternal genes, suggesting that many maternal microRNAs are the product of transcriptional hitchhiking. Comparative genomics analyses suggest that maternal transcripts tend to avoid target sites for maternal microRNAs. I also developed a microRNA target mutation model to study the functional impact of polymorphisms at microRNA target sites. The analysis of Drosophila populations suggests that there is selection against maternal microRNA target sites in maternal transcripts. A potential role of the maternal microRNA mir-9c in maternal-to-zygotic transition is also discussed. In conclusion, maternal microRNAs in Drosophila have a functional impact in maternal protein-coding transcripts.
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Affiliation(s)
- Antonio Marco
- School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
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Kumar V, Kutschera VE, Nilsson MA, Janke A. Genetic signatures of adaptation revealed from transcriptome sequencing of Arctic and red foxes. BMC Genomics 2015; 16:585. [PMID: 26250829 PMCID: PMC4528681 DOI: 10.1186/s12864-015-1724-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 06/26/2015] [Indexed: 11/17/2022] Open
Abstract
Background The genus Vulpes (true foxes) comprises numerous species that inhabit a wide range of habitats and climatic conditions, including one species, the Arctic fox (Vulpes lagopus) which is adapted to the arctic region. A close relative to the Arctic fox, the red fox (Vulpes vulpes), occurs in subarctic to subtropical habitats. To study the genetic basis of their adaptations to different environments, transcriptome sequences from two Arctic foxes and one red fox individual were generated and analyzed for signatures of positive selection. In addition, the data allowed for a phylogenetic analysis and divergence time estimate between the two fox species. Results The de novo assembly of reads resulted in more than 160,000 contigs/transcripts per individual. Approximately 17,000 homologous genes were identified using human and the non-redundant databases. Positive selection analyses revealed several genes involved in various metabolic and molecular processes such as energy metabolism, cardiac gene regulation, apoptosis and blood coagulation to be under positive selection in foxes. Branch site tests identified four genes to be under positive selection in the Arctic fox transcriptome, two of which are fat metabolism genes. In the red fox transcriptome eight genes are under positive selection, including molecular process genes, notably genes involved in ATP metabolism. Analysis of the three transcriptomes and five Sanger re-sequenced genes in additional individuals identified a lower genetic variability within Arctic foxes compared to red foxes, which is consistent with distribution range differences and demographic responses to past climatic fluctuations. A phylogenomic analysis estimated that the Arctic and red fox lineages diverged about three million years ago. Conclusions Transcriptome data are an economic way to generate genomic resources for evolutionary studies. Despite not representing an entire genome, this transcriptome analysis identified numerous genes that are relevant to arctic adaptation in foxes. Similar to polar bears, fat metabolism seems to play a central role in adaptation of Arctic foxes to the cold climate, as has been identified in the polar bear, another arctic specialist. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1724-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vikas Kumar
- Senckenberg Biodiversity and Climate Research Center, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325, Frankfurt am Main, Germany.
| | - Verena E Kutschera
- Senckenberg Biodiversity and Climate Research Center, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325, Frankfurt am Main, Germany. .,Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-75236, Uppsala, Sweden.
| | - Maria A Nilsson
- Senckenberg Biodiversity and Climate Research Center, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325, Frankfurt am Main, Germany.
| | - Axel Janke
- Senckenberg Biodiversity and Climate Research Center, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325, Frankfurt am Main, Germany. .,Evolution & Diversity, Goethe University Frankfurt, Institute for Ecology, Biologicum, Max-von-Laue-Str.13, D-60439, Frankfurt am Main, Germany.
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Abstract
Humans have acquired many distinct evolutionary traits after the human-chimpanzee divergence. These phenotypes have resulted from genetic changes that occurred in the human genome and were retained by natural selection. Comparative primate genome analyses reveal that loss-of-function mutations are common in the human genome. Some of these gene inactivation events were revealed to be associated with the emergence of advantageous phenotypes and were therefore positively selected and fixed in modern humans (the "less-ismore" hypothesis). Representative cases of human gene inactivation and their functional implications are presented in this review. Functional studies of additional inactive genes will provide insight into the molecular mechanisms underlying acquisition of various human-specific traits.
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Affiliation(s)
| | | | | | - Yoonsoo Hahn
- Department of Life Science, Research Center for Biomolecules and Biosystems, Chung-Ang University, Seoul 156-756, Korea
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28
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Insights into hominin phenotypic and dietary evolution from ancient DNA sequence data. J Hum Evol 2015; 79:55-63. [DOI: 10.1016/j.jhevol.2014.10.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 09/21/2014] [Accepted: 10/28/2014] [Indexed: 01/02/2023]
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Schwarz F, Fong JJ, Varki A. Human-specific evolutionary changes in the biology of siglecs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 842:1-16. [PMID: 25408333 DOI: 10.1007/978-3-319-11280-0_1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Flavio Schwarz
- Departments of Medicine, and Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California San Diego, La Jolla, CA, USA,
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Human knockout research: new horizons and opportunities. Trends Genet 2014; 31:108-15. [PMID: 25497971 DOI: 10.1016/j.tig.2014.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/15/2014] [Accepted: 11/17/2014] [Indexed: 12/12/2022]
Abstract
Although numerous approaches have been pursued to understand the function of human genes, Mendelian genetics has by far provided the most compelling and medically actionable dataset. Biallelic loss-of-function (LOF) mutations are observed in the majority of autosomal recessive Mendelian disorders, representing natural human knockouts and offering a unique opportunity to study the physiological and developmental context of these genes. The restriction of such context to 'disease' states is artificial, however, and the recent ability to survey entire human genomes for biallelic LOF mutations has revealed a surprising landscape of knockout events in 'healthy' individuals, sparking interest in their role in phenotypic diversity beyond disease causation. As I discuss in this review, the potentially wide implications of human knockout research warrant increased investment and multidisciplinary collaborations to overcome existing challenges and reap its benefits.
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31
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Brommage R, Liu J, Hansen GM, Kirkpatrick LL, Potter DG, Sands AT, Zambrowicz B, Powell DR, Vogel P. High-throughput screening of mouse gene knockouts identifies established and novel skeletal phenotypes. Bone Res 2014; 2:14034. [PMID: 26273529 PMCID: PMC4472125 DOI: 10.1038/boneres.2014.34] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 12/13/2022] Open
Abstract
Screening gene function in vivo is a powerful approach to discover novel drug targets. We present high-throughput screening (HTS) data for 3 762 distinct global gene knockout (KO) mouse lines with viable adult homozygous mice generated using either gene-trap or homologous recombination technologies. Bone mass was determined from DEXA scans of male and female mice at 14 weeks of age and by microCT analyses of bones from male mice at 16 weeks of age. Wild-type (WT) cagemates/littermates were examined for each gene KO. Lethality was observed in an additional 850 KO lines. Since primary HTS are susceptible to false positive findings, additional cohorts of mice from KO lines with intriguing HTS bone data were examined. Aging, ovariectomy, histomorphometry and bone strength studies were performed and possible non-skeletal phenotypes were explored. Together, these screens identified multiple genes affecting bone mass: 23 previously reported genes (Calcr, Cebpb, Crtap, Dcstamp, Dkk1, Duoxa2, Enpp1, Fgf23, Kiss1/Kiss1r, Kl (Klotho), Lrp5, Mstn, Neo1, Npr2, Ostm1, Postn, Sfrp4, Slc30a5, Slc39a13, Sost, Sumf1, Src, Wnt10b), five novel genes extensively characterized (Cldn18, Fam20c, Lrrk1, Sgpl1, Wnt16), five novel genes with preliminary characterization (Agpat2, Rassf5, Slc10a7, Slc26a7, Slc30a10) and three novel undisclosed genes coding for potential osteoporosis drug targets.
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Affiliation(s)
| | - Jeff Liu
- Lexicon Pharmaceuticals , The Woodlands, TX, USA
| | | | | | | | | | | | | | - Peter Vogel
- Lexicon Pharmaceuticals , The Woodlands, TX, USA
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Selection on a variant associated with improved viral clearance drives local, adaptive pseudogenization of interferon lambda 4 (IFNL4). PLoS Genet 2014; 10:e1004681. [PMID: 25329461 PMCID: PMC4199494 DOI: 10.1371/journal.pgen.1004681] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 08/18/2014] [Indexed: 12/18/2022] Open
Abstract
Interferon lambda 4 gene (IFNL4) encodes IFN-λ4, a new member of the IFN-λ family with antiviral activity. In humans IFNL4 open reading frame is truncated by a polymorphic frame-shift insertion that eliminates IFN-λ4 and turns IFNL4 into a polymorphic pseudogene. Functional IFN-λ4 has antiviral activity but the elimination of IFN-λ4 through pseudogenization is strongly associated with improved clearance of hepatitis C virus (HCV) infection. We show that functional IFN-λ4 is conserved and evolutionarily constrained in mammals and thus functionally relevant. However, the pseudogene has reached moderately high frequency in Africa, America, and Europe, and near fixation in East Asia. In fact, the pseudogenizing variant is among the 0.8% most differentiated SNPs between Africa and East Asia genome-wide. Its raise in frequency is associated with additional evidence of positive selection, which is strongest in East Asia, where this variant falls in the 0.5% tail of SNPs with strongest signatures of recent positive selection genome-wide. Using a new Approximate Bayesian Computation (ABC) approach we infer that the pseudogenizing allele appeared just before the out-of-Africa migration and was immediately targeted by moderate positive selection; selection subsequently strengthened in European and Asian populations resulting in the high frequency observed today. This provides evidence for a changing adaptive process that, by favoring IFN-λ4 inactivation, has shaped present-day phenotypic diversity and susceptibility to disease. The genetic association with clearance of Hepatitis C virus (HCV) is one of the strongest and most elusive known associations with disease. The genetic variant more strongly associated with improved HCV clearance inactivates the recently discovered IFNL4 gene, which encodes for antiviral IFN-λ4 protein, and turns it into a polymorphic pseudogene. We show that functional IFN-λ4 is conserved and functionally important in mammals. In humans though the inactivating mutation appeared in Africa just before the out-of-Africa migration and quickly became advantageous, with the strength of selection (the degree of advantage) varying across human groups. In particular, selection became stronger out of Africa and was strongest in East Asia, raising the frequency of the pseudogene and resulting in the virtual loss of functional IFN-λ4 protein in several Asian populations. Although the environmental force driving selection is unknown, this process resulted in variable clearance of HCV in modern human populations. The complex selective history of IFNL4-inactivating allele has thus shaped present-day heterogeneity across populations not only in genetic variation, but also in relevant phenotypes and susceptibility to disease.
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Analysis of stop-gain and frameshift variants in human innate immunity genes. PLoS Comput Biol 2014; 10:e1003757. [PMID: 25058640 PMCID: PMC4110073 DOI: 10.1371/journal.pcbi.1003757] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 06/16/2014] [Indexed: 12/03/2022] Open
Abstract
Loss-of-function variants in innate immunity genes are associated with Mendelian disorders in the form of primary immunodeficiencies. Recent resequencing projects report that stop-gains and frameshifts are collectively prevalent in humans and could be responsible for some of the inter-individual variability in innate immune response. Current computational approaches evaluating loss-of-function in genes carrying these variants rely on gene-level characteristics such as evolutionary conservation and functional redundancy across the genome. However, innate immunity genes represent a particular case because they are more likely to be under positive selection and duplicated. To create a ranking of severity that would be applicable to innate immunity genes we evaluated 17,764 stop-gain and 13,915 frameshift variants from the NHLBI Exome Sequencing Project and 1,000 Genomes Project. Sequence-based features such as loss of functional domains, isoform-specific truncation and nonsense-mediated decay were found to correlate with variant allele frequency and validated with gene expression data. We integrated these features in a Bayesian classification scheme and benchmarked its use in predicting pathogenic variants against Online Mendelian Inheritance in Man (OMIM) disease stop-gains and frameshifts. The classification scheme was applied in the assessment of 335 stop-gains and 236 frameshifts affecting 227 interferon-stimulated genes. The sequence-based score ranks variants in innate immunity genes according to their potential to cause disease, and complements existing gene-based pathogenicity scores. Specifically, the sequence-based score improves measurement of functional gene impairment, discriminates across different variants in a given gene and appears particularly useful for analysis of less conserved genes. There are well-characterized severe immunodeficiencies associated with loss-of-function variants in innate immunity genes. Genome sequencing projects identify rare stop-gain and frameshift variants in innate immunity genes whose phenotype is uncharacterized. Current methods to estimate the severity of rare stop-gains and frameshifts are based on evolutionary conservation of the gene, the likelihood for redundancy in its function or mutational burden. These parameters are not always applicable to innate immunity genes. We evaluated sequence-level characteristics of more than 30'000 stop-gains and frameshifts and prioritized variants according to their predicted functional consequences. Our scoring approach complements existing tools in the prediction of innate immunity OMIM disease variants and associates with functional readouts such as gene expression. In this framework, we show that many individuals do carry highly pathogenic variants in genes participating in antiviral defense. The clinical assessment of these variants is of significant interest.
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Effect of duplicate genes on mouse genetic robustness: an update. BIOMED RESEARCH INTERNATIONAL 2014; 2014:758672. [PMID: 25110693 PMCID: PMC4119742 DOI: 10.1155/2014/758672] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 06/15/2014] [Accepted: 06/16/2014] [Indexed: 12/28/2022]
Abstract
In contrast to S. cerevisiae and C. elegans, analyses based on the current knockout (KO) mouse phenotypes led to the conclusion that duplicate genes had almost no role in mouse genetic robustness. It has been suggested that the bias of mouse KO database toward ancient duplicates may possibly cause this knockout duplicate puzzle, that is, a very similar proportion of essential genes (PE) between duplicate genes and singletons. In this paper, we conducted an extensive and careful analysis for the mouse KO phenotype data and corroborated a strong effect of duplicate genes on mouse genetics robustness. Moreover, the effect of duplicate genes on mouse genetic robustness is duplication-age dependent, which holds after ruling out the potential confounding effect from coding-sequence conservation, protein-protein connectivity, functional bias, or the bias of duplicates generated by whole genome duplication (WGD). Our findings suggest that two factors, the sampling bias toward ancient duplicates and very ancient duplicates with a proportion of essential genes higher than that of singletons, have caused the mouse knockout duplicate puzzle; meanwhile, the effect of genetic buffering may be correlated with sequence conservation as well as protein-protein interactivity.
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35
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Angata T. Associations of genetic polymorphisms of Siglecs with human diseases. Glycobiology 2014; 24:785-93. [PMID: 24841380 DOI: 10.1093/glycob/cwu043] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Genetic polymorphism studies in humans provide unique opportunities to understand human biology and the mechanisms of diseases. Correlations between polymorphisms in the genes encoding human Siglecs and various diseases have been reported. Leading examples, such as the CD33 polymorphism associated with late-onset Alzheimer's disease, are well supported by genetic replication and mechanistic studies, while some others (such as SIGLEC8 polymorphism associated with bronchial asthma and SIGLEC14 polymorphism associated with exacerbation of chronic obstructive pulmonary disease) may benefit reinforcement by independent genetic replication or mechanistic studies. In a few cases, such as MAG polymorphism associated with psychological disorder and CD22 polymorphism associated with autoimmune disease, the phenotype associated with a genetic polymorphism of a Siglec gene and that of an enzyme gene involved in the biosynthesis of Siglec ligand show some overlap, providing indirect support for the observed genotype-phenotype association. Although studies using engineered mutant mice have provided invaluable insights into the biological functions and mechanisms of diseases, it is not always possible to develop appropriate mouse model to replicate human situations because of significant species-to-species differences, which can be a major obstacle in understanding the biology of some of human CD33/Siglec-3-related Siglecs. Further studies in genetic polymorphisms of human Siglecs, combined with appropriate functional studies, may reveal unexpected biological roles of human Siglecs, and identify possible targets for prevention and/or treatment of certain diseases.
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Affiliation(s)
- Takashi Angata
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang District, Taipei 11529, Taiwan
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36
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Takami H, Kanda M, Oya H, Hibino S, Sugimoto H, Suenaga M, Yamada S, Nishikawa Y, Asai M, Fujii T, Nomoto S, Kodera Y. Evaluation of MAGE-D4 expression in hepatocellular carcinoma in Japanese patients. J Surg Oncol 2013; 108:557-62. [PMID: 24068544 DOI: 10.1002/jso.23440] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 08/28/2013] [Indexed: 01/06/2023]
Abstract
BACKGROUND AND OBJECTIVES Though Melanoma-associated antigen (MAGE) family genes have received lots of attention as cancer-related genes and targets for immunotherapy, MAGE-D4 expression in hepatocellular carcinoma (HCC) has not yet been evaluated. METHODS MAGE-D4 mRNA expression was assayed in nine HCC cell lines and 94 HCC surgical specimens obtained from Japanese patients by quantitative real-time reverse transcription polymerase chain reaction, and the correlations between MAGE-D4 mRNA expression and clinicopathological factors were evaluated. The expression and distribution of MAGE-D4b protein were evaluated immunohistochemically. RESULTS MAGE-D4 mRNA was overexpressed in five of nine HCC cell lines and 34 of 94 primary HCCs (36.2%). Median overall survival (14.8 vs. 118 months, P < 0.001) and relapse-free survival (2.7 vs. 18.3 months, P < 0.001) were significantly shorter in patients with high than with low-moderate MAGE-D4 expression. Multivariate analysis for overall survival showed that MAGE-D4 overexpression was independently prognostic for survival (hazard ratio 2.88, P = 0.009) and significantly associated with high alpha-fetoprotein concentration (P < 0.001), poor tumor differentiation (P = 0.003) and vascular invasion (P = 0.021). MAGE-D4b protein expression patterns were consistent with those of MAGE-D4 mRNA. CONCLUSIONS Overexpression of MAGE-D4 may be a predictive marker of early recurrence and mortality in patients with HCC.
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Affiliation(s)
- Hideki Takami
- Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, Nagoya, Japan
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Sakurai T, Mochida K, Yoshida T, Akiyama K, Ishitani M, Seki M, Shinozaki K. Genome-wide discovery and information resource development of DNA polymorphisms in cassava. PLoS One 2013; 8:e74056. [PMID: 24040164 PMCID: PMC3770675 DOI: 10.1371/journal.pone.0074056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 07/29/2013] [Indexed: 01/06/2023] Open
Abstract
Cassava (Manihot esculenta Crantz) is an important crop that provides food security and income generation in many tropical countries, and is known for its adaptability to various environmental conditions. Its draft genome sequence and many expressed sequence tags are now publicly available, allowing the development of cassava polymorphism information. Here, we describe the genome-wide discovery of cassava DNA polymorphisms. Using the alignment of predicted transcribed sequences from the cassava draft genome sequence and ESTs from GenBank, we discovered 10,546 single-nucleotide polymorphisms and 647 insertions and deletions. To facilitate molecular marker development for cassava, we designed 9,316 PCR primer pairs to amplify the genomic region around each DNA polymorphism. Of the discovered SNPs, 62.7% occurred in protein-coding regions. Disease-resistance genes were found to have a significantly higher ratio of nonsynonymous-to-synonymous substitutions. We identified 24 read-through (changes of a stop codon to a coding codon) and 38 premature stop (changes of a coding codon to a stop codon) single-nucleotide polymorphisms, and found that the 5 gene ontology terms in biological process were significantly different in genes with read-through single-nucleotide polymorphisms compared with all cassava genes. All data on the discovered DNA polymorphisms were organized into the Cassava Online Archive database, which is available at http://cassava.psc.riken.jp/.
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Affiliation(s)
- Tetsuya Sakurai
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Keiichi Mochida
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa, Japan
- RIKEN Biomass Engineering Program, Tsurumi-ku, Yokohama, Kanagawa, Japan
- Kihara Institute for Biological Research, Yokohama City University, Totsuka-ku, Yokohama, Kanagawa, Japan
| | - Takuhiro Yoshida
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Kenji Akiyama
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Manabu Ishitani
- Agrobiodiversity Research Area, International Center for Tropical Agriculture (CIAT), Cali, Colombia
| | - Motoaki Seki
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa, Japan
- Kihara Institute for Biological Research, Yokohama City University, Totsuka-ku, Yokohama, Kanagawa, Japan
| | - Kazuo Shinozaki
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa, Japan
- RIKEN Biomass Engineering Program, Tsurumi-ku, Yokohama, Kanagawa, Japan
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Deleterious- and disease-allele prevalence in healthy individuals: insights from current predictions, mutation databases, and population-scale resequencing. Am J Hum Genet 2012; 91:1022-32. [PMID: 23217326 DOI: 10.1016/j.ajhg.2012.10.015] [Citation(s) in RCA: 197] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Revised: 08/22/2012] [Accepted: 10/11/2012] [Indexed: 12/19/2022] Open
Abstract
We have assessed the numbers of potentially deleterious variants in the genomes of apparently healthy humans by using (1) low-coverage whole-genome sequence data from 179 individuals in the 1000 Genomes Pilot Project and (2) current predictions and databases of deleterious variants. Each individual carried 281-515 missense substitutions, 40-85 of which were homozygous, predicted to be highly damaging. They also carried 40-110 variants classified by the Human Gene Mutation Database (HGMD) as disease-causing mutations (DMs), 3-24 variants in the homozygous state, and many polymorphisms putatively associated with disease. Whereas many of these DMs are likely to represent disease-allele-annotation errors, between 0 and 8 DMs (0-1 homozygous) per individual are predicted to be highly damaging, and some of them provide information of medical relevance. These analyses emphasize the need for improved annotation of disease alleles both in mutation databases and in the primary literature; some HGMD mutation data have been recategorized on the basis of the present findings, an iterative process that is both necessary and ongoing. Our estimates of deleterious-allele numbers are likely to be subject to both overcounting and undercounting. However, our current best mean estimates of ~400 damaging variants and ~2 bona fide disease mutations per individual are likely to increase rather than decrease as sequencing studies ascertain rare variants more effectively and as additional disease alleles are discovered.
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Hoehn KB, McGaugh SE, Noor MAF. Effects of premature termination codon polymorphisms in the Drosophila pseudoobscura subclade. J Mol Evol 2012; 75:141-50. [PMID: 23132097 PMCID: PMC3508312 DOI: 10.1007/s00239-012-9528-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/24/2012] [Indexed: 12/15/2022]
Abstract
Premature termination codon (PTC) mutations can have dramatic effects--both adaptive and deleterious--on gene expression and function. Here, we examine the number and selective effects of PTC mutations within the Drosophila pseudoobscura subclade using 18 resequenced genomes aligned to the reference genome. We located and characterized 1,679 PTC mutations in 605 genes across each of these genomes relative to the D. pseudoobscura reference genome, and use RT-PCR to confirm transcription of a subset of these genes containing PTC mutations. We confirm previous findings that genes containing PTC mutations are less selectively constrained and less broadly expressed than non-PTC-containing genes, suggesting that the most of these mutations are at least mildly deleterious. Further, we find highly significant codon usage bias in regions downstream of the PTC in 38 of these PTC-containing genes, suggesting that some of these PTC mutations--if not alternatively spliced out of the transcript--have neutral effects. Ultimately, these analyzes support the view that the PTC mutations are mostly detrimental, but are nonetheless common enough in genomes that a subset could be effectively neutral.
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Affiliation(s)
- Kenneth B Hoehn
- Biology Department, Duke University, PO Box 90388, Durham, NC 27708, USA.
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Gupta R, Ratan A, Rajesh C, Chen R, Kim HL, Burhans R, Miller W, Santhosh S, Davuluri RV, Butte AJ, Schuster SC, Seshagiri S, Thomas G. Sequencing and analysis of a South Asian-Indian personal genome. BMC Genomics 2012; 13:440. [PMID: 22938532 PMCID: PMC3534380 DOI: 10.1186/1471-2164-13-440] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 08/18/2012] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND With over 1.3 billion people, India is estimated to contain three times more genetic diversity than does Europe. Next-generation sequencing technologies have facilitated the understanding of diversity by enabling whole genome sequencing at greater speed and lower cost. While genomes from people of European and Asian descent have been sequenced, only recently has a single male genome from the Indian subcontinent been published at sufficient depth and coverage. In this study we have sequenced and analyzed the genome of a South Asian Indian female (SAIF) from the Indian state of Kerala. RESULTS We identified over 3.4 million SNPs in this genome including over 89,873 private variations. Comparison of the SAIF genome with several published personal genomes revealed that this individual shared ~50% of the SNPs with each of these genomes. Analysis of the SAIF mitochondrial genome showed that it was closely related to the U1 haplogroup which has been previously observed in Kerala. We assessed the SAIF genome for SNPs with health and disease consequences and found that the individual was at a higher risk for multiple sclerosis and a few other diseases. In analyzing SNPs that modulate drug response, we found a variation that predicts a favorable response to metformin, a drug used to treat diabetes. SNPs predictive of adverse reaction to warfarin indicated that the SAIF individual is not at risk for bleeding if treated with typical doses of warfarin. In addition, we report the presence of several additional SNPs of medical relevance. CONCLUSIONS This is the first study to report the complete whole genome sequence of a female from the state of Kerala in India. The availability of this complete genome and variants will further aid studies aimed at understanding genetic diversity, identifying clinically relevant changes and assessing disease burden in the Indian population.
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Affiliation(s)
- Ravi Gupta
- SciGenom Labs Pvt Ltd., Plot 43A, SDF 3rd Floor CSEZ, Kakkanad, Cochin, Kerala, 682037, India
| | - Aakrosh Ratan
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, 310 Wartik Lab, University Park, , Pennsylvania, 16802, USA
| | - Changanamkandath Rajesh
- SciGenom Labs Pvt Ltd., Plot 43A, SDF 3rd Floor CSEZ, Kakkanad, Cochin, Kerala, 682037, India
| | - Rong Chen
- , , Personalis, 1350 Willow Road, Suite 202, Menlo Park, CA, 94025, USA
| | - Hie Lim Kim
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, 310 Wartik Lab, University Park, , Pennsylvania, 16802, USA
| | - Richard Burhans
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, 310 Wartik Lab, University Park, , Pennsylvania, 16802, USA
| | - Webb Miller
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, 310 Wartik Lab, University Park, , Pennsylvania, 16802, USA
| | - Sam Santhosh
- SciGenom Labs Pvt Ltd., Plot 43A, SDF 3rd Floor CSEZ, Kakkanad, Cochin, Kerala, 682037, India
| | - Ramana V Davuluri
- Center for Systems The Wistar Institute,, , Philadelphia, PA, 19104, USA
| | - Atul J Butte
- Division of Systems Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Stephan C Schuster
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, 310 Wartik Lab, University Park, , Pennsylvania, 16802, USA
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, SBS-01N-27, Singapore, Singapore , 637551
| | - Somasekar Seshagiri
- Department of Molecular Biology, Genentech Inc, 1 DNA Way, South San Francisco, CA, 94080, USA
| | - George Thomas
- SciGenom Labs Pvt Ltd., Plot 43A, SDF 3rd Floor CSEZ, Kakkanad, Cochin, Kerala, 682037, India
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Olender T, Waszak SM, Viavant M, Khen M, Ben-Asher E, Reyes A, Nativ N, Wysocki CJ, Ge D, Lancet D. Personal receptor repertoires: olfaction as a model. BMC Genomics 2012; 13:414. [PMID: 22908908 PMCID: PMC3462693 DOI: 10.1186/1471-2164-13-414] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/26/2012] [Indexed: 01/07/2023] Open
Abstract
Background Information on nucleotide diversity along completely sequenced human genomes has increased tremendously over the last few years. This makes it possible to reassess the diversity status of distinct receptor proteins in different human individuals. To this end, we focused on the complete inventory of human olfactory receptor coding regions as a model for personal receptor repertoires. Results By performing data-mining from public and private sources we scored genetic variations in 413 intact OR loci, for which one or more individuals had an intact open reading frame. Using 1000 Genomes Project haplotypes, we identified a total of 4069 full-length polypeptide variants encoded by these OR loci, average of ~10 per locus, constituting a lower limit for the effective human OR repertoire. Each individual is found to harbor as many as 600 OR allelic variants, ~50% higher than the locus count. Because OR neuronal expression is allelically excluded, this has direct effect on smell perception diversity of the species. We further identified 244 OR segregating pseudogenes (SPGs), loci showing both intact and pseudogene forms in the population, twenty-six of which are annotatively “resurrected” from a pseudogene status in the reference genome. Using a custom SNP microarray we validated 150 SPGs in a cohort of 468 individuals, with every individual genome averaging 36 disrupted sequence variations, 15 in homozygote form. Finally, we generated a multi-source compendium of 63 OR loci harboring deletion Copy Number Variations (CNVs). Our combined data suggest that 271 of the 413 intact OR loci (66%) are affected by nonfunctional SNPs/indels and/or CNVs. Conclusions These results portray a case of unusually high genetic diversity, and suggest that individual humans have a highly personalized inventory of functional olfactory receptors, a conclusion that might apply to other receptor multigene families.
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Affiliation(s)
- Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
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Yavari M, Brinkley G, Klapstein KD, Hartwig WC, Rao R, Hermel E. Presence of the functional CASPASE-12 allele in Indian subpopulations. Int J Immunogenet 2012; 39:389-93. [PMID: 22471600 DOI: 10.1111/j.1744-313x.2012.01107.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Most humans lack a functional CASP12 gene, with the nonfunctional variant (CASP12p1), found in 100% of the Caucasian and east Asian population, and in approximately 80% of people of African descent. However, 20% of Africans carry an intact allele of CASP12, which produces a full-length pro-enzyme and increases the risk of sepsis. We examined CASP12 allele distribution in persons from central and southern Asia and found that CASP12 was significantly present in members of the Dravidian language group, particularly in persons from the Indian state of Tamil Nadu.
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Affiliation(s)
- M Yavari
- College of Osteopathic Medicine, Touro University-CA, Vallejo, CA, USA
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MacArthur DG, Balasubramanian S, Frankish A, Huang N, Morris J, Walter K, Jostins L, Habegger L, Pickrell JK, Montgomery SB, Albers CA, Zhang ZD, Conrad DF, Lunter G, Zheng H, Ayub Q, DePristo MA, Banks E, Hu M, Handsaker RE, Rosenfeld JA, Fromer M, Jin M, Mu XJ, Khurana E, Ye K, Kay M, Saunders GI, Suner MM, Hunt T, Barnes IHA, Amid C, Carvalho-Silva DR, Bignell AH, Snow C, Yngvadottir B, Bumpstead S, Cooper DN, Xue Y, Romero IG, Wang J, Li Y, Gibbs RA, McCarroll SA, Dermitzakis ET, Pritchard JK, Barrett JC, Harrow J, Hurles ME, Gerstein MB, Tyler-Smith C. A systematic survey of loss-of-function variants in human protein-coding genes. Science 2012; 335:823-8. [PMID: 22344438 PMCID: PMC3299548 DOI: 10.1126/science.1215040] [Citation(s) in RCA: 874] [Impact Index Per Article: 72.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Genome-sequencing studies indicate that all humans carry many genetic variants predicted to cause loss of function (LoF) of protein-coding genes, suggesting unexpected redundancy in the human genome. Here we apply stringent filters to 2951 putative LoF variants obtained from 185 human genomes to determine their true prevalence and properties. We estimate that human genomes typically contain ~100 genuine LoF variants with ~20 genes completely inactivated. We identify rare and likely deleterious LoF alleles, including 26 known and 21 predicted severe disease-causing variants, as well as common LoF variants in nonessential genes. We describe functional and evolutionary differences between LoF-tolerant and recessive disease genes and a method for using these differences to prioritize candidate genes found in clinical sequencing studies.
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Lee YCG, Reinhardt JA. Widespread polymorphism in the positions of stop codons in Drosophila melanogaster. Genome Biol Evol 2011; 4:533-49. [PMID: 22051795 PMCID: PMC3342867 DOI: 10.1093/gbe/evr113] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2011] [Indexed: 12/19/2022] Open
Abstract
The mechanisms underlying evolutionary changes in protein length are poorly understood. Protein domains are lost and gained between species and must have arisen first as within-species polymorphisms. Here, we use Drosophila melanogaster population genomic data combined with between species divergence information to understand the evolutionary forces that generate and maintain polymorphisms causing changes in protein length in D. melanogaster. Specifically, we looked for protein length variations resulting from premature termination codons (PTCs) and stop codon losses (SCLs). We discovered that 438 genes contained polymorphisms resulting in truncation of the translated region (PTCs) and 119 genes contained polymorphisms predicted to lengthen the translated region (SCLs). Stop codon polymorphisms (SCPs) (especially PTCs) appear to be more deleterious than other polymorphisms, including protein amino acid changes. Genes harboring SCPs are in general less selectively constrained, more narrowly expressed, and enriched for dispensable biological functions. However, we also observed exceptional cases such as genes that have multiple independent SCPs, alleles that are shared between D. melanogaster and Drosophila simulans, and high-frequency alleles that cause extreme changes in gene length. SCPs likely have an important role in the evolution of these genes.
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Affiliation(s)
- Yuh Chwen G. Lee
- Department of Evolution and Ecology, The University of California at Davis
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Mitra N, Banda K, Altheide TK, Schaffer L, Johnson-Pais TL, Beuten J, Leach RJ, Angata T, Varki N, Varki A. SIGLEC12, a human-specific segregating (pseudo)gene, encodes a signaling molecule expressed in prostate carcinomas. J Biol Chem 2011; 286:23003-11. [PMID: 21555517 PMCID: PMC3123068 DOI: 10.1074/jbc.m111.244152] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 05/05/2011] [Indexed: 12/15/2022] Open
Abstract
The primate SIGLEC12 gene encodes one of the CD33-related Siglec family of signaling molecules in immune cells. We had previously reported that this gene harbors a human-specific missense mutation of the codon for an Arg residue required for sialic acid recognition. Here we show that this R122C mutation of the Siglec-XII protein is fixed in the human population, i.e. it occurred prior to the origin of modern humans. Additional mutations have since completely inactivated the SIGLEC12 gene in some but not all humans. The most common inactivating mutation with a global allele frequency of 58% is a single nucleotide frameshift that markedly shortens the open reading frame. Unlike other CD33-related Siglecs that are primarily found on immune cells, we found that Siglec-XII protein is expressed not only on some macrophages but also on various epithelial cell surfaces in humans and chimpanzees. We also found expression on certain human prostate epithelial carcinomas and carcinoma cell lines. This expression correlates with the presence of the nonframeshifted, intact SIGLEC12 allele. Although SIGLEC12 allele status did not predict prostate carcinoma incidence, restoration of expression in a prostate carcinoma cell line homozygous for the frameshift mutation induced altered regulation of several genes associated with carcinoma progression. These stably transfected Siglec-XII-expressing prostate cancer cells also showed enhanced growth in nude mice. Finally, monoclonal antibodies against the protein were internalized by Siglec-XII-expressing prostate carcinoma cells, allowing targeting of a toxin to such cells. Polymorphic expression of Siglec-XII in humans thus has implications for prostate cancer biology and therapeutics.
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Affiliation(s)
- Nivedita Mitra
- From the Glycobiology Research and Training Center, Departments of Medicine, Pathology and Cellular & Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Kalyan Banda
- From the Glycobiology Research and Training Center, Departments of Medicine, Pathology and Cellular & Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Tasha K. Altheide
- From the Glycobiology Research and Training Center, Departments of Medicine, Pathology and Cellular & Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Lana Schaffer
- the Scripps Research Institute, La Jolla, California 92037, and
| | - Teresa L. Johnson-Pais
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Joke Beuten
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Robin J. Leach
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Takashi Angata
- From the Glycobiology Research and Training Center, Departments of Medicine, Pathology and Cellular & Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Nissi Varki
- From the Glycobiology Research and Training Center, Departments of Medicine, Pathology and Cellular & Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Ajit Varki
- From the Glycobiology Research and Training Center, Departments of Medicine, Pathology and Cellular & Molecular Medicine, University of California at San Diego, La Jolla, California 92093
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Rosentul DC, Plantinga TS, Scott WK, Alexander BD, van de Geer NMD, Perfect JR, Kullberg BJ, Johnson MD, Netea MG. The impact of caspase-12 on susceptibility to candidemia. Eur J Clin Microbiol Infect Dis 2011; 31:277-80. [PMID: 21706251 PMCID: PMC3274675 DOI: 10.1007/s10096-011-1307-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 05/24/2011] [Indexed: 02/07/2023]
Abstract
Candida is one of the leading causes of sepsis, and an effective host immune response to Candida critically depends on the cytokines IL-1β and IL-18, which need caspase-1 cleavage to become bioactive. Caspase-12 has been suggested to inhibit caspase-1 activation and has been implicated as a susceptibility factor for bacterial sepsis. In populations of African descent, CASPASE-12 is either functional or non-functional. Here, we have assessed the frequencies of both CASPASE-12 alleles in an African-American Candida sepsis patients cohort compared to uninfected patients with similar predisposing factors. African-American Candida sepsis patients (n = 93) and non-infected African-American patients (n = 88) were genotyped for the CASPASE-12 genotype. Serum cytokine concentrations of IL-6, IL-8, and IFNγ were measured in the serum of infected patients. Statistical comparisons were performed in order to assess the effect of the CASPASE-12 genotype on susceptibility to candidemia and on serum cytokine concentrations. Our findings demonstrate that CASPASE-12 does not influence the susceptibility to Candida sepsis, nor has any effect on the serum cytokine concentrations in Candida sepsis patients during the course of infection. Although the functional CASPASE-12 allele has been suggested to increase susceptibility to bacterial sepsis, this could not be confirmed in our larger cohort of fungal sepsis patients.
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Affiliation(s)
- D. C. Rosentul
- Department of Medicine, Radboud University Nijmegen Medical Centre, Internal postal code 463, P.O. Box 9101, Geert Grooteplein 8, 6500 HB Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity (N4i), Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - T. S. Plantinga
- Department of Medicine, Radboud University Nijmegen Medical Centre, Internal postal code 463, P.O. Box 9101, Geert Grooteplein 8, 6500 HB Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity (N4i), Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - W. K. Scott
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL 33136 USA
| | | | - N. M. D. van de Geer
- Department of Medicine, Radboud University Nijmegen Medical Centre, Internal postal code 463, P.O. Box 9101, Geert Grooteplein 8, 6500 HB Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity (N4i), Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - J. R. Perfect
- Duke University Medical Centre, Durham, NC 27708 USA
| | - B. J. Kullberg
- Department of Medicine, Radboud University Nijmegen Medical Centre, Internal postal code 463, P.O. Box 9101, Geert Grooteplein 8, 6500 HB Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity (N4i), Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - M. D. Johnson
- Duke University Medical Centre, Durham, NC 27708 USA
- Department of Clinical Research, Campbell University School of Pharmacy, Buies Creek, NC 27506 USA
| | - M. G. Netea
- Department of Medicine, Radboud University Nijmegen Medical Centre, Internal postal code 463, P.O. Box 9101, Geert Grooteplein 8, 6500 HB Nijmegen, The Netherlands
- Nijmegen Institute for Infection, Inflammation and Immunity (N4i), Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
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Rehman AU, Gul K, Morell RJ, Lee K, Ahmed ZM, Riazuddin S, Ali RA, Shahzad M, Jaleel AU, Andrade PB, Khan SN, Khan S, Brewer CC, Ahmad W, Leal SM, Riazuddin S, Friedman TB. Mutations of GIPC3 cause nonsyndromic hearing loss DFNB72 but not DFNB81 that also maps to chromosome 19p. Hum Genet 2011; 130:759-65. [PMID: 21660509 DOI: 10.1007/s00439-011-1018-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 05/24/2011] [Indexed: 01/18/2023]
Abstract
A missense mutation of Gipc3 was previously reported to cause age-related hearing loss in mice. Point mutations of human GIPC3 were found in two small families, but association with hearing loss was not statistically significant. Here, we describe one frameshift and six missense mutations in GIPC3 cosegregating with DFNB72 hearing loss in six large families that support statistically significant evidence for genetic linkage. However, GIPC3 is not the only nonsyndromic hearing impairment gene in this region; no GIPC3 mutations were found in a family cosegregating hearing loss with markers of chromosome 19p. Haplotype analysis excluded GIPC3 from the obligate linkage interval in this family and defined a novel locus spanning 4.08 Mb and 104 genes. This closely linked but distinct nonsyndromic hearing loss locus was designated DFNB81.
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Affiliation(s)
- Atteeq U Rehman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, MD 20850, USA
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48
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Casanova JL, Abel L, Quintana-Murci L. Human TLRs and IL-1Rs in host defense: natural insights from evolutionary, epidemiological, and clinical genetics. Annu Rev Immunol 2011; 29:447-91. [PMID: 21219179 DOI: 10.1146/annurev-immunol-030409-101335] [Citation(s) in RCA: 246] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs) have TIR intracellular domains that engage two main signaling pathways, via the TIR-containing adaptors MyD88 (which is not used by TLR3) and TRIF (which is used only by TLR3 and TLR4). Extensive studies in inbred mice in various experimental settings have attributed key roles in immunity to TLR- and IL-1R-mediated responses, but what contribution do human TLRs and IL-1Rs actually make to host defense in the natural setting? Evolutionary genetic studies have shown that human intracellular TLRs have evolved under stronger purifying selection than surface-expressed TLRs, for which the frequency of missense and nonsense alleles is high in the general population. Epidemiological genetic studies have yet to provide convincing evidence of a major contribution of common variants of human TLRs, IL-1Rs, or their adaptors to host defense. Clinical genetic studies have revealed that rare mutations affecting the TLR3-TRIF pathway underlie herpes simplex virus encephalitis, whereas mutations in the TIR-MyD88 pathway underlie pyogenic bacterial diseases in childhood. A careful reconsideration of the contributions of TLRs and IL-1Rs to host defense in natura is required.
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Affiliation(s)
- Jean-Laurent Casanova
- St. Giles Laboratory of Human Genetics of Infectious Diseases, The Rockefeller University, New York, NY 10021, USA.
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Study of consanguineous populations can improve the annotation of SNP databases. Eur J Med Genet 2011; 54:118-20. [DOI: 10.1016/j.ejmg.2010.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 10/19/2010] [Indexed: 01/26/2023]
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Quintana-Murci L, Barreiro LB. The role played by natural selection on Mendelian traits in humans. Ann N Y Acad Sci 2011; 1214:1-17. [PMID: 21175682 DOI: 10.1111/j.1749-6632.2010.05856.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Detecting whether and how natural selection has targeted regions of the human genome represents a complementary strategy for identifying functionally important loci and variants involved in disease resistance and adaptation to the environment. In contrast with most complex diseases or traits, the genetic architecture of most Mendelian traits is relatively well established. Most mutations associated with Mendelian disease-related traits are highly penetrant and kept at low population frequencies because of the effects of purifying selection. However, this is not always the case. Here, we review several examples of Mendelian mutations-associated with various disease conditions or other traits of anthropological interest-that have increased in frequency in the human population as a result of past positive selection. These examples clearly illustrate the value of a population genetics approach to unravel the biological mechanisms that have been central to our past and present survival against the selective pressures imposed by diseases and other environmental factors.
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Affiliation(s)
- Lluis Quintana-Murci
- Institut Pasteur, Human Evolutionary Genetics, Department of Genomes and Genetics, Paris, France.
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