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Valenzuela PL, Baggish A, Castillo-García A, Santos-Lozano A, Boraita A, Lucia A. Strenuous Endurance Exercise and the Heart: Physiological versus Pathological Adaptations. Compr Physiol 2022; 12:4067-4085. [PMID: 35950659 DOI: 10.1002/cphy.c210045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Although the benefits of regular physical activity on cardiovascular health are well established, the effects of strenuous endurance exercise (SEE) have been a matter of debate since ancient times. In this article, we aim to provide a balanced overview of what is known about SEE and the heart-from epidemiological evidence to recent cardiac imaging findings. Lifelong SEE is overall cardioprotective, with endurance master athletes showing in fact a youthful heart. Yet, some lines of research remain open, such as the need to elucidate the time-course and potential relevance of transient declines in heart function (or increases in biomarkers of cardiac injury) with SEE. The underlying mechanisms and clinical relevance of SEE-associated atrial fibrillation, myocardial fibrosis, or high coronary artery calcium scores also remain to be elucidated. © 2022 American Physiological Society. Compr Physiol 12:1-19, 2022.
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Affiliation(s)
- Pedro L Valenzuela
- Physical Activity and Health Research Group ('PaHerg'), Research Institute of the Hospital 12 de Octubre ('imas12'), Madrid, Spain
| | - Aaron Baggish
- Cardiovascular Performance Program, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Adrián Castillo-García
- Fissac - Physiology, Health and Physical Activity, Madrid, Spain.,Biology Systems Department, University of Alcalá, Madrid, Spain
| | - Alejandro Santos-Lozano
- Physical Activity and Health Research Group ('PaHerg'), Research Institute of the Hospital 12 de Octubre ('imas12'), Madrid, Spain.,i+HeALTH, European University Miguel de Cervantes, Valladolid, Spain
| | - Araceli Boraita
- Department of Cardiology, Sports Medicine Center, Spanish Agency for Health Protection in Sports, Madrid, Spain
| | - Alejandro Lucia
- Physical Activity and Health Research Group ('PaHerg'), Research Institute of the Hospital 12 de Octubre ('imas12'), Madrid, Spain.,Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain
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2
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Hernandez M, Perry GH. Scanning the human genome for "signatures" of positive selection: Transformative opportunities and ethical obligations. Evol Anthropol 2021; 30:113-121. [PMID: 33788352 DOI: 10.1002/evan.21893] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 01/25/2021] [Accepted: 03/11/2021] [Indexed: 12/15/2022]
Abstract
The relationship history of evolutionary anthropology and genetics is complex. At best, genetics is a beautifully integrative part of the discipline. Yet this integration has also been fraught, with punctuated, disruptive challenges to dogma, periodic reluctance by some members of the field to embrace results from analyses of genetic data, and occasional over-assertions of genetic definitiveness by geneticists. At worst, evolutionary genetics has been a tool for reinforcing racism and colonialism. While a number of genetics/genomics papers have disproportionately impacted evolutionary anthropology, here we highlight the 2002 presentation of an elegantly powerful approach for identifying "signatures" of past positive selection from haplotype-based patterns of genetic variation. Together with technological advances in genotyping methods, this article transformed our field by facilitating genome-wide "scans" for signatures of past positive selection in human populations. This approach helped researchers test longstanding evolutionary anthropology hypotheses while simultaneously providing opportunities to develop entirely new ones. Genome-wide scans for signatures of positive selection have since been conducted in diverse worldwide populations, with striking findings of local adaptation and convergent evolution. Yet there are ethical considerations with respect to the ubiquity of these studies and the cross-application of the genome-wide scan approach to existing datasets, which we also discuss.
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Affiliation(s)
- Margarita Hernandez
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - George H Perry
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, USA
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
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3
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Marquet N, Cardoso JCR, Louro B, Fernandes SA, Silva SC, Canário AVM. Holothurians have a reduced GPCR and odorant receptor-like repertoire compared to other echinoderms. Sci Rep 2020; 10:3348. [PMID: 32098989 PMCID: PMC7042368 DOI: 10.1038/s41598-020-60167-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 02/05/2020] [Indexed: 01/13/2023] Open
Abstract
Sea cucumbers lack vision and rely on chemical sensing to reproduce and survive. However, how they recognize and respond to environmental cues remains unknown. Possible candidates are the odorant receptors (ORs), a diverse family of G protein-coupled receptors (GPCRs) involved in olfaction. The present study aimed at characterizing the chemosensory GPCRs in sea cucumbers. At least 246 distinct GPCRs, of which ca. 20% putative ORs, were found in a transcriptome assembly of putative chemosensory (tentacles, oral cavity, calcareous ring, and papillae/tegument) and reproductive (ovary and testis) tissues from Holothuria arguinensis (57 ORs) and in the Apostichopus japonicus genome (79 ORs). The sea cucumber ORs clustered with those of sea urchin and starfish into four main clades of gene expansions sharing a common ancestor and evolving under purifying selection. However, the sea cucumber ORs repertoire was the smallest among the echinoderms and the olfactory receptor signature motif LxxPxYxxxxxLxxxDxxxxxxxxP was better conserved in cluster OR-l1 which also had more members. ORs were expressed in tentacles, oral cavity, calcareous ring, and papillae/tegument, supporting their potential role in chemosensing. This study is the first comprehensive survey of chemosensory GPCRs in sea cucumbers, and provides the molecular basis to understand how they communicate.
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Affiliation(s)
- Nathalie Marquet
- CCMAR - Centre of Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal.
| | - João C R Cardoso
- CCMAR - Centre of Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - Bruno Louro
- CCMAR - Centre of Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - Stefan A Fernandes
- CCMAR - Centre of Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - Sandra C Silva
- CCMAR - Centre of Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - Adelino V M Canário
- CCMAR - Centre of Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
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Nadachowska-Brzyska K, Burri R, Ellegren H. Footprints of adaptive evolution revealed by whole Z chromosomes haplotypes in flycatchers. Mol Ecol 2019; 28:2290-2304. [PMID: 30653779 PMCID: PMC6852393 DOI: 10.1111/mec.15021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 01/19/2023]
Abstract
Detecting positive selection using genomic data is critical to understanding the role of adaptive evolution. Of particular interest in this context is sex chromosomes since they are thought to play a special role in local adaptation and speciation. We sought to circumvent the challenges associated with statistical phasing when using haplotype-based statistics in sweep scans by benefitting from that whole chromosome haplotypes of the sex chromosomes can be obtained by resequencing of individuals of the hemizygous sex. We analyzed whole Z chromosome haplotypes from 100 females from several populations of four black and white flycatcher species (in birds, females are ZW and males ZZ). Based on integrated haplotype score (iHS) and number of segregating sites by length (nSL) statistics, we found strong and frequent haplotype structure in several regions of the Z chromosome in each species. Most of these sweep signals were population-specific, with essentially no evidence for regions under selection shared among species. Some completed sweeps were revealed by the cross-population extended haplotype homozygosity (XP-EHH) statistic. Importantly, by using statistically phased Z chromosome data from resequencing of males, we failed to recover the signals of selection detected in analyses based on whole chromosome haplotypes from females; instead, what likely represent false signals of selection were frequently seen. This highlights the power issues in statistical phasing and cautions against conclusions from selection scans using such data. The detection of frequent selective sweeps on the avian Z chromosome supports a large role of sex chromosomes in adaptive evolution.
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Affiliation(s)
| | - Reto Burri
- Department of Evolutionary Biology, University of Uppsala, Uppsala, Sweden.,Department of Population Ecology, Friedrich Schiller University Jena, Jena, Germany
| | - Hans Ellegren
- Department of Evolutionary Biology, University of Uppsala, Uppsala, Sweden
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5
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Quillen EE, Norton HL, Parra EJ, Lona-Durazo F, Ang KC, Illiescu FM, Pearson LN, Shriver MD, Lasisi T, Gokcumen O, Starr I, Lin YL, Martin AR, Jablonski NG. Shades of complexity: New perspectives on the evolution and genetic architecture of human skin. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 168 Suppl 67:4-26. [PMID: 30408154 DOI: 10.1002/ajpa.23737] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/17/2018] [Accepted: 09/20/2018] [Indexed: 02/06/2023]
Abstract
Like many highly variable human traits, more than a dozen genes are known to contribute to the full range of skin color. However, the historical bias in favor of genetic studies in European and European-derived populations has blinded us to the magnitude of pigmentation's complexity. As deliberate efforts are being made to better characterize diverse global populations and new sequencing technologies, better measurement tools, functional assessments, predictive modeling, and ancient DNA analyses become more widely accessible, we are beginning to appreciate how limited our understanding of the genetic bases of human skin color have been. Novel variants in genes not previously linked to pigmentation have been identified and evidence is mounting that there are hundreds more variants yet to be found. Even for genes that have been exhaustively characterized in European populations like MC1R, OCA2, and SLC24A5, research in previously understudied groups is leading to a new appreciation of the degree to which genetic diversity, epistatic interactions, pleiotropy, admixture, global and local adaptation, and cultural practices operate in population-specific ways to shape the genetic architecture of skin color. Furthermore, we are coming to terms with how factors like tanning response and barrier function may also have influenced selection on skin throughout human history. By examining how our knowledge of pigmentation genetics has shifted in the last decade, we can better appreciate how far we have come in understanding human diversity and the still long road ahead for understanding many complex human traits.
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Affiliation(s)
- Ellen E Quillen
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina.,Center for Precision Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Heather L Norton
- Department of Anthropology, University of Cincinnati, Cincinnati, Ohio
| | - Esteban J Parra
- Department of Anthropology, University of Toronto - Mississauga, Mississauga, Ontario, Canada
| | - Frida Lona-Durazo
- Department of Anthropology, University of Toronto - Mississauga, Mississauga, Ontario, Canada
| | - Khai C Ang
- Department of Pathology and Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, Pennsylvania
| | - Florin Mircea Illiescu
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Centro de Estudios Interculturales e Indígenas - CIIR, P. Universidad Católica de Chile, Santiago, Chile
| | - Laurel N Pearson
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Mark D Shriver
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Tina Lasisi
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Omer Gokcumen
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York
| | - Izzy Starr
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York
| | - Yen-Lung Lin
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York
| | - Alicia R Martin
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts.,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Nina G Jablonski
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
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Schielzeth H, Rios Villamil A, Burri R. Success and failure in replication of genotype-phenotype associations: How does replication help in understanding the genetic basis of phenotypic variation in outbred populations? Mol Ecol Resour 2018; 18:739-754. [PMID: 29575806 DOI: 10.1111/1755-0998.12780] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 03/09/2018] [Accepted: 03/09/2018] [Indexed: 12/29/2022]
Abstract
Recent developments in sequencing technologies have facilitated genomewide mapping of phenotypic variation in natural populations. Such mapping efforts face a number of challenges potentially leading to low reproducibility. However, reproducible research forms the basis of scientific progress. We here discuss the options for replication and the reasons for potential nonreproducibility. We then review the evidence for reproducible quantitative trait loci (QTL) with a focus on natural animal populations. Existing case studies of replication fall into three categories: (i) traits that have been mapped to major effect loci (including chromosomal inversion and supergenes) by independent research teams; (ii) QTL fine-mapped in discovery populations; and (iii) attempts to replicate QTL across multiple populations. Major effect loci, in particular those associated with inversions, have been successfully replicated in several cases within and across populations. Beyond such major effect variants, replication has been more successful within than across populations, suggesting that QTL discovered in natural populations may often be population-specific. This suggests that biological causes (differences in linkage patterns, allele frequencies or context-dependencies of QTL) contribute to nonreproducibility. Evidence from other fields, notably animal breeding and QTL mapping in humans, suggests that a significant fraction of QTL is indeed reproducible in direction and magnitude at least within populations. However, there is also a large number of QTL that cannot be easily reproduced. We put forward that more studies should explicitly address the causes and context-dependencies of QTL signals, in particular to disentangle linkage differences, allele frequency differences and gene-by-environment interactions as biological causes of nonreproducibility of QTL, especially between populations.
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Affiliation(s)
- Holger Schielzeth
- Population Ecology Group, Institute of Ecology and Evolution, Friedrich Schiller University, Jena, Germany
| | - Alejandro Rios Villamil
- Population Ecology Group, Institute of Ecology and Evolution, Friedrich Schiller University, Jena, Germany
| | - Reto Burri
- Population Ecology Group, Institute of Ecology and Evolution, Friedrich Schiller University, Jena, Germany
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7
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Abstract
Evolution sculpts the olfactory nervous system in response to the unique sensory challenges facing each species. In vertebrates, dramatic and diverse adaptations to the chemical environment are possible because of the hierarchical structure of the olfactory receptor (OR) gene superfamily: expansion or contraction of OR subfamilies accompanies major changes in habitat and lifestyle; independent selection on OR subfamilies can permit local adaptation or conserved chemical communication; and genetic variation in single OR genes can alter odor percepts and behaviors driven by precise chemical cues. However, this genetic flexibility contrasts with the relatively fixed neural architecture of the vertebrate olfactory system, which requires that new olfactory receptors integrate into segregated and functionally distinct neural pathways. This organization allows evolution to couple critical chemical signals with selectively advantageous responses, but also constrains relationships between olfactory receptors and behavior. The coevolution of the OR repertoire and the olfactory system therefore reveals general principles of how the brain solves specific sensory problems and how it adapts to new ones.
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8
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Ferrer I, Garcia-Esparcia P, Carmona M, Carro E, Aronica E, Kovacs GG, Grison A, Gustincich S. Olfactory Receptors in Non-Chemosensory Organs: The Nervous System in Health and Disease. Front Aging Neurosci 2016; 8:163. [PMID: 27458372 PMCID: PMC4932117 DOI: 10.3389/fnagi.2016.00163] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 06/21/2016] [Indexed: 12/22/2022] Open
Abstract
Olfactory receptors (ORs) and down-stream functional signaling molecules adenylyl cyclase 3 (AC3), olfactory G protein α subunit (Gαolf), OR transporters receptor transporter proteins 1 and 2 (RTP1 and RTP2), receptor expression enhancing protein 1 (REEP1), and UDP-glucuronosyltransferases (UGTs) are expressed in neurons of the human and murine central nervous system (CNS). In vitro studies have shown that these receptors react to external stimuli and therefore are equipped to be functional. However, ORs are not directly related to the detection of odors. Several molecules delivered from the blood, cerebrospinal fluid, neighboring local neurons and glial cells, distant cells through the extracellular space, and the cells’ own self-regulating internal homeostasis can be postulated as possible ligands. Moreover, a single neuron outside the olfactory epithelium expresses more than one receptor, and the mechanism of transcriptional regulation may be different in olfactory epithelia and brain neurons. OR gene expression is altered in several neurodegenerative diseases including Parkinson’s disease (PD), Alzheimer’s disease (AD), progressive supranuclear palsy (PSP) and sporadic Creutzfeldt-Jakob disease (sCJD) subtypes MM1 and VV2 with disease-, region- and subtype-specific patterns. Altered gene expression is also observed in the prefrontal cortex in schizophrenia with a major but not total influence of chlorpromazine treatment. Preliminary parallel observations have also shown the presence of taste receptors (TASRs), mainly of the bitter taste family, in the mammalian brain, whose function is not related to taste. TASRs in brain are also abnormally regulated in neurodegenerative diseases. These seminal observations point to the need for further studies on ORs and TASRs chemoreceptors in the mammalian brain.
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Affiliation(s)
- Isidro Ferrer
- Institute of Neuropathology, Bellvitge University Hospital, Hospitalet de Llobregat, University of BarcelonaBarcelona, Spain; Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED)Madrid, Spain; Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de LlobregatBarcelona, Spain
| | - Paula Garcia-Esparcia
- Institute of Neuropathology, Bellvitge University Hospital, Hospitalet de Llobregat, University of BarcelonaBarcelona, Spain; Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED)Madrid, Spain; Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de LlobregatBarcelona, Spain
| | - Margarita Carmona
- Institute of Neuropathology, Bellvitge University Hospital, Hospitalet de Llobregat, University of BarcelonaBarcelona, Spain; Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED)Madrid, Spain; Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de LlobregatBarcelona, Spain
| | - Eva Carro
- Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED)Madrid, Spain; Neuroscience Group, Research Institute HospitalMadrid, Spain
| | - Eleonora Aronica
- Department of Neuropathology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Gabor G Kovacs
- Institute of Neurology, Medical University of Vienna Vienna, Austria
| | - Alice Grison
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), Area of Neuroscience Trieste, Italy
| | - Stefano Gustincich
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), Area of Neuroscience Trieste, Italy
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9
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Purifying selection shapes the coincident SNP distribution of primate coding sequences. Sci Rep 2016; 6:27272. [PMID: 27255481 PMCID: PMC4891680 DOI: 10.1038/srep27272] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 05/17/2016] [Indexed: 12/13/2022] Open
Abstract
Genome-wide analysis has observed an excess of coincident single nucleotide polymorphisms (coSNPs) at human-chimpanzee orthologous positions, and suggested that this is due to cryptic variation in the mutation rate. While this phenomenon primarily corresponds with non-coding coSNPs, the situation in coding sequences remains unclear. Here we calculate the observed-to-expected ratio of coSNPs (coSNPO/E) to estimate the prevalence of human-chimpanzee coSNPs, and show that the excess of coSNPs is also present in coding regions. Intriguingly, coSNPO/E is much higher at zero-fold than at nonzero-fold degenerate sites; such a difference is due to an elevation of coSNPO/E at zero-fold degenerate sites, rather than a reduction at nonzero-fold degenerate ones. These trends are independent of chimpanzee subpopulation, population size, or sequencing techniques; and hold in broad generality across primates. We find that this discrepancy cannot fully explained by sequence contexts, shared ancestral polymorphisms, SNP density, and recombination rate, and that coSNPO/E in coding sequences is significantly influenced by purifying selection. We also show that selection and mutation rate affect coSNPO/E independently, and coSNPs tend to be less damaging and more correlated with human diseases than non-coSNPs. These suggest that coSNPs may represent a “signature” during primate protein evolution.
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10
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Heath KM, Axton JH, McCullough JM, Harris N. The evolutionary adaptation of the C282Y mutation to culture and climate during the European Neolithic. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 160:86-101. [PMID: 26799452 PMCID: PMC5066702 DOI: 10.1002/ajpa.22937] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 12/20/2015] [Accepted: 12/20/2015] [Indexed: 01/10/2023]
Abstract
OBJECTIVES The C282Y allele is the major cause of hemochromatosis as a result of excessive iron absorption. The mutation arose in continental Europe no earlier than 6,000 years ago, coinciding with the arrival of the Neolithic agricultural revolution. Here we hypothesize that this new Neolithic diet, which originated in the sunny warm and dry climates of the Middle East, was carried by migrating farmers into the chilly and damp environments of Europe where iron is a critical micronutrient for effective thermoregulation. We argue that the C282Y allele was an adaptation to this novel environment. MATERIALS AND METHODS To address our hypothesis, we compiled C282Y allele frequencies, known Neolithic sites in Europe and climatic data on temperature and rainfall for statistical analysis. RESULTS Our findings indicate that the geographic cline for C282Y frequency in Europe increases as average temperatures decrease below 16°C, a critical threshold for thermoregulation, with rainy days intensifying the trend. DISCUSSION The results indicate that the deleterious C282Y allele, responsible for most cases of hemochromatosis, may have evolved as a selective advantage to culture and climate during the European Neolithic.
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Affiliation(s)
- Kathleen M. Heath
- Department of Earth and Environmental SystemsIndiana State UniversityTerre HauteIN47809
| | - Jacob H. Axton
- Department of BiologyIndiana State UniversityTerre HauteIN47809
| | | | - Nathan Harris
- Department of AnthropologyUniversity of UtahSalt Lake CityUT84112
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Redwan RM, Saidin A, Kumar SV. Complete chloroplast genome sequence of MD-2 pineapple and its comparative analysis among nine other plants from the subclass Commelinidae. BMC PLANT BIOLOGY 2015; 15:196. [PMID: 26264372 PMCID: PMC4534033 DOI: 10.1186/s12870-015-0587-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/03/2015] [Indexed: 05/13/2023]
Abstract
BACKGROUND Pineapple (Ananas comosus var. comosus) is known as the king of fruits for its crown and is the third most important tropical fruit after banana and citrus. The plant, which is indigenous to South America, is the most important species in the Bromeliaceae family and is largely traded for fresh fruit consumption. Here, we report the complete chloroplast sequence of the MD-2 pineapple that was sequenced using the PacBio sequencing technology. RESULTS In this study, the high error rate of PacBio long sequence reads of A. comosus's total genomic DNA were improved by leveraging on the high accuracy but short Illumina reads for error-correction via the latest error correction module from Novocraft. Error corrected long PacBio reads were assembled by using a single tool to produce a contig representing the pineapple chloroplast genome. The genome of 159,636 bp in length is featured with the conserved quadripartite structure of chloroplast containing a large single copy region (LSC) with a size of 87,482 bp, a small single copy region (SSC) with a size of 18,622 bp and two inverted repeat regions (IRA and IRB) each with the size of 26,766 bp. Overall, the genome contained 117 unique coding regions and 30 were repeated in the IR region with its genes contents, structure and arrangement similar to its sister taxon, Typha latifolia. A total of 35 repeats structure were detected in both the coding and non-coding regions with a majority being tandem repeats. In addition, 205 SSRs were detected in the genome with six protein-coding genes contained more than two SSRs. Comparative chloroplast genomes from the subclass Commelinidae revealed a conservative protein coding gene albeit located in a highly divergence region. Analysis of selection pressure on protein-coding genes using Ka/Ks ratio showed significant positive selection exerted on the rps7 gene of the pineapple chloroplast with P less than 0.05. Phylogenetic analysis confirmed the recent taxonomical relation among the member of commelinids which support the monophyly relationship between Arecales and Dasypogonaceae and between Zingiberales to the Poales, which includes the A. comosus. CONCLUSIONS The complete sequence of the chloroplast of pineapple provides insights to the divergence of genic chloroplast sequences from the members of the subclass Commelinidae. The complete pineapple chloroplast will serve as a reference for in-depth taxonomical studies in the Bromeliaceae family when more species under the family are sequenced in the future. The genetic sequence information will also make feasible other molecular applications of the pineapple chloroplast for plant genetic improvement.
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Affiliation(s)
- R M Redwan
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
| | - A Saidin
- Novocraft Technology Sdn. Bhd., 3 Two Square, Seksyen 19, Petaling Jaya, Selangor, Malaysia.
| | - S V Kumar
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
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12
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Hoover KC, Gokcumen O, Qureshy Z, Bruguera E, Savangsuksa A, Cobb M, Matsunami H. Global Survey of Variation in a Human Olfactory Receptor Gene Reveals Signatures of Non-Neutral Evolution. Chem Senses 2015; 40:481-8. [PMID: 26072518 DOI: 10.1093/chemse/bjv030] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Allelic variation at 4 loci in the human olfactory receptor gene OR7D4 is associated with perceptual variation in the sex steroid-derived odorants, androstenone, and androstadienone. Androstadienone has been linked with chemosensory identification whereas androstenone makes pork from uncastrated pigs distasteful ("boar taint"). In a sample of 2224 individuals from 43 populations, we identified 45 OR7D4 single nucleotide polymorphisms. Coalescent modeling of frequency-site-spectrum-based statistics identified significant deviation from neutrality in human OR7D4; individual populations with statistically significant deviations from neutrality include Gujarati, Beijing Han, Great Britain, Iberia, and Puerto Rico. Analysis of molecular variation values indicated statistically significant population differentiation driven mainly by the 4 alleles associated with androstenone perception variation; however, fixation values were low suggesting that genetic structure may not have played a strong role in creating these group divisions. We also studied OR7D4 in the genomes of extinct members of the human lineage: Altai Neandertal and Denisovan. No variants were identified in Altai but 2 were in Denisova, one of which is shared by modern humans and one of which is novel. A functional test of modern human and a synthesized mutant Denisova OR7D4 indicated no statistically significant difference in responses to androstenone between the 2 species. Our results suggest non-neutral evolution for an olfactory receptor gene.
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Affiliation(s)
- Kara C Hoover
- Department of Anthropology, POB 757720, University of Alaska Fairbanks, Fairbanks, AK 99775, USA, Department of Chemistry and Biochemistry, 900 Yukon Drive, University of Alaska Fairbanks, Fairbanks, AK 99775, USA,
| | - Omer Gokcumen
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY 14260, USA
| | - Zoya Qureshy
- Department of Molecular Genetics and Microbiology, 264 CARL Building, Box 3509 Duke University Medical Center, Durham, NC 27710, USA and
| | - Elise Bruguera
- Department of Molecular Genetics and Microbiology, 264 CARL Building, Box 3509 Duke University Medical Center, Durham, NC 27710, USA and
| | - Aulaphan Savangsuksa
- Department of Molecular Genetics and Microbiology, 264 CARL Building, Box 3509 Duke University Medical Center, Durham, NC 27710, USA and
| | - Matthew Cobb
- Faculty of Life Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, 264 CARL Building, Box 3509 Duke University Medical Center, Durham, NC 27710, USA and
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Abstract
The sense of smell is mediated by the detection of chemical odours by ORs (olfactory receptors) in the nose. This initiates a neural percept of the odour in the brain, which may provoke an emotional or behavioural response. Analogous to colour-blindness in the visual system, some individuals report a very different percept of specific odours to others, in terms of intensity, valence or detection threshold. A significant proportion of variance in odour perception is heritable, and recent advances in genome sequencing and genotyping technologies have permitted studies into the genes that underpin these phenotypic differences. In the present article, I review the evidence that OR genes are extremely variable between individuals. I argue that this contributes to a unique receptor repertoire in our noses that provides us each with a personalized perception of our environment. I highlight specific examples where known OR variants influence odour detection and discuss the wider implications of this for both humans and other mammals that use chemical communication for social interaction.
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The Genetic Basis of Primate Behavior: Genetics and Genomics in Field-Based Primatology. INT J PRIMATOL 2013; 35:1-10. [PMID: 25013243 DOI: 10.1007/s10764-013-9732-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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15
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Spielman SJ, Wilke CO. Membrane environment imposes unique selection pressures on transmembrane domains of G protein-coupled receptors. J Mol Evol 2013; 76:172-82. [PMID: 23355009 DOI: 10.1007/s00239-012-9538-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 12/18/2012] [Indexed: 12/25/2022]
Abstract
We have investigated the influence of the plasma membrane environment on the molecular evolution of G protein-coupled receptors (GPCRs), the largest receptor family in Metazoa. In particular, we have analyzed the site-specific rate variation across the two primary structural partitions, transmembrane (TM) and extramembrane (EM), of these membrane proteins. We find that TM domains evolve more slowly than do EM domains, though TM domains display increased rate heterogeneity relative to their EM counterparts. Although the majority of residues across GPCRs experience strong to weak purifying selection, many GPCRs experience positive selection at both TM and EM residues, albeit with a slight bias towards the EM. Further, a subset of GPCRs, chemosensory receptors (including olfactory and taste receptors), exhibit increased rates of evolution relative to other GPCRs, an effect which is more pronounced in their TM spans. Although it has been previously suggested that the TM's low evolutionary rate is caused by their high percentage of buried residues, we show that their attenuated rate seems to stem from the strong biophysical constraints of the membrane itself, or by functional requirements. In spite of the strong evolutionary constraints acting on the TM spans of GPCRs, positive selection and high levels of evolutionary rate variability are common. Thus, biophysical constraints should not be presumed to preclude a protein's ability to evolve.
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Niimura Y. Olfactory receptor multigene family in vertebrates: from the viewpoint of evolutionary genomics. Curr Genomics 2012; 13:103-14. [PMID: 23024602 PMCID: PMC3308321 DOI: 10.2174/138920212799860706] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 07/12/2011] [Accepted: 09/29/2011] [Indexed: 01/17/2023] Open
Abstract
Olfaction is essential for the survival of animals. Diverse odor molecules in the environment are detected by the olfactory receptors (ORs) in the olfactory epithelium of the nasal cavity. There are ~400 and ~1,000 OR genes in the human and mouse genomes, respectively, forming the largest multigene family in mammals. The relationships between ORs and odorants are multiple-to-multiple, which allows for discriminating almost unlimited number of different odorants by a combination of ORs. However, the OR-ligand relationships are still largely unknown, and predicting the quality of odor from its molecular structure is unsuccessful.Extensive bioinformatic analyses using the whole genomes of various organisms revealed a great variation in number of OR genes among species, reflecting the diversity of their living environments. For example, higher primates equipped with a well-developed vision system and dolphins that are secondarily adapted to the aquatic life have considerably smaller numbers of OR genes than most of other mammals do. OR genes are characterized by extremely frequent gene duplications and losses. The OR gene repertories are also diverse among human individuals, explaining the diversity of odor perception such as the specific anosmia.OR genes are present in all vertebrates. The number of OR genes is smaller in teleost fishes than in mammals, while the diversity is higher in the former than the latter. Because the genome of amphioxus, the most basal chordate species, harbors vertebrate-like OR genes, the origin of OR genes can be traced back to the common ancestor of the phylum Chordata.
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Affiliation(s)
- Yoshihito Niimura
- Department of Bioinformatics, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
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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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Tiessen A, Pérez-Rodríguez P, Delaye-Arredondo LJ. Mathematical modeling and comparison of protein size distribution in different plant, animal, fungal and microbial species reveals a negative correlation between protein size and protein number, thus providing insight into the evolution of proteomes. BMC Res Notes 2012; 5:85. [PMID: 22296664 PMCID: PMC3296660 DOI: 10.1186/1756-0500-5-85] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 02/01/2012] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The sizes of proteins are relevant to their biochemical structure and for their biological function. The statistical distribution of protein lengths across a diverse set of taxa can provide hints about the evolution of proteomes. RESULTS Using the full genomic sequences of over 1,302 prokaryotic and 140 eukaryotic species two datasets containing 1.2 and 6.1 million proteins were generated and analyzed statistically. The lengthwise distribution of proteins can be roughly described with a gamma type or log-normal model, depending on the species. However the shape parameter of the gamma model has not a fixed value of 2, as previously suggested, but varies between 1.5 and 3 in different species. A gamma model with unrestricted shape parameter described best the distributions in ~48% of the species, whereas the log-normal distribution described better the observed protein sizes in 42% of the species. The gamma restricted function and the sum of exponentials distribution had a better fitting in only ~5% of the species. Eukaryotic proteins have an average size of 472 aa, whereas bacterial (320 aa) and archaeal (283 aa) proteins are significantly smaller (33-40% on average). Average protein sizes in different phylogenetic groups were: Alveolata (628 aa), Amoebozoa (533 aa), Fornicata (543 aa), Placozoa (453 aa), Eumetazoa (486 aa), Fungi (487 aa), Stramenopila (486 aa), Viridiplantae (392 aa). Amino acid composition is biased according to protein size. Protein length correlated negatively with %C, %M, %K, %F, %R, %W, %Y and positively with %D, %E, %Q, %S and %T. Prokaryotic proteins had a different protein size bias for %E, %G, %K and %M as compared to eukaryotes. CONCLUSIONS Mathematical modeling of protein length empirical distributions can be used to asses the quality of small ORFs annotation in genomic releases (detection of too many false positive small ORFs). There is a negative correlation between average protein size and total number of proteins among eukaryotes but not in prokaryotes. The %GC content is positively correlated to total protein number and protein size in prokaryotes but not in eukaryotes. Small proteins have a different amino acid bias than larger proteins. Compared to prokaryotic species, the evolution of eukaryotic proteomes was characterized by increased protein number (massive gene duplication) and substantial changes of protein size (domain addition/subtraction).
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Affiliation(s)
- Axel Tiessen
- Departamento de Ingeniería Genética, CINVESTAV Irapuato, Irapuato, CP 36821, Mexico
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Campbell MC, Ranciaro A, Froment A, Hirbo J, Omar S, Bodo JM, Nyambo T, Lema G, Zinshteyn D, Drayna D, Breslin PAS, Tishkoff SA. Evolution of functionally diverse alleles associated with PTC bitter taste sensitivity in Africa. Mol Biol Evol 2011; 29:1141-53. [PMID: 22130969 DOI: 10.1093/molbev/msr293] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although human bitter taste perception is hypothesized to be a dietary adaptation, little is known about genetic signatures of selection and patterns of bitter taste perception variability in ethnically diverse populations with different diets, particularly from Africa. To better understand the genetic basis and evolutionary history of bitter taste sensitivity, we sequenced a 2,975 bp region encompassing TAS2R38, a bitter taste receptor gene, in 611 Africans from 57 populations in West Central and East Africa with diverse subsistence patterns, as well as in a comparative sample of 132 non-Africans. We also examined the association between genetic variability at this locus and threshold levels of phenylthiocarbamide (PTC) bitterness in 463 Africans from the above populations to determine how variation influences bitter taste perception. Here, we report striking patterns of variation at TAS2R38, including a significant excess of novel rare nonsynonymous polymorphisms that recently arose only in Africa, high frequencies of haplotypes in Africa associated with intermediate bitter taste sensitivity, a remarkably similar frequency of common haplotypes across genetically and culturally distinct Africans, and an ancient coalescence time of common variation in global populations. Additionally, several of the rare nonsynonymous substitutions significantly modified levels of PTC bitter taste sensitivity in diverse Africans. While ancient balancing selection likely maintained common haplotype variation across global populations, we suggest that recent selection pressures may have also resulted in the unusually high level of rare nonsynonymous variants in Africa, implying a complex model of selection at the TAS2R38 locus in African populations. Furthermore, the distribution of common haplotypes in Africa is not correlated with diet, raising the possibility that common variation may be under selection due to their role in nondietary biological processes. In addition, our data indicate that novel rare mutations contribute to the phenotypic variance of PTC sensitivity, illustrating the influence of rare variation on a common trait, as well as the relatively recent evolution of functionally diverse alleles at this locus.
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Hoover KC. Smell with inspiration: The evolutionary significance of olfaction. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2010; 143 Suppl 51:63-74. [DOI: 10.1002/ajpa.21441] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Terauchi R, Yoshida K. Towards population genomics of effector-effector target interactions. THE NEW PHYTOLOGIST 2010; 187:929-39. [PMID: 20707855 DOI: 10.1111/j.1469-8137.2010.03408.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Pathogen-plant host coevolutionary interactions exert strong natural selection on both organisms, specifically on the genes coding for effectors (pathogens), as well as on those coding for effector targets and R proteins (plant hosts). Natural selection leaves behind DNA sequence signatures on such genes and on linked genomic regions. These signatures can readily be detected by studying the patterns of intraspecies polymorphisms and interspecies divergence of the DNA sequences. Recent developments in DNA sequencing technology have made whole-genome studies on patterns of DNA polymorphisms : divergence possible. This type of analysis, called 'population genomics', appears to be powerful enough to identify novel effector-effector target genes. Here, we provide an overview of the statistical tools used for population genomics and their applications. This is followed by a brief review of evolutionary studies on plant genes involved in host-pathogen interactions. Finally we provide an example from our study on Magnaporthe oryzae.
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Affiliation(s)
- Ryohei Terauchi
- Iwate Biotechnology Research Center, Kitakami, Iwate 024-0003, Japan.
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Abstract
Through cultural innovation and changes in habitat and ecology, there have been a number of major dietary shifts in human evolution, including meat eating, cooking, and those associated with plant and animal domestication. The identification of signatures of adaptations to such dietary changes in the genome of extant primates (including humans) may shed light not only on the evolutionary history of our species, but also on the mechanisms that underlie common metabolic diseases in modern human populations. In this review, we provide a brief overview of the major dietary shifts that occurred during hominin evolution, and we discuss the methods and approaches used to identify signals of natural selection in patterns of sequence variation. We then review the results of studies aimed at detecting the genetic loci that played a major role in dietary adaptations and conclude by outlining the potential of future studies in this area.
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Affiliation(s)
- F. Luca
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637
| | - G.H. Perry
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637
| | - A. Di Rienzo
- Department of Human Genetics, University of Chicago, Chicago, Illinois 60637
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Steiger SS, Fidler AE, Mueller JC, Kempenaers B. Evidence for adaptive evolution of olfactory receptor genes in 9 bird species. ACTA ACUST UNITED AC 2009; 101:325-33. [PMID: 19965911 DOI: 10.1093/jhered/esp105] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
It has been suggested that positive selection, in particular selection favoring a change in the protein sequence, plays a role in the evolution of olfactory receptor (OR) gene repertoires in fish and mammals. ORs are 7-transmembrane domain (TM) proteins, members of the G-protein-coupled receptor superfamily in vertebrate genomes, and responsible for odorant binding and discrimination. OR gene repertoires in birds are surprisingly large and diverse, suggesting that birds have a keen olfactory sense. The aim of this study is to investigate signatures of positive selection in an expanded OR clade (group-gamma-c) that seems to be a characteristic of avian genomes. Using maximum-likelihood methods that estimate the d(N)/d(S) ratios and account for the effects of recombination, we show here that there is evidence for positive selection in group-gamma-c partial OR coding sequences of 9 bird species that are likely to have different olfactory abilities: the blue tit (Cyanistes caeruleus), the black coucal (Centropus grillii), the brown kiwi (Apteryx australis), the canary (Serinus canaria), the galah (Eolophus roseicapillus), the kakapo (Strigops habroptilus), the mallard (Anas platyrhynchos), the red jungle fowl (Gallus gallus), and the snow petrel (Pagodroma nivea). Positively selected codons were predominantly located in TMs, which in other vertebrates are involved in odorant binding. Our data suggest that 1) at least some avian OR genes have been subjected to adaptive evolution, 2) the extent of such adaptive evolution differs between bird species, and 3) positive selective pressures may have been stronger on the group-gamma-c OR genes of species that have well-developed olfactory abilities.
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Affiliation(s)
- Silke S Steiger
- Department of Behavioral Ecology and Evolutionary Genetics, Max-Planck Institute for Ornithology, PO Box 1564, 82305 Starnberg.
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Dynamic functional evolution of an odorant receptor for sex-steroid-derived odors in primates. Proc Natl Acad Sci U S A 2009; 106:21247-51. [PMID: 19955411 DOI: 10.1073/pnas.0808378106] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Odorant receptors are among the fastest evolving genes in animals. However, little is known about the functional changes of individual odorant receptors during evolution. We have recently demonstrated a link between the in vitro function of a human odorant receptor, OR7D4, and in vivo olfactory perception of 2 steroidal ligands--androstenone and androstadienone--chemicals that are shown to affect physiological responses in humans. In this study, we analyzed the in vitro function of OR7D4 in primate evolution. Orthologs of OR7D4 were cloned from different primate species. Ancestral reconstruction allowed us to reconstitute additional putative OR7D4 orthologs in hypothetical ancestral species. Functional analysis of these orthologs showed an extremely diverse range of OR7D4 responses to the ligands in various primate species. Functional analysis of the nonsynonymous changes in the Old World Monkey and Great Ape lineages revealed a number of sites causing increases or decreases in sensitivity. We found that the majority of the functionally important residues in OR7D4 were not predicted by the maximum likelihood analysis detecting positive Darwinian selection.
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Steiger SS, Kuryshev VY, Stensmyr MC, Kempenaers B, Mueller JC. A comparison of reptilian and avian olfactory receptor gene repertoires: species-specific expansion of group gamma genes in birds. BMC Genomics 2009; 10:446. [PMID: 19772566 PMCID: PMC2758906 DOI: 10.1186/1471-2164-10-446] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 09/21/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The detection of odorants is mediated by olfactory receptors (ORs). ORs are G-protein coupled receptors that form a remarkably large protein superfamily in vertebrate genomes. We used data that became available through recent sequencing efforts of reptilian and avian genomes to identify the complete OR gene repertoires in a lizard, the green anole (Anolis carolinensis), and in two birds, the chicken (Gallus gallus) and the zebra finch (Taeniopygia guttata). RESULTS We identified 156 green anole OR genes, including 42 pseudogenes. The OR gene repertoire of the two bird species was substantially larger with 479 and 553 OR gene homologs in the chicken and zebra finch, respectively (including 111 and 221 pseudogenes, respectively). We show that the green anole has a higher fraction of intact OR genes (approximately 72%) compared with the chicken (approximately 66%) and the zebra finch (approximately 38%). We identified a larger number and a substantially higher proportion of intact OR gene homologs in the chicken genome than previously reported (214 versus 82 genes and 66% versus 15%, respectively). Phylogenetic analysis showed that lizard and bird OR gene repertoires consist of group alpha, theta and gamma genes. Interestingly, the vast majority of the avian OR genes are confined to a large expansion of a single branch (the so called gamma-c clade). An analysis of the selective pressure on the paralogous genes of each gamma-c clade revealed that they have been subjected to adaptive evolution. This expansion appears to be bird-specific and not sauropsid-specific, as it is lacking from the lizard genome. The gamma-c expansions of the two birds do not intermix, i.e., they are lineage-specific. Almost all (group gamma-c) OR genes mapped to the unknown chromosome. The remaining OR genes mapped to six homologous chromosomes plus three to four additional chromosomes in the zebra finch and chicken. CONCLUSION We identified a surprisingly large number of potentially functional avian OR genes. Our data supports recent evidence that avian olfactory ability may be better developed than previously thought. We hypothesize that the radiation of the group gamma-c OR genes in each bird lineage parallels the evolution of specific olfactory sensory functions.
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Affiliation(s)
- Silke S Steiger
- Department of Behavioural Ecology & Evolutionary Genetics, Max-Planck Institute for Ornithology, Eberhard-Gwinner-Strasse, 82319 Seewiesen, Germany.
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Dong D, He G, Zhang S, Zhang Z. Evolution of olfactory receptor genes in primates dominated by birth-and-death process. Genome Biol Evol 2009; 1:258-64. [PMID: 20333195 PMCID: PMC2817421 DOI: 10.1093/gbe/evp026] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2009] [Indexed: 11/14/2022] Open
Abstract
Olfactory receptor (OR) is a large family of G protein–coupled receptors that can detect odorant in order to generate the sense of smell. They constitute one of the largest multiple gene families in animals including primates. To better understand the variation in odor perception and evolution of OR genes among primates, we computationally identified OR gene repertoires in orangutans, marmosets, and mouse lemurs and investigated the birth-and-death process of OR genes in the primate lineage. The results showed that 1) all the primate species studied have no more than 400 intact OR genes, fewer than rodents and canine; 2) Despite the similar number of OR genes in the genome, the makeup of the OR gene repertoires between different primate species is quite different as they had undergone dramatic birth-and-death evolution with extensive gene losses in the lineages leading to current species; 3) Apes and Old World monkey (OWM) have similar fraction of pseudogenes, whereas New World monkey (NWM) have fewer pseudogenes. To measure the selective pressure that had affected the OR gene repertoires in primates, we compared the ratio of nonsynonymous with synonymous substitution rates by using 70 one-to-one orthologous quintets among five primate species. We found that OR genes showed relaxed selective constraints in apes (humans, chimpanzees, and orangutans) than in OWMs (macaques) and NWMs (marmosets). We concluded that OR gene repertoires in primates have evolved in such a way to adapt to their respective living environments. Differential selective constraints might play important role in the primate OR gene evolution in each primate species.
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Affiliation(s)
- Dong Dong
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
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27
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Johnson MA, Banks MA. Interlocus variance of FST provides evidence for directional selection over an olfactory receptor gene in Coho salmon (Oncorhynchus kisutch) populations. Mar Genomics 2009; 2:127-31. [DOI: 10.1016/j.margen.2009.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 07/21/2009] [Indexed: 11/25/2022]
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Wetterbom A, Gyllensten U, Cavelier L, Bergström TF. Genome-wide analysis of chimpanzee genes with premature termination codons. BMC Genomics 2009; 10:56. [PMID: 19178713 PMCID: PMC2640416 DOI: 10.1186/1471-2164-10-56] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Accepted: 01/29/2009] [Indexed: 01/22/2023] Open
Abstract
Background Premature termination codons (PTCs) cause mRNA degradation or a truncated protein and thereby contribute to the transcriptome and proteome divergence between species. Here we present the first genome-wide study of PTCs in the chimpanzee. By comparing the human and chimpanzee genome sequences we identify and characterize genes with PTCs, in order to understand the contribution of these mutations to the transcriptome diversity between the species. Results We have studied a total of 13,487 human-chimpanzee gene pairs and found that ~8% were affected by PTCs in the chimpanzee. A majority (764/1,109) of PTCs were caused by insertions or deletions and the remaining part was caused by substitutions. The distribution of PTC genes varied between chromosomes, with Y having the highest proportion. Furthermore, the density of PTC genes varied on a megabasepair scale within chromosomes and we found the density to be correlated both with indel divergence and proximity to the telomere. Within genes, PTCs were more common close to the 5' and 3' ends of the amino acid sequence. Gene Ontology classification revealed that olfactory receptor genes were over represented among the PTC genes. Conclusion Our results showed that the density of PTC genes fluctuated across the genome depending on the local genomic context. PTCs were preferentially located in the terminal parts of the transcript, which generally have a lower frequency of functional domains, indicating that selection was operating against PTCs at sites central to protein function. The enrichment of GO terms associated with olfaction suggests that PTCs may have influenced the difference in the repertoire of olfactory genes between humans and chimpanzees. In summary, 8% of the chimpanzee genes were affected by PTCs and this type of variation is likely to have an important effect on the transcript and proteomic divergence between humans and chimpanzees.
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Affiliation(s)
- Anna Wetterbom
- Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, SE-751 85, Sweden.
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29
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The evolution of animal chemosensory receptor gene repertoires: roles of chance and necessity. Nat Rev Genet 2008; 9:951-63. [PMID: 19002141 DOI: 10.1038/nrg2480] [Citation(s) in RCA: 394] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Chemosensory receptors are essential for the survival of organisms that range from bacteria to mammals. Recent studies have shown that the numbers of functional chemosensory receptor genes and pseudogenes vary enormously among the genomes of different animal species. Although much of the variation can be explained by the adaptation of organisms to different environments, it has become clear that a substantial portion is generated by genomic drift, a random process of gene duplication and deletion. Genomic drift also generates a substantial amount of copy-number variation in chemosensory receptor genes within species. It seems that mutation by gene duplication and inactivation has important roles in both the adaptive and non-adaptive evolution of chemosensation.
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Vallender EJ. Exploring the origins of the human brain through molecular evolution. BRAIN, BEHAVIOR AND EVOLUTION 2008; 72:168-77. [PMID: 18836262 DOI: 10.1159/000151476] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The emergence of the human brain is one of evolution's most compelling mysteries. With its singular importance and astounding complexity, understanding the forces that gave rise to the human brain is a major undertaking. Recently, the identification and publication of the complete genomic sequence of humans, mice, chimpanzees, and macaques has allowed for large-scale studies looking for the genic substrates of this natural selection. These investigations into positive selection, however, have generally produced incongruous results. Here we consider some of these studies and their differences in methodologies with an eye towards how they affect the results. We also clarify the strengths and weaknesses of each of these approaches and discuss how these can be synthesized to develop a more complete understanding of the genetic correlates behind the human brain and the selective events that have acted upon them.
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Affiliation(s)
- Eric J Vallender
- Division of Neurochemistry, New England Primate Research Center, Harvard Medical School, Southborough, MA 01772, USA.
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Thomas JH, Robertson HM. The Caenorhabditis chemoreceptor gene families. BMC Biol 2008; 6:42. [PMID: 18837995 PMCID: PMC2576165 DOI: 10.1186/1741-7007-6-42] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Accepted: 10/06/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chemoreceptor proteins mediate the first step in the transduction of environmental chemical stimuli, defining the breadth of detection and conferring stimulus specificity. Animal genomes contain families of genes encoding chemoreceptors that mediate taste, olfaction, and pheromone responses. The size and diversity of these families reflect the biology of chemoperception in specific species. RESULTS Based on manual curation and sequence comparisons among putative G-protein-coupled chemoreceptor genes in the nematode Caenorhabditis elegans, we identified approximately 1300 genes and 400 pseudogenes in the 19 largest gene families, most of which fall into larger superfamilies. In the related species C. briggsae and C. remanei, we identified most or all genes in each of the 19 families. For most families, C. elegans has the largest number of genes and C. briggsae the smallest number, suggesting changes in the importance of chemoperception among the species. Protein trees reveal family-specific and species-specific patterns of gene duplication and gene loss. The frequency of strict orthologs varies among the families, from just over 50% in two families to less than 5% in three families. Several families include large species-specific expansions, mostly in C. elegans and C. remanei. CONCLUSION Chemoreceptor gene families in Caenorhabditis species are large and evolutionarily dynamic as a result of gene duplication and gene loss. These dynamics shape the chemoreceptor gene complements in Caenorhabditis species and define the receptor space available for chemosensory responses. To explain these patterns, we propose the gray pawn hypothesis: individual genes are of little significance, but the aggregate of a large number of diverse genes is required to cover a large phenotype space.
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Affiliation(s)
- James H Thomas
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Hugh M Robertson
- Department of Entomology, University of Illinois, Urbana-Champaign, IL, USA
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Go Y, Niimura Y. Similar Numbers but Different Repertoires of Olfactory Receptor Genes in Humans and Chimpanzees. Mol Biol Evol 2008; 25:1897-907. [DOI: 10.1093/molbev/msn135] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Semyonov J, Park JI, Chang CL, Hsu SYT. GPCR genes are preferentially retained after whole genome duplication. PLoS One 2008; 3:e1903. [PMID: 18382678 PMCID: PMC2270905 DOI: 10.1371/journal.pone.0001903] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Accepted: 01/27/2008] [Indexed: 11/19/2022] Open
Abstract
One of the most interesting questions in biology is whether certain pathways have been favored during evolution, and if so, what properties could cause such a preference. Due to the lack of experimental evidence, whether select gene families have been preferentially retained over time after duplication in metazoan organisms remains unclear. Here, by syntenic mapping of nonchemosensory G protein-coupled receptor genes (nGPCRs which represent half the receptome for transmembrane signaling) in the vertebrate genomes, we found that, as opposed to the 8–15% retention rate for whole genome duplication (WGD)-derived gene duplicates in the entire genome of pufferfish, greater than 27.8% of WGD-derived nGPCRs which interact with a nonpeptide ligand were retained after WGD in pufferfish Tetraodon nigroviridis. In addition, we show that concurrent duplication of cognate ligand genes by WGD could impose selection of nGPCRs that interact with a polypeptide ligand. Against less than 2.25% probability for parallel retention of a pair of WGD-derived ligands and a pair of cognate receptor duplicates, we found a more than 8.9% retention of WGD-derived ligand-nGPCR pairs–threefold greater than one would surmise. These results demonstrate that gene retention is not uniform after WGD in vertebrates, and suggest a Darwinian selection of GPCR-mediated intercellular communication in metazoan organisms.
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Affiliation(s)
- Jenia Semyonov
- Division of Reproductive Biology, Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Jae-Il Park
- Division of Reproductive Biology, Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Chia Lin Chang
- Chang Gung University School of Medicine, and Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan
| | - Sheau Yu Teddy Hsu
- Division of Reproductive Biology, Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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GARDINER ANASTASIA, BARKER DANIEL, BUTLIN ROGERK, JORDAN WILLIAMC, RITCHIE MICHAELG. Drosophilachemoreceptor gene evolution: selection, specialization and genome size. Mol Ecol 2008; 17:1648-57. [DOI: 10.1111/j.1365-294x.2008.03713.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Young JM, Waters H, Dong C, Fülle HJ, Liman ER. Degeneration of the olfactory guanylyl cyclase D gene during primate evolution. PLoS One 2007; 2:e884. [PMID: 17849013 PMCID: PMC1964805 DOI: 10.1371/journal.pone.0000884] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Accepted: 08/20/2007] [Indexed: 02/04/2023] Open
Abstract
Background The mammalian olfactory system consists of several subsystems that detect specific sets of chemical cues and underlie a variety of behavioral responses. Within the main olfactory epithelium at least three distinct types of chemosensory neurons can be defined by their expression of unique sets of signal transduction components. In rodents, one set of neurons expresses the olfactory-specific guanylyl cyclase (GC)-D gene (Gucy2d, guanylyl cyclase 2d) and other cell-type specific molecules. GC-D-positive neurons project their axons to a small group of atypical “necklace” glomeruli in the olfactory bulb, some of which are activated in response to suckling in neonatal rodents and to atmospheric CO2 in adult mice. Because GC-D is a pseudogene in humans, signaling through this system appears to have been lost at some point in primate evolution. Principal Findings Here we used a combination of bioinformatic analysis of trace-archive and genome-assembly data and sequencing of PCR-amplified genomic DNA to determine when during primate evolution the functional gene was lost. Our analysis reveals that GC-D is a pseudogene in a large number of primate species, including apes, Old World and New World monkeys and tarsier. In contrast, the gene appears intact and has evolved under purifying selection in mouse, rat, dog, lemur and bushbaby. Conclusions These data suggest that signaling through GC-D-expressing cells was probably compromised more than 40 million years ago, prior to the divergence of New World monkeys from Old World monkeys and apes, and thus cannot be involved in chemosensation in most primates.
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Affiliation(s)
- Janet M. Young
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * To whom correspondence should be addressed. E-mail: (EL), (JY)
| | - Hang Waters
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Cora Dong
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Hans-Jürgen Fülle
- Departments of Cell and Neurobiology and Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Emily R. Liman
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
- Program in Neuroscience, University of Southern California, Los Angeles, California, United States of America
- * To whom correspondence should be addressed. E-mail: (EL), (JY)
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McBride CS. Rapid evolution of smell and taste receptor genes during host specialization in Drosophila sechellia. Proc Natl Acad Sci U S A 2007; 104:4996-5001. [PMID: 17360391 PMCID: PMC1829253 DOI: 10.1073/pnas.0608424104] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Our understanding of the genetic basis of host specialization in insects is limited to basic information on the number and location of genetic factors underlying changes in conspicuous phenotypes. We know nothing about general patterns of molecular evolution that may accompany host specialization but are not traceable to a single prominent phenotypic change. Here, I describe changes in the entire repertoire of 136 olfactory receptor (Or) and gustatory receptor (Gr) genes of the recently specialized vinegar fly Drosophila sechellia. I find that D. sechellia is losing Or and Gr genes nearly 10 times faster than its generalist sibling Drosophila simulans. Moreover, those D. sechellia receptors that remain intact have fixed amino acid replacement mutations at a higher rate relative to silent mutations than have their D. simulans orthologs. Comparison of these patterns with those observed in a random sample of genes indicates that the changes at Or and Gr loci are likely to reflect positive selection and/or relaxed constraint associated with the altered ecological niche of this fly.
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Affiliation(s)
- Carolyn S McBride
- Center for Population Biology, University of California, Davis, CA 95616, USA.
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Sánchez-Gracia A, Rozas J. Unusual pattern of nucleotide sequence variation at the OS-E and OS-F genomic regions of Drosophila simulans. Genetics 2007; 175:1923-35. [PMID: 17277360 PMCID: PMC1855126 DOI: 10.1534/genetics.106.068015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nucleotide variation at the genomic region encompassing the odorant-binding protein genes OS-E and OS-F (OS region) was surveyed in two populations of Drosophila simulans, one from Europe and the other from Africa. We found that the European population shows an atypical and large haplotype structure, which extends throughout the approximately 5-kb surveyed genomic region. This structure is depicted by two major haplotype groups segregating at intermediate frequency in the sample, one haplogroup with nearly no variation, and the other at levels more typical for this species. This pattern of variation was incompatible with neutral predictions for a population at a stationary equilibrium. Nevertheless, neutrality tests contrasting polymorphism and divergence data fail to detect any departure from the standard neutral model in this species, whereas they confirm the non-neutral behavior previously observed at the OS-E gene in D. melanogaster. Although positive Darwinian selection may have been responsible for the observed unusual nucleotide variation structure, coalescent simulation results do not allow rejecting the hypothesis that the pattern was generated by a recent bottleneck in the history of European populations of D. simulans.
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Abstract
In mammals, olfaction is mediated by two distinct organs that are located in the nasal cavity: the main olfactory epithelium (MOE) that binds volatile odorants is responsible for the conscious perception of odors, and the vomeronasal organ (VNO) that binds pheromones is responsible for various behavioral and neuroendocrine responses between individuals of a same species. Odorants and pheromones bind to seven transmembrane domain G-protein-coupled receptors that permit signal transduction. These receptors are encoded by large multigene families that evolved in mammal species in function of specific olfactory needs.
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Affiliation(s)
- Sylvie Rouquier
- Institut de Genetique Humaine, CNRS UPR 1142, rue de la Cardonille, 34396 Montpellier Cedex 5, France
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Blasi P, Palmerio F, Aiello A, Rocchi M, Malaspina P, Novelletto A. SSADH Variation in Primates: Intra- and Interspecific Data on a Gene with a Potential Role in Human Cognitive Functions. J Mol Evol 2006; 63:54-68. [PMID: 16786440 DOI: 10.1007/s00239-005-0154-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Accepted: 12/22/2005] [Indexed: 10/24/2022]
Abstract
In the present study we focus on the nucleotide and the inferred amino acid variation occurring in humans and other primate species for mitochondrial NAD(+)-dependent succinic semialdehyde dehydrogenase, a gene recently supposed to contribute to cognitive performance in humans. We determined 2527 bp of coding, intronic, and flanking sequences from chimpanzee, bonobo, gorilla, orangutan, gibbon, and macaque. We also resequenced the entire coding sequence on 39 independent chromosomes from Italian families. Four variable coding sites were genotyped in additional populations from Europe, Africa, and Asia. A test for constancy of the nonsynonymous vs. synonymous rates of nucleotide changes revealed that primates are characterized by largely variable d(N)/d(S) ratios. On a background of strong conservation, probably controlled by selective constraints, the lineage leading to humans showed a ratio increased to 0.42. Human polymorphic levels fall in the range reported for other genes, with a pattern of frequency and haplotype structure strongly suggestive of nonneutrality. The comparison with the primate sequences allowed inferring the ancestral state at all variable positions, suggesting that the c.538(C) allele and the associated functional variant is indeed a derived state that is proceeding to fixation. The unexpected pattern of human polymorphism compared to interspecific findings outlines the possibility of a recent positive selection on some variants relevant to new cognitive capabilities unique to humans.
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Affiliation(s)
- Paola Blasi
- Department of Biology, University "Tor Vergata", via della Ricerca Scientifica, snc, 00133, Rome, Italy
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Niimura Y, Nei M. Evolutionary dynamics of olfactory and other chemosensory receptor genes in vertebrates. J Hum Genet 2006; 51:505-517. [PMID: 16607462 PMCID: PMC1850483 DOI: 10.1007/s10038-006-0391-8] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 02/02/2006] [Indexed: 10/24/2022]
Abstract
The numbers of functional olfactory receptor (OR) genes in humans and mice are about 400 and 1,000 respectively. In both humans and mice, these genes exist as genomic clusters and are scattered over almost all chromosomes. The difference in the number of genes between the two species is apparently caused by massive inactivation of OR genes in the human lineage and a substantial increase of OR genes in the mouse lineage after the human-mouse divergence. Compared with mammals, fishes have a much smaller number of OR genes. However, the OR gene family in fishes is much more divergent than that in mammals. Fishes have many different groups of genes that are absent in mammals, suggesting that the mammalian OR gene family is characterized by the loss of many group genes that existed in the ancestor of vertebrates and the subsequent expansion of specific groups of genes. Therefore, this gene family apparently changed dynamically depending on the evolutionary lineage and evolved under the birth-and-death model of evolution. Study of the evolutionary changes of two gene families for vomeronasal receptors and two gene families for taste receptors, which are structurally similar, but remotely related to OR genes, showed that some of the gene families evolved in the same fashion as the OR gene family. It appears that the number and types of genes in chemosensory receptor gene families have evolved in response to environmental needs, but they are also affected by fortuitous factors.
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Affiliation(s)
- Yoshihito Niimura
- Department of Bioinformatics, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Masatoshi Nei
- Institute of Molecular Evolutionary Genetics and Department of Biology, Pennsylvania State University, 328 Mueller Laboratory, University Park, PA, 16802, USA.
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Alioto TS, Ngai J. The odorant receptor repertoire of teleost fish. BMC Genomics 2005; 6:173. [PMID: 16332259 PMCID: PMC1325023 DOI: 10.1186/1471-2164-6-173] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Accepted: 12/06/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Vertebrate odorant receptors comprise three types of G protein-coupled receptors: the OR, V1R and V2R receptors. The OR superfamily contains over 1,000 genes in some mammalian species, representing the largest gene superfamily in the mammalian genome. RESULTS To facilitate an informed analysis of OR gene phylogeny, we identified the complete set of 143 OR genes in the zebrafish genome, as well as the OR repertoires in two pufferfish species, fugu (44 genes) and tetraodon (42 genes). Although the genomes analyzed here contain fewer genes than in mammalian species, the teleost OR genes can be grouped into a larger number of major clades, representing greater overall OR diversity in the fish. CONCLUSION Based on the phylogeny of fish and mammalian repertoires, we propose a model for OR gene evolution in which different ancestral OR genes or gene families were selectively lost or expanded in different vertebrate lineages. In addition, our calculations of the ratios of non-synonymous to synonymous codon substitutions among more recently expanding OR subgroups in zebrafish implicate residues that may be involved in odorant binding.
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Affiliation(s)
- Tyler S Alioto
- Department of Molecular and Cell Biology, Functional Genomics Laboratory, Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA
- Grup de Recerca en Informàtica Biomèdica, Institut Municipal d'Investigació Mèdica, Universitat Pompeu Fabra, Centre de Regulació Genòmica, Psg. Marítim 37-49, 08003 Barcelona, Spain
| | - John Ngai
- Department of Molecular and Cell Biology, Functional Genomics Laboratory, Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA
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Lynn DJ, Freeman AR, Murray C, Bradley DG. A genomics approach to the detection of positive selection in cattle: adaptive evolution of the T-cell and natural killer cell-surface protein CD2. Genetics 2005; 170:1189-96. [PMID: 15802510 PMCID: PMC1451189 DOI: 10.1534/genetics.104.039040] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Accepted: 02/16/2005] [Indexed: 11/18/2022] Open
Abstract
The detection of adaptive evolution at the molecular level is of interest not only as an insight into the process of evolution but also because of its functional implications for genes of interest. Here, we present the first genomics approach to detecting positive selection operating on the Bos taurus lineage, an important domestic species. This analysis led to the identification of the T-cell and natural killer (NK) cell receptor cluster of differentiation 2 (CD2) as having a strong signal of selection. Further detailed investigation of CD2 revealed that this gene was subject to positive selection during the evolution of a number of mammalian lineages. Moreover, we show that selection has operated primarily on the extracellular domain of CD2 and discuss the implications of this for an important regulator of the adaptive immune response.
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Affiliation(s)
- David J. Lynn
- Department of Genetics, Smurfit Institute, Trinity College, Dublin 2, Ireland
| | - Abigail R. Freeman
- Department of Genetics, Smurfit Institute, Trinity College, Dublin 2, Ireland
| | - Caitriona Murray
- Department of Genetics, Smurfit Institute, Trinity College, Dublin 2, Ireland
| | - Daniel G. Bradley
- Department of Genetics, Smurfit Institute, Trinity College, Dublin 2, Ireland
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Harding RM, McVean G. A structured ancestral population for the evolution of modern humans. Curr Opin Genet Dev 2005; 14:667-74. [PMID: 15531162 DOI: 10.1016/j.gde.2004.08.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The view that modern humans evolved through a bottleneck from a single founding group of archaic Homo is being challenged by new analyses of contemporary genetic variation. A wide range of middle to late Pleistocene ages for gene genealogies and evidence for early population structures point to a diverse and scattered ancestry associated with a metapopulation history of local extinctions, re-colonization and admixture. A different balance of the same processes has shaped chimpanzee diversity.
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Affiliation(s)
- Rosalind M Harding
- Biological Anthropology Unit and Statistics Department, University of Oxford, 1 South Parks Road, Oxford OX1 3TG, UK.
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Parry CM, Erkner A, le Coutre J. Divergence of T2R chemosensory receptor families in humans, bonobos, and chimpanzees. Proc Natl Acad Sci U S A 2004; 101:14830-4. [PMID: 15466715 PMCID: PMC522029 DOI: 10.1073/pnas.0404894101] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
T2R (Tas2R) genes encode a family of G protein-coupled gustatory receptors, several involved in bitter taste perception. So far, few ligands for these receptors have been identified, and the specificity of most T2Rs is unclear. Differences between individual T2Rs result in altered taste perception in either specificity or sensitivity. All 33 human T2Rs are characterized by significant sequence homology. However, with a total of eight pseudogenes and >83 coding region single-nucleotide polymorphisms, the family displays broad diversity. The underlying variability of individual T2Rs might be the source for personalized taste perception. To test this hypothesis and also to identify T2Rs that possibly function beyond bitter taste, we compared all human T2R genes with those of the closely related primate species Pan paniscus (bonobo) and Pan troglodytes (chimpanzee). The differences identified range from large sequence alterations to nonsynonymous and synonymous changes of single base pairs. In contrast to olfactory receptors, no human-specific loss of the amount of functional genes was observed. Taken together, the results indicate ongoing evolutionary diversification of T2R receptors and a role for T2Rs in dietary adaptation and personalized food uptake.
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Wang X, Thomas SD, Zhang J. Relaxation of selective constraint and loss of function in the evolution of human bitter taste receptor genes. Hum Mol Genet 2004; 13:2671-8. [PMID: 15367488 DOI: 10.1093/hmg/ddh289] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bitter taste perception prevents mammals from ingesting poisonous substances because many toxins taste bitter and cause aversion. We hypothesize that human bitter taste receptor (TAS2R) genes might be relaxed from selective constraints because of the change in diet, use of fire and reliance on other means of toxin avoidance that emerged in human evolution. Here, we examine the intra-specific variations of all 25 genes of the human TAS2R repertoire. Our data show hallmarks of neutral evolution, including similar rates of synonymous (d(S)) and non-synonymous (d(N)) nucleotide changes among rare polymorphisms, common polymorphisms and substitutions; no variation in d(N)/d(S) among functional domains; segregation of pseudogene alleles within species and fixation of loss-of-function mutations. These results, together with previous findings of large numbers of loss-of-function mutations in olfactory, pheromonal and visual sensory genes in humans, suggest surprisingly reduced sensory capabilities of humans in comparison with many other mammals.
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Affiliation(s)
- Xiaoxia Wang
- Department of Ecology and Evolutionary Biology, University of Michigan, 830 North University Avenue, Ann Arbor, MI 48109, USA
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