151
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Mazzucco R, Nolte V, Vijayan T, Schlötterer C. Long-Term Dynamics Among Wolbachia Strains During Thermal Adaptation of Their Drosophila melanogaster Hosts. Front Genet 2020; 11:482. [PMID: 32477411 PMCID: PMC7241558 DOI: 10.3389/fgene.2020.00482] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/17/2020] [Indexed: 11/13/2022] Open
Abstract
Climate change is a major evolutionary force triggering thermal adaptation in a broad range of species. While the consequences of global warming are being studied for an increasing number of species, limited attention has been given to the evolutionary dynamics of endosymbionts in response to climate change. Here, we address this question by studying the dynamics of Wolbachia, a well-studied endosymbiont of Drosophila melanogaster. D. melanogaster populations infected with 13 different Wolbachia strains were exposed to novel hot and cold laboratory environments for up to 180 generations. The short-term dynamics suggested a temperature-related fitness difference resulting in the increase of clade V strains in the cold environment only. Our long-term analysis now uncovers that clade V dominates in all replicates after generation 60 irrespective of temperature treatment. We propose that adaptation of the Drosophila host to either temperature or Drosophila C virus (DCV) infection are the cause of the replicated, temporally non-concordant Wolbachia dynamics. Our study provides an interesting case demonstrating that even simple, well-controlled experiments can result in complex, but repeatable evolutionary dynamics, thus providing a cautionary note on too simple interpretations on the impact of climate change.
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Affiliation(s)
- Rupert Mazzucco
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Wien, Austria
| | - Viola Nolte
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Wien, Austria
| | - Thapasya Vijayan
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Wien, Austria
- Vienna Graduate School of Population Genetics, Vienna, Austria
| | - Christian Schlötterer
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Wien, Austria
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152
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Nimmo C, Brien K, Millard J, Grant AD, Padayatchi N, Pym AS, O'Donnell M, Goldstein R, Breuer J, Balloux F. Dynamics of within-host Mycobacterium tuberculosis diversity and heteroresistance during treatment. EBioMedicine 2020; 55:102747. [PMID: 32361247 PMCID: PMC7195533 DOI: 10.1016/j.ebiom.2020.102747] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/02/2020] [Accepted: 03/19/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Studying within-host genetic diversity of Mycobacterium tuberculosis (Mtb) in patients during treatment may identify adaptations to antibiotic and immune pressure. Understanding the significance of genetic heteroresistance, and more specifically heterozygous resistance-associated variants (RAVs), is clinically important given increasing use of rapid molecular tests and whole genome sequencing (WGS). METHODS We analyse data from six studies in KwaZulu-Natal, South Africa. Most patients (>75%) had baseline rifampicin resistance. Sputum was collected for culture at baseline and at between two and nine intervals until month six. Positive cultures underwent WGS. Mixed infections and reinfections were excluded from analysis. FINDINGS Baseline Mtb overall genetic diversity (at treatment initiation or major change to regimen) was associated with cavitary disease, not taking antiretroviral therapy if HIV infected, infection with lineage 2 strains and absence of second-line drug resistance on univariate analyses. Baseline genetic diversity was not associated with six-month outcome. Genetic diversity increased from baseline to weeks one and two before returning to previous levels. Baseline genetic heteroresistance was most common for bedaquiline (6/10 [60%] of isolates with RAVs) and fluoroquinolones (9/62 [13%]). Most patients with heterozygous RAVs on WGS with sequential isolates available demonstrated RAV persistence or fixation (17/20, 85%). New RAVs emerged in 9/286 (3%) patients during treatment. We could detect low-frequency RAVs preceding emergent resistance in only one case, although validation of deep sequencing to detect rare variants is required. INTERPRETATION In this study of single-strain Mtb infections, baseline within-host bacterial genetic diversity did not predict outcome but may reveal adaptations to host and drug pressures. Predicting emergent resistance from low-frequency RAVs requires further work to separate transient from consequential mutations. FUNDING Wellcome Trust, NIH/NIAID.
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MESH Headings
- Adult
- Antitubercular Agents/therapeutic use
- Cohort Studies
- Diarylquinolines/therapeutic use
- Drug Resistance, Multiple, Bacterial/genetics
- Female
- Fluoroquinolones/therapeutic use
- Gene Expression Regulation, Bacterial
- Genes, Bacterial
- Genetic Variation
- Host-Pathogen Interactions/genetics
- Humans
- Male
- Metabolic Networks and Pathways/genetics
- Microbial Sensitivity Tests
- Middle Aged
- Mycobacterium tuberculosis/drug effects
- Mycobacterium tuberculosis/genetics
- Mycobacterium tuberculosis/metabolism
- Rifampin/therapeutic use
- South Africa
- Sputum/microbiology
- Tuberculosis, Multidrug-Resistant/drug therapy
- Tuberculosis, Multidrug-Resistant/microbiology
- Tuberculosis, Multidrug-Resistant/pathology
- Tuberculosis, Pulmonary/drug therapy
- Tuberculosis, Pulmonary/microbiology
- Tuberculosis, Pulmonary/pathology
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Affiliation(s)
- Camus Nimmo
- Division of Infection and Immunity, University College London, London, UK; UCL Genetics Institute, University College London, London, UK; Africa Health Research Institute, Durban, South Africa.
| | - Kayleen Brien
- Africa Health Research Institute, Durban, South Africa
| | - James Millard
- Africa Health Research Institute, Durban, South Africa; Wellcome Trust Liverpool Glasgow Centre for Global Health Research, Liverpool, UK; Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Alison D Grant
- Africa Health Research Institute, Durban, South Africa; London School of Hygiene & Tropical Medicine, London, UK
| | - Nesri Padayatchi
- CAPRISA MRC-HIV-TB Pathogenesis and Treatment Research Unit, Durban, South Africa
| | | | - Max O'Donnell
- CAPRISA MRC-HIV-TB Pathogenesis and Treatment Research Unit, Durban, South Africa; Department of Medicine & Epidemiology, Columbia University Medical Center, New York, NY, USA
| | - Richard Goldstein
- Division of Infection and Immunity, University College London, London, UK
| | - Judith Breuer
- Division of Infection and Immunity, University College London, London, UK
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153
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Weiss-Lehman C, Tittes S, Kane NC, Hufbauer RA, Melbourne BA. Stochastic processes drive rapid genomic divergence during experimental range expansions. Proc Biol Sci 2020; 286:20190231. [PMID: 30940062 DOI: 10.1098/rspb.2019.0231] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Range expansions are crucibles for rapid evolution, acting via both selective and neutral mechanisms. While selection on traits such as dispersal and fecundity may increase expansion speed, neutral mechanisms arising from repeated bottlenecks and genetic drift in edge populations (i.e. gene surfing) could slow spread or make it less predictable. Thus, it is necessary to disentangle the effects of selection from neutral mechanisms to robustly predict expansion dynamics. This is difficult to do with expansions in nature, as replicated expansions are required to distinguish selective and neutral processes in the genome. Using replicated microcosms of the red flour beetle ( Tribolium castaneum), we identify a robust signature of stochastic, neutral mechanisms in genomic changes arising over only eight generations of expansion and assess the role of standing variation and de novo mutations in driving these changes. Average genetic diversity was reduced within edge populations, but with substantial among-replicate variability in the changes at specific genomic windows. Such variability in genomic changes is consistent with a large role for stochastic, neutral processes. This increased genomic divergence among populations was mirrored by heightened variation in population size and expansion speed, suggesting that stochastic variation in the genome could increase unpredictability of range expansions.
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Affiliation(s)
- Christopher Weiss-Lehman
- 1 Department of Ecology and Evolutionary Biology, University of Colorado , Boulder, CO 80309 , USA
| | - Silas Tittes
- 1 Department of Ecology and Evolutionary Biology, University of Colorado , Boulder, CO 80309 , USA
| | - Nolan C Kane
- 1 Department of Ecology and Evolutionary Biology, University of Colorado , Boulder, CO 80309 , USA
| | - Ruth A Hufbauer
- 2 Department of Bioagricultural Sciences and Pest Management and Graduate Degree Program in Ecology, Colorado State University , Fort Collins, CO 80523-1177 , USA.,3 UMR Centre de Biologie et Gestion des Populations, INRA , 34988 Montferrier sur Lez , France
| | - Brett A Melbourne
- 1 Department of Ecology and Evolutionary Biology, University of Colorado , Boulder, CO 80309 , USA
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154
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Scossa F, Fernie AR. The evolution of metabolism: How to test evolutionary hypotheses at the genomic level. Comput Struct Biotechnol J 2020; 18:482-500. [PMID: 32180906 PMCID: PMC7063335 DOI: 10.1016/j.csbj.2020.02.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 01/21/2023] Open
Abstract
The origin of primordial metabolism and its expansion to form the metabolic networks extant today represent excellent systems to study the impact of natural selection and the potential adaptive role of novel compounds. Here we present the current hypotheses made on the origin of life and ancestral metabolism and present the theories and mechanisms by which the large chemical diversity of plants might have emerged along evolution. In particular, we provide a survey of statistical methods that can be used to detect signatures of selection at the gene and population level, and discuss potential and limits of these methods for investigating patterns of molecular adaptation in plant metabolism.
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Affiliation(s)
- Federico Scossa
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
- Council for Agricultural Research and Economics (CREA), Research Centre for Genomics and Bioinformatics (CREA-GB), Via Ardeatina 546, 00178 Rome, Italy
| | - Alisdair R. Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam-Golm, Germany
- Center of Plant Systems Biology and Biotechnology (CPSBB), Plovdiv, Bulgaria
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155
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Pfenninger M, Foucault Q. Genomic processes underlying rapid adaptation of a natural
Chironomus riparius
population to unintendedly applied experimental selection pressures. Mol Ecol 2020; 29:536-548. [DOI: 10.1111/mec.15347] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/13/2019] [Accepted: 12/24/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Markus Pfenninger
- Department of Molecular Ecology Senckenberg Biodiversity and Climate Research Centre Frankfurt am Main Germany
- Institute for Molecular and Organismic Evolution Johannes Gutenberg University Mainz Germany
- LOEWE Centre for Translational Biodiversity Genomics Senckenberg Biodiversity and Climate Research Centre Frankfurt am Main Germany
| | - Quentin Foucault
- Department of Molecular Ecology Senckenberg Biodiversity and Climate Research Centre Frankfurt am Main Germany
- Institute for Molecular and Organismic Evolution Johannes Gutenberg University Mainz Germany
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156
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Phair NL, Toonen RJ, Knapp ISS, von der Heyden S. Anthropogenic pressures negatively impact genomic diversity of the vulnerable seagrass Zostera capensis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 255:109831. [PMID: 32063316 DOI: 10.1016/j.jenvman.2019.109831] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 11/03/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
Zostera capensis is a keystone species providing essential ecosystem services to southern African coastal systems. Like most seagrasses globally, Z. capensis is declining and under threat from anthropogenic pressures, and indicators of seagrass health and resilience may be of interest in preventing further declines. As intraspecific diversity is an important component of resilience, we used a pooled RADseq approach to generate genome-wide measures of variation across the entire South African distribution of Z. capensis. Using nucleotide diversity, heterozygosity and allelic richness we tested for associations with fine-scale anthropogenic pressure data compiled by the South African National Biodiversity Assessment using generalised linear models. Increased fishing effort, habitat loss, sand mining and a change in estuary flow dynamics were found to play an important role in decreasing nucleotide diversity and expected heterozygosity, most likely due to the loss of less resilient genotypes as a result of direct physical damage or indirect consequences. As the building block for adaptation, nucleotide diversity is particularly important for resilience. Because of this, as well as the fact that nucleotide diversity displayed the most distinct difference between the west and east coast, and responded most strongly to anthropogenic pressures, we suggest that this may be a useful measure for monitoring genetic or genomic variation. As genomic diversity influences resilience and resistance to disturbances, the remaining diversity in South African seagrass beds urgently needs to be conserved through restoration efforts and careful management of pressures.
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Affiliation(s)
- Nikki Leanne Phair
- Evolutionary Genomics Group, Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland, South Africa.
| | - Robert John Toonen
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, USA.
| | - Ingrid Sally Sigrid Knapp
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, USA.
| | - Sophie von der Heyden
- Evolutionary Genomics Group, Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland, South Africa.
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157
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Walden N, Lucek K, Willi Y. Lineage‐specific adaptation to climate involves flowering time in North American
Arabidopsis lyrata. Mol Ecol 2020; 29:1436-1451. [DOI: 10.1111/mec.15338] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/16/2019] [Accepted: 12/10/2019] [Indexed: 01/06/2023]
Affiliation(s)
- Nora Walden
- Department of Environmental Sciences University of Basel Basel Switzerland
- Centre for Organismal Studies Heidelberg University of Heidelberg Heidelberg Germany
| | - Kay Lucek
- Department of Environmental Sciences University of Basel Basel Switzerland
| | - Yvonne Willi
- Department of Environmental Sciences University of Basel Basel Switzerland
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158
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Aardema ML, vonHoldt BM, Fritz ML, Davis SR. Global evaluation of taxonomic relationships and admixture within the Culex pipiens complex of mosquitoes. Parasit Vectors 2020; 13:8. [PMID: 31915057 PMCID: PMC6950815 DOI: 10.1186/s13071-020-3879-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 01/01/2020] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Within the Culex pipiens mosquito complex, there are six contemporarily recognized taxa: Cx. quinquefasciatus, Cx. pipiens f. pipiens, Cx. pipiens f. molestus, Cx. pipiens pallens, Cx. australicus and Cx. globocoxitus. Many phylogenetic aspects within this complex have eluded resolution, such as the relationship of the two Australian endemic taxa to the other four members, as well as the evolutionary origins and taxonomic status of Cx. pipiens pallens and Cx. pipiens f. molestus. Ultimately, insights into lineage relationships within the complex will facilitate a better understanding of differential disease transmission by these mosquitoes. To this end, we have combined publicly available data with our own sequencing efforts to examine these questions. RESULTS We found that the two Australian endemic complex members, Cx. australicus and Cx. globocoxitus, comprise a monophyletic group, are genetically distinct, and are most closely related to the cosmopolitan Cx. quinquefasciatus. Our results also show that Cx. pipiens pallens is genetically distinct, but may have arisen from past hybridization. Lastly, we observed complicated patterns of genetic differentiation within and between Cx. pipiens f. pipiens and Cx. pipiens f. molestus. CONCLUSIONS Two Australian endemic Culex taxa, Cx. australicus and Cx. globocoxitus, belong within the Cx. pipiens complex, but have a relatively older evolutionary origin. They likely diverged from Cx. quinquefasciatus after its colonization of Australia. The taxon Cx. pipiens pallens is a distinct evolutionary entity that likely arose from past hybridization between Cx. quinquefasciatus and Cx. pipiens f. pipiens/Cx. pipiens f. molestus. Our results do not suggest it derives from ongoing hybridization. Finally, genetic differentiation within the Cx. pipiens f. pipiens and Cx. pipiens f. molestus samples suggests that they collectively form two separate geographic clades, one in North America and one in Europe and the Mediterranean. This may indicate that the Cx. pipiens f. molestus form has two distinct origins, arising from Cx. pipiens f. pipiens in each region. However, ongoing genetic exchange within and between these taxa have obscured their evolutionary histories, and could also explain the absence of monophyly among our samples. Overall, this work suggests many avenues that warrant further investigation.
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Affiliation(s)
- Matthew L. Aardema
- Department of Biology, Montclair State University, Montclair, NJ USA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY USA
| | | | - Megan L. Fritz
- Department of Entomology, University of Maryland, College Park, MD USA
| | - Steven R. Davis
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY USA
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159
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Vendrell-Mir P, Barteri F, Merenciano M, González J, Casacuberta JM, Castanera R. A benchmark of transposon insertion detection tools using real data. Mob DNA 2019; 10:53. [PMID: 31892957 PMCID: PMC6937713 DOI: 10.1186/s13100-019-0197-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/17/2019] [Indexed: 02/01/2023] Open
Abstract
Background Transposable elements (TEs) are an important source of genomic variability in eukaryotic genomes. Their activity impacts genome architecture and gene expression and can lead to drastic phenotypic changes. Therefore, identifying TE polymorphisms is key to better understand the link between genotype and phenotype. However, most genotype-to-phenotype analyses have concentrated on single nucleotide polymorphisms as they are easier to reliable detect using short-read data. Many bioinformatic tools have been developed to identify transposon insertions from resequencing data using short reads. Nevertheless, the performance of most of these tools has been tested using simulated insertions, which do not accurately reproduce the complexity of natural insertions. Results We have overcome this limitation by building a dataset of insertions from the comparison of two high-quality rice genomes, followed by extensive manual curation. This dataset contains validated insertions of two very different types of TEs, LTR-retrotransposons and MITEs. Using this dataset, we have benchmarked the sensitivity and precision of 12 commonly used tools, and our results suggest that in general their sensitivity was previously overestimated when using simulated data. Our results also show that, increasing coverage leads to a better sensitivity but with a cost in precision. Moreover, we found important differences in tool performance, with some tools performing better on a specific type of TEs. We have also used two sets of experimentally validated insertions in Drosophila and humans and show that this trend is maintained in genomes of different size and complexity. Conclusions We discuss the possible choice of tools depending on the goals of the study and show that the appropriate combination of tools could be an option for most approaches, increasing the sensitivity while maintaining a good precision.
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Affiliation(s)
- Pol Vendrell-Mir
- 1Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, Campus UAB, Edifici CRAG, Bellaterra, 08193 Barcelona, Spain
| | - Fabio Barteri
- 1Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, Campus UAB, Edifici CRAG, Bellaterra, 08193 Barcelona, Spain
| | - Miriam Merenciano
- 2Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Maritim Barceloneta 37-49, 08003 Barcelona, Spain
| | - Josefa González
- 2Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Maritim Barceloneta 37-49, 08003 Barcelona, Spain
| | - Josep M Casacuberta
- 1Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, Campus UAB, Edifici CRAG, Bellaterra, 08193 Barcelona, Spain
| | - Raúl Castanera
- 1Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, Campus UAB, Edifici CRAG, Bellaterra, 08193 Barcelona, Spain
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160
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Bitter MC, Kapsenberg L, Gattuso JP, Pfister CA. Standing genetic variation fuels rapid adaptation to ocean acidification. Nat Commun 2019; 10:5821. [PMID: 31862880 PMCID: PMC6925106 DOI: 10.1038/s41467-019-13767-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 11/22/2019] [Indexed: 11/21/2022] Open
Abstract
Global climate change has intensified the need to assess the capacity for natural populations to adapt to abrupt shifts in the environment. Reductions in seawater pH constitute a conspicuous global change stressor that is affecting marine ecosystems globally. Here, we quantify the phenotypic and genetic modifications associated with rapid adaptation to reduced seawater pH in the Mediterranean mussel, Mytilus galloprovincialis. We reared a genetically diverse larval population in two pH treatments (pHT 8.1 and 7.4) and tracked changes in the shell-size distribution and genetic variation through settlement. Additionally, we identified differences in the signatures of selection on shell growth in each pH environment. Both phenotypic and genetic data show that standing variation can facilitate adaptation to declines in seawater pH. This work provides insight into the processes underpinning rapid evolution, and demonstrates the importance of maintaining variation within natural populations to bolster species’ adaptive capacity as global change progresses. Reductions in seawater pH are affecting marine ecosystems globally. Here, the authors describe phenotypic and genetic modifications associated with rapid adaptation to reduced seawater pH in the mussel Mytilus galloprovincialis, and suggest that standing variation within natural populations plays an important role in bolstering species’ adaptive capacity to global change.
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Affiliation(s)
- M C Bitter
- Department of Ecology and Evolution, University of Chicago, 1101 E. 57th St., Chicago, IL, 60637, USA.
| | - L Kapsenberg
- Department of Marine Biology and Oceanography, CSIC Institute of Marine Sciences, Passeig Marítim de la Barceloneta, 37-49, E-08003, Barcelona, Spain
| | - J-P Gattuso
- Laboratoire d'Océanographie de Villefranche, Sorbonne Université, CNRS, 181 chemin du Lazaret, 06230, Villefranche-sur-mer, France.,Institute for Sustainable Development and International Relations, Sciences Po, 27 rue Saint Guillame, 75007, Paris, France
| | - C A Pfister
- Department of Ecology and Evolution, University of Chicago, 1101 E. 57th St., Chicago, IL, 60637, USA
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161
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Woronik A, Tunström K, Perry MW, Neethiraj R, Stefanescu C, Celorio-Mancera MDLP, Brattström O, Hill J, Lehmann P, Käkelä R, Wheat CW. A transposable element insertion is associated with an alternative life history strategy. Nat Commun 2019; 10:5757. [PMID: 31848330 PMCID: PMC6917731 DOI: 10.1038/s41467-019-13596-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 11/15/2019] [Indexed: 12/11/2022] Open
Abstract
Tradeoffs affect resource allocation during development and result in fitness consequences that drive the evolution of life history strategies. Yet despite their importance, we know little about the mechanisms underlying life history tradeoffs. Many species of Colias butterflies exhibit an alternative life history strategy (ALHS) where females divert resources from wing pigment synthesis to reproductive and somatic development. Due to this reallocation, a wing color polymorphism is associated with the ALHS: either yellow/orange or white. Here we map the locus associated with this ALHS in Colias crocea to a transposable element insertion located downstream of the Colias homolog of BarH-1, a homeobox transcription factor. Using CRISPR/Cas9 gene editing, antibody staining, and electron microscopy we find white-specific expression of BarH-1 suppresses the formation of pigment granules in wing scales and gives rise to white wing color. Lipid and transcriptome analyses reveal physiological differences associated with the ALHS. Together, these findings characterize a mechanism for a female-limited ALHS. Tradeoffs are central to life history theory and evolutionary biology, yet almost nothing is known about their mechanistic basis. Here the authors characterize one such mechanism and find a transposable element insertion is associated with the switch between alternative life history strategies.
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Affiliation(s)
- Alyssa Woronik
- Department of Zoology, Stockholm University, S106 91, Stockholm, Sweden. .,Department of Biology, New York University, New York, NY, 10003, USA.
| | - Kalle Tunström
- Department of Zoology, Stockholm University, S106 91, Stockholm, Sweden
| | - Michael W Perry
- Department of Biology, New York University, New York, NY, 10003, USA.,Division of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | | | - Constanti Stefanescu
- Museum of Natural Sciences of Granollers, Granollers, Catalonia, 08402, Spain.,CREAF, Cerdanyola del Valles, Catalonia, 08193, Spain
| | | | - Oskar Brattström
- Department of Zoology, University of Cambridge, Cambridge, CB23EJ, UK
| | - Jason Hill
- Department of Zoology, Stockholm University, S106 91, Stockholm, Sweden.,Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Philipp Lehmann
- Department of Zoology, Stockholm University, S106 91, Stockholm, Sweden
| | - Reijo Käkelä
- Helsinki University Lipidomics Unit (HiLIPID), Helsinki Institute for Life Science (HiLIFE) and Molecular and Integrative Biosciences Research Programme, University of Helsinki, FI00014, Helsinki, Finland
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162
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Guo X, Wang J, Ma C, Wang Z, Chen H, Su H, Wan Y, Jiang R. Genome-wide re-sequencing and transcriptome analysis reveal candidate genes associated with the pendulous comb phenotype in domestic chickens. Anim Sci J 2019; 91:e13308. [PMID: 31808219 DOI: 10.1111/asj.13308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 09/21/2019] [Accepted: 10/17/2019] [Indexed: 12/25/2022]
Abstract
To determine the causative variations associated with two chicken comb phenotypes, pendulous comb (PC) or upright comb (UC), two pooled genomic DNA samples from PC and UC chickens were re-sequenced by Next-Generation Sequencer, and genome-wide Single nucleotide polymorphisms (SNPs) were detected. Using three selective sweep approaches, FST , θπ, and Tajima's D, with top 5% window values serving as the threshold, a total of 84 positively selective genes (PSGs) were identified. There were no SNPs in exons of the PSGs with significant differences in allele frequencies between the two comb phenotype groups. Then, 515 differentially expressed genes (DEGs) between the PC and UC were identified by RNA-seq. Three genes including CD36 (CD36 molecule), ADAMTSL3 (ADAMTS-like 3), and AOX1 (aldehyde oxidases 1) are overlapped between PSGs and DEGs. After genotyping seven candidate SNPs in the regulatory regions of the three overlapping genes in 120 chickens from two other breeds, two variants (rs14607046 and rs731818051) in the regulatory regions of AOX1 and ADAMTSL3 were found to have significant differences in allele frequency between the PC and UC, suggesting that the two variants may be causative mutations for PC. Overall, our study shed light on the genetic basis underlying the PC phenotype in chickens.
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Affiliation(s)
- Xing Guo
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Jiangxian Wang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Chendong Ma
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Zhicheng Wang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Hong Chen
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Hu Su
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Yi Wan
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Runshen Jiang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
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163
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Lucek K, Hohmann N, Willi Y. Postglacial ecotype formation under outcrossing and self-fertilization in Arabidopsis lyrata. Mol Ecol 2019; 28:1043-1055. [PMID: 30719799 DOI: 10.1111/mec.15035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/18/2019] [Accepted: 01/28/2019] [Indexed: 12/01/2022]
Abstract
The formation of ecotypes has been invoked as an important driver of postglacial biodiversity, because many species colonized heterogeneous habitats and experienced divergent selection. Ecotype formation has been predominantly studied in outcrossing taxa, while far less attention has been paid to the implications of mating system shifts. Here, we addressed whether substrate-related ecotypes exist in selfing and outcrossing populations of Arabidopsis lyrata subsp. lyrata and whether the genomic footprint differs between mating systems. The North American subspecies colonized both rocky and sandy habitats during postglacial range expansion and shifted the mating system from predominantly outcrossing to predominantly selfing in a number of regions. We performed an association study on pooled whole-genome sequence data of 20 selfing or outcrossing populations, which suggested genes involved in adaptation to substrate. Motivated by enriched gene ontology terms, we compared root growth between plants from the two substrates in a common environment and found that plants originating from sand grew roots faster and produced more side roots, independent of mating system. Furthermore, single nucleotide polymorphisms associated with substrate-related ecotypes were more clustered among selfing populations. Our study provides evidence for substrate-related ecotypes in A. lyrata and divergence in the genomic footprint between mating systems. The latter is the likely result of selfing populations having experienced divergent selection on larger genomic regions due to higher genome-wide linkage disequilibrium.
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Affiliation(s)
- Kay Lucek
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Nora Hohmann
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Yvonne Willi
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
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164
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Sayadi A, Martinez Barrio A, Immonen E, Dainat J, Berger D, Tellgren-Roth C, Nystedt B, Arnqvist G. The genomic footprint of sexual conflict. Nat Ecol Evol 2019; 3:1725-1730. [DOI: 10.1038/s41559-019-1041-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/15/2019] [Indexed: 12/28/2022]
Abstract
AbstractGenes with sex-biased expression show a number of unique properties and this has been seen as evidence for conflicting selection pressures in males and females, forming a genetic ‘tug-of-war’ between the sexes. However, we lack studies of taxa where an understanding of conflicting phenotypic selection in the sexes has been linked with studies of genomic signatures of sexual conflict. Here, we provide such a link. We used an insect where sexual conflict is unusually well understood, the seed beetle Callosobruchus maculatus, to test for molecular genetic signals of sexual conflict across genes with varying degrees of sex-bias in expression. We sequenced, assembled and annotated its genome and performed population resequencing of three divergent populations. Sex-biased genes showed increased levels of genetic diversity and bore a remarkably clear footprint of relaxed purifying selection. Yet, segregating genetic variation was also affected by balancing selection in weakly female-biased genes, while male-biased genes showed signs of overall purifying selection. Female-biased genes contributed disproportionally to shared polymorphism across populations, while male-biased genes, male seminal fluid protein genes and sex-linked genes did not. Genes showing genomic signatures consistent with sexual conflict generally matched life-history phenotypes known to experience sexually antagonistic selection in this species. Our results highlight metabolic and reproductive processes, confirming the key role of general life-history traits in sexual conflict.
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165
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Viruses in the Invasive Hornet Vespa velutina. Viruses 2019; 11:v11111041. [PMID: 31717432 PMCID: PMC6893812 DOI: 10.3390/v11111041] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/16/2019] [Accepted: 10/25/2019] [Indexed: 12/22/2022] Open
Abstract
The Asian yellow-legged hornet Vespa velutina nigrithorax, a major predator of honeybees, is spreading in Europe in part due to a lack of efficient control methods. In this study, as a first step to identify biological control agents, we characterized viral RNA sequences present in asymptomatic or symptomatic hornets. Among 19 detected viruses, the honey bee virus Deformed wing virus-B was predominant in all the samples, particularly in muscles from the symptomatic hornet, suggesting a putative cause of the deformed wing symptom. Interestingly, two new viruses closely related to Acyrthosiphon pisumvirus and Himetobi Pvirus and viruses typically associated with honey bees, Acute bee paralysis virus and Black queen cell virus, were detected in the brain and muscles, and may correspond to the circulation and possible replication forms of these viruses in the hornet. Aphid lethal paralysis virus, Bee Macula-like virus, and Moku virus, which are known to infect honey bees, were also identified in the gut virus metagenome of hornets. Therefore, our study underlined the urgent need to study the host range of these newly discovered viruses in hornets to determine whether they represent a new threat for honey bees or a hope for the biocontrol of V. velutina.
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166
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Martinez J, Bruner-Montero G, Arunkumar R, Smith SCL, Day JP, Longdon B, Jiggins FM. Virus evolution in Wolbachia-infected Drosophila. Proc Biol Sci 2019; 286:20192117. [PMID: 31662085 PMCID: PMC6823055 DOI: 10.1098/rspb.2019.2117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 10/08/2019] [Indexed: 12/30/2022] Open
Abstract
Wolbachia, a common vertically transmitted symbiont, can protect insects against viral infection and prevent mosquitoes from transmitting viral pathogens. For this reason, Wolbachia-infected mosquitoes are being released to prevent the transmission of dengue and other arboviruses. An important question for the long-term success of these programmes is whether viruses can evolve to escape the antiviral effects of Wolbachia. We have found that Wolbachia altered the outcome of competition between strains of the DCV virus in Drosophila. However, Wolbachia still effectively blocked the virus genotypes that were favoured in the presence of the symbiont. We conclude that Wolbachia did cause an evolutionary response in viruses, but this has little or no impact on the effectiveness of virus blocking.
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Affiliation(s)
- Julien Martinez
- Department of Genetics, University of Cambridge, Cambridge, UK
| | | | | | | | - Jonathan P. Day
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Ben Longdon
- Department of Genetics, University of Cambridge, Cambridge, UK
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
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167
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Gebiola M, Streicher JW, Rugman-Jones PF, Morse JG, Stouthamer R. Genome-wide analyses of single nucleotide polymorphisms reveal the consequences of traditional mass-rearing on genetic variation in Aphytis melinus (Hymenoptera: Aphelinidae): the danger of putting all eggs in one basket. PEST MANAGEMENT SCIENCE 2019; 75:3102-3112. [PMID: 30924276 DOI: 10.1002/ps.5427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 02/15/2019] [Accepted: 03/23/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Aphytis melinus DeBach (Hymenoptera: Aphelinidae) is a highly effective biocontrol agent of the California red scale Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae). It is commercially reared and used for augmentative releases within integrated pest management programs. However, mass rearing of biocontrol agents can result in population bottlenecks and high levels of inbreeding and/or adaptation to the factitious rearing conditions. Although these factors can all negatively impact field performance of biocontrol agents, few empirical studies have examined the genetic consequences of mass rearing. We used double-digest RAD sequencing (ddRADseq) to investigate the effect of traditional mass rearing on genetic variation among insectary colonies of A. melinus relative to wild populations in native (Pakistan) and introduced (California) ranges. RESULTS Analyses of up to 9700 single nucleotide polymorphisms (SNPs) revealed that insectary populations had less genomic variation than introduced populations. This was evidenced by fewer private alleles, reduced heterozygosity, and greater missing data in the insectary populations. Further, California insectaries formed a distinct genomic cluster relative to the other samples, a surprising result given that the insectary colonies were putatively established at different times and from different source populations. These differences were evident across most data sets also after we filtered out contaminant DNA from the most common host species (Aspidiotus nerii Bouché and A. aurantii). CONCLUSION We hypothesize that this pattern would only result if: (i) directional selection for 'captive' phenotypes produces convergent patterns of genomic variation across insectaries; or (ii) the California insectary colonies were all founded from a unifying source population and/or that the insectaries regularly exchange 'genetic' stocks. We show that RADseq is an effective method to investigate the effects of mass rearing on genetics of biocontrol agents. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Marco Gebiola
- Department of Entomology, University of California, Riverside, CA, USA
| | | | | | - Joseph G Morse
- Department of Entomology, University of California, Riverside, CA, USA
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168
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Stam R, Silva-Arias GA, Tellier A. Subsets of NLR genes show differential signatures of adaptation during colonization of new habitats. THE NEW PHYTOLOGIST 2019; 224:367-379. [PMID: 31230368 DOI: 10.1111/nph.16017] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 06/14/2019] [Indexed: 06/09/2023]
Abstract
Nucleotide binding site, leucine-rich repeat receptors (NLRs) are canonical resistance (R) genes in plants, fungi and animals, functioning as central (helper) and peripheral (sensor) genes in a signalling network. We investigate NLR evolution during the colonization of novel habitats in a model tomato species, Solanum chilense. We used R-gene enrichment sequencing to obtain polymorphism data at NLRs of 140 plants sampled across 14 populations covering the whole species range. We inferred the past demographic history of habitat colonization by resequencing whole genomes from three S. chilense plants from three key populations and performing approximate Bayesian computation using data from the 14 populations. Using these parameters, we simulated the genetic differentiation statistics distribution expected under neutral NLR evolution and identified small subsets of outlier NLRs exhibiting signatures of selection across populations. NLRs under selection between habitats are more often helper genes, whereas those showing signatures of adaptation in single populations are more often sensor-NLRs. Thus, centrality in the NLR network does not constrain NLR evolvability, and new mutations in central genes in the network are key for R-gene adaptation during colonization of different habitats.
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Affiliation(s)
- Remco Stam
- Phytopathology, Technical University Munich, 85354, Freising, Germany
- Population Genetics, Technical University Munich, 85354, Freising, Germany
| | | | - Aurelien Tellier
- Population Genetics, Technical University Munich, 85354, Freising, Germany
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169
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Kurland S, Wheat CW, de la Paz Celorio Mancera M, Kutschera VE, Hill J, Andersson A, Rubin C, Andersson L, Ryman N, Laikre L. Exploring a Pool-seq-only approach for gaining population genomic insights in nonmodel species. Ecol Evol 2019; 9:11448-11463. [PMID: 31641485 PMCID: PMC6802065 DOI: 10.1002/ece3.5646] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/12/2022] Open
Abstract
Developing genomic insights is challenging in nonmodel species for which resources are often scarce and prohibitively costly. Here, we explore the potential of a recently established approach using Pool-seq data to generate a de novo genome assembly for mining exons, upon which Pool-seq data are used to estimate population divergence and diversity. We do this for two pairs of sympatric populations of brown trout (Salmo trutta): one naturally sympatric set of populations and another pair of populations introduced to a common environment. We validate our approach by comparing the results to those from markers previously used to describe the populations (allozymes and individual-based single nucleotide polymorphisms [SNPs]) and from mapping the Pool-seq data to a reference genome of the closely related Atlantic salmon (Salmo salar). We find that genomic differentiation (F ST) between the two introduced populations exceeds that of the naturally sympatric populations (F ST = 0.13 and 0.03 between the introduced and the naturally sympatric populations, respectively), in concordance with estimates from the previously used SNPs. The same level of population divergence is found for the two genome assemblies, but estimates of average nucleotide diversity differ ( π ¯ ≈ 0.002 and π ¯ ≈ 0.001 when mapping to S. trutta and S. salar, respectively), although the relationships between population values are largely consistent. This discrepancy might be attributed to biases when mapping to a haploid condensed assembly made of highly fragmented read data compared to using a high-quality reference assembly from a divergent species. We conclude that the Pool-seq-only approach can be suitable for detecting and quantifying genome-wide population differentiation, and for comparing genomic diversity in populations of nonmodel species where reference genomes are lacking.
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Affiliation(s)
- Sara Kurland
- Division of Population GeneticsDepartment of ZoologyStockholm UniversityStockholmSweden
| | - Christopher W. Wheat
- Division of Population GeneticsDepartment of ZoologyStockholm UniversityStockholmSweden
| | | | - Verena E. Kutschera
- Science for Life Laboratory and Department for Biochemistry and BiophysicsStockholm UniversitySolnaSweden
| | - Jason Hill
- Division of Population GeneticsDepartment of ZoologyStockholm UniversityStockholmSweden
| | - Anastasia Andersson
- Division of Population GeneticsDepartment of ZoologyStockholm UniversityStockholmSweden
| | - Carl‐Johan Rubin
- Department of Medical Biochemistry and MicrobiologyUppsala UniversityUppsalaSweden
| | - Leif Andersson
- Department of Medical Biochemistry and MicrobiologyUppsala UniversityUppsalaSweden
- Department of Animal Breeding and GeneticsSwedish University of Agricultural SciencesUppsalaSweden
- Department of Veterinary Integrative BiosciencesTexas A&M UniversityCollege StationTXUSA
| | - Nils Ryman
- Division of Population GeneticsDepartment of ZoologyStockholm UniversityStockholmSweden
| | - Linda Laikre
- Division of Population GeneticsDepartment of ZoologyStockholm UniversityStockholmSweden
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170
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Khan S, Zhao X, Hou Y, Yuan C, Li Y, Luo X, Liu J, Feng X. Analysis of genome-wide SNPs based on 2b-RAD sequencing of pooled samples reveals signature of selection in different populations of Haemonchus contortus. J Biosci 2019; 44:97. [PMID: 31502575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The parasitic nematode Haemonchus contortus is one of the world's most important parasites of small ruminants that causes significant economic losses to the livestock sector. The population structure and selection in its various strains are poorly understood. No study so far compared its different populations using genome-wide data. Here, we focused on different geographic populations of H. contours from China (Tibet, TB; Hubei, HB; Inner Mongolia, IM; Sichuan, SC), UK and Australia (AS), using genome-wide population-genomic approaches, to explore genetic diversity, population structure and selection. We first performed next-generation high-throughput 2b RAD pool sequencing using Illumina technology, and identified single-nucleotide polymorphisms (SNPs) in all the strains. We identified 75,187 SNPs for TB, 82,271 for HB, 82,420 for IM, 79,803 for SC, 83,504 for AS and 78,747 for UK strain. The SNPs revealed low-nucleotide diversity (pi= 0.0092-0.0133) within each strain, and a significant differentiation level (average Fst = 0.34264) among them. Chinese populations TB and SC, along with the UK strain, were more divergent populations. Chinese populations IM and HB showed affinities to the Australian strain. We then analysed signature of selection and detected 44 (UK) and 03 (AS) private selective sweeps containing 49 and 05 genes, respectively. Finally, we performed the functional annotation of selective sweeps and proposed biological significance to signature of selection. Our data suggest that 2b-RAD pool sequencing can be used to assess the signature of selection in H. contortus.
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Affiliation(s)
- Sawar Khan
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, Shanghai 200241, People's Republic of China
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171
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Chapman JR, Hill T, Unckless RL. Balancing Selection Drives the Maintenance of Genetic Variation in Drosophila Antimicrobial Peptides. Genome Biol Evol 2019; 11:2691-2701. [PMID: 31504505 PMCID: PMC6764478 DOI: 10.1093/gbe/evz191] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2019] [Indexed: 12/19/2022] Open
Abstract
Genes involved in immune defense against pathogens provide some of the most well-known examples of both directional and balancing selection. Antimicrobial peptides (AMPs) are innate immune effector genes, playing a key role in pathogen clearance in many species, including Drosophila. Conflicting lines of evidence have suggested that AMPs may be under directional, balancing, or purifying selection. Here, we use both a linear model and control-gene-based approach to show that balancing selection is an important force shaping AMP diversity in Drosophila. In Drosophila melanogaster, this is most clearly observed in ancestral African populations. Furthermore, the signature of balancing selection is even more striking once background selection has been accounted for. Balancing selection also acts on AMPs in Drosophila mauritiana, an isolated island endemic separated from D. melanogaster by about 4 Myr of evolution. This suggests that balancing selection may be broadly acting to maintain adaptive diversity in Drosophila AMPs, as has been found in other taxa.
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Affiliation(s)
| | - Tom Hill
- Department of Molecular Biosciences, University of Kansas
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172
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Ramaekers A, Claeys A, Kapun M, Mouchel-Vielh E, Potier D, Weinberger S, Grillenzoni N, Dardalhon-Cuménal D, Yan J, Wolf R, Flatt T, Buchner E, Hassan BA. Altering the Temporal Regulation of One Transcription Factor Drives Evolutionary Trade-Offs between Head Sensory Organs. Dev Cell 2019; 50:780-792.e7. [PMID: 31447264 DOI: 10.1016/j.devcel.2019.07.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 04/24/2019] [Accepted: 07/25/2019] [Indexed: 12/30/2022]
Abstract
Size trade-offs of visual versus olfactory organs is a pervasive feature of animal evolution. This could result from genetic or functional constraints. We demonstrate that head sensory organ size trade-offs in Drosophila are genetically encoded and arise through differential subdivision of the head primordium into visual versus non-visual fields. We discover that changes in the temporal regulation of the highly conserved eyeless/Pax6 gene expression during development is a conserved mechanism for sensory trade-offs within and between Drosophila species. We identify a natural single nucleotide polymorphism in the cis-regulatory region of eyeless in a binding site of its repressor Cut that is sufficient to alter its temporal regulation and eye size. Because eyeless/Pax6 is a conserved regulator of head sensory placode subdivision, we propose that its temporal regulation is key to define the relative size of head sensory organs.
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Affiliation(s)
- Ariane Ramaekers
- Institut du Cerveau et de la Moelle Epinière (ICM) - Hôpital Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, France.
| | - Annelies Claeys
- VIB Center for Brain and Disease, VIB, Leuven, Belgium; Center for Human Genetics, University of Leuven School of Medicine, Leuven, Belgium
| | - Martin Kapun
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Emmanuèle Mouchel-Vielh
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement, Institut de Biologie Paris Seine, LBD-IBPS), Paris, France
| | - Delphine Potier
- Aix-Marseille Université, CNRS, INSERM, CIML, Marseille, France
| | - Simon Weinberger
- VIB Center for Brain and Disease, VIB, Leuven, Belgium; Center for Human Genetics, University of Leuven School of Medicine, Leuven, Belgium
| | - Nicola Grillenzoni
- Institut du Cerveau et de la Moelle Epinière (ICM) - Hôpital Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, France
| | - Delphine Dardalhon-Cuménal
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement, Institut de Biologie Paris Seine, LBD-IBPS), Paris, France
| | - Jiekun Yan
- VIB Center for Brain and Disease, VIB, Leuven, Belgium; Center for Human Genetics, University of Leuven School of Medicine, Leuven, Belgium
| | - Reinhard Wolf
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Thomas Flatt
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Erich Buchner
- Institute for Clinical Neurobiology, University Hospital Würzburg, Würzburg, Germany
| | - Bassem A Hassan
- Institut du Cerveau et de la Moelle Epinière (ICM) - Hôpital Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, France.
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173
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Doyle JM, Willoughby JR, Bell DA, Bloom PH, Bragin EA, Fernandez NB, Katzner TE, Leonard K, DeWoody JA. Elevated Heterozygosity in Adults Relative to Juveniles Provides Evidence of Viability Selection on Eagles and Falcons. J Hered 2019; 110:696-706. [DOI: 10.1093/jhered/esz048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 08/01/2019] [Indexed: 02/06/2023] Open
Abstract
AbstractViability selection yields adult populations that are more genetically variable than those of juveniles, producing a positive correlation between heterozygosity and survival. Viability selection could be the result of decreased heterozygosity across many loci in inbred individuals and a subsequent decrease in survivorship resulting from the expression of the deleterious alleles. Alternatively, locus-specific differences in genetic variability between adults and juveniles may be driven by forms of balancing selection, including heterozygote advantage, frequency-dependent selection, or selection across temporal and spatial scales. We use a pooled-sequencing approach to compare genome-wide and locus-specific genetic variability between 74 golden eagle (Aquila chrysaetos), 62 imperial eagle (Aquila heliaca), and 69 prairie falcon (Falco mexicanus) juveniles and adults. Although genome-wide genetic variability is comparable between juvenile and adult golden eagles and prairie falcons, imperial eagle adults are significantly more heterozygous than juveniles. This evidence of viability selection may stem from a relatively smaller imperial eagle effective population size and potentially greater genetic load. We additionally identify ~2000 single-nucleotide polymorphisms across the 3 species with extreme differences in heterozygosity between juveniles and adults. Many of these markers are associated with genes implicated in immune function or olfaction. These loci represent potential targets for studies of how heterozygote advantage, frequency-dependent selection, and selection over spatial and temporal scales influence survivorship in avian species. Overall, our genome-wide data extend previous studies that used allozyme or microsatellite markers and indicate that viability selection may be a more common evolutionary phenomenon than often appreciated.
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Affiliation(s)
- Jacqueline M Doyle
- Department of Biological Sciences, Towson University, Baltimore, MD
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN
| | - Janna R Willoughby
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama
- Department of Biological Sciences, Purdue University, West Lafayette, IN
| | - Douglas A Bell
- Department of Biological Sciences, Towson University, Baltimore, MD
- East Bay Regional Park District, Oakland, CA
- Department of Ornithology and Mammalogy, California Academy of Sciences, San Francisco, CA
| | - Peter H Bloom
- Department of Biological Sciences, Towson University, Baltimore, MD
- Bloom Research Inc., Los Angeles, CA
| | - Evgeny A Bragin
- Department of Biological Sciences, Towson University, Baltimore, MD
- Faculty of Natural Science, Kostanay State Pedagogical University, Kostanay, Kazakhstan
- The Peregrine Fund, Boise, ID
- Science Department, Naurzum National Nature Reserve, Kostanay Oblast, Naurzumski Raijon, Karamendy, Kazakhstan
| | - Nadia B Fernandez
- Department of Biological Sciences, Towson University, Baltimore, MD
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA
| | - Todd E Katzner
- Department of Biological Sciences, Towson University, Baltimore, MD
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, ID
| | - Kolbe Leonard
- Department of Biological Sciences, Towson University, Baltimore, MD
- Department of Computer and Information Sciences, Towson University, Baltimore, MD
| | - J Andrew DeWoody
- Department of Biological Sciences, Towson University, Baltimore, MD
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN
- Department of Biological Sciences, Purdue University, West Lafayette, IN
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174
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Khan S, Zhao X, Hou Y, Yuan C, Li Y, Luo X, Liu J, Feng X. Analysis of genome-wide SNPs based on 2b-RAD sequencing of pooled samples reveals signature of selection in different populations of Haemonchus contortus. J Biosci 2019. [DOI: 10.1007/s12038-019-9917-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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175
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Lebeuf-Taylor E, McCloskey N, Bailey SF, Hinz A, Kassen R. The distribution of fitness effects among synonymous mutations in a gene under directional selection. eLife 2019; 8:45952. [PMID: 31322500 PMCID: PMC6692132 DOI: 10.7554/elife.45952] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 07/18/2019] [Indexed: 12/21/2022] Open
Abstract
The fitness effects of synonymous mutations, nucleotide changes that do not alter the encoded amino acid, have often been assumed to be neutral, but a growing body of evidence suggests otherwise. We used site-directed mutagenesis coupled with direct measures of competitive fitness to estimate the distribution of fitness effects among synonymous mutations for a gene under directional selection and capable of adapting via synonymous nucleotide changes. Synonymous mutations had highly variable fitness effects, both deleterious and beneficial, resembling those of nonsynonymous mutations in the same gene. This variation in fitness was underlain by changes in transcription linked to the creation of internal promoter sites. A positive correlation between fitness and the presence of synonymous substitutions across a phylogeny of related Pseudomonads suggests these mutations may be common in nature. Taken together, our results provide the most compelling evidence to date that synonymous mutations with non-neutral fitness effects may in fact be commonplace.
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Affiliation(s)
| | - Nick McCloskey
- Department of Biology, University of Ottawa, Ottawa, Canada
| | - Susan F Bailey
- Department of Biology, Clarkson University, Potsdam, United States
| | - Aaron Hinz
- Department of Biology, University of Ottawa, Ottawa, Canada
| | - Rees Kassen
- Department of Biology, University of Ottawa, Ottawa, Canada
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176
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Cai Z, Zhou L, Ren NN, Xu X, Liu R, Huang L, Zheng XM, Meng QL, Du YS, Wang MX, Geng MF, Chen WL, Jing CY, Zou XH, Guo J, Chen CB, Zeng HZ, Liang YT, Wei XH, Guo YL, Zhou HF, Zhang FM, Ge S. Parallel Speciation of Wild Rice Associated with Habitat Shifts. Mol Biol Evol 2019; 36:875-889. [PMID: 30861529 PMCID: PMC6501882 DOI: 10.1093/molbev/msz029] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The occurrence of parallel speciation strongly implies the action of natural selection. However, it is unclear how general a phenomena parallel speciation is since it was only shown in a small number of animal species. In particular, the adaptive process and mechanisms underlying the process of parallel speciation remain elusive. Here, we used an integrative approach incorporating population genomics, common garden, and crossing experiments to investigate parallel speciation of the wild rice species Oryza nivara from O. rufipogon. We demonstrated that O. nivara originated multiple times from different O. rufipogon populations and revealed that different O. nivara populations have evolved similar phenotypes under divergent selection, a reflection of recurrent local adaptation of ancient O. rufipogon populations to dry habitats. Almost completed premating isolation was detected between O. nivara and O. rufipogon in the absence of any postmating barriers between and within these species. These results suggest that flowering time is a “magic” trait that contributes to both local adaptation and reproductive isolation in the origin of wild rice species. Our study thus demonstrates a convincing case of parallel ecological speciation as a consequence of adaptation to new environments.
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Affiliation(s)
- Zhe Cai
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lian Zhou
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ning-Ning Ren
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xun Xu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Rong Liu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Lei Huang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xiao-Ming Zheng
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Qing-Lin Meng
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yu-Su Du
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Mei-Xia Wang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Mu-Fan Geng
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wen-Li Chen
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Chun-Yan Jing
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xin-Hui Zou
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jie Guo
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Cheng-Bin Chen
- Guangxi Academy Agricultural Sciences, Nanning, Guangxi, China
| | - Hua-Zhong Zeng
- Guangxi Academy Agricultural Sciences, Nanning, Guangxi, China
| | - Yun-Tao Liang
- Guangxi Academy Agricultural Sciences, Nanning, Guangxi, China
| | - Xing-Hua Wei
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Ya-Long Guo
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Hai-Fei Zhou
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Fu-Min Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Song Ge
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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177
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Brennan RS, Garrett AD, Huber KE, Hargarten H, Pespeni MH. Rare genetic variation and balanced polymorphisms are important for survival in global change conditions. Proc Biol Sci 2019; 286:20190943. [PMID: 31185858 PMCID: PMC6571474 DOI: 10.1098/rspb.2019.0943] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 05/17/2019] [Indexed: 12/14/2022] Open
Abstract
Standing genetic variation is important for population persistence in extreme environmental conditions. While some species may have the capacity to adapt to predicted average future global change conditions, the ability to survive extreme events is largely unknown. We used single-generation selection experiments on hundreds of thousands of Strongylocentrotus purpuratus sea urchin larvae generated from wild-caught adults to identify adaptive genetic variation responsive to moderate (pH 8.0) and extreme (pH 7.5) low-pH conditions. Sequencing genomic DNA from pools of larvae, we identified consistent changes in allele frequencies across replicate cultures for each pH condition and observed increased linkage disequilibrium around selected loci, revealing selection on recombined standing genetic variation. We found that loci responding uniquely to either selection regime were at low starting allele frequencies while variants that responded to both pH conditions (11.6% of selected variants) started at high frequencies. Loci under selection performed functions related to energetics, pH tolerance, cell growth and actin/cytoskeleton dynamics. These results highlight that persistence in future conditions will require two classes of genetic variation: common, pH-responsive variants maintained by balancing selection in a heterogeneous environment, and rare variants, particularly for extreme conditions, that must be maintained by large population sizes.
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178
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Favia M, Fitak R, Guerra L, Pierri CL, Faye B, Oulmouden A, Burger PA, Ciani E. Beyond the Big Five: Investigating Myostatin Structure, Polymorphism and Expression in Camelus dromedarius. Front Genet 2019; 10:502. [PMID: 31231423 PMCID: PMC6566074 DOI: 10.3389/fgene.2019.00502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 05/07/2019] [Indexed: 12/19/2022] Open
Abstract
Myostatin, a negative regulator of skeletal muscle mass in animals, has been shown to play a role in determining muscular hypertrophy in several livestock species, and a high degree of polymorphism has been previously reported for this gene in humans and cattle. In this study, we provide a characterization of the myostatin gene in the dromedary (Camelus dromedarius) at the genomic, transcript and protein level. The gene was found to share high structural and sequence similarity with other mammals, notably Old World camelids. 3D modeling highlighted several non-conservative SNP variants compared to the bovine, as well as putative functional variants involved in the stability of the myostatin dimer. NGS data for nine dromedaries from various countries revealed 66 novel SNPs, all of them falling either upstream or downstream the coding region. The analysis also confirmed the presence of three previously described SNPs in intron 1, predicted here to alter both splicing and transcription factor binding sites (TFBS), thus possibly impacting myostatin processing and/or regulation. Several putative TFBS were identified in the myostatin upstream region, some of them belonging to the myogenic regulatory factor family. Patterns of SNP distribution across countries, as suggested by Bayesian clustering of the nine dromedaries using the 69 SNPs, pointed to weak geographic differentiation, in line with known recurrent gene flow at ancient trading centers along caravan routes. Myostatin expression was investigated in a set of 8 skeletal muscles, both at transcript and protein level, via Digital Droplet PCR and Western Blotting, respectively. No significant differences were observed at the transcript level, while, at the protein level, the only significant differences concerned the promyostatin dimer (75 kDa), in four pair-wise comparisons, all involving the tensor fasciae latae muscle. Beside the mentioned band at 75 kDa, additional bands were observed at around 40 and 25 kDa, corresponding to the promyostatin monomer and the active C-terminal myostatin dimer, respectively. Their weaker intensity suggests that the unprocessed myostatin dimers could act as important reservoirs of slowly available myostatin forms. Under this assumption, the sequential cleavage steps may contribute additional layers of control within an already complex regulatory framework.
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Affiliation(s)
- Maria Favia
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Robert Fitak
- Research Institute of Wildlife Ecology, Vetmeduni, Vienna, Austria.,Department of Biology, Duke University, Durham, NC, United States
| | - Lorenzo Guerra
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Ciro Leonardo Pierri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | | | - Ahmad Oulmouden
- Département Sciences du Vivant, Université de Limoges, Limoges, France
| | | | - Elena Ciani
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
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179
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Shockey AC, Dabney J, Pepperell CS. Effects of Host, Sample, and in vitro Culture on Genomic Diversity of Pathogenic Mycobacteria. Front Genet 2019; 10:477. [PMID: 31214242 PMCID: PMC6558051 DOI: 10.3389/fgene.2019.00477] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 05/03/2019] [Indexed: 12/16/2022] Open
Abstract
Mycobacterium tuberculosis (M. tb), an obligate human pathogen and the etiological agent of tuberculosis (TB), remains a major threat to global public health. Comparative genomics has been invaluable for monitoring the emergence and spread of TB and for gaining insight into adaptation of M. tb. Most genomic studies of M. tb are based on single bacterial isolates that have been cultured for several weeks in vitro. However, in its natural human host, M. tb comprises complex, in some cases massive bacterial populations that diversify over the course of infection and cannot be wholly represented by a single genome. Recently, enrichment via hybridization capture has been used as a rapid diagnostic tool for TB, circumventing culturing protocols and enabling the recovery of M. tb genomes directly from sputum. This method has further applicability to the study of M. tb adaptation, as it enables a higher resolution and more direct analysis of M. tb genetic diversity within hosts with TB. Here we analyzed genomic material from M. tb and Mycobacterium bovis populations captured directly from sputum and from cultured samples using metagenomic and Pool-Seq approaches. We identified effects of sampling, patient, and sample type on bacterial genetic diversity. Bacterial genetic diversity was more variable and on average higher in sputum than in culture samples, suggesting that manipulation in the laboratory reshapes the bacterial population. Using outlier analyses, we identified candidate bacterial genetic loci mediating adaptation to these distinct environments. The study of M. tb in its natural human host is a powerful tool for illuminating host pathogen interactions and understanding the bacterial genetic underpinnings of virulence.
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Affiliation(s)
- Abigail C. Shockey
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Jesse Dabney
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Caitlin S. Pepperell
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
- Department of Medicine, Division of Infectious Diseases, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
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180
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Dorant Y, Benestan L, Rougemont Q, Normandeau E, Boyle B, Rochette R, Bernatchez L. Comparing Pool-seq, Rapture, and GBS genotyping for inferring weak population structure: The American lobster ( Homarus americanus) as a case study. Ecol Evol 2019; 9:6606-6623. [PMID: 31236247 PMCID: PMC6580275 DOI: 10.1002/ece3.5240] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/10/2019] [Accepted: 04/13/2019] [Indexed: 01/02/2023] Open
Abstract
Unraveling genetic population structure is challenging in species potentially characterized by large population size and high dispersal rates, often resulting in weak genetic differentiation. Genotyping a large number of samples can improve the detection of subtle genetic structure, but this may substantially increase sequencing cost and downstream bioinformatics computational time. To overcome this challenge, alternative, cost-effective sequencing approaches, namely Pool-seq and Rapture, have been developed. We empirically measured the power of resolution and congruence of these two methods in documenting weak population structure in nonmodel species with high gene flow comparatively to a conventional genotyping-by-sequencing (GBS) approach. For this, we used the American lobster (Homarus americanus) as a case study. First, we found that GBS, Rapture, and Pool-seq approaches gave similar allele frequency estimates (i.e., correlation coefficient over 0.90) and all three revealed the same weak pattern of population structure. Yet, Pool-seq data showed F ST estimates three to five times higher than GBS and Rapture, while the latter two methods returned similar F ST estimates, indicating that individual-based approaches provided more congruent results than Pool-seq. We conclude that despite higher costs, GBS and Rapture are more convenient approaches to use in the case of species exhibiting very weak differentiation. While both GBS and Rapture approaches provided similar results with regard to estimates of population genetic parameters, GBS remains more cost-effective in project involving a relatively small numbers of genotyped individuals (e.g., <1,000). Overall, this study illustrates the complexity of estimating genetic differentiation and other summary statistics in complex biological systems characterized by large population size and migration rates.
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Affiliation(s)
- Yann Dorant
- Institut de Biologie Intégrative et des Systèmes (IBIS)Université LavalQuébecCanada
| | - Laura Benestan
- Institut de Biologie Intégrative et des Systèmes (IBIS)Université LavalQuébecCanada
- Pêches et Océans CanadaInstitut Maurice‐LamontagneMont‐JoliCanada
| | - Quentin Rougemont
- Institut de Biologie Intégrative et des Systèmes (IBIS)Université LavalQuébecCanada
| | - Eric Normandeau
- Institut de Biologie Intégrative et des Systèmes (IBIS)Université LavalQuébecCanada
| | - Brian Boyle
- Institut de Biologie Intégrative et des Systèmes (IBIS)Université LavalQuébecCanada
- Plateforme d'analyses génomiques, Institut de Biologie Intégrative et des Systèmes (IBIS)Université LavalQuébecCanada
| | - Rémy Rochette
- Department of BiologyUniversity of New BrunswickSaint JohnCanada
| | - Louis Bernatchez
- Institut de Biologie Intégrative et des Systèmes (IBIS)Université LavalQuébecCanada
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181
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Genomic divergence and adaptive convergence in Drosophila simulans from Evolution Canyon, Israel. Proc Natl Acad Sci U S A 2019; 116:11839-11844. [PMID: 31127048 PMCID: PMC6576144 DOI: 10.1073/pnas.1720938116] [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] [Indexed: 12/30/2022] Open
Abstract
Biodiversity refugia formed by unique features of the Mediterranean arid landscape, such as the dramatic ecological contrast of "Evolution Canyon," provide a natural laboratory in which local adaptations to divergent microclimate conditions can be investigated. Significant insights have been provided by studies of Drosophila melanogaster diversifying along the thermal gradient in Evolution Canyon, but a comparative framework to survey adaptive convergence across sister species at the site has been lacking. To fill this void, we present an analysis of genomic polymorphism and evolutionary divergence of Drosophila simulans, a close relative of Drosophila melanogaster with which it co-occurs on both slopes of the canyon. Our results show even deeper interslope divergence in D. simulans than in D. melanogaster, with extensive signatures of selective sweeps present in flies from both slopes but enhanced in the population from the hotter and drier south-facing slope. Interslope divergence was enriched for genes related to electrochemical balance and transmembrane transport, likely in response to increased selection for dehydration resistance on the hotter slope. Both species shared genomic regions that underwent major selective sweeps, but the overall level of adaptive convergence was low, demonstrating no shortage of alternative genomic solutions to cope with the challenges of the microclimate contrast. Mobile elements were a major source of genetic polymorphism and divergence, affecting all parts of the genome, including coding sequences of mating behavior-related genes.
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182
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Elbers JP, Rogers MF, Perelman PL, Proskuryakova AA, Serdyukova NA, Johnson WE, Horin P, Corander J, Murphy D, Burger PA. Improving Illumina assemblies with Hi-C and long reads: An example with the North African dromedary. Mol Ecol Resour 2019; 19:1015-1026. [PMID: 30972949 PMCID: PMC6618069 DOI: 10.1111/1755-0998.13020] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 03/24/2019] [Accepted: 03/25/2019] [Indexed: 12/22/2022]
Abstract
Researchers have assembled thousands of eukaryotic genomes using Illumina reads, but traditional mate‐pair libraries cannot span all repetitive elements, resulting in highly fragmented assemblies. However, both chromosome conformation capture techniques, such as Hi‐C and Dovetail Genomics Chicago libraries and long‐read sequencing, such as Pacific Biosciences and Oxford Nanopore, help span and resolve repetitive regions and therefore improve genome assemblies. One important livestock species of arid regions that does not have a high‐quality contiguous reference genome is the dromedary (Camelus dromedarius). Draft genomes exist but are highly fragmented, and a high‐quality reference genome is needed to understand adaptation to desert environments and artificial selection during domestication. Dromedaries are among the last livestock species to have been domesticated, and together with wild and domestic Bactrian camels, they are the only representatives of the Camelini tribe, which highlights their evolutionary significance. Here we describe our efforts to improve the North African dromedary genome. We used Chicago and Hi‐C sequencing libraries from Dovetail Genomics to resolve the order of previously assembled contigs, producing almost chromosome‐level scaffolds. Remaining gaps were filled with Pacific Biosciences long reads, and then scaffolds were comparatively mapped to chromosomes. Long reads added 99.32 Mbp to the total length of the new assembly. Dovetail Chicago and Hi‐C libraries increased the longest scaffold over 12‐fold, from 9.71 Mbp to 124.99 Mbp and the scaffold N50 over 50‐fold, from 1.48 Mbp to 75.02 Mbp. We demonstrate that Illumina de novo assemblies can be substantially upgraded by combining chromosome conformation capture and long‐read sequencing.
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Affiliation(s)
- Jean P Elbers
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, Vetmeduni Vienna, Vienna, Austria
| | - Mark F Rogers
- Intelligent Systems Laboratory, University of Bristol, Bristol, UK
| | - Polina L Perelman
- Institute of Molecular and Cellular Biology, SB RAS and Novosibirsk State University, Novosibirsk, Russia
| | - Anastasia A Proskuryakova
- Institute of Molecular and Cellular Biology, SB RAS and Novosibirsk State University, Novosibirsk, Russia
| | - Natalia A Serdyukova
- Institute of Molecular and Cellular Biology, SB RAS and Novosibirsk State University, Novosibirsk, Russia
| | - Warren E Johnson
- The Walter Reed Biosystematics Unit, Smithsonian Institution, Museum Support Center MRC-534, Suitland, Maryland
| | - Petr Horin
- Department of Animal Genetics, Faculty of Veterinary Medicine, Ceitec VFU, RG Animal Immunogenomics, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
| | - Jukka Corander
- Department of Biostatistics, University of Oslo, Oslo, Norway.,Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
| | - David Murphy
- Bristol Medical School: Translational Health Sciences, Molecular Neuroendocrinology Research Group, University of Bristol, Bristol, UK
| | - Pamela A Burger
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, Vetmeduni Vienna, Vienna, Austria
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183
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Vignal A, Boitard S, Thébault N, Dayo GK, Yapi-Gnaore V, Youssao Abdou Karim I, Berthouly-Salazar C, Pálinkás-Bodzsár N, Guémené D, Thibaud-Nissen F, Warren WC, Tixier-Boichard M, Rognon X. A guinea fowl genome assembly provides new evidence on evolution following domestication and selection in galliformes. Mol Ecol Resour 2019; 19:997-1014. [PMID: 30945415 PMCID: PMC6579635 DOI: 10.1111/1755-0998.13017] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 03/19/2019] [Accepted: 03/25/2019] [Indexed: 01/25/2023]
Abstract
The helmeted guinea fowl Numida meleagris belongs to the order Galliformes. Its natural range includes a large part of sub‐Saharan Africa, from Senegal to Eritrea and from Chad to South Africa. Archaeozoological and artistic evidence suggest domestication of this species may have occurred about 2,000 years BP in Mali and Sudan primarily as a food resource, although villagers also benefit from its capacity to give loud alarm calls in case of danger, of its ability to consume parasites such as ticks and to hunt snakes, thus suggesting its domestication may have resulted from a commensal association process. Today, it is still farmed in Africa, mainly as a traditional village poultry, and is also bred more intensively in other countries, mainly France and Italy. The lack of available molecular genetic markers has limited the genetic studies conducted to date on guinea fowl. We present here a first‐generation whole‐genome sequence draft assembly used as a reference for a study by a Pool‐seq approach of wild and domestic populations from Europe and Africa. We show that the domestic populations share a higher genetic similarity between each other than they do to wild populations living in the same geographical area. Several genomic regions showing selection signatures putatively related to domestication or importation to Europe were detected, containing candidate genes, most notably EDNRB2, possibly explaining losses in plumage coloration phenotypes in domesticated populations.
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Affiliation(s)
- Alain Vignal
- GenPhySE, INRA, INPT, INP-ENVT, Université de Toulouse, Castanet Tolosan, France
| | - Simon Boitard
- GenPhySE, INRA, INPT, INP-ENVT, Université de Toulouse, Castanet Tolosan, France
| | - Noémie Thébault
- GenPhySE, INRA, INPT, INP-ENVT, Université de Toulouse, Castanet Tolosan, France
| | | | | | | | | | | | | | - Francoise Thibaud-Nissen
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland
| | - Wesley C Warren
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri.,Bond Life Sciences Center, University of Missouri, Columbia, Missouri
| | | | - Xavier Rognon
- GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
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184
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Peters MJ, Suwannapong G, Pelin A, Corradi N. Genetic and Genome Analyses Reveal Genetically Distinct Populations of the Bee Pathogen Nosema ceranae from Thailand. MICROBIAL ECOLOGY 2019; 77:877-889. [PMID: 30288544 DOI: 10.1007/s00248-018-1268-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/25/2018] [Indexed: 06/08/2023]
Abstract
The recent global decline in Western honeybee (Apis mellifera) populations is of great concern for pollination and honey production worldwide. Declining honeybee populations are frequently infected by the microsporidian pathogen Nosema ceranae. This species was originally described in the Asiatic honeybee (Apis cerana), and its identification in global A. mellifera hives could result from a recent host transfer. Recent genome studies have found that global populations of this parasite are polyploid and that humans may have fueled their global expansion. To better understand N. ceranae biology, we investigated its genetic diversity within part of their native range (Thailand) and among different hosts (A. mellifera, A. cerana) using both PCR and genome-based methods. We find that Thai N. ceranae populations share many SNPs with other global populations and appear to be clonal. However, in stark contrast with previous studies, we found that these populations also carry many SNPs not found elsewhere, indicating that these populations have evolved in their current geographic location for some time. Our genome analyses also indicate the potential presence of diploidy within Thai populations of N. ceranae.
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Affiliation(s)
- Melissa J Peters
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Adrian Pelin
- Department of Biochemistry, University of Ottawa, Ottawa, Ontario, Canada
- Center for Cancer Therapeutics, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Nicolas Corradi
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.
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185
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Phair NL, Toonen RJ, Knapp I, von der Heyden S. Shared genomic outliers across two divergent population clusters of a highly threatened seagrass. PeerJ 2019; 7:e6806. [PMID: 31106053 PMCID: PMC6497040 DOI: 10.7717/peerj.6806] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 03/18/2019] [Indexed: 12/15/2022] Open
Abstract
The seagrass, Zostera capensis, occurs across a broad stretch of coastline and wide environmental gradients in estuaries and sheltered bays in southern and eastern Africa. Throughout its distribution, habitats are highly threatened and poorly protected, increasing the urgency of assessing the genomic variability of this keystone species. A pooled genomic approach was employed to obtain SNP data and examine neutral genomic variation and to identify potential outlier loci to assess differentiation across 12 populations across the ∼9,600 km distribution of Z. capensis. Results indicate high clonality and low genomic diversity within meadows, which combined with poor protection throughout its range, increases the vulnerability of this seagrass to further declines or local extinction. Shared variation at outlier loci potentially indicates local adaptation to temperature and precipitation gradients, with Isolation-by-Environment significantly contributing towards shaping spatial variation in Z. capensis. Our results indicate the presence of two population clusters, broadly corresponding to populations on the west and east coasts, with the two lineages shaped only by frequency differences of outlier loci. Notably, ensemble modelling of suitable seagrass habitat provides evidence that the clusters are linked to historical climate refugia around the Last Glacial Maxi-mum. Our work suggests a complex evolutionary history of Z. capensis in southern and eastern Africa that will require more effective protection in order to safeguard this important ecosystem engineer into the future.
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Affiliation(s)
- Nikki Leanne Phair
- Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South Africa
| | - Robert John Toonen
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, Hawai’i, United States of America
| | - Ingrid Knapp
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, Hawai’i, United States of America
| | - Sophie von der Heyden
- Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South Africa
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186
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Cavedon M, Gubili C, Heppenheimer E, vonHoldt B, Mariani S, Hebblewhite M, Hegel T, Hervieux D, Serrouya R, Steenweg R, Weckworth BV, Musiani M. Genomics, environment and balancing selection in behaviourally bimodal populations: The caribou case. Mol Ecol 2019; 28:1946-1963. [PMID: 30714247 DOI: 10.1111/mec.15039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 01/09/2019] [Accepted: 01/23/2019] [Indexed: 02/03/2023]
Abstract
Selection forces that favour different phenotypes in different environments can change frequencies of genes between populations along environmental clines. Clines are also compatible with balancing forces, such as negative frequency-dependent selection (NFDS), which maintains phenotypic polymorphisms within populations. For example, NFDS is hypothesized to maintain partial migration, a dimorphic behavioural trait prominent in species where only a fraction of the population seasonally migrates. Overall, NFDS is believed to be a common phenomenon in nature, yet a scarcity of studies were published linking naturally occurring allelic variation with bimodal or multimodal phenotypes and balancing selection. We applied a Pool-seq approach and detected selection on alleles associated with environmental variables along a North-South gradient in western North American caribou, a species displaying partially migratory behaviour. On 51 loci, we found a signature of balancing selection, which could be related to NFDS and ultimately the maintenance of the phenotypic polymorphisms known within these populations. Yet, remarkably, we detected directional selection on a locus when our sample was divided into two behaviourally distinctive groups regardless of geographic provenance (a subset of GPS-collared migratory or sedentary individuals), indicating that, within populations, phenotypically homogeneous groups were genetically distinctive. Loci under selection were linked to functional genes involved in oxidative stress response, body development and taste perception. Overall, results indicated genetic differentiation along an environmental gradient of caribou populations, which we found characterized by genes potentially undergoing balancing selection. We suggest that the underlining balancing force, NFDS, plays a strong role within populations harbouring multiple haplotypes and phenotypes, as it is the norm in animals, plants and humans too.
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Affiliation(s)
- Maria Cavedon
- Faculty of Environmental Design, University of Calgary, Calgary, Alberta, Canada
| | - Chrysoula Gubili
- Faculty of Environmental Design, University of Calgary, Calgary, Alberta, Canada.,School of Environment and Life Sciences, University of Salford, Salford, UK.,Hellenic Agricultural Organisation, Fisheries Research Institute, Kavala, Greece
| | - Elizabeth Heppenheimer
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey
| | - Bridgett vonHoldt
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey
| | - Stefano Mariani
- School of Environment and Life Sciences, University of Salford, Salford, UK
| | - Mark Hebblewhite
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, Missoula, Montana
| | - Troy Hegel
- Yukon Department of Environment, Whitehorse, Yukon, Canada
| | - Dave Hervieux
- Resource Management - Operations Division, Alberta Environment and Sustainable Resource Development, Grande Prairie, Alberta, Canada
| | - Robert Serrouya
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Robin Steenweg
- Resource Management - Operations Division, Alberta Environment and Sustainable Resource Development, Grande Prairie, Alberta, Canada
| | | | - Marco Musiani
- Department of Biological Sciences, Faculty of Science and Veterinary Medicine (Joint Appointment), University of Calgary, Calgary, Alberta, Canada
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187
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Bidirectional Selection for Body Weight on Standing Genetic Variation in a Chicken Model. G3-GENES GENOMES GENETICS 2019; 9:1165-1173. [PMID: 30737239 PMCID: PMC6469407 DOI: 10.1534/g3.119.400038] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Experimental populations of model organisms provide valuable opportunities to unravel the genomic impact of selection in a controlled system. The Virginia body weight chicken lines represent a unique resource to investigate signatures of selection in a system where long-term, single-trait, bidirectional selection has been carried out for more than 60 generations. At 55 generations of divergent selection, earlier analyses of pooled genome resequencing data from these lines revealed that 14.2% of the genome showed extreme differentiation between the selected lines, contained within 395 genomic regions. Here, we report more detailed analyses of these data exploring the regions displaying within- and between-line genomic signatures of the bidirectional selection applied in these lines. Despite the strict selection regime for opposite extremes in body weight, this did not result in opposite genomic signatures between the lines. The lines often displayed a duality of the sweep signatures, where an extended region of homozygosity in one line, in contrast to mosaic pattern of heterozygosity in the other line. These haplotype mosaics consisted of short, distinct haploblocks of variable between-line divergence, likely the results of a complex demographic history involving bottlenecks, introgressions and moderate inbreeding. We demonstrate this using the example of complex haplotype mosaicism in the growth1 QTL. These mosaics represent the standing genetic variation available at the onset of selection in the founder population. Selection on standing genetic variation can thus result in different signatures depending on the intensity and direction of selection.
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188
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Knorst V, Byrne S, Yates S, Asp T, Widmer F, Studer B, Kölliker R. Pooled DNA sequencing to identify SNPs associated with a major QTL for bacterial wilt resistance in Italian ryegrass (Lolium multiflorum Lam.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:947-958. [PMID: 30506318 PMCID: PMC6449324 DOI: 10.1007/s00122-018-3250-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/23/2018] [Indexed: 05/27/2023]
Abstract
SNPs and candidate genes associated with bacterial wilt resistance in Italian ryegrass were identified by sequencing the parental plants and pooled F1 progeny of a segregating population. Italian ryegrass (Lolium multiflorum Lam.) is one of the most important forage grass species in temperate regions. Its yield, quality and persistency can significantly be reduced by bacterial wilt, a serious disease caused by Xanthomonas translucens pv. graminis. Although a major QTL for bacterial wilt resistance has previously been reported, detailed knowledge on underlying genes and DNA markers to allow for efficient resistance breeding strategies is currently not available. We used pooled DNA sequencing to characterize a major QTL for bacterial wilt resistance of Italian ryegrass and to develop inexpensive sequence-based markers to efficiently target resistance alleles for marker-assisted recurrent selection. From the mapping population segregating for the QTL, DNA of 44 of the most resistant and 44 of the most susceptible F1 individuals was pooled and sequenced using the Illumina HiSeq 2000 platform. Allele frequencies of 18 × 106 single nucleotide polymorphisms (SNP) were determined in the resistant and susceptible pool. A total of 271 SNPs on 140 scaffold sequences of the reference parental genome showed significantly different allele frequencies in both pools. We converted 44 selected SNPs to KASP™ markers, genetically mapped these proximal to the major QTL and thus validated their association with bacterial wilt resistance. This study highlights the power of pooled DNA sequencing to efficiently target binary traits in biparental mapping populations. It delivers genome sequence data, SNP markers and potential candidate genes which will allow to implement marker-assisted strategies to fix bacterial wilt resistance in outcrossing breeding populations of Italian ryegrass.
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Affiliation(s)
- Verena Knorst
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zürich, Universitätsstrasse 2, 8092, Zurich, Switzerland
- Molecular Ecology, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland
| | - Stephen Byrne
- Crops Science Department, Teagasc, Oak Park, Carlow, R93 XE12, Ireland
| | - Steven Yates
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zürich, Universitätsstrasse 2, 8092, Zurich, Switzerland
| | - Torben Asp
- Department of Molecular Biology and Genetics, Section for Crop Genetics and Biotechnology, Forsøgsvej 1, 4200, Slagelse, Denmark
| | - Franco Widmer
- Molecular Ecology, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland
| | - Bruno Studer
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zürich, Universitätsstrasse 2, 8092, Zurich, Switzerland
| | - Roland Kölliker
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zürich, Universitätsstrasse 2, 8092, Zurich, Switzerland.
- Molecular Ecology, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland.
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189
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Andrade P, Pinho C, Pérez I de Lanuza G, Afonso S, Brejcha J, Rubin CJ, Wallerman O, Pereira P, Sabatino SJ, Bellati A, Pellitteri-Rosa D, Bosakova Z, Bunikis I, Carretero MA, Feiner N, Marsik P, Paupério F, Salvi D, Soler L, While GM, Uller T, Font E, Andersson L, Carneiro M. Regulatory changes in pterin and carotenoid genes underlie balanced color polymorphisms in the wall lizard. Proc Natl Acad Sci U S A 2019; 116:5633-5642. [PMID: 30819892 DOI: 10.1101/481895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
Reptiles use pterin and carotenoid pigments to produce yellow, orange, and red colors. These conspicuous colors serve a diversity of signaling functions, but their molecular basis remains unresolved. Here, we show that the genomes of sympatric color morphs of the European common wall lizard (Podarcis muralis), which differ in orange and yellow pigmentation and in their ecology and behavior, are virtually undifferentiated. Genetic differences are restricted to two small regulatory regions near genes associated with pterin [sepiapterin reductase (SPR)] and carotenoid [beta-carotene oxygenase 2 (BCO2)] metabolism, demonstrating that a core gene in the housekeeping pathway of pterin biosynthesis has been coopted for bright coloration in reptiles and indicating that these loci exert pleiotropic effects on other aspects of physiology. Pigmentation differences are explained by extremely divergent alleles, and haplotype analysis revealed abundant transspecific allele sharing with other lacertids exhibiting color polymorphisms. The evolution of these conspicuous color ornaments is the result of ancient genetic variation and cross-species hybridization.
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Affiliation(s)
- Pedro Andrade
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - Catarina Pinho
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Guillem Pérez I de Lanuza
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Sandra Afonso
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Jindřich Brejcha
- Department of Philosophy and History of Science, Faculty of Science, Charles University, 128 00 Prague 2, Czech Republic
- Department of Zoology, National Museum, 193 00 Prague, Czech Republic
- Ethology Laboratory, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, 469 80 Paterna, Spain
| | - Carl-Johan Rubin
- Science for Life Laboratory Uppsala, Department of Medical Biochemistry and Microbiology, Uppsala University, 752 36 Uppsala, Sweden
| | - Ola Wallerman
- Science for Life Laboratory Uppsala, Department of Medical Biochemistry and Microbiology, Uppsala University, 752 36 Uppsala, Sweden
| | - Paulo Pereira
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - Stephen J Sabatino
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Adriana Bellati
- Department of Earth and Environmental Sciences, University of Pavia, 27100 Pavia, Italy
| | | | - Zuzana Bosakova
- Department of Analytical Chemistry, Faculty of Science, Charles University, 128 43 Prague 2, Czech Republic
| | - Ignas Bunikis
- Science for Life Laboratory Uppsala, Department of Immunology, Genetics and Pathology, Uppsala University, 752 36 Uppsala, Sweden
| | - Miguel A Carretero
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal
| | | | - Petr Marsik
- Department of Food Science, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, 165 21 Prague 6, Czech Republic
| | - Francisco Paupério
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - Daniele Salvi
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal
- Department of Health, Life and Environmental Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Lucile Soler
- Science for Life Laboratory, National Bioinformatics Infrastructure Sweden (NBIS), 751 23 Uppsala, Sweden
| | - Geoffrey M While
- School of Biological Sciences, University of Tasmania, Hobart, TAS 7005 Tasmania, Australia
- Department of Zoology, University of Oxford, OX1 3PS Oxford, United Kingdom
| | - Tobias Uller
- Department of Biology, Lund University, 223 62 Lund, Sweden
| | - Enrique Font
- Ethology Laboratory, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, 469 80 Paterna, Spain
| | - Leif Andersson
- Science for Life Laboratory Uppsala, Department of Medical Biochemistry and Microbiology, Uppsala University, 752 36 Uppsala, Sweden;
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Miguel Carneiro
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal;
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
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190
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Willi Y, Fracassetti M, Zoller S, Van Buskirk J. Accumulation of Mutational Load at the Edges of a Species Range. Mol Biol Evol 2019; 35:781-791. [PMID: 29346601 DOI: 10.1093/molbev/msy003] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Why species have geographically restricted distributions is an unresolved question in ecology and evolutionary biology. Here, we test a new explanation that mutation accumulation due to small population size or a history of range expansion can contribute to restricting distributions by reducing population growth rate at the edge. We examined genomic diversity and mutational load across the entire geographic range of the North American plant Arabidopsis lyrata, including old, isolated populations predominantly at the southern edge and regions of postglacial range expansion at the northern and southern edges. Genomic diversity in intergenic regions declined toward distribution edges and signatures of mutational load in exon regions increased. Genomic signatures of mutational load were highly linked to phenotypically expressed load, measured as reduced performance of individual plants and lower estimated rate of population growth. The geographic pattern of load and the connection between load and population growth demonstrate that mutation accumulation reduces fitness at the edge and helps restrict species' distributions.
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Affiliation(s)
- Yvonne Willi
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Marco Fracassetti
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Stefan Zoller
- Genetic Diversity Centre, ETH Zürich, Zürich, Switzerland
| | - Josh Van Buskirk
- Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland
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191
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Salvo MA, Aliota MT, Moncla LH, Velez ID, Trujillo AI, Friedrich TC, Osorio JE. Tracking dengue virus type 1 genetic diversity during lineage replacement in an hyperendemic area in Colombia. PLoS One 2019; 14:e0212947. [PMID: 30845200 PMCID: PMC6405123 DOI: 10.1371/journal.pone.0212947] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/12/2019] [Indexed: 12/16/2022] Open
Abstract
Dengue virus (DENV) is a flavivirus responsible for the most common and burdensome arthropod-borne viral disease of humans[1]. DENV evolution has been extensively studied on broad geographic and time scales, using sequences from a single gene[2,3]. It is believed that DENV evolution in humans is dominated primarily by purifying selection due to the constraint of maintaining fitness in both humans and mosquitoes[4,5]. Few studies have explored DENV evolutionary dynamics using whole genome sequences, nor have they explored changes in viral diversity that occur during intra-epidemic periods. We used deep sequencing of the viral coding region to characterize DENV-1 evolution in a Colombian population sampled during two high-prevalence dengue seasons in which serotype dominance shifted. Our data demonstrate patterns of strain extinction and replacement within DENV-1 as its prevalence waned and DENV-3 became established. A comparison of whole-genome versus single-gene-based phylogenetic analyses highlights an important difference in evolutionary patterns. We report a trend of higher nonsynonymous to synonymous diversity ratios among non-structural (NS) genes, and statistically significantly higher values among these ratios in the NS1 gene after DENV-1 strain replacement. These results suggest that positive selection could be driving DENV evolution within individual communities. Signals of positive selection coming from distinct samples may be drowned out when combining multiple regions with differing patterns of endemic transmission as commonly done by large-scale geo-temporal assessments. Here, we frame our findings within a small, local transmission history which aids significance. Moreover, these data suggest that the NS1 gene, rather than the E gene, may be a target of positive selection, although not mutually exclusive, and potentially useful sentinel of adaptive changes at the population level.
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Affiliation(s)
- Mauricio A. Salvo
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Matthew T. Aliota
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Louise H. Moncla
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ivan D. Velez
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, Medellin, Colombia
| | - Andrea I. Trujillo
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, Medellin, Colombia
| | - Thomas C. Friedrich
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jorge E. Osorio
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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192
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Cao Y, Xu H, Li R, Gao S, Chen N, Luo J, Jiang Y. Genetic Basis of Phenotypic Differences Between Chinese Yunling Black Goats and Nubian Goats Revealed by Allele-Specific Expression in Their F1 Hybrids. Front Genet 2019; 10:145. [PMID: 30891061 PMCID: PMC6411798 DOI: 10.3389/fgene.2019.00145] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 02/12/2019] [Indexed: 01/18/2023] Open
Abstract
Chinese Yunling black goats and African Nubian goats are divergent breeds showing significant differences in body size, milk production, and environmental adaptation. However, the genetic mechanisms underlying these phenotypic differences remain to be elucidated. In this report, we provide a detailed portrait of allele-specific expression (ASE) from 54 RNA-Seq analyses across six tissues from nine F1 hybrid offspring generated by crossing the two breeds combined with 13 genomes of the two breeds. We identified a total of 524 genes with ASE, which are involved in bone development, muscle cell differentiation, and the regulation of lipid metabolic processes. We further found that 38 genes with ASE were also under directional selection by comparing 13 genomes of the two breeds; these 38 genes play important roles in metabolism, immune responses, and the adaptation to hot and humid environments. In conclusion, our study shows that the exploration of genes with ASE in F1 hybrids provides an efficient way to understand the genetic basis underlying the phenotypic differences of two diverse goat breeds.
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Affiliation(s)
- Yanhong Cao
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China.,Guangxi Key Laboratory of Livestock Genetic Improvement, The Animal Husbandry Research Institute of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Han Xu
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Ran Li
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Shan Gao
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Ningbo Chen
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Jun Luo
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Yu Jiang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
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193
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Lima TG, Burton RS, Willett CS. Genomic scans reveal multiple mito‐nuclear incompatibilities in population crosses of the copepod
Tigriopus californicus. Evolution 2019; 73:609-620. [DOI: 10.1111/evo.13690] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 12/20/2018] [Accepted: 01/11/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Thiago G. Lima
- Department of Biology University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599
- Marine Biology Research Division Scripps Institution of Oceanography La Jolla California 92037
| | - Ronald S. Burton
- Marine Biology Research Division Scripps Institution of Oceanography La Jolla California 92037
| | - Christopher S. Willett
- Department of Biology University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599
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194
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Dennenmoser S, Sedlazeck FJ, Schatz MC, Altmüller J, Zytnicki M, Nolte AW. Genome‐wide patterns of transposon proliferation in an evolutionary young hybrid fish. Mol Ecol 2019; 28:1491-1505. [DOI: 10.1111/mec.14969] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 10/15/2018] [Accepted: 10/23/2018] [Indexed: 01/19/2023]
Affiliation(s)
- Stefan Dennenmoser
- Institute for Biology and Environmental Sciences Carl von Ossietzky University Oldenburg Oldenburg Germany
| | | | - Michael C. Schatz
- Cold Spring Harbor Laboratory Cold Spring Harbor New York
- Departments of Computer Science and Biology Johns Hopkins University Baltimore Maryland
| | - Janine Altmüller
- Cologne Center for Genomics, and Institute of Human Genetics University of Cologne Cologne Germany
| | | | - Arne W. Nolte
- Institute for Biology and Environmental Sciences Carl von Ossietzky University Oldenburg Oldenburg Germany
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195
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Velie BD, Lillie M, Fegraeus KJ, Rosengren MK, Solé M, Wiklund M, Ihler CF, Strand E, Lindgren G. Exploring the genetics of trotting racing ability in horses using a unique Nordic horse model. BMC Genomics 2019; 20:104. [PMID: 30717660 PMCID: PMC6360714 DOI: 10.1186/s12864-019-5484-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/28/2019] [Indexed: 01/07/2023] Open
Abstract
Background Horses have been strongly selected for speed, strength, and endurance-exercise traits since the onset of domestication. As a result, highly specialized horse breeds have developed with many modern horse breeds often representing closed populations with high phenotypic and genetic uniformity. However, a great deal of variation still exists between breeds, making the horse particularly well suited for genetic studies of athleticism. To identify genomic regions associated with athleticism as it pertains to trotting racing ability in the horse, the current study applies a pooled sequence analysis approach using a unique Nordic horse model. Results Pooled sequence data from three Nordic horse populations were used for FST analysis. After strict filtering, FST analysis yielded 580 differentiated regions for trotting racing ability. Candidate regions on equine chromosomes 7 and 11 contained the largest number of SNPs (n = 214 and 147, respectively). GO analyses identified multiple genes related to intelligence, energy metabolism, and skeletal development as potential candidate genes. However, only one candidate region for trotting racing ability overlapped a known racing ability QTL. Conclusions Not unexpected for genomic investigations of complex traits, the current study identified hundreds of candidate regions contributing to trotting racing ability in the horse. Likely resulting from the cumulative effects of many variants across the genome, racing ability continues to demonstrate its polygenic nature with candidate regions implicating genes influencing both musculature and neurological development. Electronic supplementary material The online version of this article (10.1186/s12864-019-5484-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Brandon D Velie
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden. .,School of Life and Environmental Sciences, University of Sydney, Sydney, Australia.
| | - Mette Lillie
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.,Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Kim Jäderkvist Fegraeus
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Maria K Rosengren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Marina Solé
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Maja Wiklund
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Carl-Fredrik Ihler
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Eric Strand
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Livestock Genetics, Department of Biosystems, KU Leuven, Leuven, Belgium
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196
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De novo assembly of white poplar genome and genetic diversity of white poplar population in Irtysh River basin in China. SCIENCE CHINA-LIFE SCIENCES 2019; 62:609-618. [DOI: 10.1007/s11427-018-9455-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 12/02/2018] [Indexed: 12/30/2022]
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197
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Kahnt B, Theodorou P, Soro A, Hollens-Kuhr H, Kuhlmann M, Pauw A, Paxton RJ. Small and genetically highly structured populations in a long-legged bee, Rediviva longimanus, as inferred by pooled RAD-seq. BMC Evol Biol 2018; 18:196. [PMID: 30567486 PMCID: PMC6300007 DOI: 10.1186/s12862-018-1313-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 11/28/2018] [Indexed: 11/10/2022] Open
Abstract
Adaptation to local host plants may impact a pollinator's population genetic structure by reducing gene flow and driving population genetic differentiation, representing an early stage of ecological speciation. South African Rediviva longimanus bees exhibit elongated forelegs, a bizarre adaptation for collecting oil from floral spurs of their Diascia hosts. Furthermore, R. longimanus foreleg length (FLL) differs significantly among populations, which has been hypothesised to result from selection imposed by inter-population variation in Diascia floral spur length. Here, we used a pooled restriction site-associated DNA sequencing (pooled RAD-seq) approach to investigate the population genetic structure of R. longimanus and to test if phenotypic differences in FLL translate into increased genetic differentiation (i) between R. longimanus populations and (ii) between phenotypes across populations. We also inferred the effects of demographic processes on population genetic structure and tested for genetic markers underpinning local adaptation. RESULTS: Populations showed marked genetic differentiation (average FST = 0.165), though differentiation was not statistically associated with differences between populations in FLL. All populations exhibited very low genetic diversity and were inferred to have gone through recent bottleneck events, suggesting extremely low effective population sizes. Genetic differentiation between samples pooled by leg length (short versus long) rather than by population of origin was even higher (FST = 0.260) than between populations, suggesting reduced interbreeding between long and short-legged individuals. Signatures of selection were detected in 1119 (3.8%) of a total of 29,721 SNP markers, CONCLUSIONS: Populations of R. longimanus appear to be small, bottlenecked and isolated. Though we could not detect the effect of local adaptation (FLL in response to floral spurs of host plants) on population genetic differentiation, short and long legged bees appeared to be partially differentiated, suggesting incipient ecological speciation. To test this hypothesis, greater resolution through the use of individual-based whole-genome analyses is now needed to quantify the degree of reproductive isolation between long and short legged bees between and even within populations.
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Affiliation(s)
- Belinda Kahnt
- General Zoology, Institute of Biology, Martin-Luther-University Halle-Wittenberg, Hoher Weg 8, 06120, Halle (Saale), Germany.
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany.
| | - Panagiotis Theodorou
- General Zoology, Institute of Biology, Martin-Luther-University Halle-Wittenberg, Hoher Weg 8, 06120, Halle (Saale), Germany
| | - Antonella Soro
- General Zoology, Institute of Biology, Martin-Luther-University Halle-Wittenberg, Hoher Weg 8, 06120, Halle (Saale), Germany
| | - Hilke Hollens-Kuhr
- Institute of Landscape Ecology, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 2, 48149, Münster, Germany
| | - Michael Kuhlmann
- Zoological Museum, Kiel University, Hegewischstr. 3, 24105, Kiel, Germany
- Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Anton Pauw
- Department of Botany and Zoology, Stellenbosch University, Matieland, 7602, South Africa
| | - Robert J Paxton
- General Zoology, Institute of Biology, Martin-Luther-University Halle-Wittenberg, Hoher Weg 8, 06120, Halle (Saale), Germany.
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany.
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198
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Nelson TC, Monnahan PJ, McIntosh MK, Anderson K, MacArthur-Waltz E, Finseth FR, Kelly JK, Fishman L. Extreme copy number variation at a tRNA ligase gene affecting phenology and fitness in yellow monkeyflowers. Mol Ecol 2018; 28:1460-1475. [PMID: 30346101 DOI: 10.1111/mec.14904] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/03/2018] [Accepted: 10/08/2018] [Indexed: 12/15/2022]
Abstract
Copy number variation (CNV) is a major part of the genetic diversity segregating within populations, but remains poorly understood relative to single nucleotide variation. Here, we report on a tRNA ligase gene (Migut.N02091; RLG1a) exhibiting unprecedented, and fitness-relevant, CNV within an annual population of the yellow monkeyflower Mimulus guttatus. RLG1a variation was associated with multiple traits in pooled population sequencing (PoolSeq) scans of phenotypic and phenological cohorts. Resequencing of inbred lines revealed intermediate-frequency three-copy variants of RLG1a (trip+; 5/35 = 14%), and trip+ lines exhibited elevated RLG1a expression under multiple conditions. trip+ carriers, in addition to being over-represented in late-flowering and large-flowered PoolSeq populations, flowered later under stressful conditions in a greenhouse experiment (p < 0.05). In wild population samples, we discovered an additional rare RLG1a variant (high+) that carries 250-300 copies of RLG1a totalling ~5.7 Mb (20-40% of a chromosome). In the progeny of a high+ carrier, Mendelian segregation of diagnostic alleles and qPCR-based copy counts indicate that high+ is a single tandem array unlinked to the single-copy RLG1a locus. In the wild, high+ carriers had highest fitness in two particularly dry and/or hot years (2015 and 2017; both p < 0.01), while single-copy individuals were twice as fecund as either CNV type in a lush year (2016: p < 0.005). Our results demonstrate fluctuating selection on CNVs affecting phenological traits in a wild population, suggest that plant tRNA ligases mediate stress-responsive life-history traits, and introduce a novel system for investigating the molecular mechanisms of gene amplification.
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Affiliation(s)
- Thomas C Nelson
- Division of Biological Sciences, University of Montana, Missoula, Montana
| | - Patrick J Monnahan
- Department of Ecology and Evolution, University of Kansas, Lawrence, Kansas
| | - Mariah K McIntosh
- Division of Biological Sciences, University of Montana, Missoula, Montana
| | - Kayli Anderson
- Division of Biological Sciences, University of Montana, Missoula, Montana
| | | | - Findley R Finseth
- Division of Biological Sciences, University of Montana, Missoula, Montana
| | - John K Kelly
- Department of Ecology and Evolution, University of Kansas, Lawrence, Kansas
| | - Lila Fishman
- Division of Biological Sciences, University of Montana, Missoula, Montana
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199
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Mutation of a serine near the catalytic site of the choline acetyltransferase a gene almost completely abolishes motility of the zebrafish embryo. PLoS One 2018; 13:e0207747. [PMID: 30458023 PMCID: PMC6245786 DOI: 10.1371/journal.pone.0207747] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/06/2018] [Indexed: 12/29/2022] Open
Abstract
In zebrafish, the gene choline acetyltransferase a (chata) encodes one of the two ChAT orthologs responsible for the synthesis of acetylcholine. Acetylcholine (ACh) is essential for neuromuscular transmission and its impaired synthesis by ChAT can lead to neuromuscular junction disorders such as congenital myasthenic syndromes in humans. We have identified a novel mutation in the chata gene of zebrafish, chatatk64, in a collection of uncharacterised ENU-induced mutants. This mutant carries a missense mutation in the codon of a highly conserved serine changing it to an arginine (S102R). This serine is conserved among ChATs from zebrafish, rat, mice and chicken to humans. It resides within the catalytic domain and in the vicinity of the active site of the enzyme. However, it has not been reported so far to be required for enzymatic activity. Modelling of the S102R variant change in the ChAT protein crystal structure suggests that the change affects protein structure and has a direct impact on the catalytic domain of the protein which abolishes embryo motility almost completely.
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200
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Mapping and Sequencing of a Significant Quantitative Trait Locus Affecting Resistance to Koi Herpesvirus in Common Carp. G3-GENES GENOMES GENETICS 2018; 8:3507-3513. [PMID: 30150301 PMCID: PMC6222565 DOI: 10.1534/g3.118.200593] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cyprinids are the most highly produced group of fishes globally, with common carp being one of the most valuable species of the group. Koi herpesvirus (KHV) infections can result in high levels of mortality, causing major economic losses, and is listed as a notifiable disease by the World Organization for Animal Health. Selective breeding for host resistance has the potential to reduce morbidity and losses due to KHV. Therefore, improving knowledge about host resistance and methods of incorporating genomic data into breeding for resistance may contribute to a decrease in economic losses in carp farming. In the current study, a population of 1,425 carp juveniles, originating from a factorial cross between 40 sires and 20 dams was challenged with KHV. Mortalities and survivors were recorded and sampled for genotyping by sequencing using Restriction Site-Associated DNA sequencing (RADseq). Genome-wide association analyses were performed to investigate the genetic architecture of resistance to KHV. A genome-wide significant QTL affecting resistance to KHV was identified on linkage group 44, explaining approximately 7% of the additive genetic variance. Pooled whole genome resequencing of a subset of resistant (n = 60) and susceptible animals (n = 60) was performed to characterize QTL regions, including identification of putative candidate genes and functional annotation of associated polymorphisms. The TRIM25 gene was identified as a promising positional and functional candidate within the QTL region of LG 44, and a putative premature stop mutation in this gene was discovered.
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