1
|
Gutiérrez-Guerrero YT, Phifer-Rixey M, Nachman MW. Across two continents: The genomic basis of environmental adaptation in house mice (Mus musculus domesticus) from the Americas. PLoS Genet 2024; 20:e1011036. [PMID: 38968323 PMCID: PMC11253941 DOI: 10.1371/journal.pgen.1011036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 07/17/2024] [Accepted: 06/10/2024] [Indexed: 07/07/2024] Open
Abstract
Replicated clines across environmental gradients can be strong evidence of adaptation. House mice (Mus musculus domesticus) were introduced to the Americas by European colonizers and are now widely distributed from Tierra del Fuego to Alaska. Multiple aspects of climate, such as temperature, vary predictably across latitude in the Americas. Past studies of North American populations across latitudinal gradients provided evidence of environmental adaptation in traits related to body size, metabolism, and behavior and identified candidate genes using selection scans. Here, we investigate genomic signals of environmental adaptation on a second continent, South America, and ask whether there is evidence of parallel adaptation across multiple latitudinal transects in the Americas. We first identified loci across the genome showing signatures of selection related to climatic variation in mice sampled across a latitudinal transect in South America, accounting for neutral population structure. Consistent with previous results, most candidate SNPs were in putatively regulatory regions. Genes that contained the most extreme outliers relate to traits such as body weight or size, metabolism, immunity, fat, eye function, and the cardiovascular system. We then compared these results with the results of analyses of published data from two transects in North America. While most candidate genes were unique to individual transects, we found significant overlap among candidate genes identified independently in the three transects. These genes are diverse, with functions relating to metabolism, immunity, cardiac function, and circadian rhythm, among others. We also found parallel shifts in allele frequency in candidate genes across latitudinal gradients. Finally, combining data from all three transects, we identified several genes associated with variation in body weight. Overall, our results provide strong evidence of shared responses to selection and identify genes that likely underlie recent environmental adaptation in house mice across North and South America.
Collapse
Affiliation(s)
- Yocelyn T. Gutiérrez-Guerrero
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
| | - Megan Phifer-Rixey
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Michael W. Nachman
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
| |
Collapse
|
2
|
Padilla Perez DJ. Geographic and seasonal variation of the for gene reveal signatures of local adaptation in Drosophila melanogaster. J Evol Biol 2024; 37:201-211. [PMID: 38301664 DOI: 10.1093/jeb/voad018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 11/18/2023] [Accepted: 12/16/2023] [Indexed: 02/03/2024]
Abstract
In the early 1980s, the observation that Drosophila melanogaster larvae differed in their foraging behaviour laid the foundation for the work that would later lead to the discovery of the foraging gene (for) and its associated foraging phenotypes, rover and sitter. Since then, the molecular characterization of the for gene and our understanding of the mechanisms that maintain its phenotypic variants in the laboratory have progressed enormously. However, the significance and dynamics of such variation are yet to be investigated in nature. With the advent of next-generation sequencing, it is now possible to identify loci underlying the adaptation of populations in response to environmental variation. Here, I present the results of a genotype-environment association analysis that quantifies variation at the for gene among samples of D. melanogaster structured across space and time. These samples consist of published genomes of adult flies collected worldwide, and at least twice per site of collection (during spring and fall). Both an analysis of genetic differentiation based on Fst values and an analysis of population structure revealed an east-west gradient in allele frequency. This gradient may be the result of spatially varying selection driven by the seasonality of precipitation. These results support the hypothesis that different patterns of gene flow as expected under models of isolation by distance and potentially isolation by environment are driving genetic differentiation among populations. Overall, this study is essential for understanding the mechanisms underlying the evolution of foraging behaviour in D. melanogaster.
Collapse
|
3
|
Gutiérrez-Guerrero YT, Phifer-Rixey M, Nachman MW. Across two continents: the genomic basis of environmental adaptation in house mice ( Mus musculus domesticus) from the Americas. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.30.564674. [PMID: 37961195 PMCID: PMC10634997 DOI: 10.1101/2023.10.30.564674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Parallel clines across environmental gradients can be strong evidence of adaptation. House mice (Mus musculus domesticus) were introduced to the Americas by European colonizers and are now widely distributed from Tierra del Fuego to Alaska. Multiple aspects of climate, such as temperature, vary predictably across latitude in the Americas. Past studies of North American populations across latitudinal gradients provided evidence of environmental adaptation in traits related to body size, metabolism, and behavior and identified candidate genes using selection scans. Here, we investigate genomic signals of environmental adaptation on a second continent, South America, and ask whether there is evidence of parallel adaptation across multiple latitudinal transects in the Americas. We first identified loci across the genome showing signatures of selection related to climatic variation in mice sampled across a latitudinal transect in South America, accounting for neutral population structure. Consistent with previous results, most candidate SNPs were in regulatory regions. Genes containing the most extreme outliers relate to traits such as body weight or size, metabolism, immunity, fat, and development or function of the eye as well as traits associated with the cardiovascular and renal systems. We then combined these results with published results from two transects in North America. While most candidate genes were unique to individual transects, we found significant overlap among candidate genes identified independently in the three transects, providing strong evidence of parallel adaptation and identifying genes that likely underlie recent environmental adaptation in house mice across North and South America.
Collapse
Affiliation(s)
- Yocelyn T. Gutiérrez-Guerrero
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, United States of America
| | - Megan Phifer-Rixey
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, United States of America
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Michael W. Nachman
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, United States of America
| |
Collapse
|
4
|
Szlachcic E, Labecka AM, Privalova V, Sikorska A, Czarnoleski M. Systemic orchestration of cell size throughout the body: influence of sex and rapamycin exposure in Drosophila melanogaster. Biol Lett 2023; 19:20220611. [PMID: 36946132 PMCID: PMC10031402 DOI: 10.1098/rsbl.2022.0611] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
Along with differences in life histories, metazoans have also evolved vast differences in cellularity, involving changes in the molecular pathways controlling the cell cycle. The extent to which the signalling network systemically determines cellular composition throughout the body and whether tissue cellularity is organized locally to match tissue-specific functions are unclear. We cultured genetic lines of Drosophila melanogaster on food with and without rapamycin to manipulate the activity of target of rapamycin (TOR)/insulin pathways and evaluate cell-size changes in five types of adult cells: wing and leg epidermal cells, ommatidial cells, indirect flight muscle cells and Malpighian tubule epithelial cells. Rapamycin blocks TOR multiprotein complex 1, reducing cell growth, but this effect has been studied in single cell types. As adults, rapamycin-treated flies had smaller bodies and consistently smaller cells in all tissues. Regardless, females eclosed with larger bodies and larger cells in all tissues than males. Thus, differences in TOR activity and sex were associated with the orchestration of cell size throughout the body, leading to differences in body size. We postulate that the activity of TOR/insulin pathways and their effects on cellularity should be considered when investigating the origin of ecological and evolutionary patterns in life histories.
Collapse
Affiliation(s)
- Ewa Szlachcic
- Life History Evolution Group, Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Anna Maria Labecka
- Life History Evolution Group, Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Valeriya Privalova
- Life History Evolution Group, Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Anna Sikorska
- Life History Evolution Group, Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Marcin Czarnoleski
- Life History Evolution Group, Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| |
Collapse
|
5
|
Kapun M, Nunez JCB, Bogaerts-Márquez M, Murga-Moreno J, Paris M, Outten J, Coronado-Zamora M, Tern C, Rota-Stabelli O, Guerreiro MPG, Casillas S, Orengo DJ, Puerma E, Kankare M, Ometto L, Loeschcke V, Onder BS, Abbott JK, Schaeffer SW, Rajpurohit S, Behrman EL, Schou MF, Merritt TJS, Lazzaro BP, Glaser-Schmitt A, Argyridou E, Staubach F, Wang Y, Tauber E, Serga SV, Fabian DK, Dyer KA, Wheat CW, Parsch J, Grath S, Veselinovic MS, Stamenkovic-Radak M, Jelic M, Buendía-Ruíz AJ, Gómez-Julián MJ, Espinosa-Jimenez ML, Gallardo-Jiménez FD, Patenkovic A, Eric K, Tanaskovic M, Ullastres A, Guio L, Merenciano M, Guirao-Rico S, Horváth V, Obbard DJ, Pasyukova E, Alatortsev VE, Vieira CP, Vieira J, Torres JR, Kozeretska I, Maistrenko OM, Montchamp-Moreau C, Mukha DV, Machado HE, Lamb K, Paulo T, Yusuf L, Barbadilla A, Petrov D, Schmidt P, Gonzalez J, Flatt T, Bergland AO. Drosophila Evolution over Space and Time (DEST): A New Population Genomics Resource. Mol Biol Evol 2021; 38:5782-5805. [PMID: 34469576 PMCID: PMC8662648 DOI: 10.1093/molbev/msab259] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Drosophila melanogaster is a leading model in population genetics and genomics, and a growing number of whole-genome data sets from natural populations of this species have been published over the last years. A major challenge is the integration of disparate data sets, often generated using different sequencing technologies and bioinformatic pipelines, which hampers our ability to address questions about the evolution of this species. Here we address these issues by developing a bioinformatics pipeline that maps pooled sequencing (Pool-Seq) reads from D. melanogaster to a hologenome consisting of fly and symbiont genomes and estimates allele frequencies using either a heuristic (PoolSNP) or a probabilistic variant caller (SNAPE-pooled). We use this pipeline to generate the largest data repository of genomic data available for D. melanogaster to date, encompassing 271 previously published and unpublished population samples from over 100 locations in >20 countries on four continents. Several of these locations have been sampled at different seasons across multiple years. This data set, which we call Drosophila Evolution over Space and Time (DEST), is coupled with sampling and environmental metadata. A web-based genome browser and web portal provide easy access to the SNP data set. We further provide guidelines on how to use Pool-Seq data for model-based demographic inference. Our aim is to provide this scalable platform as a community resource which can be easily extended via future efforts for an even more extensive cosmopolitan data set. Our resource will enable population geneticists to analyze spatiotemporal genetic patterns and evolutionary dynamics of D. melanogaster populations in unprecedented detail.
Collapse
Affiliation(s)
- Martin Kapun
- Department of Evolutionary Biology and Environmental Studies, University of
Zürich, Switzerland
- Department of Cell & Developmental Biology, Center of Anatomy and Cell
Biology, Medical University of Vienna, Vienna, Austria
| | - Joaquin C B Nunez
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| | | | - Jesús Murga-Moreno
- Department of Genetics and Microbiology, Universitat Autònoma de
Barcelona, Barcelona, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de
Barcelona, Barcelona, Spain
| | - Margot Paris
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Joseph Outten
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| | | | - Courtney Tern
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| | - Omar Rota-Stabelli
- Center Agriculture Food Environment, University of Trento, San Michele all'
Adige, Italy
| | | | - Sònia Casillas
- Department of Genetics and Microbiology, Universitat Autònoma de
Barcelona, Barcelona, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de
Barcelona, Barcelona, Spain
| | - Dorcas J Orengo
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia,
Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de
Barcelona, Barcelona, Spain
| | - Eva Puerma
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia,
Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de
Barcelona, Barcelona, Spain
| | - Maaria Kankare
- Department of Biological and Environmental Science, University of
Jyväskylä, Jyväskylä, Finland
| | - Lino Ometto
- Department of Biology and Biotechnology, University of Pavia,
Pavia, Italy
| | | | - Banu S Onder
- Department of Biology, Hacettepe University, Ankara, Turkey
| | | | - Stephen W Schaeffer
- Department of Biology, The Pennsylvania State University,
University Park, PA, USA
| | - Subhash Rajpurohit
- Department of Biology, University of Pennsylvania, Philadelphia,
PA, USA
- Division of Biological and Life Sciences, School of Arts and Sciences,
Ahmedabad University, Ahmedabad, India
| | - Emily L Behrman
- Department of Biology, University of Pennsylvania, Philadelphia,
PA, USA
- Janelia Research Campus, Ashburn, VA, USA
| | - Mads F Schou
- Department of Biology, Aarhus University, Aarhus, Denmark
- Department of Biology, Lund University, Lund, Sweden
| | - Thomas J S Merritt
- Department of Chemistry & Biochemistry, Laurentian
University, Sudbury, ON, Canada
| | - Brian P Lazzaro
- Department of Entomology, Cornell University, Ithaca, NY,
USA
| | - Amanda Glaser-Schmitt
- Division of Evolutionary Biology, Faculty of Biology,
Ludwig-Maximilians-Universität, Munich, Germany
| | - Eliza Argyridou
- Division of Evolutionary Biology, Faculty of Biology,
Ludwig-Maximilians-Universität, Munich, Germany
| | - Fabian Staubach
- Department of Evolution and Ecology, University of Freiburg,
Freiburg, Germany
| | - Yun Wang
- Department of Evolution and Ecology, University of Freiburg,
Freiburg, Germany
| | - Eran Tauber
- Department of Evolutionary and Environmental Biology, Institute of Evolution,
University of Haifa, Haifa, Israel
| | - Svitlana V Serga
- Department of General and Medical Genetics, Taras Shevchenko National
University of Kyiv, Kyiv, Ukraine
- State Institution National Antarctic Scientific Center, Ministry of Education
and Science of Ukraine, Kyiv, Ukraine
| | - Daniel K Fabian
- Department of Genetics, University of Cambridge, Cambridge,
United Kingdom
| | - Kelly A Dyer
- Department of Genetics, University of Georgia, Athens, GA,
USA
| | | | - John Parsch
- Division of Evolutionary Biology, Faculty of Biology,
Ludwig-Maximilians-Universität, Munich, Germany
| | - Sonja Grath
- Division of Evolutionary Biology, Faculty of Biology,
Ludwig-Maximilians-Universität, Munich, Germany
| | | | | | - Mihailo Jelic
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | | | | | | | | | - Aleksandra Patenkovic
- Institute for Biological Research “Siniša Stanković”, National Institute of
Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Katarina Eric
- Institute for Biological Research “Siniša Stanković”, National Institute of
Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Marija Tanaskovic
- Institute for Biological Research “Siniša Stanković”, National Institute of
Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Anna Ullastres
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Lain Guio
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Miriam Merenciano
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Sara Guirao-Rico
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Vivien Horváth
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Darren J Obbard
- Institute of Evolutionary Biology, University of Edinburgh,
Edinburgh, United Kingdom
| | - Elena Pasyukova
- Institute of Molecular Genetics of the National Research Centre “Kurchatov
Institute”, Moscow, Russia
| | - Vladimir E Alatortsev
- Institute of Molecular Genetics of the National Research Centre “Kurchatov
Institute”, Moscow, Russia
| | - Cristina P Vieira
- Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do
Porto, Porto, Portugal
| | - Jorge Vieira
- Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do
Porto, Porto, Portugal
| | | | - Iryna Kozeretska
- Department of General and Medical Genetics, Taras Shevchenko National
University of Kyiv, Kyiv, Ukraine
- State Institution National Antarctic Scientific Center, Ministry of Education
and Science of Ukraine, Kyiv, Ukraine
| | - Oleksandr M Maistrenko
- Department of General and Medical Genetics, Taras Shevchenko National
University of Kyiv, Kyiv, Ukraine
- Structural and Computational Biology Unit, European Molecular Biology
Laboratory, Heidelberg, Germany
| | | | - Dmitry V Mukha
- Vavilov Institute of General Genetics, Russian Academy of
Sciences, Moscow, Russia
| | - Heather E Machado
- Department of Biology, Stanford University, Stanford, CA,
USA
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Keric Lamb
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| | - Tânia Paulo
- Departamento de Biologia Animal, Instituto Gulbenkian de Ciência,
Oeiras, Portugal
| | - Leeban Yusuf
- Center for Biological Diversity, University of St. Andrews, St
Andrews, United Kingdom
| | - Antonio Barbadilla
- Department of Genetics and Microbiology, Universitat Autònoma de
Barcelona, Barcelona, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de
Barcelona, Barcelona, Spain
| | - Dmitri Petrov
- Department of Biology, Stanford University, Stanford, CA,
USA
| | - Paul Schmidt
- Department of Biology, The Pennsylvania State University,
University Park, PA, USA
| | - Josefa Gonzalez
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Thomas Flatt
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Alan O Bergland
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| |
Collapse
|
6
|
Kurogi Y, Mizuno Y, Imura E, Niwa R. Neuroendocrine Regulation of Reproductive Dormancy in the Fruit Fly Drosophila melanogaster: A Review of Juvenile Hormone-Dependent Regulation. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.715029] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Animals can adjust their physiology, helping them survive and reproduce under a wide range of environmental conditions. One of the strategies to endure unfavorable environmental conditions such as low temperature and limited food supplies is dormancy. In some insect species, this may manifest as reproductive dormancy, which causes their reproductive organs to be severely depleted under conditions unsuitable for reproduction. Reproductive dormancy in insects is induced by a reduction in juvenile hormones synthesized in the corpus allatum (pl. corpora allata; CA) in response to winter-specific environmental cues, such as low temperatures and short-day length. In recent years, significant progress has been made in the study of dormancy-inducing conditions dependent on CA control mechanisms in Drosophila melanogaster. This review summarizes dormancy control mechanisms in D. melanogaster and discusses the implications for future studies of insect dormancy, particularly focusing on juvenile hormone-dependent regulation.
Collapse
|
7
|
Rodrigues MF, Cogni R. Genomic Responses to Climate Change: Making the Most of the Drosophila Model. Front Genet 2021; 12:676218. [PMID: 34326859 PMCID: PMC8314211 DOI: 10.3389/fgene.2021.676218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/15/2021] [Indexed: 11/18/2022] Open
Abstract
It is pressing to understand how animal populations evolve in response to climate change. We argue that new sequencing technologies and the use of historical samples are opening unprecedented opportunities to investigate genome-wide responses to changing environments. However, there are important challenges in interpreting the emerging findings. First, it is essential to differentiate genetic adaptation from phenotypic plasticity. Second, it is extremely difficult to map genotype, phenotype, and fitness. Third, neutral demographic processes and natural selection affect genetic variation in similar ways. We argue that Drosophila melanogaster, a classical model organism with decades of climate adaptation research, is uniquely suited to overcome most of these challenges. In the near future, long-term time series genome-wide datasets of D. melanogaster natural populations will provide exciting opportunities to study adaptation to recent climate change and will lay the groundwork for related research in non-model systems.
Collapse
Affiliation(s)
- Murillo F. Rodrigues
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States
| | - Rodrigo Cogni
- Department of Ecology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| |
Collapse
|
8
|
Rodrigues MF, Vibranovski MD, Cogni R. Clinal and seasonal changes are correlated in Drosophila melanogaster natural populations. Evolution 2021; 75:2042-2054. [PMID: 34184262 DOI: 10.1111/evo.14300] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 06/08/2021] [Accepted: 06/14/2021] [Indexed: 12/22/2022]
Abstract
Spatial and seasonal variations in the environment are ubiquitous. Environmental heterogeneity can affect natural populations and lead to covariation between environment and allele frequencies. Drosophila melanogaster is known to harbor polymorphisms that change both with latitude and seasons. Identifying the role of selection in driving these changes is not trivial, because nonadaptive processes can cause similar patterns. Given the environment changes in similar ways across seasons and along the latitudinal gradient, one promising approach may be to look for parallelism between clinal and seasonal changes. Here, we test whether there is a genome-wide correlation between clinal and seasonal changes, and whether the pattern is consistent with selection. Allele frequency estimates were obtained from pooled samples from seven different locations along the east coast of the United States, and across seasons within Pennsylvania. We show that there is a genome-wide correlation between clinal and seasonal variations, which cannot be explained by linked selection alone. This pattern is stronger in genomic regions with higher functional content, consistent with natural selection. We derive a way to biologically interpret these correlations and show that around 3.7% of the common, autosomal variants could be under parallel seasonal and spatial selection. Our results highlight the contribution of natural selection in driving fluctuations in allele frequencies in natural fly populations and point to a shared genomic basis to climate adaptation that happens over space and time in D. melanogaster.
Collapse
Affiliation(s)
- Murillo F Rodrigues
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of Sao Paulo, Sao Paulo, 05508-090, Brazil.,Current Address: Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, 97403
| | - Maria D Vibranovski
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of Sao Paulo, Sao Paulo, 05508-090, Brazil
| | - Rodrigo Cogni
- Department of Ecology, Institute of Biosciences, University of Sao Paulo, Sao Paulo, 05508-090, Brazil
| |
Collapse
|
9
|
Schramm BW, Labecka AM, Gudowska A, Antoł A, Sikorska A, Szabla N, Bauchinger U, Kozlowski J, Czarnoleski M. Concerted evolution of body mass, cell size and metabolic rate among carabid beetles. JOURNAL OF INSECT PHYSIOLOGY 2021; 132:104272. [PMID: 34186071 DOI: 10.1016/j.jinsphys.2021.104272] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 05/25/2023]
Abstract
Alterations in cell number and size are apparently associated with the body mass differences between species and sexes, but we rarely know which of the two mechanisms underlies the observed variance in body mass. We used phylogenetically informed comparisons of males and females of 19 Carabidae beetle species to compare body mass, resting metabolic rate, and cell size in the ommatidia and Malpighian tubules. We found that the larger species or larger sex (males or females, depending on the species) consistently possessed larger cells in the two tissues, indicating organism-wide coordination of cell size changes in different tissues and the contribution of these changes to the origin of evolutionary and sex differences in body mass. The species or sex with larger cells also exhibited lower mass-specific metabolic rates, and the interspecific mass scaling of metabolism was negatively allometric, indicating that large beetles with larger cells spent relatively less energy on maintenance than small beetles. These outcomes also support existing hypotheses about the fitness consequences of cell size changes, postulating that the low surface-to-volume ratio of large cells helps decrease the energetic demand of maintaining ionic gradients across cell membranes. Analyses with and without phylogenetic information yielded similar results, indicating that the observed patterns were not biased by shared ancestry. Overall, we suggest that natural selection does not operate on each trait independently and that the linkages between concerted cell size changes in different tissues, body mass and metabolic rate should thus be viewed as outcomes of correlational selection.
Collapse
Affiliation(s)
- Bartosz W Schramm
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland; Sable Systems Europe GmbH, Ostendstraße 25, 12459 Berlin, Germany
| | - Anna Maria Labecka
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland
| | - Agnieszka Gudowska
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland
| | - Andrzej Antoł
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland; Institute of Nature Conservation, Polish Academy of Sciences, Al. Adama Mickiewicza 33, 31-120 Kraków, Poland
| | - Anna Sikorska
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland
| | - Natalia Szabla
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland
| | - Ulf Bauchinger
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland; Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteura 3, 02-093 Warsaw, Poland
| | - Jan Kozlowski
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland
| | - Marcin Czarnoleski
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków 30-387, Poland.
| |
Collapse
|
10
|
Betancourt NJ, Rajpurohit S, Durmaz E, Fabian DK, Kapun M, Flatt T, Schmidt P. Allelic polymorphism at foxo contributes to local adaptation in Drosophila melanogaster. Mol Ecol 2021; 30:2817-2830. [PMID: 33914989 PMCID: PMC8693798 DOI: 10.1111/mec.15939] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 04/13/2021] [Indexed: 01/09/2023]
Abstract
The insulin/insulin-like growth factor signalling pathway has been hypothesized as a major determinant of life-history profiles that vary adaptively in natural populations. In Drosophila melanogaster, multiple components of this pathway vary predictably with latitude; this includes foxo, a conserved gene that regulates insulin signalling and has pleiotropic effects on a variety of fitness-associated traits. We hypothesized that allelic variation at foxo contributes to genetic variance for size-related traits that vary adaptively with latitude. We first examined patterns of variation among natural populations along a latitudinal transect in the eastern United States and show that thorax length, wing area, wing loading, and starvation tolerance exhibit significant latitudinal clines for both males and females but that development time does not vary predictably with latitude. We then generated recombinant outbred populations and show that naturally occurring allelic variation at foxo, which exhibits stronger clinality than expected, is associated with the same traits that vary with latitude in the natural populations. Our results suggest that allelic variation at foxo contributes to adaptive patterns of life-history variation in natural populations of this genetic model.
Collapse
Affiliation(s)
| | - Subhash Rajpurohit
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
- Division of Biological and Life Sciences, Ahmedabad University, Ahmedabad, India
| | - Esra Durmaz
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Daniel K. Fabian
- Department of Genetics, University of Cambridge, Cambridge, UK
- European Bioinformatics Institute (EMBL-EBI), Hinxton, UK
| | - Martin Kapun
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Thomas Flatt
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Paul Schmidt
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
11
|
DNMT3.1 controls trade-offs between growth, reproduction, and life span under starved conditions in Daphnia magna. Sci Rep 2021; 11:7326. [PMID: 33795753 PMCID: PMC8016896 DOI: 10.1038/s41598-021-86578-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 02/25/2021] [Indexed: 02/01/2023] Open
Abstract
The cladoceran crustacean Daphnia has long been a model of energy allocation studies due to its important position in the trophic cascade of freshwater ecosystems. However, the loci for controlling energy allocation between life history traits still remain unknown. Here, we report CRISPR/Cas-mediated target mutagenesis of DNA methyltransferase 3.1 (DNMT3.1) that is upregulated in response to caloric restriction in Daphnia magna. The resulting biallelic mutant is viable and did not show any change in growth rate, reproduction, and longevity under nutrient rich conditions. In contrast, under starved conditions, the growth rate of this DNMT3.1 mutant was increased but its reproduction was reciprocally reduced compared to the wild type when the growth and reproduction activities competed during a period from instar 4 to 8. The life span of this mutant was significantly shorter than that of the wild type. We also compared transcriptomes between DNMT3.1 mutant and wild type under nutrient-rich and starved conditions. Consistent with the DNMT3.1 mutant phenotypes, the starved condition led to changes in the transcriptomes of the mutant including differential expression of vitellogenin genes. In addition, we found upregulation of the I am not dead yet (INDY) ortholog, which has been known to shorten the life span in Drosophila, explaining the shorter life span of the DNMT3.1 mutant. These results establish DNMT3.1 as a key regulator for life span and energy allocation between growth and reproduction during caloric restriction. Our findings reveal how energy allocation is implemented by selective expression of a DNMT3 ortholog that is widely distributed among animals. We also infer a previously unidentified adaptation of Daphnia that invests more energy for reproduction than growth under starved conditions.
Collapse
|
12
|
Kapun M, Barrón MG, Staubach F, Obbard DJ, Wiberg RAW, Vieira J, Goubert C, Rota-Stabelli O, Kankare M, Bogaerts-Márquez M, Haudry A, Waidele L, Kozeretska I, Pasyukova EG, Loeschcke V, Pascual M, Vieira CP, Serga S, Montchamp-Moreau C, Abbott J, Gibert P, Porcelli D, Posnien N, Sánchez-Gracia A, Grath S, Sucena É, Bergland AO, Guerreiro MPG, Onder BS, Argyridou E, Guio L, Schou MF, Deplancke B, Vieira C, Ritchie MG, Zwaan BJ, Tauber E, Orengo DJ, Puerma E, Aguadé M, Schmidt P, Parsch J, Betancourt AJ, Flatt T, González J. Genomic Analysis of European Drosophila melanogaster Populations Reveals Longitudinal Structure, Continent-Wide Selection, and Previously Unknown DNA Viruses. Mol Biol Evol 2020; 37:2661-2678. [PMID: 32413142 PMCID: PMC7475034 DOI: 10.1093/molbev/msaa120] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Genetic variation is the fuel of evolution, with standing genetic variation especially important for short-term evolution and local adaptation. To date, studies of spatiotemporal patterns of genetic variation in natural populations have been challenging, as comprehensive sampling is logistically difficult, and sequencing of entire populations costly. Here, we address these issues using a collaborative approach, sequencing 48 pooled population samples from 32 locations, and perform the first continent-wide genomic analysis of genetic variation in European Drosophila melanogaster. Our analyses uncover longitudinal population structure, provide evidence for continent-wide selective sweeps, identify candidate genes for local climate adaptation, and document clines in chromosomal inversion and transposable element frequencies. We also characterize variation among populations in the composition of the fly microbiome, and identify five new DNA viruses in our samples.
Collapse
Affiliation(s)
- Martin Kapun
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Department of Evolutionary Biology and Environmental Sciences, University of Zürich, Zürich, Switzerland
- Division of Cell and Developmental Biology, Medical University of Vienna, Vienna, Austria
| | - Maite G Barrón
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| | - Fabian Staubach
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Evolutionary Biology and Ecology, University of Freiburg, Freiburg, Germany
| | - Darren J Obbard
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - R Axel W Wiberg
- The European Drosophila Population Genomics Consortium (DrosEU)
- Centre for Biological Diversity, School of Biology, University of St. Andrews, St Andrews, Scotland
- Department of Environmental Sciences, Zoological Institute, University of Basel, Basel, Switzerland
| | - Jorge Vieira
- The European Drosophila Population Genomics Consortium (DrosEU)
- Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), University of Porto, Porto, Portugal
| | - Clément Goubert
- The European Drosophila Population Genomics Consortium (DrosEU)
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, CNRS, Université Lyon 1, Université de Lyon, Villeurbanne, France
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY
| | - Omar Rota-Stabelli
- The European Drosophila Population Genomics Consortium (DrosEU)
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’ Adige, Italy
| | - Maaria Kankare
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - María Bogaerts-Márquez
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| | - Annabelle Haudry
- The European Drosophila Population Genomics Consortium (DrosEU)
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, CNRS, Université Lyon 1, Université de Lyon, Villeurbanne, France
| | - Lena Waidele
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Evolutionary Biology and Ecology, University of Freiburg, Freiburg, Germany
| | - Iryna Kozeretska
- The European Drosophila Population Genomics Consortium (DrosEU)
- General and Medical Genetics Department, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
- State Institution National Antarctic Scientific Center of Ministry of Education and Science of Ukraine, Kyiv, Ukraine
| | - Elena G Pasyukova
- The European Drosophila Population Genomics Consortium (DrosEU)
- Laboratory of Genome Variation, Institute of Molecular Genetics of RAS, Moscow, Russia
| | - Volker Loeschcke
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Bioscience—Genetics, Ecology and Evolution, Aarhus University, Aarhus C, Denmark
| | - Marta Pascual
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Cristina P Vieira
- The European Drosophila Population Genomics Consortium (DrosEU)
- Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), University of Porto, Porto, Portugal
| | - Svitlana Serga
- The European Drosophila Population Genomics Consortium (DrosEU)
- General and Medical Genetics Department, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Catherine Montchamp-Moreau
- The European Drosophila Population Genomics Consortium (DrosEU)
- Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement et Écologie, 91198, Gif-sur-Yvette, France
| | - Jessica Abbott
- The European Drosophila Population Genomics Consortium (DrosEU)
- Section for Evolutionary Ecology, Department of Biology, Lund University, Lund, Sweden
| | - Patricia Gibert
- The European Drosophila Population Genomics Consortium (DrosEU)
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, CNRS, Université Lyon 1, Université de Lyon, Villeurbanne, France
| | - Damiano Porcelli
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Animal and Plant Sciences, Sheffield, United Kingdom
| | - Nico Posnien
- The European Drosophila Population Genomics Consortium (DrosEU)
- Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Universität Göttingen, Göttingen, Germany
| | - Alejandro Sánchez-Gracia
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Sonja Grath
- The European Drosophila Population Genomics Consortium (DrosEU)
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg, Germany
| | - Élio Sucena
- The European Drosophila Population Genomics Consortium (DrosEU)
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Departamento de Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
| | - Alan O Bergland
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology, University of Virginia, Charlottesville, VA
| | - Maria Pilar Garcia Guerreiro
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Banu Sebnem Onder
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology, Faculty of Science, Hacettepe University, Ankara, Turkey
| | - Eliza Argyridou
- The European Drosophila Population Genomics Consortium (DrosEU)
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg, Germany
| | - Lain Guio
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| | - Mads Fristrup Schou
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Bioscience—Genetics, Ecology and Evolution, Aarhus University, Aarhus C, Denmark
- Section for Evolutionary Ecology, Department of Biology, Lund University, Lund, Sweden
| | - Bart Deplancke
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute of Bio-engineering, School of Life Sciences, EPFL, Lausanne, Switzerland
| | - Cristina Vieira
- The European Drosophila Population Genomics Consortium (DrosEU)
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, CNRS, Université Lyon 1, Université de Lyon, Villeurbanne, France
| | - Michael G Ritchie
- The European Drosophila Population Genomics Consortium (DrosEU)
- Centre for Biological Diversity, School of Biology, University of St. Andrews, St Andrews, Scotland
| | - Bas J Zwaan
- The European Drosophila Population Genomics Consortium (DrosEU)
- Laboratory of Genetics, Department of Plant Sciences, Wageningen University, Wageningen, Netherlands
| | - Eran Tauber
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Dorcas J Orengo
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Eva Puerma
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Montserrat Aguadé
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Paul Schmidt
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology, University of Pennsylvania, Philadelphia, PA
| | - John Parsch
- The European Drosophila Population Genomics Consortium (DrosEU)
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg, Germany
| | - Andrea J Betancourt
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Evolution, Ecology, and Behaviour, University of Liverpool, Liverpool, United Kingdom
| | - Thomas Flatt
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Josefa González
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| |
Collapse
|
13
|
Ng'oma E, Williams-Simon PA, Rahman A, King EG. Diverse biological processes coordinate the transcriptional response to nutritional changes in a Drosophila melanogaster multiparent population. BMC Genomics 2020; 21:84. [PMID: 31992183 PMCID: PMC6988245 DOI: 10.1186/s12864-020-6467-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/08/2020] [Indexed: 12/19/2022] Open
Abstract
Background Environmental variation in the amount of resources available to populations challenge individuals to optimize the allocation of those resources to key fitness functions. This coordination of resource allocation relative to resource availability is commonly attributed to key nutrient sensing gene pathways in laboratory model organisms, chiefly the insulin/TOR signaling pathway. However, the genetic basis of diet-induced variation in gene expression is less clear. Results To describe the natural genetic variation underlying nutrient-dependent differences, we used an outbred panel derived from a multiparental population, the Drosophila Synthetic Population Resource. We analyzed RNA sequence data from multiple female tissue samples dissected from flies reared in three nutritional conditions: high sugar (HS), dietary restriction (DR), and control (C) diets. A large proportion of genes in the experiment (19.6% or 2471 genes) were significantly differentially expressed for the effect of diet, and 7.8% (978 genes) for the effect of the interaction between diet and tissue type (LRT, Padj. < 0.05). Interestingly, we observed similar patterns of gene expression relative to the C diet, in the DR and HS treated flies, a response likely reflecting diet component ratios. Hierarchical clustering identified 21 robust gene modules showing intra-modularly similar patterns of expression across diets, all of which were highly significant for diet or diet-tissue interaction effects (FDR Padj. < 0.05). Gene set enrichment analysis for different diet-tissue combinations revealed a diverse set of pathways and gene ontology (GO) terms (two-sample t-test, FDR < 0.05). GO analysis on individual co-expressed modules likewise showed a large number of terms encompassing many cellular and nuclear processes (Fisher exact test, Padj. < 0.01). Although a handful of genes in the IIS/TOR pathway including Ilp5, Rheb, and Sirt2 showed significant elevation in expression, many key genes such as InR, chico, most insulin peptide genes, and the nutrient-sensing pathways were not observed. Conclusions Our results suggest that a more diverse network of pathways and gene networks mediate the diet response in our population. These results have important implications for future studies focusing on diet responses in natural populations.
Collapse
Affiliation(s)
- E Ng'oma
- University of Missouri, 401 Tucker Hall, Columbia, MO, 65211, USA.
| | | | - A Rahman
- University of Missouri, 401 Tucker Hall, Columbia, MO, 65211, USA
| | - E G King
- University of Missouri, 401 Tucker Hall, Columbia, MO, 65211, USA
| |
Collapse
|
14
|
Flatt T. Life-History Evolution and the Genetics of Fitness Components in Drosophila melanogaster. Genetics 2020; 214:3-48. [PMID: 31907300 PMCID: PMC6944413 DOI: 10.1534/genetics.119.300160] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 10/03/2019] [Indexed: 12/28/2022] Open
Abstract
Life-history traits or "fitness components"-such as age and size at maturity, fecundity and fertility, age-specific rates of survival, and life span-are the major phenotypic determinants of Darwinian fitness. Analyzing the evolution and genetics of these phenotypic targets of selection is central to our understanding of adaptation. Due to its simple and rapid life cycle, cosmopolitan distribution, ease of maintenance in the laboratory, well-understood evolutionary genetics, and its versatile genetic toolbox, the "vinegar fly" Drosophila melanogaster is one of the most powerful, experimentally tractable model systems for studying "life-history evolution." Here, I review what has been learned about the evolution and genetics of life-history variation in D. melanogaster by drawing on numerous sources spanning population and quantitative genetics, genomics, experimental evolution, evolutionary ecology, and physiology. This body of work has contributed greatly to our knowledge of several fundamental problems in evolutionary biology, including the amount and maintenance of genetic variation, the evolution of body size, clines and climate adaptation, the evolution of senescence, phenotypic plasticity, the nature of life-history trade-offs, and so forth. While major progress has been made, important facets of these and other questions remain open, and the D. melanogaster system will undoubtedly continue to deliver key insights into central issues of life-history evolution and the genetics of adaptation.
Collapse
Affiliation(s)
- Thomas Flatt
- Department of Biology, University of Fribourg, CH-1700, Switzerland
| |
Collapse
|
15
|
Hoedjes KM, van den Heuvel J, Kapun M, Keller L, Flatt T, Zwaan BJ. Distinct genomic signals of lifespan and life history evolution in response to postponed reproduction and larval diet in Drosophila. Evol Lett 2019; 3:598-609. [PMID: 31867121 PMCID: PMC6906992 DOI: 10.1002/evl3.143] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 09/08/2019] [Accepted: 09/11/2019] [Indexed: 12/14/2022] Open
Abstract
Reproduction and diet are two major factors controlling the physiology of aging and life history, but how they interact to affect the evolution of longevity is unknown. Moreover, although studies of large-effect mutants suggest an important role of nutrient sensing pathways in regulating aging, the genetic basis of evolutionary changes in lifespan remains poorly understood. To address these questions, we analyzed the genomes of experimentally evolved Drosophila melanogaster populations subjected to a factorial combination of two selection regimes: reproductive age (early versus postponed), and diet during the larval stage ("low," "control," "high"), resulting in six treatment combinations with four replicate populations each. Selection on reproductive age consistently affected lifespan, with flies from the postponed reproduction regime having evolved a longer lifespan. In contrast, larval diet affected lifespan only in early-reproducing populations: flies adapted to the "low" diet lived longer than those adapted to control diet. Here, we find genomic evidence for strong independent evolutionary responses to either selection regime, as well as loci that diverged in response to both regimes, thus representing genomic interactions between the two. Overall, we find that the genomic basis of longevity is largely independent of dietary adaptation. Differentiated loci were not enriched for "canonical" longevity genes, suggesting that naturally occurring genic targets of selection for longevity differ qualitatively from variants found in mutant screens. Comparing our candidate loci to those from other "evolve and resequence" studies of longevity demonstrated significant overlap among independent experiments. This suggests that the evolution of longevity, despite its presumed complex and polygenic nature, might be to some extent convergent and predictable.
Collapse
Affiliation(s)
- Katja M. Hoedjes
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Joost van den Heuvel
- Laboratory of Genetics, Plant Sciences GroupWageningen UniversityWageningenThe Netherlands
- Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastle Upon TyneUnited Kingdom
| | - Martin Kapun
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
- Department of BiologyUniversity of FribourgFribourgSwitzerland
- Current Address: Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
| | - Laurent Keller
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Thomas Flatt
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
- Department of BiologyUniversity of FribourgFribourgSwitzerland
| | - Bas J. Zwaan
- Laboratory of Genetics, Plant Sciences GroupWageningen UniversityWageningenThe Netherlands
| |
Collapse
|
16
|
Ragland GJ, Armbruster PA, Meuti ME. Evolutionary and functional genetics of insect diapause: a call for greater integration. CURRENT OPINION IN INSECT SCIENCE 2019; 36:74-81. [PMID: 31539788 PMCID: PMC7212789 DOI: 10.1016/j.cois.2019.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/29/2019] [Accepted: 08/07/2019] [Indexed: 06/10/2023]
Abstract
Diapause in response to seasonality is an important model for rapid evolutionary adaptation that is highly genetically variable, and experiences strong natural selection. Forward genetic methods using various genomic and transcriptomic approaches have begun to characterize the genetic architecture and candidate genes underlying diapause evolution. Largely in parallel, reverse genetic studies have identified functional roles for candidate genes that may or may not be genetically variable. We illustrate the disconnect between the evolutionary and physiological literature using a suite of studies of the role of the circadian clock in diapause regulation. These extensive studies in two different disciplines provide excellent opportunities for integration, which should facilitate rapid progress in understanding both the regulation and evolution of diapause.
Collapse
Affiliation(s)
- Gregory J Ragland
- Department of Integrative Biology, University of Colorado, Denver, 1151 Arapahoe St., SI 2071, Denver, CO 80204, USA.
| | - Peter A Armbruster
- Department of Biology, Georgetown University, Reiss Science Building, Room 406 37th and O Streets, NW Washington DC 20057, USA
| | - Megan E Meuti
- Department of Entomology, The Ohio State University, 216 Kottman Hall 2021 Coffey Road, Columbus, OH 43210, USA
| |
Collapse
|
17
|
Payankaulam S, Raicu AM, Arnosti DN. Transcriptional Regulation of INSR, the Insulin Receptor Gene. Genes (Basel) 2019; 10:genes10120984. [PMID: 31795422 PMCID: PMC6947883 DOI: 10.3390/genes10120984] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/19/2019] [Accepted: 11/23/2019] [Indexed: 01/19/2023] Open
Abstract
The insulin receptor gene encodes an evolutionarily conserved signaling protein with a wide spectrum of functions in metazoan development. The insulin signaling pathway plays key roles in processes such as metabolic regulation, growth control, and neuronal function. Misregulation of the pathway features in diabetes, cancer, and neurodegenerative diseases, making it an important target for clinical interventions. While much attention has been focused on differential pathway activation through ligand availability, sensitization of overall signaling may also be mediated by differential expression of the insulin receptor itself. Although first characterized as a “housekeeping” gene with stable expression, comparative studies have shown that expression levels of the human INSR mRNA differ by tissue and in response to environmental signals. Our recent analysis of the transcriptional controls affecting expression of the Drosophila insulin receptor gene indicates that a remarkable amount of DNA is dedicated to encoding sophisticated feedback and feed forward signals. The human INSR gene is likely to contain a similar level of transcriptional complexity; here, we summarize over three decades of molecular biology and genetic research that points to a still incompletely understood regulatory control system. Further elucidation of transcriptional controls of INSR will provide the basis for understanding human genetic variation that underlies population-level physiological differences and disease.
Collapse
Affiliation(s)
- Sandhya Payankaulam
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Rd. 413 Biochemistry, East Lansing, MI 48824, USA;
| | - Ana-Maria Raicu
- Cell and Molecular Biology Program, Michigan State University, 603 Wilson Rd. 413 Biochemistry, East Lansing, MI 48824, USA;
| | - David N. Arnosti
- Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Rd. 413 Biochemistry, East Lansing, MI 48824, USA;
- Cell and Molecular Biology Program, Michigan State University, 603 Wilson Rd. 413 Biochemistry, East Lansing, MI 48824, USA;
- Correspondence: ; Tel.: +1-(517)-432-5504
| |
Collapse
|
18
|
Structural variants exhibit widespread allelic heterogeneity and shape variation in complex traits. Nat Commun 2019; 10:4872. [PMID: 31653862 PMCID: PMC6814777 DOI: 10.1038/s41467-019-12884-1] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 09/25/2019] [Indexed: 12/11/2022] Open
Abstract
It has been hypothesized that individually-rare hidden structural variants (SVs) could account for a significant fraction of variation in complex traits. Here we identified more than 20,000 euchromatic SVs from 14 Drosophila melanogaster genome assemblies, of which ~40% are invisible to high specificity short-read genotyping approaches. SVs are common, with 31.5% of diploid individuals harboring a SV in genes larger than 5kb, and 24% harboring multiple SVs in genes larger than 10kb. SV minor allele frequencies are rarer than amino acid polymorphisms, suggesting that SVs are more deleterious. We show that a number of functionally important genes harbor previously hidden structural variants likely to affect complex phenotypes. Furthermore, SVs are overrepresented in candidate genes associated with quantitative trait loci mapped using the Drosophila Synthetic Population Resource. We conclude that SVs are ubiquitous, frequently constitute a heterogeneous allelic series, and can act as rare alleles of large effect.
Collapse
|
19
|
Durmaz E, Rajpurohit S, Betancourt N, Fabian DK, Kapun M, Schmidt P, Flatt T. A clinal polymorphism in the insulin signaling transcription factor foxo contributes to life-history adaptation in Drosophila. Evolution 2019; 73:1774-1792. [PMID: 31111462 PMCID: PMC6771989 DOI: 10.1111/evo.13759] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 05/04/2019] [Accepted: 05/06/2019] [Indexed: 12/11/2022]
Abstract
A fundamental aim of adaptation genomics is to identify polymorphisms that underpin variation in fitness traits. In Drosophila melanogaster, latitudinal life-history clines exist on multiple continents and make an excellent system for dissecting the genetics of adaptation. We have previously identified numerous clinal single-nucleotide polymorphism in insulin/insulin-like growth factor signaling (IIS), a pathway known from mutant studies to affect life history. However, the effects of natural variants in this pathway remain poorly understood. Here we investigate how two clinal alternative alleles at foxo, a transcriptional effector of IIS, affect fitness components (viability, size, starvation resistance, fat content). We assessed this polymorphism from the North American cline by reconstituting outbred populations, fixed for either the low- or high-latitude allele, from inbred DGRP lines. Because diet and temperature modulate IIS, we phenotyped alleles across two temperatures (18°C, 25°C) and two diets differing in sugar source and content. Consistent with clinal expectations, the high-latitude allele conferred larger body size and reduced wing loading. Alleles also differed in starvation resistance and expression of insulin-like receptor, a transcriptional target of FOXO. Allelic reaction norms were mostly parallel, with few GxE interactions. Together, our results suggest that variation in IIS makes a major contribution to clinal life-history adaptation.
Collapse
Affiliation(s)
- Esra Durmaz
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
- Department of BiologyUniversity of FribourgFribourgSwitzerland
| | - Subhash Rajpurohit
- Department of BiologyUniversity of PennsylvaniaPhiladelphiaPennsylvania19140
- Division of Biological and Life SciencesAhmedabad UniversityAhmedabadIndia
| | - Nicolas Betancourt
- Department of BiologyUniversity of PennsylvaniaPhiladelphiaPennsylvania19140
| | - Daniel K. Fabian
- European Molecular Biology LaboratoryEuropean Bioinformatics InstituteWellcome Genome Campus, HinxtonCambridgeUnited Kingdom
- Institut für PopulationsgenetikVetmeduni ViennaViennaAustria
- Vienna Graduate School of Population, GeneticsViennaAustria
| | - Martin Kapun
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
- Department of BiologyUniversity of FribourgFribourgSwitzerland
| | - Paul Schmidt
- Department of BiologyUniversity of PennsylvaniaPhiladelphiaPennsylvania19140
| | - Thomas Flatt
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
- Department of BiologyUniversity of FribourgFribourgSwitzerland
| |
Collapse
|
20
|
El‐Deeb O. Digest: A clinal polymorphism and life‐history adaptations in
Drosophila
*. Evolution 2019; 73:2026-2027. [DOI: 10.1111/evo.13828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 07/10/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Omar El‐Deeb
- Department of BiologyWestern University London ON N6A 3K7 Canada
| |
Collapse
|
21
|
Regan JC, Froy H, Walling CA, Moatt JP, Nussey DH. Dietary restriction and insulin‐like signalling pathways as adaptive plasticity: A synthesis and re‐evaluation. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13418] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Jennifer C. Regan
- Institute of Immunology and Infection Research, School of Biological Sciences University of Edinburgh Edinburgh UK
| | - Hannah Froy
- Centre for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
| | - Craig A. Walling
- Institute for Evolutionary Biology, School of Biological Sciences University of Edinburgh Edinburgh UK
| | - Joshua P. Moatt
- Institute for Evolutionary Biology, School of Biological Sciences University of Edinburgh Edinburgh UK
| | - Daniel H. Nussey
- Institute of Immunology and Infection Research, School of Biological Sciences University of Edinburgh Edinburgh UK
- Institute for Evolutionary Biology, School of Biological Sciences University of Edinburgh Edinburgh UK
| |
Collapse
|
22
|
Krittika S, Yadav P. An overview of two decades of diet restriction studies using Drosophila. Biogerontology 2019; 20:723-740. [PMID: 31375967 DOI: 10.1007/s10522-019-09827-0] [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: 04/25/2019] [Accepted: 07/25/2019] [Indexed: 12/12/2022]
Abstract
Dietary restriction (DR) is a potent forerunner in aging studies capable of influencing lifespan and improving health in various model organisms even in their old age. Despite the importance of protein and carbohydrates in the diet (regulation of fecundity and body maintenance respectively), different ratio based combinations of these components has played a major role in lifespan extension studies. In spite of differences existing in dietary protocols across laboratories, diet manipulations have evolved as a major area of research in Drosophila lifespan studies, prominently shedding light on the multi-faceted process over the last two decades. Here, we review various advances and technicalities involved in understanding the DR-mediated lifespan alongside discussing the pros and cons of various existing approaches/diets used across labs. The current review also focuses on the importance of life-stage specific DR implementation and their influence on the life-history traits including lifespan and fecundity, by taking examples of results from different studies comprising diet dilution, calorie restriction, protein restriction, carbohydrate: protein ratios and the modulations in various minor diet components. We thereby intend to gather the major advances made in these fields alongside reviewing the practical implementations that need to be made to get a better view of the DR-mediated lifespan studies.
Collapse
Affiliation(s)
- Sudhakar Krittika
- Fly Laboratory # 210, Anusandhan Kendra-II, School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, Tamil Nadu, 613401, India
| | - Pankaj Yadav
- Fly Laboratory # 210, Anusandhan Kendra-II, School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, Tamil Nadu, 613401, India.
| |
Collapse
|
23
|
Gerritsma S, Jalvingh KM, van de Beld C, Beerda J, van de Zande L, Vrieling K, Wertheim B. Natural and Artificial Selection for Parasitoid Resistance in Drosophila melanogaster Leave Different Genetic Signatures. Front Genet 2019; 10:479. [PMID: 31214243 PMCID: PMC6557190 DOI: 10.3389/fgene.2019.00479] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 05/03/2019] [Indexed: 12/20/2022] Open
Abstract
Adaptation of complex traits depends on standing genetic variation at multiple loci. The allelic variants that have positive fitness effects, however, can differ depending on the genetic background and the selective pressure. Previously, we interrogated the Drosophila melanogaster genome at the population level for polymorphic positions and identified 215 single nucleotide polymorphisms (SNPs) that had significantly changed in frequency after experimental evolution for increased parasitoid resistance. In the current study, we follow up on 11 of these SNPs as putative targets of the experimental selection process (Jalvingh et al., 2014). We study the patterns of genetic variation for these SNPs in several European field populations. Furthermore, we associate the genetic variation of these SNPs to variation in resistance against the parasitoid Asobara tabida, by determining the individual phenotype and SNP genotype for 144 individuals from four Selection lines and four non-selected Control lines and for 400 individuals from 12 Field lines that differ in parasitoid resistance. For the Selection lines we additionally monitored the changes in allele frequencies throughout the five generations of experimental selection. For three genes, mbl (Zn-finger protein), mthl4 (G-protein coupled receptor) and CG17287 (protein-cysteine S-palmitoyltransferase) individual SNP genotypes were significantly associated with resistance level in the Selection and Control lines. Additionally, the minor allele in mbl and mthl4 were consistently and gradually favored throughout the five generations of experimental evolution. However, none of these alleles did appear to be associated to high resistance in the Field lines. We suggest that, within field populations, selection for parasitoid resistance is a gradual process that involves co-adapted gene complexes. Fast artificial selection, however, enforces the sudden cumulating of particular alleles that confer high resistance (genetic sweep). We discuss our findings in the context of local adaptation.
Collapse
Affiliation(s)
- Sylvia Gerritsma
- Evolutionary Genetics, Development and Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Kirsten M Jalvingh
- Evolutionary Genetics, Development and Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Carmen van de Beld
- Evolutionary Genetics, Development and Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Jelmer Beerda
- Evolutionary Genetics, Development and Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Louis van de Zande
- Evolutionary Genetics, Development and Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Klaas Vrieling
- Plant Cluster, Institute of Biology, Sylvius Laboratory, Leiden University, Leiden, Netherlands
| | - Bregje Wertheim
- Evolutionary Genetics, Development and Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| |
Collapse
|
24
|
Hardy CM, Burke MK, Everett LJ, Han MV, Lantz KM, Gibbs AG. Genome-Wide Analysis of Starvation-Selected Drosophila melanogaster-A Genetic Model of Obesity. Mol Biol Evol 2019; 35:50-65. [PMID: 29309688 DOI: 10.1093/molbev/msx254] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Experimental evolution affords the opportunity to investigate adaptation to stressful environments. Studies combining experimental evolution with whole-genome resequencing have provided insight into the dynamics of adaptation and a new tool to uncover genes associated with polygenic traits. Here, we selected for starvation resistance in populations of Drosophila melanogaster for over 80 generations. In response, the starvation-selected lines developed an obese condition, storing nearly twice the level of total lipids than their unselected controls. Although these fats provide a ∼3-fold increase in starvation resistance, the imbalance in lipid homeostasis incurs evolutionary cost. Some of these tradeoffs resemble obesity-associated pathologies in mammals including metabolic depression, low activity levels, dilated cardiomyopathy, and disrupted sleeping patterns. To determine the genetic basis of these traits, we resequenced genomic DNA from the selected lines and their controls. We found 1,046,373 polymorphic sites, many of which diverged between selection treatments. In addition, we found a wide range of genetic heterogeneity between the replicates of the selected lines, suggesting multiple mechanisms of adaptation. Genome-wide heterozygosity was low in the selected populations, with many large blocks of SNPs nearing fixation. We found candidate loci under selection by using an algorithm to control for the effects of genetic drift. These loci were mapped to a set of 382 genes, which associated with many processes including nutrient response, catabolic metabolism, and lipid droplet function. The results of our study speak to the evolutionary origins of obesity and provide new targets to understand the polygenic nature of obesity in a unique model system.
Collapse
Affiliation(s)
- Christopher M Hardy
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV.,Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV
| | - Molly K Burke
- Department of Integrative Biology, Oregon State University, Corvallis, OR
| | - Logan J Everett
- Department of Biological Sciences, North Carolina State University, Raleigh, NC
| | - Mira V Han
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV.,Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV
| | - Kathryn M Lantz
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV.,Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV
| | - Allen G Gibbs
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV.,Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV
| |
Collapse
|
25
|
Fabian DK, Garschall K, Klepsatel P, Santos‐Matos G, Sucena É, Kapun M, Lemaitre B, Schlötterer C, Arking R, Flatt T. Evolution of longevity improves immunity in Drosophila. Evol Lett 2018; 2:567-579. [PMID: 30564440 PMCID: PMC6292704 DOI: 10.1002/evl3.89] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 10/24/2018] [Indexed: 12/20/2022] Open
Abstract
Much has been learned about the genetics of aging from studies in model organisms, but still little is known about naturally occurring alleles that contribute to variation in longevity. For example, analysis of mutants and transgenes has identified insulin signaling as a major regulator of longevity, yet whether standing variation in this pathway underlies microevolutionary changes in lifespan and correlated fitness traits remains largely unclear. Here, we have analyzed the genomes of a set of Drosophila melanogaster lines that have been maintained under direct selection for postponed reproduction and indirect selection for longevity, relative to unselected control lines, for over 35 years. We identified many candidate loci shaped by selection for longevity and late-life fertility, but - contrary to expectation - we did not find overrepresentation of canonical longevity genes. Instead, we found an enrichment of immunity genes, particularly in the Toll pathway, suggesting that evolutionary changes in immune function might underpin - in part - the evolution of late-life fertility and longevity. To test whether this genomic signature is causative, we performed functional experiments. In contrast to control flies, long-lived flies tended to downregulate the expression of antimicrobial peptides upon infection with age yet survived fungal, bacterial, and viral infections significantly better, consistent with alleviated immunosenescence. To examine whether genes of the Toll pathway directly affect longevity, we employed conditional knockdown using in vivo RNAi. In adults, RNAi against the Toll receptor extended lifespan, whereas silencing the pathway antagonist cactus--causing immune hyperactivation - dramatically shortened lifespan. Together, our results suggest that genetic changes in the age-dependent regulation of immune homeostasis might contribute to the evolution of longer life.
Collapse
Affiliation(s)
- Daniel K. Fabian
- Centre for Pathogen Evolution, Department of ZoologyUniversity of CambridgeCambridgeUnited Kingdom
- Institut für PopulationsgenetikVetmeduni ViennaViennaAustria
- Vienna Graduate School of Population GeneticsViennaAustria
| | - Kathrin Garschall
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Peter Klepsatel
- Institut für PopulationsgenetikVetmeduni ViennaViennaAustria
- Institute of ZoologySlovak Academy of Sciences845 06 BratislavaSlovakia
| | | | - Élio Sucena
- Instituto Gulbenkian de CiênciaOeirasPortugal
- Departamento de Biologia AnimalFaculdade de Ciências da Universidade de LisboaLisboaPortugal
| | - Martin Kapun
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Bruno Lemaitre
- Global Health InstituteSchool of Life Sciences, EPFLLausanneSwitzerland
| | | | - Robert Arking
- Department of Biological SciencesWayne State UniversityDetroitMichigan
| | - Thomas Flatt
- Institut für PopulationsgenetikVetmeduni ViennaViennaAustria
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
- Department of BiologyUniversity of FribourgFribourgSwitzerland
| |
Collapse
|
26
|
Kapun M, Flatt T. The adaptive significance of chromosomal inversion polymorphisms inDrosophila melanogaster. Mol Ecol 2018; 28:1263-1282. [DOI: 10.1111/mec.14871] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/01/2018] [Accepted: 09/10/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Martin Kapun
- Department of BiologyUniversity of Fribourg Fribourg Switzerland
| | - Thomas Flatt
- Department of BiologyUniversity of Fribourg Fribourg Switzerland
| |
Collapse
|
27
|
Fincke OM, Xu M, Khazan ES, Wilson M, Ware JL. Tests of hypotheses for morphological and genetic divergence in Megaloprepus damselflies across Neotropical forests. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Ola M Fincke
- Department of Biology, University of Oklahoma, Norman, OK, USA
| | - Mingzi Xu
- Department of Biology, University of Oklahoma, Norman, OK, USA
| | - Emily S Khazan
- Department of Biology, University of Oklahoma, Norman, OK, USA
| | - Megan Wilson
- Department of Biological Sciences, Rutgers University, Newark, NJ, USA
| | - Jessica L Ware
- Department of Biological Sciences, Rutgers University, Newark, NJ, USA
| |
Collapse
|
28
|
Abstract
Between the 1930s and 50s, evolutionary biologists developed a successful theory of why organisms age, firmly rooted in population genetic principles. By the 1980s the evolution of aging had a secure experimental basis. Since the force of selection declines with age, aging evolves due to mutation accumulation or a benefit to fitness early in life. Here we review major insights and challenges that have emerged over the last 35 years: selection does not always necessarily decline with age; higher extrinsic (i.e., environmentally caused) mortality does not always accelerate aging; conserved pathways control aging rate; senescence patterns are more diverse than previously thought; aging is not universal; trade-offs involving lifespan can be 'broken'; aging might be 'druggable'; and human life expectancy continues to rise but compressing late-life morbidity remains a pressing challenge.
Collapse
Affiliation(s)
- Thomas Flatt
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700, Fribourg, Switzerland
| | - Linda Partridge
- Max Planck Institute for Biology of Aging, Joseph-Stelzmann-Strasse 9b, D-50931, Cologne, Germany.
- Institute for Healthy Aging and GEE, University College London, Darwin Building, Gower Street, London, WC1E6BT, UK.
| |
Collapse
|
29
|
Durmaz E, Benson C, Kapun M, Schmidt P, Flatt T. An inversion supergene in Drosophila underpins latitudinal clines in survival traits. J Evol Biol 2018; 31:1354-1364. [PMID: 29904977 DOI: 10.1111/jeb.13310] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 04/09/2018] [Accepted: 06/04/2018] [Indexed: 01/18/2023]
Abstract
Chromosomal inversions often contribute to local adaptation across latitudinal clines, but the underlying selective mechanisms remain poorly understood. We and others have previously shown that a clinal inversion polymorphism in Drosophila melanogaster, In(3R)Payne, underpins body size clines along the North American and Australian east coasts. Here, we ask whether this polymorphism also contributes to clinal variation in other fitness-related traits, namely survival traits (lifespan, survival upon starvation and survival upon cold shock). We generated homokaryon lines, either carrying the inverted or standard chromosomal arrangement, isolated from populations approximating the endpoints of the North American cline (Florida, Maine) and phenotyped the flies at two growth temperatures (18 °C, 25 °C). Across both temperatures, high-latitude flies from Maine lived longer and were more stress resistant than low-latitude flies from Florida, as previously observed. Interestingly, we find that this latitudinal pattern is partly explained by the clinal distribution of the In(3R)P polymorphism, which is at ~ 50% frequency in Florida but absent in Maine: inverted karyotypes tended to be shorter-lived and less stress resistant than uninverted karyotypes. We also detected an interaction between karyotype and temperature on survival traits. As In(3R)P influences body size and multiple survival traits, it can be viewed as a 'supergene', a cluster of tightly linked loci affecting multiple complex phenotypes. We conjecture that the inversion cline is maintained by fitness trade-offs and balancing selection across geography; elucidating the mechanisms whereby this inversion affects alternative, locally adapted phenotypes across the cline is an important task for future work.
Collapse
Affiliation(s)
- Esra Durmaz
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.,Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Clare Benson
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.,School of Biological Sciences, University of Manchester, Manchester, UK
| | - Martin Kapun
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.,Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Paul Schmidt
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas Flatt
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.,Department of Biology, University of Fribourg, Fribourg, Switzerland
| |
Collapse
|
30
|
Lirakis M, Dolezal M, Schlötterer C. Redefining reproductive dormancy in Drosophila as a general stress response to cold temperatures. JOURNAL OF INSECT PHYSIOLOGY 2018; 107:175-185. [PMID: 29649483 DOI: 10.1016/j.jinsphys.2018.04.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 04/07/2018] [Accepted: 04/08/2018] [Indexed: 06/08/2023]
Abstract
Organisms regularly encounter unfavorable conditions and the genetic adaptations facilitating survival have been of long-standing interest to evolutionary biologists. Winter is one particularly stressful condition for insects, during which they encounter low temperatures and scarcity of food. Despite dormancy being a well-studied adaptation to facilitate overwintering, there is still considerable controversy about the distribution of dormancy among natural populations and between species in Drosophila. The current definition of dormancy as developmental arrest of oogenesis at the previtellogenic stage (stage 7) distinguishes dormancy from general stress related block of oogenesis at early vitellogenic stages (stages 8 - 9). In an attempt to resolve this, we scrutinized reproductive dormancy in D. melanogaster and D. simulans. We show that dormancy shows the same hallmarks of arrest of oogenesis at stage 9, as described for other stressors and propose a new classification for dormancy. Applying this modified classification, we show that both species express dormancy in cosmopolitan and African populations, further supporting that dormancy uses an ancestral pathway induced by environmental stress. While we found significant differences between individuals and the two Drosophila species in their sensitivity to cold temperature stress, we also noted that extreme temperature stress (8 °C) resulted in very strong dormancy incidence, which strongly reduced the differences seen at less extreme temperatures. We conclude that dormancy in Drosophila should not be considered a special trait, but is better understood as a generic stress response occurring at low temperatures.
Collapse
Affiliation(s)
- Manolis Lirakis
- Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, 1210 Wien, Austria; Vienna Graduate School of Population Genetics, Vetmeduni Vienna, Veterinärplatz 1, 1210 Wien, Austria.
| | - Marlies Dolezal
- Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, 1210 Wien, Austria
| | - Christian Schlötterer
- Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, 1210 Wien, Austria
| |
Collapse
|
31
|
Czarnoleski M, Labecka AM, Dragosz-Kluska D, Pis T, Pawlik K, Kapustka F, Kilarski WM, Kozłowski J. Concerted evolution of body mass and cell size: similar patterns among species of birds (Galliformes) and mammals (Rodentia). Biol Open 2018. [PMID: 29540429 PMCID: PMC5936057 DOI: 10.1242/bio.029603] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs). In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells) and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity.
Collapse
Affiliation(s)
- Marcin Czarnoleski
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Anna Maria Labecka
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Dominika Dragosz-Kluska
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Tomasz Pis
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Katarzyna Pawlik
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Filip Kapustka
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Wincenty M Kilarski
- Institute of Zoology, Department of Biology and Cell Imaging, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
| | - Jan Kozłowski
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| |
Collapse
|
32
|
Veale AJ, Russello MA. Genomic Changes Associated with Reproductive and Migratory Ecotypes in Sockeye Salmon (Oncorhynchus nerka). Genome Biol Evol 2017; 9:2921-2939. [PMID: 29045601 PMCID: PMC5737441 DOI: 10.1093/gbe/evx215] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2017] [Indexed: 12/12/2022] Open
Abstract
Mechanisms underlying adaptive evolution can best be explored using paired populations displaying similar phenotypic divergence, illuminating the genomic changes associated with specific life history traits. Here, we used paired migratory [anadromous vs. resident (kokanee)] and reproductive [shore- vs. stream-spawning] ecotypes of sockeye salmon (Oncorhynchus nerka) sampled from seven lakes and two rivers spanning three catchments (Columbia, Fraser, and Skeena) in British Columbia, Canada to investigate the patterns and processes underlying their divergence. Restriction-site associated DNA sequencing was used to genotype this sampling at 7,347 single nucleotide polymorphisms, 334 of which were identified as outlier loci and candidates for divergent selection within at least one ecotype comparison. Sixty-eight of these outliers were present in two or more comparisons, with 33 detected across multiple catchments. Of particular note, one locus was detected as the most significant outlier between shore and stream-spawning ecotypes in multiple comparisons and across catchments (Columbia, Fraser, and Snake). We also detected several genomic islands of divergence, some shared among comparisons, potentially showing linked signals of differential selection. The single nucleotide polymorphisms and genomic regions identified in our study offer a range of mechanistic hypotheses associated with the genetic basis of O. nerka life history variation and provide novel tools for informing fisheries management.
Collapse
Affiliation(s)
- Andrew J. Veale
- Department of Biology, The University of British Columbia, Kelowna, British Columbia, Canada
- Present address: Department of Environmental and Animal Sciences, Unitec, 139 Carrington Rd, Auckland, New Zealand
| | - Michael A. Russello
- Department of Biology, The University of British Columbia, Kelowna, British Columbia, Canada
| |
Collapse
|
33
|
Positive diversifying selection is a pervasive adaptive force throughout the Drosophila radiation. Mol Phylogenet Evol 2017; 112:230-243. [DOI: 10.1016/j.ympev.2017.04.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 04/26/2017] [Accepted: 04/26/2017] [Indexed: 01/02/2023]
|
34
|
Ng'oma E, Perinchery AM, King EG. How to get the most bang for your buck: the evolution and physiology of nutrition-dependent resource allocation strategies. Proc Biol Sci 2017; 284:20170445. [PMID: 28637856 PMCID: PMC5489724 DOI: 10.1098/rspb.2017.0445] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/23/2017] [Indexed: 12/31/2022] Open
Abstract
All organisms use resources to grow, survive and reproduce. The supply of these resources varies widely across landscapes and time, imposing ultimate constraints on the maximal trait values for allocation-related traits. In this review, we address three key questions fundamental to our understanding of the evolution of allocation strategies and their underlying mechanisms. First, we ask: how diverse are flexible resource allocation strategies among different organisms? We find there are many, varied, examples of flexible strategies that depend on nutrition. However, this diversity is often ignored in some of the best-known cases of resource allocation shifts, such as the commonly observed pattern of lifespan extension under nutrient limitation. A greater appreciation of the wide variety of flexible allocation strategies leads directly to our second major question: what conditions select for different plastic allocation strategies? Here, we highlight the need for additional models that explicitly consider the evolution of phenotypically plastic allocation strategies and empirical tests of the predictions of those models in natural populations. Finally, we consider the question: what are the underlying mechanisms determining resource allocation strategies? Although evolutionary biologists assume differential allocation of resources is a major factor limiting trait evolution, few proximate mechanisms are known that specifically support the model. We argue that an integrated framework can reconcile evolutionary models with proximate mechanisms that appear at first glance to be in conflict with these models. Overall, we encourage future studies to: (i) mimic ecological conditions in which those patterns evolve, and (ii) take advantage of the 'omic' opportunities to produce multi-level data and analytical models that effectively integrate across physiological and evolutionary theory.
Collapse
Affiliation(s)
- Enoch Ng'oma
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Anna M Perinchery
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Elizabeth G King
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA
| |
Collapse
|
35
|
Veale AJ, Russello MA. An ancient selective sweep linked to reproductive life history evolution in sockeye salmon. Sci Rep 2017; 7:1747. [PMID: 28496186 PMCID: PMC5431894 DOI: 10.1038/s41598-017-01890-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 04/05/2017] [Indexed: 11/09/2022] Open
Abstract
Study of parallel (or convergent) phenotypic evolution can provide important insights into processes driving sympatric, ecologically-mediated divergence and speciation, as ecotype pairs may provide a biological replicate of the underlying signals and mechanisms. Here, we provide evidence for a selective sweep creating an island of divergence associated with reproductive behavior in sockeye salmon (Oncorhynchus nerka), identifying a series of linked single nucleotide polymorphisms across a ~22,733 basepair region spanning the leucine-rich repeat-containing protein 9 gene exhibiting signatures of divergent selection associated with stream- and shore-spawning in both anadromous and resident forms across their pan-Pacific distribution. This divergence likely occurred ~3.8 Mya (95% HPD = 2.1–6.03 Mya), after sockeye separated from pink (O. gorbuscha) and chum (O. keta) salmon, but prior to the Pleistocene glaciations. Our results suggest recurrent evolution of reproductive ecotypes across the native range of O. nerka is at least partially associated with divergent selection of pre-existing genetic variation within or linked to this region. As sockeye salmon are unique among Pacific salmonids in their flexibility to spawn in lake-shore benthic environments, this region provides great promise for continued investigation of the genomic basis of O. nerka life history evolution, and, more broadly, for increasing our understanding of the heritable basis of adaptation of complex traits in novel environments.
Collapse
Affiliation(s)
- Andrew J Veale
- Department of Biology, The University of British Columbia, Okanagan Campus, 3247 University Way, Kelowna, British Columbia, V1V 1V7, Canada.,Department of Zoology, University of Otago, 340 Great King Street, Dunedin, 9016, New Zealand
| | - Michael A Russello
- Department of Biology, The University of British Columbia, Okanagan Campus, 3247 University Way, Kelowna, British Columbia, V1V 1V7, Canada.
| |
Collapse
|
36
|
Pegoraro M, Zonato V, Tyler ER, Fedele G, Kyriacou CP, Tauber E. Geographical analysis of diapause inducibility in European Drosophila melanogaster populations. JOURNAL OF INSECT PHYSIOLOGY 2017; 98:238-244. [PMID: 28131702 DOI: 10.1016/j.jinsphys.2017.01.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/18/2017] [Accepted: 01/23/2017] [Indexed: 06/06/2023]
Abstract
Seasonal overwintering in insects represents an adaptation to stressful environments and in European Drosophila melanogaster females, low temperatures and short photoperiods can induce an ovarian diapause. Diapause may represent a recent (<15Ky) adaptation to the colonisation of temperate Europe by D. melanogaster from tropical sub-Saharan Africa, because African D. melanogaster and the sibling species D. simulans, have been reported to fail to undergo diapause. Over the past few centuries, D. melanogaster have also invaded North America and Australia, and eastern populations on both continents show a predictable latitudinal cline in diapause induction. In Europe however, a new diapause-enhancing timeless allele, ls-tim, is observed at high levels in southern Italy (∼80%), where it appears to have arisen and has spread throughout the continent with a frequency of ∼20% in Scandinavia. Given the phenotype of ls-tim and its geographical distribution, we might predict that it would work against any latitudinal cline in diapause induction within Europe. Indeed we reveal that any latitudinal cline for diapause in Europe is very weak, as predicted by ls-tim frequencies. In contrast, we determine ls-tim frequencies in North America and observe that they would be expected to strengthen the latitudinal pattern of diapause. Our results reveal how a newly arisen mutation, can, via the stochastic nature of where it initially arose, blur an otherwise adaptive geographical pattern.
Collapse
Affiliation(s)
- Mirko Pegoraro
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Valeria Zonato
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Elizabeth R Tyler
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Giorgio Fedele
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | | | - Eran Tauber
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK; Department of Evolutionary & Environmental Biology, University of Haifa, Haifa 3498838, Israel
| |
Collapse
|
37
|
Zonato V, Collins L, Pegoraro M, Tauber E, Kyriacou CP. Is diapause an ancient adaptation in Drosophila? JOURNAL OF INSECT PHYSIOLOGY 2017; 98:267-274. [PMID: 28161445 DOI: 10.1016/j.jinsphys.2017.01.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/25/2017] [Accepted: 01/31/2017] [Indexed: 06/06/2023]
Abstract
D. melanogaster enters a state of reproductive arrest when exposed to low temperatures (12°C) and shorter photoperiods. A number of studies have suggested that diapause has recently evolved in European D. melanogaster populations, that it is not present in the sibling species D. simulans, that it is non-photoperiodic in American D. melanogaster populations, and that it spontaneously terminates after 6-8weeks. We have studied the overwintering phenotype under different conditions and observe that American, European and, surprisingly, African D. melanogaster populations can show photoperiodic diapause, as can European, but not African D. simulans. Surprisingly other Drosophila species from pan-tropical regions can also show significant levels of photoperiodic diapause. We observe that spontaneous termination of diapause after a few weeks can be largely avoided with a more realistic winter simulation for D. melanogaster, but not D. simulans. Examining metabolite accumulation during diapause reveals that the shallow diapause of D. melanogaster has similar features to that of other more robustly-diapausing species. Our results suggest that diapause may be an ancient character that emerged in the tropics to resist unfavourable seasonal conditions and which has been enhanced during D. melanogaster's colonisation of temperate regions. Our results also highlight how different methodologies to quantify diapause can lead to apparently conflicting results that we believe can now largely be resolved.
Collapse
Affiliation(s)
- Valeria Zonato
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Lewis Collins
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Mirko Pegoraro
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK
| | - Eran Tauber
- Department of Genetics, University of Leicester, Leicester LE1 7RH, UK; Department of Evolutionary & Environmental Biology, University of Haifa, Haifa 3498838, Israel(2)
| | | |
Collapse
|
38
|
Hughes KA, Leips J. Pleiotropy, constraint, and modularity in the evolution of life histories: insights from genomic analyses. Ann N Y Acad Sci 2017; 1389:76-91. [PMID: 27936291 PMCID: PMC5318229 DOI: 10.1111/nyas.13256] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 08/10/2016] [Accepted: 08/22/2016] [Indexed: 12/20/2022]
Abstract
Multicellular organisms display an enormous range of life history (LH) strategies and present an evolutionary conundrum; despite strong natural selection, LH traits are characterized by high levels of genetic variation. To understand the evolution of life histories and maintenance of this variation, the specific phenotypic effects of segregating alleles and the genetic networks in which they act need to be elucidated. In particular, the extent to which LH evolution is constrained by the pleiotropy of alleles contributing to LH variation is generally unknown. Here, we review recent empirical results that shed light on this question, with an emphasis on studies employing genomic analyses. While genome-scale analyses are increasingly practical and affordable, they face limitations of genetic resolution and statistical power. We describe new research approaches that we believe can produce new insights and evaluate their promise and applicability to different kinds of organisms. Two approaches seem particularly promising: experiments that manipulate selection in multiple dimensions and measure phenotypic and genomic response and analytical approaches that take into account genome-wide associations between markers and phenotypes, rather than applying a traditional marker-by-marker approach.
Collapse
Affiliation(s)
- Kimberly A. Hughes
- Department of Biological Science, Florida State University, Tallahassee, Florida
| | - Jeff Leips
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland
| |
Collapse
|
39
|
Rajpurohit S, Hanus R, Vrkoslav V, Behrman EL, Bergland AO, Petrov D, Cvačka J, Schmidt PS. Adaptive dynamics of cuticular hydrocarbons in Drosophila. J Evol Biol 2016; 30:66-80. [PMID: 27718537 DOI: 10.1111/jeb.12988] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/04/2016] [Accepted: 10/06/2016] [Indexed: 01/19/2023]
Abstract
Cuticular hydrocarbons (CHCs) are hydrophobic compounds deposited on the arthropod cuticle that are of functional significance with respect to stress tolerance, social interactions and mating dynamics. We characterized CHC profiles in natural populations of Drosophila melanogaster at five levels: across a latitudinal transect in the eastern United States, as a function of developmental temperature during culture, across seasonal time in replicate years, and as a function of rapid evolution in experimental mesocosms in the field. Furthermore, we also characterized spatial and temporal changes in allele frequencies for SNPs in genes that are associated with the production and chemical profile of CHCs. Our data demonstrate a striking degree of parallelism for clinal and seasonal variation in CHCs in this taxon; CHC profiles also demonstrate significant plasticity in response to rearing temperature, and the observed patterns of plasticity parallel the spatiotemporal patterns observed in nature. We find that these congruent shifts in CHC profiles across time and space are also mirrored by predictable shifts in allele frequencies at SNPs associated with CHC chain length. Finally, we observed rapid and predictable evolution of CHC profiles in experimental mesocosms in the field. Together, these data strongly suggest that CHC profiles respond rapidly and adaptively to environmental parameters that covary with latitude and season, and that this response reflects the process of local adaptation in natural populations of D. melanogaster.
Collapse
Affiliation(s)
- S Rajpurohit
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - R Hanus
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - V Vrkoslav
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - E L Behrman
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - A O Bergland
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - D Petrov
- Department of Biology, Stanford University, Stanford, CA, USA
| | - J Cvačka
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - P S Schmidt
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
40
|
McAssey EV, Corbi J, Burke JM. Range-wide phenotypic and genetic differentiation in wild sunflower. BMC PLANT BIOLOGY 2016; 16:249. [PMID: 27829377 PMCID: PMC5103407 DOI: 10.1186/s12870-016-0937-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/28/2016] [Indexed: 05/20/2023]
Abstract
BACKGROUND Divergent phenotypes and genotypes are key signals for identifying the targets of natural selection in locally adapted populations. Here, we used a combination of common garden phenotyping for a variety of growth, plant architecture, and seed traits, along with single-nucleotide polymorphism (SNP) genotyping to characterize range-wide patterns of diversity in 15 populations of wild sunflower (Helianthus annuus L.) sampled along a latitudinal gradient in central North America. We analyzed geographic patterns of phenotypic diversity, quantified levels of within-population SNP diversity, and also determined the extent of population structure across the range of this species. We then used these data to identify significantly over-differentiated loci as indicators of genomic regions that likely contribute to local adaptation. RESULTS Traits including flowering time, plant height, and seed oil composition (i.e., percentage of saturated fatty acids) were significantly correlated with latitude, and thus differentiated northern vs. southern populations. Average pairwise FST was found to be 0.21, and a STRUCTURE analysis identified two significant clusters that largely separated northern and southern individuals. The significant FST outliers included a SNP in HaFT2, a flowering time gene that has been previously shown to co-localize with flowering time QTL, and which exhibits a known cline in gene expression. CONCLUSIONS Latitudinal differentiation in both phenotypic traits and SNP allele frequencies is observed across wild sunflower populations in central North America. Such differentiation may play an important adaptive role across the range of this species, and could facilitate adaptation to a changing climate.
Collapse
Affiliation(s)
- Edward V. McAssey
- Department of Plant Biology, University of Georgia, Miller Plant Sciences Building, Athens, GA 30602 USA
- University of Georgia, Center for Applied Genetic Technologies, 111 Riverbend Road, Athens, GA 30602 USA
| | - Jonathan Corbi
- Department of Plant Biology, University of Georgia, Miller Plant Sciences Building, Athens, GA 30602 USA
- Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622 Villeurbanne, France
| | - John M. Burke
- Department of Plant Biology, University of Georgia, Miller Plant Sciences Building, Athens, GA 30602 USA
| |
Collapse
|
41
|
Rajpurohit S, Schmidt PS. Measuring thermal behavior in smaller insects: A case study in Drosophila melanogaster demonstrates effects of sex, geographic origin, and rearing temperature on adult behavior. Fly (Austin) 2016; 10:149-61. [PMID: 27230726 PMCID: PMC5036927 DOI: 10.1080/19336934.2016.1194145] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/20/2016] [Accepted: 05/20/2016] [Indexed: 10/21/2022] Open
Abstract
Measuring thermal behavior in smaller insects is particularly challenging. In this study, we describe a new horizontal thermal gradient apparatus designed to study adult thermal behavior in small insects and apply it using D. melanogaster as a model and case study. Specifically, we used this apparatus and associated methodology to examine the effects of sex, geographic origin, and developmental rearing temperature on temperature preferences exhibited by adults in a controlled laboratory environment. The thermal gradient established by the apparatus was stable over diurnal and calendar time. Furthermore, the distribution of adult flies across thermal habitats within the apparatus remained stable following the period of acclimation, as evidenced by the high degree of repeatability across both biological and technical replicates. Our data demonstrate significant and predictable variation in temperature preference for all 3 assayed variables. Behaviorally, females were more sensitive than males to higher temperatures. Flies originating from high latitude, temperate populations exhibited a greater preference for cooler temperatures; conversely, flies originating from low latitude, tropical habitats demonstrated a relative preference for higher temperatures. Similarly, larval rearing temperature was positively associated with adult thermal behavior: low culture temperatures increased the relative adult preference for cooler temperatures, and this response was distinct between the sexes and for flies from the temperate and subtropical geographic regions. Together, these results demonstrate that the temperature chamber apparatus elicits robust, predictable, and quantifiable thermal preference behavior that could readily be applied to other taxa to examine the role of temperature-mediated behavior in a variety of contexts.
Collapse
Affiliation(s)
- Subhash Rajpurohit
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Paul S. Schmidt
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
42
|
Altitudinal variation in lifespan of Drosophila melanogaster populations from the Firtina Valley, northeastern Turkey. J Therm Biol 2016; 61:91-97. [DOI: 10.1016/j.jtherbio.2016.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 11/21/2022]
|
43
|
Schiesari L, Andreatta G, Kyriacou CP, O’Connor MB, Costa R. The Insulin-Like Proteins dILPs-2/5 Determine Diapause Inducibility in Drosophila. PLoS One 2016; 11:e0163680. [PMID: 27689881 PMCID: PMC5045170 DOI: 10.1371/journal.pone.0163680] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 09/12/2016] [Indexed: 01/28/2023] Open
Abstract
Diapause is an actively induced dormancy that has evolved in Metazoa to resist environmental stresses. In temperate regions, many diapausing insects overwinter at low temperatures by blocking embryonic, larval or adult development. Despite its Afro-tropical origin, Drosophila melanogaster migrated to temperate regions of Asia and Europe where females overwinter as adults by arresting gonadal development (reproductive diapause) at temperatures <13°C. Recent work in D. melanogaster has implicated the developmental hormones dILPs-2 and/or dILP3, and dILP5, homologues of vertebrate insulin/insulin-like growth factors (IGFs), in reproductive arrest. However, polymorphisms in timeless (tim) and couch potato (cpo) dramatically affect diapause inducibility and these dILP experiments could not exclude this common genetic variation contributing to the diapause phenotype. Here, we apply an extensive genetic dissection of the insulin signaling pathway which allows us to see both enhancements and reductions in egg development that are independent of tim and cpo variations. We show that a number of manipulations dramatically enhance diapause to ~100%. These include ablating, or reducing the excitability of the insulin-producing cells (IPCs) that express dILPs-2,3,5 employing the dilp2,3,5-/- triple mutant, desensitizing insulin signaling using a chico mutation, or inhibiting dILP2 and 5 in the hemolymph by over-expressing Imaginal Morphogenesis Protein-Late 2 (Imp-L2). In addition, triple mutant dilp2,3,5-/- females maintain high levels of diapause even when temperatures are raised in adulthood to 19°C. However at 22°C, these females all show egg development revealing that the effects are conditional on temperature and not a general female sterility. In contrast, over-expression of dilps-2/5 or enhancing IPC excitability, led to levels of ovarian arrest that approached zero, underscoring dILPs-2 and 5 as key antagonists of diapause.
Collapse
Affiliation(s)
- Luca Schiesari
- Department of Biology, University of Padova, Padova, Italy
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States of America
| | | | | | - Michael B. O’Connor
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States of America
| | - Rodolfo Costa
- Department of Biology, University of Padova, Padova, Italy
- * E-mail:
| |
Collapse
|
44
|
Zonato V, Fedele G, Kyriacou CP. An Intronic Polymorphism in couch potato Is Not Distributed Clinally in European Drosophila melanogaster Populations nor Does It Affect Diapause Inducibility. PLoS One 2016; 11:e0162370. [PMID: 27598401 PMCID: PMC5012703 DOI: 10.1371/journal.pone.0162370] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/22/2016] [Indexed: 12/24/2022] Open
Abstract
couch potato (cpo) encodes an RNA binding protein that has been reported to be expressed in the peripheral and central nervous system of embryos, larvae and adults, including the major endocrine organ, the ring gland. A polymorphism in the D. melanogaster cpo gene coding region displays a latitudinal cline in frequency in North American populations, but as cpo lies within the inversion In(3R)Payne, which is at high frequencies and itself shows a strong cline on this continent, interpretation of the cpo cline is not straightforward. A second downstream SNP in strong linkage disequilibrium with the first has been claimed to be primarily responsible for the latitudinal cline in diapause incidence in USA populations.Here, we investigate the frequencies of these two cpo SNPs in populations of Drosophila throughout continental Europe. The advantage of studying cpo variation in Europe is the very low frequency of In(3R)Payne, which we reveal here, does not appear to be clinally distributed. We observe a very different geographical scenario for cpo variation from the one in North America, suggesting that the downstream SNP does not play a role in diapause. In an attempt to verify whether the SNPs influence diapause we subsequently generated lines with different combinations of the two cpo SNPs on known timeless (tim) genetic backgrounds, because polymorphism in the clock gene tim plays a significant role in diapause inducibility. Our results reveal that the downstream cpo SNP does not seem to play any role in diapause induction in European populations in contrast to the upstream coding cpo SNP. Consequently, all future diapause studies on strains of D. melanogaster should initially determine their tim and cpo status.
Collapse
Affiliation(s)
- Valeria Zonato
- Department of Genetics, University of Leicester, Leicester, LE1 7RH, United Kingdom
| | - Giorgio Fedele
- Department of Genetics, University of Leicester, Leicester, LE1 7RH, United Kingdom
| | - Charalambos P. Kyriacou
- Department of Genetics, University of Leicester, Leicester, LE1 7RH, United Kingdom
- * E-mail:
| |
Collapse
|
45
|
Fournier-Level A, Neumann-Mondlak A, Good RT, Green LM, Schmidt JM, Robin C. Behavioural response to combined insecticide and temperature stress in natural populations of Drosophila melanogaster. J Evol Biol 2016; 29:1030-44. [DOI: 10.1111/jeb.12844] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 02/03/2016] [Accepted: 02/05/2016] [Indexed: 12/25/2022]
Affiliation(s)
- A. Fournier-Level
- School of BioSciences; The University of Melbourne; Parkville Vic. Australia
| | - A. Neumann-Mondlak
- School of BioSciences; The University of Melbourne; Parkville Vic. Australia
| | - R. T. Good
- School of BioSciences; The University of Melbourne; Parkville Vic. Australia
| | - L. M. Green
- School of BioSciences; The University of Melbourne; Parkville Vic. Australia
| | - J. M. Schmidt
- School of BioSciences; The University of Melbourne; Parkville Vic. Australia
- Max Planck Institute for Evolutionary Anthropology; Leipzig Germany
| | - C. Robin
- School of BioSciences; The University of Melbourne; Parkville Vic. Australia
| |
Collapse
|
46
|
Zhao X, Bergland AO, Behrman EL, Gregory BD, Petrov DA, Schmidt PS. Global Transcriptional Profiling of Diapause and Climatic Adaptation in Drosophila melanogaster. Mol Biol Evol 2016; 33:707-20. [PMID: 26568616 PMCID: PMC5009998 DOI: 10.1093/molbev/msv263] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Wild populations of the model organism Drosophila melanogaster experience highly heterogeneous environments over broad geographical ranges as well as over seasonal and annual timescales. Diapause is a primary adaptation to environmental heterogeneity, and in D. melanogaster the propensity to enter diapause varies predictably with latitude and season. Here we performed global transcriptomic profiling of naturally occurring variation in diapause expression elicited by short day photoperiod and moderately low temperature in two tissue types associated with neuroendocrine and endocrine signaling, heads, and ovaries. We show that diapause in D. melanogaster is an actively regulated phenotype at the transcriptional level, suggesting that diapause is not a simple physiological or reproductive quiescence. Differentially expressed genes and pathways are highly distinct in heads and ovaries, demonstrating that the diapause response is not uniform throughout the soma and suggesting that it may be comprised of functional modules associated with specific tissues. Genes downregulated in heads of diapausing flies are significantly enriched for clinally varying single nucleotide polymorphism (SNPs) and seasonally oscillating SNPs, consistent with the hypothesis that diapause is a driving phenotype of climatic adaptation. We also show that chromosome location-based coregulation of gene expression is present in the transcriptional regulation of diapause. Taken together, these results demonstrate that diapause is a complex phenotype actively regulated in multiple tissues, and support the hypothesis that natural variation in diapause propensity underlies adaptation to spatially and temporally varying selective pressures.
Collapse
Affiliation(s)
- Xiaqing Zhao
- Department of Biology, University of Pennsylvania
| | | | | | | | | | | |
Collapse
|
47
|
Genomic Patterns of Geographic Differentiation in Drosophila simulans. Genetics 2016; 202:1229-40. [PMID: 26801179 DOI: 10.1534/genetics.115.185496] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Accepted: 01/16/2016] [Indexed: 11/18/2022] Open
Abstract
Geographic patterns of genetic differentiation have long been used to understand population history and to learn about the biological mechanisms of adaptation. Here we present an examination of genomic patterns of differentiation between northern and southern populations of Australian and North American Drosophila simulans, with an emphasis on characterizing signals of parallel differentiation. We report on the genomic scale of differentiation and functional enrichment of outlier SNPs. While, overall, signals of shared differentiation are modest, we find the strongest support for parallel differentiation in genomic regions that are associated with regulation. Comparisons to Drosophila melanogaster yield potential candidate genes involved in local adaptation in both species, providing insight into common selective pressures and responses. In contrast to D. melanogaster, in D. simulans we observe patterns of variation that are inconsistent with a model of temperate adaptation out of a tropical ancestral range, highlighting potential differences in demographic and colonization histories of this cosmopolitan species pair.
Collapse
|
48
|
Kapun M, Fabian DK, Goudet J, Flatt T. Genomic Evidence for Adaptive Inversion Clines in Drosophila melanogaster. Mol Biol Evol 2016; 33:1317-36. [PMID: 26796550 DOI: 10.1093/molbev/msw016] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Clines in chromosomal inversion polymorphisms-presumably driven by climatic gradients-are common but there is surprisingly little evidence for selection acting on them. Here we address this long-standing issue in Drosophila melanogaster by using diagnostic single nucleotide polymorphism (SNP) markers to estimate inversion frequencies from 28 whole-genome Pool-seq samples collected from 10 populations along the North American east coast. Inversions In(3L)P, In(3R)Mo, and In(3R)Payne showed clear latitudinal clines, and for In(2L)t, In(2R)NS, and In(3R)Payne the steepness of the clinal slopes changed between summer and fall. Consistent with an effect of seasonality on inversion frequencies, we detected small but stable seasonal fluctuations of In(2R)NS and In(3R)Payne in a temperate Pennsylvanian population over 4 years. In support of spatially varying selection, we observed that the cline in In(3R)Payne has remained stable for >40 years and that the frequencies of In(2L)t and In(3R)Payne are strongly correlated with climatic factors that vary latitudinally, independent of population structure. To test whether these patterns are adaptive, we compared the amount of genetic differentiation of inversions versus neutral SNPs and found that the clines in In(2L)t and In(3R)Payne are maintained nonneutrally and independent of admixture. We also identified numerous clinal inversion-associated SNPs, many of which exhibit parallel differentiation along the Australian cline and reside in genes known to affect fitness-related traits. Together, our results provide strong evidence that inversion clines are maintained by spatially-and perhaps also temporally-varying selection. We interpret our data in light of current hypotheses about how inversions are established and maintained.
Collapse
Affiliation(s)
- Martin Kapun
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Daniel K Fabian
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Jérôme Goudet
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Thomas Flatt
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
49
|
Machado HE, Bergland AO, O'Brien KR, Behrman EL, Schmidt PS, Petrov DA. Comparative population genomics of latitudinal variation in Drosophila simulans and Drosophila melanogaster. Mol Ecol 2016; 25:723-40. [PMID: 26523848 DOI: 10.1111/mec.13446] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 10/26/2015] [Accepted: 10/28/2015] [Indexed: 12/15/2022]
Abstract
Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, we find that clinally varying loci in D. simulans are less stable over multiple years than comparable clines in D. melanogaster. D. simulans shows a significantly weaker pattern of isolation by distance than D. melanogaster and we find evidence for a stronger contribution of migration to D. simulans population genetic structure. While population bottlenecks and migration can plausibly explain the differences in stability of clinal variation between the two species, we also observe a significant enrichment of shared clinal genes, suggesting that the selective forces associated with climate are acting on the same genes and phenotypes in D. simulans and D. melanogaster.
Collapse
Affiliation(s)
- Heather E Machado
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA, 94305-5020, USA
| | - Alan O Bergland
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA, 94305-5020, USA
| | - Katherine R O'Brien
- School of Biological Sciences, University of Nebraska-Lincoln, 348 Manter Hall, Lincoln, NE, 68588, USA.,Department of Biology, University of Pennsylvania, 102 Leidy Laboratories, Philadelphia, PA, 19104-6313, USA
| | - Emily L Behrman
- Department of Biology, University of Pennsylvania, 102 Leidy Laboratories, Philadelphia, PA, 19104-6313, USA
| | - Paul S Schmidt
- Department of Biology, University of Pennsylvania, 102 Leidy Laboratories, Philadelphia, PA, 19104-6313, USA
| | - Dmitri A Petrov
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA, 94305-5020, USA
| |
Collapse
|
50
|
Bergland AO, Tobler R, González J, Schmidt P, Petrov D. Secondary contact and local adaptation contribute to genome-wide patterns of clinal variation in Drosophila melanogaster. Mol Ecol 2016; 25:1157-74. [PMID: 26547394 DOI: 10.1111/mec.13455] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 10/29/2015] [Accepted: 11/02/2015] [Indexed: 12/12/2022]
Abstract
Populations arrayed along broad latitudinal gradients often show patterns of clinal variation in phenotype and genotype. Such population differentiation can be generated and maintained by both historical demographic events and local adaptation. These evolutionary forces are not mutually exclusive and can in some cases produce nearly identical patterns of genetic differentiation among populations. Here, we investigate the evolutionary forces that generated and maintain clinal variation genome-wide among populations of Drosophila melanogaster sampled in North America and Australia. We contrast patterns of clinal variation in these continents with patterns of differentiation among ancestral European and African populations. Using established and novel methods we derive here, we show that recently derived North America and Australia populations were likely founded by both European and African lineages and that this hybridization event likely contributed to genome-wide patterns of parallel clinal variation between continents. The pervasive effects of admixture mean that differentiation at only several hundred loci can be attributed to the operation of spatially varying selection using an FST outlier approach. Our results provide novel insight into the well-studied system of clinal differentiation in D. melanogaster and provide a context for future studies seeking to identify loci contributing to local adaptation in a wide variety of organisms, including other invasive species as well as temperate endemics.
Collapse
Affiliation(s)
- Alan O Bergland
- Department of Biology, Stanford University, Stanford, CA, 94305-5020, USA
| | - Ray Tobler
- Department of Biology, Stanford University, Stanford, CA, 94305-5020, USA.,Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, Vienna, A-1210, Austria
| | - Josefa González
- Department of Biology, Stanford University, Stanford, CA, 94305-5020, USA.,Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Maritim de la Barceloneta 37-49, 0800, 3 Barcelona, Spain
| | - Paul Schmidt
- Department of Biology, The University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Dmitri Petrov
- Department of Biology, Stanford University, Stanford, CA, 94305-5020, USA
| |
Collapse
|