101
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The gut microbial community of Midas cichlid fish in repeatedly evolved limnetic-benthic species pairs. PLoS One 2014; 9:e95027. [PMID: 24733403 PMCID: PMC3986361 DOI: 10.1371/journal.pone.0095027] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 03/22/2014] [Indexed: 12/22/2022] Open
Abstract
Gut bacterial communities are now known to influence a range of fitness related aspects of organisms. But how different the microbial community is in closely related species, and if these differences can be interpreted as adaptive is still unclear. In this study we compared microbial communities in two sets of closely related sympatric crater lake cichlid fish species pairs that show similar adaptations along the limnetic-benthic axis. The gut microbial community composition differs in the species pair inhabiting the older of two crater lakes. One major difference, relative to other fish, is that in these cichlids that live in hypersaline crater lakes, the microbial community is largely made up of Oceanospirillales (52.28%) which are halotolerant or halophilic bacteria. This analysis opens up further avenues to identify candidate symbiotic or co-evolved bacteria playing a role in adaptation to similar diets and life-styles or even have a role in speciation. Future functional and phylosymbiotic analyses might help to address these issues.
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102
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Schielzeth H, Husby A. Challenges and prospects in genome-wide quantitative trait loci mapping of standing genetic variation in natural populations. Ann N Y Acad Sci 2014; 1320:35-57. [PMID: 24689944 DOI: 10.1111/nyas.12397] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A considerable challenge in evolutionary genetics is to understand the genetic mechanisms that facilitate or impede evolutionary adaptation in natural populations. For this, we must understand the genetic loci contributing to trait variation and the selective forces acting on them. The decreased costs and increased feasibility of obtaining genotypic data on a large number of individuals have greatly facilitated gene mapping in natural populations, particularly because organisms whose genetics have been historically difficult to study are now within reach. Here we review the methods available to evolutionary ecologists interested in dissecting the genetic basis of traits in natural populations. Our focus lies on standing genetic variation in outbred populations. We present an overview of the current state of research in the field, covering studies on both plants and animals. We also draw attention to particular challenges associated with the discovery of quantitative trait loci and discuss parallels to studies on crops, livestock, and humans. Finally, we point to some likely future developments in genetic mapping studies.
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Affiliation(s)
- Holger Schielzeth
- Department of Evolutionary Biology, Bielefeld University, Bielefeld, Germany
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103
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Watanabe K, Kazama S, Omura T, Monaghan MT. Adaptive genetic divergence along narrow environmental gradients in four stream insects. PLoS One 2014; 9:e93055. [PMID: 24681871 PMCID: PMC3969376 DOI: 10.1371/journal.pone.0093055] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 03/02/2014] [Indexed: 01/30/2023] Open
Abstract
A central question linking ecology with evolutionary biology is how environmental heterogeneity can drive adaptive genetic divergence among populations. We examined adaptive divergence of four stream insects from six adjacent catchments in Japan by combining field measures of habitat and resource components with genome scans of non-neutral Amplified Fragment Length Polymorphism (AFLP) loci. Neutral genetic variation was used to measure gene flow and non-neutral genetic variation was used to test for adaptive divergence. We identified the environmental characteristics contributing to divergence by comparing genetic distances at non-neutral loci between sites with Euclidean distances for each of 15 environmental variables. Comparisons were made using partial Mantel tests to control for geographic distance. In all four species, we found strong evidence for non-neutral divergence along environmental gradients at between 6 and 21 loci per species. The relative contribution of these environmental variables to each species' ecological niche was quantified as the specialization index, S, based on ecological data. In each species, the variable most significantly correlated with genetic distance at non-neutral loci was the same variable along which each species was most narrowly distributed (i.e., highest S). These were gradients of elevation (two species), chlorophyll-a, and ammonia-nitrogen. This adaptive divergence occurred in the face of ongoing gene flow (Fst = 0.01-0.04), indicating that selection was strong enough to overcome homogenization at the landscape scale. Our results suggest that adaptive divergence is pronounced, occurs along different environmental gradients for different species, and may consistently occur along the narrowest components of species' niche.
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Affiliation(s)
- Kozo Watanabe
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, Berlin, Germany
- Present address: Department of Civil and Environmental Engineering, Ehime University, Bunkyo-cho 3, Matsuyama, Japan
| | - So Kazama
- Department of Civil and Environmental Engineering, Tohoku University, Aoba-yama 6-6-06, Sendai, Japan
| | - Tatsuo Omura
- New Industry Creation Hatchery Center (NIChe), Tohoku University, Aoba-yama 6-6-04, Sendai, Japan
| | - Michael T. Monaghan
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, Berlin, Germany
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104
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Merrill RM, Chia A, Nadeau NJ. Divergent warning patterns contribute to assortative mating between incipient Heliconius species. Ecol Evol 2014; 4:911-7. [PMID: 24772270 PMCID: PMC3997309 DOI: 10.1002/ece3.996] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/24/2014] [Accepted: 01/27/2014] [Indexed: 11/06/2022] Open
Abstract
Theoretical models suggest that traits under divergent ecological selection, which also contribute to assortative mating, will facilitate speciation with gene flow. Evidence for these so-called "magic traits" now exists across a range of taxa. However, their importance during speciation will depend on the extent to which they contribute to reproductive isolation. Addressing this requires experiments to determine the exact cues involved as well as estimates of assortative mating in the wild. Heliconius butterflies are well known for their diversity of bright warning color patterns, and their amenability to experimental manipulation has provided an excellent opportunity to test their role in reproductive isolation. Here, we reveal that divergent color patterns contribute to mate recognition between the incipient species Heliconius himera and H. erato, a taxon pair for which assortative mating by color pattern has been demonstrated among wild individuals: First, we demonstrate that males are more likely to attempt to mate conspecific females; second, we show that males are more likely to approach pinned females that share their own warning pattern. These data are valuable as these taxa likely represent the early stages of speciation, but unusually also allow comparisons with rates of interbreeding between divergent ecologically relevant phenotypes measured in the wild.
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Affiliation(s)
| | - Audrey Chia
- Department of Zoology, University of Cambridge Cambridge, U.K
| | - Nicola J Nadeau
- Department of Zoology, University of Cambridge Cambridge, U.K ; Department of Animal and Plant Sciences, University of Sheffield Sheffield, U.K
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105
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Differences in tolerance to host cactus alkaloids in Drosophila koepferae and D. buzzatii. PLoS One 2014; 9:e88370. [PMID: 24520377 PMCID: PMC3919786 DOI: 10.1371/journal.pone.0088370] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/07/2014] [Indexed: 11/19/2022] Open
Abstract
The evolution of cactophily in the genus Drosophila was a major ecological transition involving over a hundred species in the Americas that acquired the capacity to cope with a variety of toxic metabolites evolved as feeding deterrents in Cactaceae. D. buzzatii and D. koepferae are sibling cactophilic species in the D. repleta group. The former is mainly associated with the relatively toxic-free habitat offered by prickly pears (Opuntia sulphurea) and the latter has evolved the ability to use columnar cacti of the genera Trichocereus and Cereus that contain an array of alkaloid secondary compounds. We assessed the effects of cactus alkaloids on fitness-related traits and evaluated the ability of D. buzzatii and D. koepferae to exploit an artificial novel toxic host. Larvae of both species were raised in laboratory culture media to which we added increasing doses of an alkaloid fraction extracted from the columnar cactus T. terschekii. In addition, we evaluated performance on an artificial novel host by rearing larvae in a seminatural medium that combined the nutritional quality of O. sulphurea plus amounts of alkaloids found in fresh T. terschekii. Performance scores in each rearing treatment were calculated using an index that took into account viability, developmental time, and adult body size. Only D. buzzatii suffered the effects of increasing doses of alkaloids and the artificial host impaired viability in D. koepferae, but did not affect performance in D. buzzatii. These results provide the first direct evidence that alkaloids are key determinants of host plant use in these species. However, the results regarding the artificial novel host suggest that the effects of alkaloids on performance are not straightforward as D. koepferae was heavily affected. We discuss these results in the light of patterns of host plan evolution in the Drosophila repleta group.
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106
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Mills MG, Greenwood AK, Peichel CL. Pleiotropic effects of a single gene on skeletal development and sensory system patterning in sticklebacks. EvoDevo 2014; 5:5. [PMID: 24499504 PMCID: PMC3976036 DOI: 10.1186/2041-9139-5-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/20/2013] [Indexed: 11/10/2022] Open
Abstract
Background Adaptation to a new environment can be facilitated by co-inheritance of a suite of phenotypes that are all advantageous in the new habitat. Although experimental evidence demonstrates that multiple phenotypes often map to the same genomic regions, it is challenging to determine whether phenotypes are associated due to pleiotropic effects of a single gene or to multiple tightly linked genes. In the threespine stickleback fish (Gasterosteus aculeatus), multiple phenotypes are associated with a genomic region around the gene Ectodysplasin (Eda), but only the presence of bony lateral plates has been conclusively shown to be caused by Eda. Results Here, we ask whether pleiotropy or linkage is responsible for the association between lateral plates and the distribution of the neuromasts of the lateral line. We first identify a strong correlation between plate appearance and changes in the spatial distribution of neuromasts through development. We then use an Eda transgene to induce the formation of ectopic plates in low plated fish, which also results in alterations to neuromast distribution. Our results also show that other loci may modify the effects of Eda on plate formation and neuromast distribution. Conclusions Together, these results demonstrate that Eda has pleiotropic effects on at least two phenotypes, highlighting the role of pleiotropy in the genetic basis of adaptation.
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Affiliation(s)
| | | | - Catherine L Peichel
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle WA, 98109, USA.
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107
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Faria R, Renaut S, Galindo J, Pinho C, Melo-Ferreira J, Melo M, Jones F, Salzburger W, Schluter D, Butlin R. Advances in Ecological Speciation: an integrative approach. Mol Ecol 2014; 23:513-21. [DOI: 10.1111/mec.12616] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 11/28/2013] [Accepted: 11/30/2013] [Indexed: 12/19/2022]
Affiliation(s)
- Rui Faria
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio; Laboratório Associado; Universidade do Porto. Campus Agrário de Vairão; 4485-661 Vairão Portugal
- IBE, Institute of Evolutionary Biology (UPF-CSIC); Universitat Pompeu Fabra. PRBB; Av. Doctor Aiguader N88 08003 Barcelona Spain
| | - Sebastien Renaut
- Department of Botany; Biodiversity Research Centre; University of British Columbia; Vancouver British Columbia Canada V6T 1Z4
| | - Juan Galindo
- Departamento de Bioquímica, Xenética e Inmunoloxía; Facultade de Bioloxía; Universidade de Vigo; Campus Universitario 36310 Vigo Spain
| | - Catarina Pinho
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio; Laboratório Associado; Universidade do Porto. Campus Agrário de Vairão; 4485-661 Vairão Portugal
| | - José Melo-Ferreira
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio; Laboratório Associado; Universidade do Porto. Campus Agrário de Vairão; 4485-661 Vairão Portugal
| | - Martim Melo
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio; Laboratório Associado; Universidade do Porto. Campus Agrário de Vairão; 4485-661 Vairão Portugal
| | - Felicity Jones
- Friedrich Miescher Laboratory of the Max Planck Society; Tuebingen 72070 Germany
| | - Walter Salzburger
- Zoological Institute; University of Basel; Vesalgasse 1 4051 Basel Switzerland
| | - Dolph Schluter
- Department of Zoology; Biodiversity Research Centre; University of British Columbia; Vancouver British Columbia Canada V6T 1Z4
| | - Roger Butlin
- Animal and Plant Sciences; University of Sheffield; Sheffield S10 2TN UK
- Sven Lovén Centre - Tjärnö; University of Gothenburg; S-452 96 Strömstad Sweden
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108
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Etges WJ. No boundaries: genomes, organisms, and ecological interactions responsible for divergence and reproductive isolation. J Hered 2014; 105 Suppl 1:756-70. [PMID: 25149252 PMCID: PMC4170711 DOI: 10.1093/jhered/esu039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 05/31/2014] [Indexed: 12/23/2022] Open
Abstract
Revealing the genetic basis of traits that cause reproductive isolation, particularly premating or sexual isolation, usually involves the same challenges as most attempts at genotype-phenotype mapping and so requires knowledge of how these traits are expressed in different individuals, populations, and environments, particularly under natural conditions. Genetic dissection of speciation phenotypes thus requires understanding of the internal and external contexts in which underlying genetic elements are expressed. Gene expression is a product of complex interacting factors internal and external to the organism including developmental programs, the genetic background including nuclear-cytotype interactions, epistatic relationships, interactions among individuals or social effects, stochasticity, and prevailing variation in ecological conditions. Understanding of genomic divergence associated with reproductive isolation will be facilitated by functional expression analysis of annotated genomes in organisms with well-studied evolutionary histories, phylogenetic affinities, and known patterns of ecological variation throughout their life cycles. I review progress and prospects for understanding the pervasive role of host plant use on genetic and phenotypic expression of reproductive isolating mechanisms in cactophilic Drosophila mojavensis and suggest how this system can be used as a model for revealing the genetic basis for species formation in organisms where speciation phenotypes are under the joint influences of genetic and environmental factors.
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Affiliation(s)
- William J Etges
- From Program in Ecology and Evolutionary Biology, Department of Biological Sciences, 1 University of Arkansas, Fayetteville, AR.
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109
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Van Belleghem SM, Hendrickx F. A tight association in two genetically unlinked dispersal related traits in sympatric and allopatric salt marsh beetle populations. Genetica 2013; 142:1-9. [DOI: 10.1007/s10709-013-9749-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 11/25/2013] [Indexed: 11/28/2022]
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110
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Feder JL, Flaxman SM, Egan SP, Comeault AA, Nosil P. Geographic Mode of Speciation and Genomic Divergence. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2013. [DOI: 10.1146/annurev-ecolsys-110512-135825] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jeffrey L. Feder
- Department of Biological Sciences,
- Environmental Change Initiative, and
- Advanced Diagnostics and Therapeutics, University of Notre Dame, Notre Dame, Indiana 46556; ,
| | - Samuel M. Flaxman
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309;
| | - Scott P. Egan
- Department of Biological Sciences,
- Advanced Diagnostics and Therapeutics, University of Notre Dame, Notre Dame, Indiana 46556; ,
| | - Aaron A. Comeault
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S102TN, United Kingdom; ,
| | - Patrik Nosil
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S102TN, United Kingdom; ,
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111
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Genetic mapping of two components of reproductive isolation between two sibling species of moths, Ostrinia nubilalis and O. scapulalis. Heredity (Edinb) 2013; 112:370-81. [PMID: 24220089 DOI: 10.1038/hdy.2013.113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 07/16/2013] [Accepted: 09/06/2013] [Indexed: 01/24/2023] Open
Abstract
We report the quantitative trait loci (QTL) mapping of reproductive isolation traits between Ostrinia nubilalis (the European corn borer) and its sibling species O. scapulalis (the Adzuki bean borer), focusing on two traits: mating isolation (mi) and pheromone production (Pher). Four genetic maps were generated from two backcross families, with two maps (one chromosomal map and one linkage map) per backcross. We located 165-323 AFLP markers on these four maps, resulting in the identification of 27-31 linkage groups, depending on the map considered. No-choice mating experiments with the offspring of each backcross led to the detection of at least two QTLs for mi in different linkage groups. QTLs underlying Pher were located in a third linkage group. The Z heterochromosome was identified by a specific marker (Tpi) and did not carry any of these QTLs. Finally, we considered the global divergence between the two sibling species, distortions of segregation throughout the genome, and the location and effect of mi and Pher QTLs in light of the known candidate genes for reproductive isolation within the genus Ostrinia and, more broadly, in phytophagous insects.
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112
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Mullen SP, Shaw KL. Insect speciation rules: unifying concepts in speciation research. ANNUAL REVIEW OF ENTOMOLOGY 2013; 59:339-361. [PMID: 24160421 DOI: 10.1146/annurev-ento-120710-100621] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The study of speciation is concerned with understanding the connection between causes of divergent evolution and the origin and maintenance of barriers to gene exchange between incipient species. Although the field has historically focused either on examples of recent divergence and its causes or on the genetic basis of reproductive isolation between already divergent species, current efforts seek to unify these two approaches. Here we integrate these perspectives through a discussion of recent progress in several insect speciation model systems. We focus on the evolution of speciation phenotypes in each system (i.e., those phenotypes causally involved in reducing gene flow between incipient species), drawing an explicit connection between cause and effect (process and pattern). We emphasize emerging insights into the genomic architecture of speciation as well as timely areas for future research.
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Affiliation(s)
- Sean P Mullen
- Department of Biology, Boston University, Boston, Massachusetts 02215;
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113
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Is ecological speciation a major trend in aphids? Insights from a molecular phylogeny of the conifer-feeding genus Cinara. Front Zool 2013; 10:56. [PMID: 24044736 PMCID: PMC3848992 DOI: 10.1186/1742-9994-10-56] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 09/13/2013] [Indexed: 12/13/2022] Open
Abstract
Introduction In the past decade ecological speciation has been recognized as having an important role in the diversification of plant-feeding insects. Aphids are host-specialised phytophagous insects that mate on their host plants and, as such, they are prone to experience reproductive isolation linked with host plant association that could ultimately lead to species formation. The generality of such a scenario remains to be tested through macroevolutionary studies. To explore the prevalence of host-driven speciation in the diversification of the aphid genus Cinara and to investigate alternative modes of speciation, we reconstructed a phylogeny of this genus based on mitochondrial, nuclear and Buchnera aphidicola DNA sequence fragments and applied a DNA-based method of species delimitation. Using a recent software (PhyloType), we explored evolutionary transitions in host-plant genera, feeding sites and geographic distributions in the diversification of Cinara and investigated how transitions in these characters have accompanied speciation events. Results The diversification of Cinara has been constrained by host fidelity to conifer genera sometimes followed by sequential colonization onto different host species and by feeding-site specialisation. Nevertheless, our analyses suggest that, at the most, only half of the speciation events were accompanied by ecological niche shifts. The contribution of geographical isolation in the speciation process is clearly apparent in the occurrence of species from two continents in the same clades in relatively terminal positions in our phylogeny. Furthermore, in agreement with predictions from scenarios in which geographic isolation accounts for speciation events, geographic overlap between species increased significantly with time elapsed since their separation. Conclusions The history of Cinara offers a different perspective on the mode of speciation of aphids than that provided by classic models such as the pea aphid. In this genus of aphids, the role of climate and landscape history has probably been as important as host-plant specialisation in having shaped present-day diversity.
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114
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Abstract
Many insects feed on only one or a few types of host. These host specialists often evolve a preference for chemical cues emanating from their host and develop mechanisms for circumventing their host's defenses. Adaptations like these are central to evolutionary biology, yet our understanding of their genetics remains incomplete. Drosophila sechellia, an emerging model for the genetics of host specialization, is an island endemic that has adapted to chemical toxins present in the fruit of its host plant, Morinda citrifolia. Its sibling species, D. simulans, and many other Drosophila species do not tolerate these toxins and avoid the fruit. Earlier work found a region with a strong effect on tolerance to the major toxin, octanoic acid, on chromosome arm 3R. Using a novel assay, we narrowed this region to a small span near the centromere containing 18 genes, including three odorant binding proteins. It has been hypothesized that the evolution of host specialization is facilitated by genetic linkage between alleles contributing to host preference and alleles contributing to host usage, such as tolerance to secondary compounds. We tested this hypothesis by measuring the effect of this tolerance locus on host preference behavior. Our data were inconsistent with the linkage hypothesis, as flies bearing this tolerance region showed no increase in preference for media containing M. citrifolia toxins, which D. sechellia prefers. Thus, in contrast to some models for host preference, preference and tolerance are not tightly linked at this locus nor is increased tolerance per se sufficient to change preference. Our data are consistent with the previously proposed model that the evolution of D. sechellia as a M. citrifolia specialist occurred through a stepwise loss of aversion and gain of tolerance to M. citrifolia's toxins.
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115
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Stukenbrock EH. Evolution, selection and isolation: a genomic view of speciation in fungal plant pathogens. THE NEW PHYTOLOGIST 2013; 199:895-907. [PMID: 23782262 DOI: 10.1111/nph.12374] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/16/2013] [Indexed: 05/26/2023]
Abstract
895 I. 895 II. 896 III. 898 IV. 900 V. 902 VI. 904 VII. 905 905 References 905 SUMMARY: Speciation of fungal plant pathogens has been associated with host jumps, host domestication, clonal divergence, and hybridization. Although we have substantial insight into the speciation histories of several important plant pathogens, we still know very little about the underlying genetics of reproductive isolation. Studies in Saccharomyces cerevisiae, Neurospora crassa, and nonfungal model systems illustrate that reproductive barriers can evolve by different mechanisms, including genetic incompatibilities between neutral and adaptive substitutions, reinforcement selection, and chromosomal rearrangements. Advances in genome sequencing and sequence analyses provide a new framework to identify those traits that have driven the divergence of populations or caused reproductive isolation between species of fungal plant pathogens. These traits can be recognized based on signatures of strong divergent selection between species or through the association of allelic combination conferring hybrid inferiority. Comparative genome analyses also provide information about the contribution of genome rearrangements to speciation. This is particularly relevant for species of fungal pathogens with extreme levels of genomic rearrangements and within-species genome plasticity.
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Affiliation(s)
- Eva Holtgrewe Stukenbrock
- Max Planck Institute for Terrestrial Microbiology, Max Planck Research Group Fungal Biodiversity, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany
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116
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Hansen AK, Moran NA. The impact of microbial symbionts on host plant utilization by herbivorous insects. Mol Ecol 2013; 23:1473-1496. [PMID: 23952067 DOI: 10.1111/mec.12421] [Citation(s) in RCA: 281] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 06/02/2013] [Accepted: 06/12/2013] [Indexed: 01/18/2023]
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117
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Merrill RM, Naisbit RE, Mallet J, Jiggins CD. Ecological and genetic factors influencing the transition between host-use strategies in sympatric Heliconius butterflies. J Evol Biol 2013; 26:1959-67. [PMID: 23961921 DOI: 10.1111/jeb.12194] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 11/27/2022]
Abstract
Shifts in host-plant use by phytophagous insects have played a central role in their diversification. Evolving host-use strategies will reflect a trade-off between selection pressures. The ecological niche of herbivorous insects is partitioned along several dimensions, and if populations remain in contact, recombination will break down associations between relevant loci. As such, genetic architecture can profoundly affect the coordinated divergence of traits and subsequently the ability to exploit novel habitats. The closely related species Heliconius cydno and H. melpomene differ in mimetic colour pattern, habitat and host-plant use. We investigate the selection pressures and genetic basis underlying host-use differences in these two species. Host-plant surveys reveal that H. melpomene specializes on a single species of Passiflora. This is also true for the majority of other Heliconius species in secondary growth forest at our study site, as expected under a model of interspecific competition. In contrast, H. cydno, which uses closed-forest habitats where both Heliconius and Passiflora are less common, appears not to be restricted by competition and uses a broad selection of the available Passiflora. However, other selection pressures are likely involved, and field experiments reveal that early larval survival of both butterfly species is highest on Passiflora menispermifolia, but most markedly so for H. melpomene, the specialist on that host. Finally, we demonstrate an association between host-plant acceptance and colour pattern amongst interspecific hybrids, suggesting that major loci underlying these important ecological traits are physically linked in the genome. Together, our results reveal ecological and genetic associations between shifts in habitat, host use and mimetic colour pattern that have likely facilitated both speciation and coexistence.
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Affiliation(s)
- R M Merrill
- Department of Zoology, University of Cambridge, Cambridge, UK.
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118
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Sanchez JA, La-Spina M, Guirao P, Cánovas F. Inferring the population structure of Myzus persicae in diverse agroecosystems using microsatellite markers. BULLETIN OF ENTOMOLOGICAL RESEARCH 2013; 103:473-484. [PMID: 23448321 DOI: 10.1017/s0007485313000059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Diverse agroecosystems offer phytophagous insects a wide choice of host plants. Myzus persicae is a polyphagous aphid common in moderate climates. During its life cycle it alternates between primary and secondary hosts. A spatial genetic population structure may arise due to environmental factors and reproduction modes. The aim of this work was to determine the spatial and temporal genetic population structure of M. persicae in relation to host plants and climatic conditions. For this, 923 individuals of M. persicae collected from six plant families between 2005 and 2008 in south-eastern Spain were genotyped for eight microsatellite loci. The population structure was inferred by neighbour-joining, analysis of molecular variance (AMOVA) and Bayesian analyses. Moderate polymorphism was observed for the eight loci in almost all the samples. No differences in the number of alleles were observed between primary and secondary hosts or between geographical areas. The proportion of unique genotypes found in the primary host was similar in the north (0.961 ± 0.036) and the south (0.987 ± 0.013), while in the secondary host it was higher in the north (0.801 ± 0.159) than in the south (0.318 ± 0.063). Heterozygosity excess and linkage disequilibrium suggest a high representation of obligate parthenogens in areas with warmer climate and in the secondary hosts. The F ST-values pointed to no genetic differentiation of M. persicae on the different plant families. F ST-values, AMOVA and Bayesian model-based cluster analyses pointed to a significant population structure that was related to primary and secondary hosts. Differences between primary and secondary hosts could be due to the overrepresentation of parthenogens on herbaceous plants.
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Affiliation(s)
- Juan Antonio Sanchez
- Departamento de Biotecnología y Protección de Cultivos, Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario, C/Mayor, 1, 30150 La Alberca (Murcia), Spain
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Thibert-Plante X, Gavrilets S. Evolution of mate choice and the so-called magic traits in ecological speciation. Ecol Lett 2013; 16:1004-13. [PMID: 23782866 DOI: 10.1111/ele.12131] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/07/2013] [Accepted: 05/01/2013] [Indexed: 01/17/2023]
Abstract
Non-random mating provides multiple evolutionary benefits and can result in speciation. Biological organisms are characterised by a myriad of different traits, many of which can serve as mating cues. We consider multiple mechanisms of non-random mating simultaneously within a unified modelling framework in an attempt to understand better which are more likely to evolve in natural populations going through the process of local adaptation and ecological speciation. We show that certain traits that are under direct natural selection are more likely to be co-opted as mating cues, leading to the appearance of magic traits (i.e. phenotypic traits involved in both local adaptation and mating decisions). Multiple mechanisms of non-random mating can interact so that trait co-evolution enables the evolution of non-random mating mechanisms that would not evolve alone. The presence of magic traits may suggest that ecological selection was acting during the origin of new species.
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Affiliation(s)
- Xavier Thibert-Plante
- National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, TN 37996, USA.
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de Vos MGJ, Poelwijk FJ, Battich N, Ndika JDT, Tans SJ. Environmental dependence of genetic constraint. PLoS Genet 2013; 9:e1003580. [PMID: 23825963 PMCID: PMC3694820 DOI: 10.1371/journal.pgen.1003580] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 05/04/2013] [Indexed: 11/25/2022] Open
Abstract
The epistatic interactions that underlie evolutionary constraint have mainly been studied for constant external conditions. However, environmental changes may modulate epistasis and hence affect genetic constraints. Here we investigate genetic constraints in the adaptive evolution of a novel regulatory function in variable environments, using the lac repressor, LacI, as a model system. We have systematically reconstructed mutational trajectories from wild type LacI to three different variants that each exhibit an inverse response to the inducing ligand IPTG, and analyzed the higher-order interactions between genetic and environmental changes. We find epistasis to depend strongly on the environment. As a result, mutational steps essential to inversion but inaccessible by positive selection in one environment, become accessible in another. We present a graphical method to analyze the observed complex higher-order interactions between multiple mutations and environmental change, and show how the interactions can be explained by a combination of mutational effects on allostery and thermodynamic stability. This dependency of genetic constraint on the environment should fundamentally affect evolutionary dynamics and affects the interpretation of phylogenetic data.
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121
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Abstract
Changes in genome architecture often have a significant effect on ecological specialization and speciation. This effect may be further enhanced by involvement of sex chromosomes playing a disproportionate role in reproductive isolation. We have physically mapped the Z chromosome of the major pome fruit pest, the codling moth, Cydia pomonella (Tortricidae), and show that it arose by fusion between an ancestral Z chromosome and an autosome corresponding to chromosome 15 in the Bombyx mori reference genome. We further show that the fusion originated in a common ancestor of the main tortricid subfamilies, Olethreutinae and Tortricinae, comprising almost 700 pest species worldwide. The Z-autosome fusion brought two major genes conferring insecticide resistance and clusters of genes involved in detoxification of plant secondary metabolites under sex-linked inheritance. We suggest that this fusion significantly increased the adaptive potential of tortricid moths and thus contributed to their radiation and subsequent speciation.
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de Vienne DM, Refrégier G, López-Villavicencio M, Tellier A, Hood ME, Giraud T. Cospeciation vs host-shift speciation: methods for testing, evidence from natural associations and relation to coevolution. THE NEW PHYTOLOGIST 2013; 198:347-385. [PMID: 23437795 DOI: 10.1111/nph.12150] [Citation(s) in RCA: 259] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 12/19/2012] [Indexed: 05/26/2023]
Abstract
Hosts and their symbionts are involved in intimate physiological and ecological interactions. The impact of these interactions on the evolution of each partner depends on the time-scale considered. Short-term dynamics - 'coevolution' in the narrow sense - has been reviewed elsewhere. We focus here on the long-term evolutionary dynamics of cospeciation and speciation following host shifts. Whether hosts and their symbionts speciate in parallel, by cospeciation, or through host shifts, is a key issue in host-symbiont evolution. In this review, we first outline approaches to compare divergence between pairwise associated groups of species, their advantages and pitfalls. We then consider recent insights into the long-term evolution of host-parasite and host-mutualist associations by critically reviewing the literature. We show that convincing cases of cospeciation are rare (7%) and that cophylogenetic methods overestimate the occurrence of such events. Finally, we examine the relationships between short-term coevolutionary dynamics and long-term patterns of diversification in host-symbiont associations. We review theoretical and experimental studies showing that short-term dynamics can foster parasite specialization, but that these events can occur following host shifts and do not necessarily involve cospeciation. Overall, there is now substantial evidence to suggest that coevolutionary dynamics of hosts and parasites do not favor long-term cospeciation.
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Affiliation(s)
- D M de Vienne
- Centre for Genomic Regulation (CRG), Dr. Aiguader 88, 08003, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), 08003, Barcelona, Spain
| | - G Refrégier
- Université Paris-Sud, Institut de Génétique et Microbiologie, UMR 8621, 91405, Orsay, France
- CNRS, UMR8621, 91405, Orsay, France
| | - M López-Villavicencio
- Muséum National d'Histoire Naturelle, 57 rue Cuvier, F-75231, Paris Cedex 05, France
| | - A Tellier
- Section of Population Genetics, Center of Life and Food Sciences Weihenstephan, Technische Universität München, D-85354, Freising, Germany
| | - M E Hood
- Department of Biology, Amherst College, Amherst, MA, USA
| | - T Giraud
- Université Paris-Sud, Ecologie, Systématique et Evolution, UMR 8079, 91405, Orsay, France
- CNRS, UMR8079, 91405, Orsay, France
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123
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Non-random gene flow: an underappreciated force in evolution and ecology. Trends Ecol Evol 2012; 27:659-65. [DOI: 10.1016/j.tree.2012.07.009] [Citation(s) in RCA: 231] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 06/28/2012] [Accepted: 07/18/2012] [Indexed: 01/15/2023]
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Ong’amo GO, Le Ru BP, Campagne P, Branca A, Calatayud PA, Capdevielle-Dulac C, Silvain JF. Genetic Diversity and Population Structure of Busseola segeta Bowden (Lepidoptera; Noctuidae): A Case Study of Host Use Diversification in Guineo-Congolian Rainforest Relic Area, Kenya. INSECTS 2012; 3:1156-70. [PMID: 26466732 PMCID: PMC4553569 DOI: 10.3390/insects3041156] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 08/22/2012] [Accepted: 08/30/2012] [Indexed: 11/29/2022]
Abstract
Habitat modification and fragmentation are considered as some of the factors that drive organism distribution and host use diversification. Indigenous African stem borer pests are thought to have diversified their host ranges to include maize [Zea mays L.] and sorghum [Sorghum bicolor (L.) Moench] in response to their increased availability through extensive cultivation. However, management efforts have been geared towards reducing pest populations in the cultivated fields with few attempts to understand possible evolution of "new" pest species. Recovery and growing persistence of Busseola segeta Bowden on maize (Zea mays L.) in Kakamega called for studies on the role of wild host plants on the invasion of crops by wild borer species. A two-year survey was carried out in a small agricultural landscape along the edge of Kakamega forest (Kenya) to assess host range and population genetic structure of B. segeta. The larvae of B. segeta were found on nine different plant species with the majority occurring on maize and sorghum. Of forty cytochrome b haplotypes identified, twenty-three occurred in both wild and cultivated habitats. The moths appear to fly long distances across the habitats with genetic analyses revealing weak differentiation between hosts in different habitats (FST = 0.016; p = 0.015). However, there was strong evidence of variation in genetic composition between growing seasons in the wild habitat (FST = 0.060; p < 0.001) with emergence or disappearance of haplotypes between habitats. Busseola segeta is an example of a phytophagous insect that utilizes plants with a human induced distribution range, maize, but does not show evidence of host race formation or reduction of gene flow among populations using different hosts. However, B. segeta is capable of becoming an important pest in the area and the current low densities may be attributed to the general low infestation levels and presence of a wide range of alternative hosts in the area.
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Affiliation(s)
- George O. Ong’amo
- School of Biological Science, College of Physical and Biological Sciences (Chiromo Campus), University of Nairobi, Nairobi 30197, Kenya
- Author to whom correspondence should be addressed; E-Mail:
| | - Bruno P. Le Ru
- Unité de Recherche IRD 072, International Centre of Insect Physiology and Ecology (ICIPE), Nairobi 30772, Kenya; E-Mails: (B.P.L.R.); (P.-A.C.)
- Unité de Recherche IRD 072, International Centre of Insect Physiology and Ecology (ICIPE), Université Paris-Sud 11, Orsay cedex 91405, France; E-Mail:
| | - Pascal Campagne
- Unité de Recherche IRD 072, International Centre of Insect Physiology and Ecology (ICIPE), Université Paris-Sud 11, Orsay cedex 91405, France; E-Mail:
| | - Antoine Branca
- Unité de Recherche IRD 072, CNRS, Laboratoire Evolution, Génomes et spéciation, UPR 9034, 91198 Gif-sur-Yvette cedex, France et Université Paris-Sud 11, Orsay cedex 91405, France; E-Mails: (A.B.); (C.C.-D.); (J.-F.S.)
| | - Paul-Andre Calatayud
- Unité de Recherche IRD 072, International Centre of Insect Physiology and Ecology (ICIPE), Nairobi 30772, Kenya; E-Mails: (B.P.L.R.); (P.-A.C.)
- Unité de Recherche IRD 072, International Centre of Insect Physiology and Ecology (ICIPE), Université Paris-Sud 11, Orsay cedex 91405, France; E-Mail:
| | - Claire Capdevielle-Dulac
- Unité de Recherche IRD 072, CNRS, Laboratoire Evolution, Génomes et spéciation, UPR 9034, 91198 Gif-sur-Yvette cedex, France et Université Paris-Sud 11, Orsay cedex 91405, France; E-Mails: (A.B.); (C.C.-D.); (J.-F.S.)
| | - Jean-Francois Silvain
- Unité de Recherche IRD 072, CNRS, Laboratoire Evolution, Génomes et spéciation, UPR 9034, 91198 Gif-sur-Yvette cedex, France et Université Paris-Sud 11, Orsay cedex 91405, France; E-Mails: (A.B.); (C.C.-D.); (J.-F.S.)
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Jaquiéry J, Stoeckel S, Nouhaud P, Mieuzet L, Mahéo F, Legeai F, Bernard N, Bonvoisin A, Vitalis R, Simon JC. Genome scans reveal candidate regions involved in the adaptation to host plant in the pea aphid complex. Mol Ecol 2012; 21:5251-64. [PMID: 23017212 DOI: 10.1111/mec.12048] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 08/06/2012] [Indexed: 11/26/2022]
Abstract
A major goal in evolutionary biology is to uncover the genetic basis of adaptation. Divergent selection exerted on ecological traits may result in adaptive population differentiation and reproductive isolation and affect differentially the level of genetic divergence along the genome. Genome-wide scan of large sets of individuals from multiple populations is a powerful approach to identify loci or genomic regions under ecologically divergent selection. Here, we focused on the pea aphid, a species complex of divergent host races, to explore the organization of the genomic divergence associated with host plant adaptation and ecological speciation. We analysed 390 microsatellite markers located at variable distances from predicted genes in replicate samples of sympatric populations of the pea aphid collected on alfalfa, red clover and pea, which correspond to three common host-adapted races reported in this species complex. Using a method that accounts for the hierarchical structure of our data set, we found a set of 11 outlier loci that show higher genetic differentiation between host races than expected under the null hypothesis of neutral evolution. Two of the outliers are close to olfactory receptor genes and three other nearby genes encoding salivary proteins. The remaining outliers are located in regions with genes of unknown functions, or which functions are unlikely to be involved in interactions with the host plant. This study reveals genetic signatures of divergent selection across the genome and provides an inventory of candidate genes responsible for plant specialization in the pea aphid, thereby setting the stage for future functional studies.
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Affiliation(s)
- J Jaquiéry
- INRA, UMR 1349, Institute of Genetics, Environment and Plant Protection, Domaine de la Motte, BP 35327, 35653, Le Rheu Cedex, France
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Quantitative genetic analysis of subspecific differences in body shape in the snail-feeding carabid beetle Damaster blaptoides. Heredity (Edinb) 2012; 110:86-93. [PMID: 23073391 DOI: 10.1038/hdy.2012.68] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
A dimorphic pattern of macrocephalic (wide, short) and stenocephalic (narrow, long) body shapes is observed in snail-feeding carabid beetles globally. The former exhibits high performance in crushing snail shells with powerful jaws, whereas the latter specializes in eating snails' soft body directly by inserting the head into the shell. In the snail-feeding species Damaster blaptoides, the subspecies D. b. capito has a wide, short forebody, and D. b. fortunei has a narrow, long forebody. They exhibit distinct morphologies despite their geographic and phylogenetic proximity. To examine the genetic basis of the morphological differences between these two subspecies, we conducted quantitative genetic analyses by crossing these subspecies and producing F(1) and backcross hybrids. The hybrids had body shapes intermediate between the parental subspecies. The variation between wide, short and narrow, long forebodies was based on negative genetic correlations between width and length of the head and thorax. Between one and eight genetic factors were involved in the morphological differences between subspecies. We suggest that the morphological integration of forebody parts in a small number of loci has facilitated the marked morphological diversification between subspecies of D. blaptoides.
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127
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Via S, Conte G, Mason-Foley C, Mills K. Localizing F(ST) outliers on a QTL map reveals evidence for large genomic regions of reduced gene exchange during speciation-with-gene-flow. Mol Ecol 2012; 21:5546-60. [PMID: 23057835 DOI: 10.1111/mec.12021] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Revised: 06/24/2012] [Accepted: 07/11/2012] [Indexed: 12/15/2022]
Abstract
Populations that maintain phenotypic divergence in sympatry typically show a mosaic pattern of genomic divergence, requiring a corresponding mosaic of genomic isolation (reduced gene flow). However, mechanisms that could produce the genomic isolation required for divergence-with-gene-flow have barely been explored, apart from the traditional localized effects of selection and reduced recombination near centromeres or inversions. By localizing F(ST) outliers from a genome scan of wild pea aphid host races on a Quantitative Trait Locus (QTL) map of key traits, we test the hypothesis that between-population recombination and gene exchange are reduced over large 'divergence hitchhiking' (DH) regions. As expected under divergence hitchhiking, our map confirms that QTL and divergent markers cluster together in multiple large genomic regions. Under divergence hitchhiking, the nonoutlier markers within these regions should show signs of reduced gene exchange relative to nonoutlier markers in genomic regions where ongoing gene flow is expected. We use this predicted difference among nonoutliers to perform a critical test of divergence hitchhiking. Results show that nonoutlier markers within clusters of F(ST) outliers and QTL resolve the genetic population structure of the two host races nearly as well as the outliers themselves, while nonoutliers outside DH regions reveal no population structure, as expected if they experience more gene flow. These results provide clear evidence for divergence hitchhiking, a mechanism that may dramatically facilitate the process of speciation-with-gene-flow. They also show the power of integrating genome scans with genetic analyses of the phenotypic traits involved in local adaptation and population divergence.
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Affiliation(s)
- Sara Via
- Department of Biology, University of Maryland, College Park, MD 21042, USA.
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128
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Specificity, rank preference, and the colonization of a non-native host plant by the Melissa blue butterfly. Oecologia 2012; 172:177-88. [PMID: 23053234 DOI: 10.1007/s00442-012-2476-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 09/07/2012] [Indexed: 10/27/2022]
Abstract
Animals often express behavioral preferences for different types of food or other resources, and these preferences can evolve or shift following association with novel food types. Shifts in preference can involve at least two phenomena: a change in rank preference or a change in specificity. The former corresponds to a change in the order in which hosts are preferred, while a shift in specificity can be an increase in the tendency to utilize multiple hosts. These possibilities have been examined in relatively few systems that include extensive population-level replication. The Melissa blue butterfly, Lycaeides melissa, has colonized exotic alfalfa, Medicago sativa, throughout western North America. We assayed the host preferences of 229 females from ten populations associated with novel and native hosts. In four out of five native-associated populations, a native host was preferred over the exotic host, while preference for a native host characterized only two out of five of the alfalfa-associated populations. Across all individuals from alfalfa-associated populations, there appears to have been a decrease in specificity: females from these populations lay fewer eggs on the native host and more eggs on the exotic relative to females from native-host populations. However, females from alfalfa-associated populations did not lay more eggs on a third plant species, which suggests that preferences for specific hosts in this system can potentially be gained and lost independently. Geographic variation in oviposition preference in L. melissa highlights the value of surveying a large number of populations when studying the evolution of a complex behavioral trait.
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129
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Bérénos C, Schmid-Hempel P, Wegner KM. Antagonistic Coevolution Accelerates the Evolution of Reproductive Isolation in Tribolium castaneum. Am Nat 2012; 180:520-8. [DOI: 10.1086/667589] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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130
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Oppenheim SJ, Gould F, Hopper KR. The genetic architecture of a complex ecological trait: host plant use in the specialist moth, Heliothis subflexa. Evolution 2012; 66:3336-51. [PMID: 23106701 DOI: 10.1111/j.1558-5646.2012.01712.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We used genetic mapping to examine the genetic architecture of differences in host plant use between two species of noctuid moths, Heliothis subflexa, a specialist on Physalis spp., and its close relative, the broad generalist H. virescens. We introgressed H. subflexa chromosomes into the H. virescens background and analyzed 1462 backcross insects. The effects of H. subflexa-origin chromosomes were small when measured as the percent variation explained in backcross populations (0.2-5%), but were larger when considered in relation to the interspecific difference explained (1.5-165%). Most significant chromosomes had effects on more than one trait, and their effects varied between years, sexes, and genetic backgrounds. Different chromosomes could produce similar phenotypes, suggesting that the same trait might be controlled by different chromosomes in different backcross populations. It appears that many loci of small effect contribute to the use of Physalis by H. subflexa. We hypothesize that behavioral changes may have paved the way for physiological adaptation to Physalis by the generalist ancestor of H. subflexa and H. virescens.
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Affiliation(s)
- Sara J Oppenheim
- Department of Entomology, North Carolina State University, Raleigh, North Carolina 27695, USA.
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131
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Ballerini ES, Brothers AN, Tang S, Knapp SJ, Bouck A, Taylor SJ, Arnold ML, Martin NH. QTL mapping reveals the genetic architecture of loci affecting pre- and post-zygotic isolating barriers in Louisiana Iris. BMC PLANT BIOLOGY 2012; 12:91. [PMID: 22702308 PMCID: PMC3490880 DOI: 10.1186/1471-2229-12-91] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 05/18/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Hybridization among Louisiana Irises has been well established and the genetic architecture of reproductive isolation is known to affect the potential for and the directionality of introgression between taxa. Here we use co-dominant markers to identify regions where QTL are located both within and between backcross maps to compare the genetic architecture of reproductive isolation and fitness traits across treatments and years. RESULTS QTL mapping was used to elucidate the genetic architecture of reproductive isolation between Iris fulva and Iris brevicaulis. Homologous co-dominant EST-SSR markers scored in two backcross populations between I. fulva and I. brevicaulis were used to generate genetic linkage maps. These were used as the framework for mapping QTL associated with variation in 11 phenotypic traits likely responsible for reproductive isolation and fitness. QTL were dispersed throughout the genome, with the exception of one region of a single linkage group (LG) where QTL for flowering time, sterility, and fruit production clustered. In most cases, homologous QTL were not identified in both backcross populations, however, homologous QTL for flowering time, number of growth points per rhizome, number of nodes per inflorescence, and number of flowers per node were identified on several linkage groups. CONCLUSIONS Two different traits affecting reproductive isolation, flowering time and sterility, exhibit different genetic architectures, with numerous QTL across the Iris genome controlling flowering time and fewer, less distributed QTL affecting sterility. QTL for traits affecting fitness are largely distributed across the genome with occasional overlap, especially on LG 4, where several QTL increasing fitness and decreasing sterility cluster. Given the distribution and effect direction of QTL affecting reproductive isolation and fitness, we have predicted genomic regions where introgression may be more likely to occur (those regions associated with an increase in fitness and unlinked to loci controlling reproductive isolation) and those that are less likely to exhibit introgression (those regions linked to traits decreasing fitness and reproductive isolation).
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Affiliation(s)
| | | | | | | | | | - Sunni J Taylor
- Department of Biology, Texas State University, San Marcos, TX, USA
| | | | - Noland H Martin
- Department of Biology, Texas State University, San Marcos, TX, USA
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132
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Malek TB, Boughman JW, Dworkin I, Peichel CL. Admixture mapping of male nuptial colour and body shape in a recently formed hybrid population of threespine stickleback. Mol Ecol 2012; 21:5265-79. [PMID: 22681397 DOI: 10.1111/j.1365-294x.2012.05660.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Despite recent progress, we still know relatively little about the genetic architecture that underlies adaptation to divergent environments. Determining whether the genetic architecture of phenotypic adaptation follows any predictable patterns requires data from a wide variety of species. However, in many organisms, genetic studies are hindered by the inability to perform genetic crosses in the laboratory or by long generation times. Admixture mapping is an approach that circumvents these issues by taking advantage of hybridization that occurs between populations or species in the wild. Here, we demonstrate the utility of admixture mapping in a naturally occurring hybrid population of threespine sticklebacks (Gasterosteus aculeatus) from Enos Lake, British Columbia. Until recently, this lake contained two species of sticklebacks adapted to divergent habitats within the lake. This benthic-limnetic species pair diverged in a number of phenotypes, including male nuptial coloration and body shape, which were previously shown to contribute to reproductive isolation between them. However, recent ecological disturbance has contributed to extensive hybridization between the species, and there is now a single, admixed population within Enos Lake. We collected over 500 males from Enos Lake and found that most had intermediate nuptial colour and body shape. By genotyping males with nuptial colour at the two extremes of the phenotypic distribution, we identified seven genomic regions on three chromosomes associated with divergence in male nuptial colour. These genomic regions are also associated with variation in body shape, suggesting that tight linkage and/or pleiotropy facilitated adaptation to divergent environments in benthic-limnetic species pairs.
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Affiliation(s)
- Tiffany B Malek
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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Bilodeau E, Simon JC, Guay JF, Turgeon J, Cloutier C. Does variation in host plant association and symbiont infection of pea aphid populations induce genetic and behaviour differentiation of its main parasitoid, Aphidius ervi? Evol Ecol 2012. [DOI: 10.1007/s10682-012-9577-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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134
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Abstract
The relationship between form and function can have profound effects on evolutionary dynamics and such effects may differ for simple versus complex systems. In particular, functions produced by multiple structural configurations (many-to-one mapping, MTOM) may dampen constituent trade-offs and promote diversification. Unfortunately, we lack information about the genetic architecture of MTOM functional systems. The skulls of teleost fishes contain both simple (lower jaw levers) as well as more complex (jaws modeled as 4-bar linkages) functional systems within the same craniofacial unit. We examined the mapping of form to function and the genetic basis of these systems by identifying quantitative trait loci (QTL) in hybrids of two Lake Malawi cichlid species. Hybrid individuals exhibited novelty (transgressive segregation) in morphological components and function of the simple and complex jaw systems. Functional novelty was proportional to the prevalence of extreme morphologies in the simple levers; by contrast, recombination of parental morphologies produced transgression in the MTOM 4-bar linkage. We found multiple loci of moderate effect and epistasis controlling jaw phenotypes in both the simple and complex systems, with less phenotypic variance explained by QTL for the 4-bar. Genetic linkage between components of the simple and complex systems partly explains phenotypic correlations and may constrain functional evolution.
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Affiliation(s)
- Nicholas F Parnell
- School of Biology, Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
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Via S. Divergence hitchhiking and the spread of genomic isolation during ecological speciation-with-gene-flow. Philos Trans R Soc Lond B Biol Sci 2012; 367:451-60. [PMID: 22201174 DOI: 10.1098/rstb.2011.0260] [Citation(s) in RCA: 207] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In allopatric populations, geographical separation simultaneously isolates the entire genome, allowing genetic divergence to accumulate virtually anywhere in the genome. In sympatric populations, however, the strong divergent selection required to overcome migration produces a genetic mosaic of divergent and non-divergent genomic regions. In some recent genome scans, each divergent genomic region has been interpreted as an independent incidence of migration/selection balance, such that the reduction of gene exchange is restricted to a few kilobases around each divergently selected gene. I propose an alternative mechanism, 'divergence hitchhiking' (DH), in which divergent selection can reduce gene exchange for several megabases around a gene under strong divergent selection. Not all genes/markers within a DH region are divergently selected, yet the entire region is protected to some degree from gene exchange, permitting genetic divergence from mechanisms other than divergent selection to accumulate secondarily. After contrasting DH and multilocus migration/selection balance (MM/SB), I outline a model in which genomic isolation at a given genomic location is jointly determined by DH and genome-wide effects of the progressive reduction in realized migration, then illustrate DH using data from several pairs of incipient species in the wild.
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Affiliation(s)
- Sara Via
- Departments of Biology and Entomology, University of Maryland, College Park, MD 20742, USA.
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136
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Renaut S, Maillet N, Normandeau E, Sauvage C, Derome N, Rogers SM, Bernatchez L. Genome-wide patterns of divergence during speciation: the lake whitefish case study. Philos Trans R Soc Lond B Biol Sci 2012; 367:354-63. [PMID: 22201165 DOI: 10.1098/rstb.2011.0197] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The nature, size and distribution of the genomic regions underlying divergence and promoting reproductive isolation remain largely unknown. Here, we summarize ongoing efforts using young (12 000 yr BP) species pairs of lake whitefish (Coregonus clupeaformis) to expand our understanding of the initial genomic patterns of divergence observed during speciation. Our results confirmed the predictions that: (i) on average, phenotypic quantitative trait loci (pQTL) show higher F(ST) values and are more likely to be outliers (and therefore candidates for being targets of divergent selection) than non-pQTL markers; (ii) large islands of divergence rather than small independent regions under selection characterize the early stages of adaptive divergence of lake whitefish; and (iii) there is a general trend towards an increase in terms of numbers and size of genomic regions of divergence from the least (East L.) to the most differentiated species pair (Cliff L.). This is consistent with previous estimates of reproductive isolation between these species pairs being driven by the same selective forces responsible for environment specialization. Altogether, dwarf and normal whitefish species pairs represent a continuum of both morphological and genomic differentiation contributing to ecological speciation. Admittedly, much progress is still required to more finely map and circumscribe genomic islands of speciation. This will be achieved through the use of next generation sequencing data but also through a better quantification of phenotypic traits moulded by selection as organisms adapt to new environmental conditions.
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Affiliation(s)
- S Renaut
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada.
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137
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138
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VILAS A, PÉREZ-FIGUEROA A, CABALLERO A. A simulation study on the performance of differentiation-based methods to detect selected loci using linked neutral markers. J Evol Biol 2012; 25:1364-76. [DOI: 10.1111/j.1420-9101.2012.02526.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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139
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Joy JB, Crespi BJ. Island phytophagy: explaining the remarkable diversity of plant-feeding insects. Proc Biol Sci 2012; 279:3250-5. [PMID: 22553094 DOI: 10.1098/rspb.2012.0397] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plant-feeding insects have undergone unparalleled diversification among different plant taxa, yet explanations for variation in their diversity lack a quantitative, predictive framework. Island biogeographic theory has been applied to spatially discrete habitats but not to habitats, such as host plants, separated by genetic distance. We show that relationships between the diversity of gall-inducing flies and their host plants meet several fundamental predictions from island biogeographic theory. First, plant-taxon genetic distinctiveness, an integrator for long-term evolutionary history of plant lineages, is a significant predictor of variance in the diversity of gall-inducing flies among host-plant taxa. Second, range size and structural complexity also explain significant proportions of the variance in diversity of gall-inducing flies among different host-plant taxa. Third, as with other island systems, plant-lineage age does not predict species diversity. Island biogeographic theory, applied to habitats defined by genetic distance, provides a novel, comprehensive framework for analysing and explaining the diversity of plant-feeding insects and other host-specific taxa.
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Affiliation(s)
- Jeffrey B Joy
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada, V5A 1S6.
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140
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Barrett LG, Heil M. Unifying concepts and mechanisms in the specificity of plant-enemy interactions. TRENDS IN PLANT SCIENCE 2012; 17:282-92. [PMID: 22465042 DOI: 10.1016/j.tplants.2012.02.009] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Revised: 02/13/2012] [Accepted: 02/28/2012] [Indexed: 05/08/2023]
Abstract
Host ranges are commonly quantified to classify herbivores and plant pathogens as either generalists or specialists. Here, we summarize patterns and mechanisms in the interactions of plants with these enemies along different axes of specificity. We highlight the many dimensions within which plant enemies can specify and consider the underlying ecological, evolutionary and molecular mechanisms. Host resistance traits and enemy effectors emerge as central players determining host utilization and thus host range. Finally, we review approaches to studying the causes and consequences of variation in the specificity of plant-enemy interactions. Knowledge of the molecular mechanisms that determine host range is required to understand host shifts, and evolutionary transitions among specialist and generalist strategies, and to predict potential host ranges of pathogens and herbivores.
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Affiliation(s)
- Luke G Barrett
- CSIRO Plant Industry, GPO Box 1600, Canberra ACT, 2601, Australia
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141
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142
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Brucker RM, Bordenstein SR. Speciation by symbiosis. Trends Ecol Evol 2012; 27:443-51. [PMID: 22541872 DOI: 10.1016/j.tree.2012.03.011] [Citation(s) in RCA: 238] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 03/27/2012] [Accepted: 03/28/2012] [Indexed: 01/21/2023]
Abstract
In the Origin of Species, Darwin struggled with how continuous changes within a species lead to the emergence of discrete species. Molecular analyses have since identified nuclear genes and organelles that underpin speciation. In this review, we explore the microbiota as a third genetic component that spurs species formation. We first recall Ivan Wallin's original conception from the early 20th century on the role that bacteria play in speciation. We then describe three fundamental observations that justify a prominent role for microbes in eukaryotic speciation, consolidate exemplar studies of microbe-assisted speciation and incorporate the microbiota into classic models of speciation.
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Affiliation(s)
- Robert M Brucker
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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143
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Feder JL, Egan SP, Nosil P. The genomics of speciation-with-gene-flow. Trends Genet 2012; 28:342-50. [PMID: 22520730 DOI: 10.1016/j.tig.2012.03.009] [Citation(s) in RCA: 528] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 03/16/2012] [Accepted: 03/19/2012] [Indexed: 10/28/2022]
Abstract
The emerging field of speciation genomics is advancing our understanding of the evolution of reproductive isolation from the individual gene to a whole-genome perspective. In this new view it is important to understand the conditions under which 'divergence hitchhiking' associated with the physical linkage of gene regions, versus 'genome hitchhiking' associated with reductions in genome-wide rates of gene flow caused by selection, can enhance speciation-with-gene-flow. We describe here a theory predicting four phases of speciation, defined by changes in the relative effectiveness of divergence and genome hitchhiking, and review empirical data in light of the theory. We outline future directions, emphasizing the need to couple next-generation sequencing with selection, transplant, functional genomics, and mapping studies. This will permit a natural history of speciation genomics that will help to elucidate the factors responsible for population divergence and the roles that genome structure and different forms of hitchhiking play in facilitating the genesis of new biodiversity.
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Affiliation(s)
- Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
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144
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Smadja CM, Canbäck B, Vitalis R, Gautier M, Ferrari J, Zhou JJ, Butlin RK. Large-scale candidate gene scan reveals the role of chemoreceptor genes in host plant specialization and speciation in the pea aphid. Evolution 2012; 66:2723-38. [PMID: 22946799 DOI: 10.1111/j.1558-5646.2012.01612.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Understanding the drivers of speciation is critical to interpreting patterns of biodiversity. The identification of the genetic changes underlying adaptation and reproductive isolation is necessary to link barriers to gene flow to the causal origins of divergence. Here, we present a novel approach to the genetics of speciation, which should complement the commonly used approaches of quantitative trait locus mapping and genome-wide scans for selection. We present a large-scale candidate gene approach by means of sequence capture, applied to identifying the genetic changes underlying reproductive isolation in the pea aphid, a model system for the study of ecological speciation. Targeted resequencing enabled us to scale up the candidate gene approach, specifically testing for the role of chemosensory gene families in host plant specialization. Screening for the signature of divergence under selection at 172 candidate and noncandidate loci, we revealed a handful of loci that show high levels of differentiation among host races, which almost all correspond to odorant and gustatory receptor genes. This study offers the first indication that some chemoreceptor genes, often tightly linked together in the genome, could play a key role in local adaptation and reproductive isolation in the pea aphid and potentially other phytophagous insects. Our approach opens a new route toward the functional genomics of ecological speciation.
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Affiliation(s)
- Carole M Smadja
- Centre National de la Recherche Scientifique CNRS-Institut des Sciences de l'Evolution UMR 5554, cc065 Université Montpellier 2, 34095 Montpellier, France.
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145
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Non-ecological speciation, niche conservatism and thermal adaptation: how are they connected? ORG DIVERS EVOL 2012. [DOI: 10.1007/s13127-012-0082-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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146
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HUANG XIAOLEI, XIANG-YU JINGGONG, REN SHANSHAN, ZHANG RUILING, ZHANG YAPING, QIAO GEXIA. Molecular phylogeny and divergence times of Hormaphidinae (Hemiptera: Aphididae) indicate Late Cretaceous tribal diversification. Zool J Linn Soc 2012. [DOI: 10.1111/j.1096-3642.2011.00795.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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147
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Anderson JT, Lee CR, Rushworth CA, Colautti RI, Mitchell-Olds T. Genetic trade-offs and conditional neutrality contribute to local adaptation. Mol Ecol 2012; 22:699-708. [PMID: 22420446 DOI: 10.1111/j.1365-294x.2012.05522.x] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Divergent natural selection promotes local adaptation and can lead to reproductive isolation of populations in contrasting environments; however, the genetic basis of local adaptation remains largely unresolved in natural populations. Local adaptation might result from antagonistic pleiotropy, where alternate alleles are favoured in distinct habitats, and polymorphism is maintained by selection. Alternatively, under conditional neutrality some alleles may be favoured in one environment but neutral at other locations. Antagonistic pleiotropy maintains genetic variation across the landscape; however, there is a systematic bias against discovery of antagonistic pleiotropy because the fitness benefits of local alleles need to be significant in at least two environments. Here, we develop a generally applicable method to investigate polygenic local adaptation and identify loci that are the targets of selection. This approach evaluates allele frequency changes after selection at loci across the genome to distinguish antagonistic pleiotropy from conditional neutrality and deleterious variation. We investigate local adaptation at the qualitative trait loci (QTL) level in field experiments, in which we expose 177 F(6) recombinant inbred lines and parental lines of Boechera stricta (Brassicaceae) to their parental environments over two seasons. We demonstrate polygenic selection for native alleles in both environments, with 2.8% of the genome exhibiting antagonistic pleiotropy and 8% displaying conditional neutrality. Our study strongly supports antagonistic pleiotropy at one large-effect flowering phenology QTL (nFT): native homozygotes had significantly greater probabilities of flowering than foreign homozygotes in both parental environments. Such large-scale field studies are essential to elucidate the genetic basis of adaptation in natural populations.
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Affiliation(s)
- Jill T Anderson
- Department of Biology, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA
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148
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Abstract
The role of habitat choice in reproductive isolation and ecological speciation has often been overlooked, despite acknowledgement of its ability to facilitate local adaptation. It can form part of the speciation process through various evolutionary mechanisms, yet where habitat choice has been included in models of ecological speciation little thought has been given to these underlying mechanisms. Here, we propose and describe three independent criteria underlying ten different evolutionary scenarios in which habitat choice may promote or maintain local adaptation. The scenarios are the result of all possible combinations of the independent criteria, providing a conceptual framework in which to discuss examples which illustrate each scenario. These examples show that the different roles of habitat choice in ecological speciation have rarely been effectively distinguished. Making such distinctions is an important challenge for the future, allowing better experimental design, stronger inferences and more meaningful comparisons among systems. We show some of the practical difficulties involved by reviewing the current evidence for the role of habitat choice in local adaptation and reproductive isolation in the intertidal gastropodLittorina saxatilis, a model system for the study of ecological speciation, assessing whether any of the proposed scenarios can be reliably distinguished, given current research.
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149
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Janz N. Ehrlich and Raven Revisited: Mechanisms Underlying Codiversification of Plants and Enemies. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2011. [DOI: 10.1146/annurev-ecolsys-102710-145024] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Niklas Janz
- Department of Zoology, Stockholm University, 106 91 Stockholm, Sweden;
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150
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SMADJA CAROLEM, BUTLIN ROGERK. A framework for comparing processes of speciation in the presence of gene flow. Mol Ecol 2011; 20:5123-40. [DOI: 10.1111/j.1365-294x.2011.05350.x] [Citation(s) in RCA: 251] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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