1
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Nevado B, Chapman MA, Brennan AC, Clark JW, Wong ELY, Batstone T, McCarthy SA, Tracey A, Torrance J, Sims Y, Abbott RJ, Filatov D, Hiscock SJ. Genomic changes and stabilization following homoploid hybrid speciation of the Oxford ragwort Senecio squalidus. Curr Biol 2024:S0960-9822(24)01085-6. [PMID: 39260362 DOI: 10.1016/j.cub.2024.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 06/10/2024] [Accepted: 08/07/2024] [Indexed: 09/13/2024]
Abstract
Oxford ragwort (Senecio squalidus) is one of only two homoploid hybrid species known to have originated very recently, so it is a unique model for determining genomic changes and stabilization following homoploid hybrid speciation. Here, we provide a chromosome-level genome assembly of S. squalidus with 95% of the assembly contained in the 10 longest scaffolds, corresponding to its haploid chromosome number. We annotated 30,249 protein-coding genes and estimated that ∼62% of the genome consists of repetitive elements. We then characterized genome-wide patterns of linkage disequilibrium, polymorphism, and divergence in S. squalidus and its two parental species, finding that (1) linkage disequilibrium is highly heterogeneous, with a region on chromosome 4 showing increased values across all three species but especially in S. squalidus; (2) regions harboring genetic incompatibilities between the two parental species tend to be large, show reduced recombination, and have lower polymorphism in S. squalidus; (3) the two parental species have an unequal contribution (70:30) to the genome of S. squalidus, with long blocks of parent-specific ancestry supporting a very rapid stabilization of the hybrid lineage after hybrid formation; and (4) genomic regions with major parent ancestry exhibit an overrepresentation of loci with evidence for divergent selection occurring between the two parental species on Mount Etna. Our results show that both genetic incompatibilities and natural selection play a role in determining genome-wide reorganization following hybrid speciation and that patterns associated with homoploid hybrid speciation-typically seen in much older systems-can evolve very quickly following hybridization.
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Affiliation(s)
- Bruno Nevado
- Department of Biology, University of Oxford, Oxford OX1 3RB, UK; cE3c, Centre for Ecology, Evolution and Environmental Changes & CHANGE - Global Change and Sustainability Institute, Faculty of Sciences, University of Lisbon, Lisbon 1749-016, Portugal; Department of Animal Biology, Faculty of Sciences, University of Lisbon, Lisbon 1749-016, Portugal.
| | - Mark A Chapman
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Adrian C Brennan
- Biosciences Department, University of Durham, Durham DH1 3LE, UK
| | - James W Clark
- Department of Biology, University of Oxford, Oxford OX1 3RB, UK; Milner Centre for Evolution, Department of Life Sciences, University of Bath, Bath BA2 7AY, UK
| | - Edgar L Y Wong
- Department of Biology, University of Oxford, Oxford OX1 3RB, UK
| | - Tom Batstone
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, Bath BA2 7AY, UK
| | | | - Alan Tracey
- Wellcome Sanger Institute, Cambridge CB10 1SA, UK
| | | | - Ying Sims
- Wellcome Sanger Institute, Cambridge CB10 1SA, UK
| | - Richard J Abbott
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | - Dmitry Filatov
- Department of Biology, University of Oxford, Oxford OX1 3RB, UK
| | - Simon J Hiscock
- Department of Biology, University of Oxford, Oxford OX1 3RB, UK; University of Oxford Botanic Garden and Arboretum, Rose Lane, Oxford OX1 4AZ, UK
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2
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Nota A, Bertolino S, Tiralongo F, Santovito A. Adaptation to bioinvasions: When does it occur? GLOBAL CHANGE BIOLOGY 2024; 30:e17362. [PMID: 38822565 DOI: 10.1111/gcb.17362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 06/03/2024]
Abstract
The presence of alien species represents a major cause of habitat degradation and biodiversity loss worldwide, constituting a critical environmental challenge of our time. Despite sometimes experiencing reduced propagule pressure, leading to a reduced genetic diversity and an increased chance of inbreeding depression, alien invaders are often able to thrive in the habitats of introduction, giving rise to the so-called "genetic paradox" of biological invasions. The adaptation of alien species to the new habitats is therefore a complex aspect of biological invasions, encompassing genetic, epigenetic, and ecological processes. Albeit numerous studies and reviews investigated the mechanistic foundation of the invaders' success, and aimed to solve the genetic paradox, still remains a crucial oversight regarding the temporal context in which adaptation takes place. Given the profound knowledge and management implications, this neglected aspect of invasion biology should receive more attention when examining invaders' ability to thrive in the habitats of introduction. Here, we discuss the adaptation mechanisms exhibited by alien species with the purpose of highlighting the timing of their occurrence during the invasion process. We analyze each stage of the invasion separately, providing evidence that adaptation mechanisms play a role in all of them. However, these mechanisms vary across the different stages of invasion, and are also influenced by other factors, such as the transport speed, the reproduction type of the invader, and the presence of human interventions. Finally, we provide insights into the implications for management, and identify knowledge gaps, suggesting avenues for future research that can shed light on species adaptability. This, in turn, will contribute to a more comprehensive understanding of biological invasions.
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Affiliation(s)
- Alessandro Nota
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
- Ente Fauna Marina Mediterranea, Scientific Organization for Research and Conservation of Marine Biodiversity, Avola, Italy
| | - Sandro Bertolino
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Francesco Tiralongo
- Ente Fauna Marina Mediterranea, Scientific Organization for Research and Conservation of Marine Biodiversity, Avola, Italy
- Department of Biological, Geological, and Environmental Sciences, University of Catania, Catania, Italy
- National Research Council, Institute of Marine Biological Resources and Biotechnologies, Ancona, Italy
| | - Alfredo Santovito
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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3
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Long Z, Rieseberg LH. Documenting homoploid hybrid speciation. Mol Ecol 2024:e17412. [PMID: 38780141 DOI: 10.1111/mec.17412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/11/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Homoploid hybrid speciation is challenging to document because hybridization can lead to outcomes other than speciation. Thus, some authors have argued that establishment of homoploid hybrid speciation should include evidence that reproductive barriers isolating the hybrid neo-species from its parental species were derived from hybridization. While this criterion is difficult to satisfy, several recent papers have successfully employed a common pipeline to identify candidate genes underlying such barriers and (in one case) to validate their function. We describe this pipeline, its application to several plant and animal species and what we have learned about homoploid hybrid speciation as a consequence. We argue that - given the ubiquity of admixture and the polygenic basis of reproductive isolation - homoploid hybrid speciation could be much more common and more protracted than suggested by earlier conceptual arguments and theoretical studies.
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Affiliation(s)
- Zhiqin Long
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
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4
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Ålund M, Cenzer M, Bierne N, Boughman JW, Cerca J, Comerford MS, Culicchi A, Langerhans B, McFarlane SE, Möst MH, North H, Qvarnström A, Ravinet M, Svanbäck R, Taylor SA. Anthropogenic Change and the Process of Speciation. Cold Spring Harb Perspect Biol 2023; 15:a041455. [PMID: 37788888 PMCID: PMC10691492 DOI: 10.1101/cshperspect.a041455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Anthropogenic impacts on the environment alter speciation processes by affecting both geographical contexts and selection patterns on a worldwide scale. Here we review evidence of these effects. We find that human activities often generate spatial isolation between populations and thereby promote genetic divergence but also frequently cause sudden secondary contact and hybridization between diverging lineages. Human-caused environmental changes produce new ecological niches, altering selection in diverse ways that can drive diversification; but changes also often remove niches and cause extirpations. Human impacts that alter selection regimes are widespread and strong in magnitude, ranging from local changes in biotic and abiotic conditions to direct harvesting to global climate change. Altered selection, and evolutionary responses to it, impacts early-stage divergence of lineages, but does not necessarily lead toward speciation and persistence of separate species. Altogether, humans both promote and hinder speciation, although new species would form very slowly relative to anthropogenic hybridization, which can be nearly instantaneous. Speculating about the future of speciation, we highlight two key conclusions: (1) Humans will have a large influence on extinction and "despeciation" dynamics in the short term and on early-stage lineage divergence, and thus potentially speciation in the longer term, and (2) long-term monitoring combined with easily dated anthropogenic changes will improve our understanding of the processes of speciation. We can use this knowledge to preserve and restore ecosystems in ways that promote (re-)diversification, increasing future opportunities of speciation and enhancing biodiversity.
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Affiliation(s)
- Murielle Ålund
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala 75236, Sweden
| | - Meredith Cenzer
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois 60637, USA
| | - Nicolas Bierne
- ISEM, Université de Montpellier, CNRS, IRD, Montpellier 34095, France
| | - Janette W Boughman
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - José Cerca
- CEES - Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo 0316, Norway
| | | | - Alessandro Culicchi
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala 75236, Sweden
| | - Brian Langerhans
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - S Eryn McFarlane
- Department of Botany, University of Wyoming, Laramie, Wyoming 82071, USA
- Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada
| | - Markus H Möst
- Research Department for Limnology, University of Innsbruck, Innsbruck 6020, Austria
| | - Henry North
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, United Kingdom
| | - Anna Qvarnström
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala 75236, Sweden
| | - Mark Ravinet
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Richard Svanbäck
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala 75236, Sweden
| | - Scott A Taylor
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, Colorado 80309, USA
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Bock DG, Cai Z, Elphinstone C, González-Segovia E, Hirabayashi K, Huang K, Keais GL, Kim A, Owens GL, Rieseberg LH. Genomics of plant speciation. PLANT COMMUNICATIONS 2023; 4:100599. [PMID: 37050879 PMCID: PMC10504567 DOI: 10.1016/j.xplc.2023.100599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/21/2023] [Accepted: 04/06/2023] [Indexed: 06/19/2023]
Abstract
Studies of plants have been instrumental for revealing how new species originate. For several decades, botanical research has complemented and, in some cases, challenged concepts on speciation developed via the study of other organisms while also revealing additional ways in which species can form. Now, the ability to sequence genomes at an unprecedented pace and scale has allowed biologists to settle decades-long debates and tackle other emerging challenges in speciation research. Here, we review these recent genome-enabled developments in plant speciation. We discuss complications related to identification of reproductive isolation (RI) loci using analyses of the landscape of genomic divergence and highlight the important role that structural variants have in speciation, as increasingly revealed by new sequencing technologies. Further, we review how genomics has advanced what we know of some routes to new species formation, like hybridization or whole-genome duplication, while casting doubt on others, like population bottlenecks and genetic drift. While genomics can fast-track identification of genes and mutations that confer RI, we emphasize that follow-up molecular and field experiments remain critical. Nonetheless, genomics has clarified the outsized role of ancient variants rather than new mutations, particularly early during speciation. We conclude by highlighting promising avenues of future study. These include expanding what we know so far about the role of epigenetic and structural changes during speciation, broadening the scope and taxonomic breadth of plant speciation genomics studies, and synthesizing information from extensive genomic data that have already been generated by the plant speciation community.
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Affiliation(s)
- Dan G Bock
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Zhe Cai
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Cassandra Elphinstone
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Eric González-Segovia
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | | | - Kaichi Huang
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Graeme L Keais
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Amy Kim
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Gregory L Owens
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.
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6
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Boyle JH, Strickler S, Twyford AD, Ricono A, Powell A, Zhang J, Xu H, Smith R, Dalgleish HJ, Jander G, Agrawal AA, Puzey JR. Temporal matches between monarch butterfly and milkweed population changes over the past 25,000 years. Curr Biol 2023; 33:3702-3710.e5. [PMID: 37607548 DOI: 10.1016/j.cub.2023.07.057] [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: 11/09/2022] [Revised: 04/13/2023] [Accepted: 07/26/2023] [Indexed: 08/24/2023]
Abstract
In intimate ecological interactions, the interdependency of species may result in correlated demographic histories. For species of conservation concern, understanding the long-term dynamics of such interactions may shed light on the drivers of population decline. Here, we address the demographic history of the monarch butterfly, Danaus plexippus, and its dominant host plant, the common milkweed Asclepias syriaca (A. syriaca), using broad-scale sampling and genomic inference. Because genetic resources for milkweed have lagged behind those for monarchs, we first release a chromosome-level genome assembly and annotation for common milkweed. Next, we show that despite its enormous geographic range across eastern North America, A. syriaca is best characterized as a single, roughly panmictic population. Using approximate Bayesian computation with random forests (ABC-RF), a machine learning method for reconstructing demographic histories, we show that both monarchs and milkweed experienced population expansion during the most recent recession of North American glaciers 10,000-20,000 years ago. Our data also identify concurrent population expansions in both species during the large-scale clearing of eastern forests (∼200 years ago). Finally, we find no evidence that either species experienced a reduction in effective population size over the past 75 years. Thus, the well-documented decline of monarch abundance over the past 40 years is not visible in our genomic dataset, reflecting a possible mismatch of the overwintering census population to effective population size in this species.
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Affiliation(s)
- John H Boyle
- Biology Department, College of William & Mary, 540 Landrum Dr., Williamsburg, VA 23185, USA; Biology Department, University of Mary, 7500 University Dr., Bismarck, ND 58504, USA
| | - Susan Strickler
- Boyce Thompson Institute, 533 Tower Rd., Ithaca, NY 14853, USA; Chicago Botanic Garden, Plant Science and Conservation, 1000 Lake Cook Rd., Glencoe, IL 60022, USA; Northwestern University, Plant Biology and Conservation Program, 2145 Sheridan Rd., Evanston, IL 60208, USA
| | - Alex D Twyford
- Institute of Ecology and Evolution, University of Edinburgh, Charlotte Auerbach Rd., Edinburgh EH9 3FL, UK; Royal Botanic Garden Edinburgh, Edinburgh EH3 5NZ, UK
| | - Angela Ricono
- Biology Department, College of William & Mary, 540 Landrum Dr., Williamsburg, VA 23185, USA
| | - Adrian Powell
- Boyce Thompson Institute, 533 Tower Rd., Ithaca, NY 14853, USA
| | - Jing Zhang
- Boyce Thompson Institute, 533 Tower Rd., Ithaca, NY 14853, USA
| | - Hongxing Xu
- Boyce Thompson Institute, 533 Tower Rd., Ithaca, NY 14853, USA; College of Life Sciences, Shaanxi Normal University, South Chang'an Rd., Xi'an 710062, China
| | - Ronald Smith
- Data Science Program, College of William & Mary, 540 Landrum Dr., Williamsburg, VA 23185, USA
| | - Harmony J Dalgleish
- Biology Department, College of William & Mary, 540 Landrum Dr., Williamsburg, VA 23185, USA
| | - Georg Jander
- Boyce Thompson Institute, 533 Tower Rd., Ithaca, NY 14853, USA
| | - Anurag A Agrawal
- Department of Ecology and Evolutionary Biology, Cornell University, Corson Hall, Ithaca, NY 14853, USA
| | - Joshua R Puzey
- Biology Department, College of William & Mary, 540 Landrum Dr., Williamsburg, VA 23185, USA.
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7
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Gawrońska B, Marszałek M, Kosiński P, Podsiedlik M, Bednorz L, Zeyland J. No wonder, it is a hybrid. Natural hybridization between Jacobaea vulgaris and J. erucifolia revealed by molecular marker systems and its potential ecological impact. Ecol Evol 2023; 13:e10467. [PMID: 37664498 PMCID: PMC10468328 DOI: 10.1002/ece3.10467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/09/2023] [Accepted: 08/18/2023] [Indexed: 09/05/2023] Open
Abstract
Progressive changes in the environment are related to modifications of the habitat. Introducing exotic species, and interbreeding between species can lead to processes that in the case of rare species or small populations threatens their integrity. Given the declining trends of many populations due to increased hybridization, early recognition of hybrids becomes important in conservation management. Natural hybridization is prevalent in Jacobaea. There are many naturally occurring interspecific hybrids in this genus, including those between Jacobaea vulgaris and its relatives. Although Jacobaea erucifolia and J. vulgaris often co-occur and are considered closely related, apart from the few reports of German botanists on the existence of such hybrids, there is no information on research confirming hybridization between them. Morphologically intermediate individuals, found in the sympatric distributions of J. vulgaris and J. erucifolia, were hypothesized to be their hybrids. Two molecular marker systems (nuclear and chloroplast DNA markers) were employed to test this hypothesis and characterize putative hybrids. Nuclear and chloroplast DNA sequencing results and taxon-specific amplified fragment length polymorphism (AFLP) fragment distribution analysis confirmed the hybrid nature of all 25 putative hybrids. The AFLP patterns of most hybrids demonstrated a closer relationship to J. erucifolia, suggesting frequent backcrossing. Moreover, they showed that several individuals previously described as pure were probably also of hybrid origin, backcrosses to J. erucifolia and J. vulgaris. This study provides the first molecular confirmation that natural hybrids between J. vulgaris and J. erucifolia occur in Poland. Hybridization appeared to be bidirectional but asymmetrical with J. vulgaris as the usual maternal parent.
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Affiliation(s)
- Barbara Gawrońska
- Department of Biochemistry and Biotechnology, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
| | - Małgorzata Marszałek
- Department of Biochemistry and Biotechnology, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
| | - Piotr Kosiński
- Department of Botany, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
- Institute of DendrologyPolish Academy of SciencesKórnikPoland
| | - Marek Podsiedlik
- Natural History Collections, Faculty of BiologyAdam Mickiewicz University in PoznańPoznańPoland
| | - Leszek Bednorz
- Department of Botany, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
| | - Joanna Zeyland
- Department of Biochemistry and Biotechnology, Faculty of Agronomy, Horticulture and BioengineeringPoznań University of Life SciencesPoznańPoland
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8
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Wong ELY, Nevado B, Hiscock SJ, Filatov DA. Rapid evolution of hybrid breakdown following recent divergence with gene flow in Senecio species on Mount Etna, Sicily. Heredity (Edinb) 2023; 130:40-52. [PMID: 36494489 PMCID: PMC9814926 DOI: 10.1038/s41437-022-00576-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 12/13/2022] Open
Abstract
How do nascent species evolve reproductive isolation during speciation with on-going gene flow? How do hybrid lineages become stabilised hybrid species? While commonly used genomic approaches provide an indirect way to identify species incompatibility factors, synthetic hybrids generated from interspecific crosses allow direct pinpointing of phenotypic traits involved in incompatibilities and the traits that are potentially adaptive in hybrid species. Here we report the analysis of phenotypic variation and hybrid breakdown in crosses between closely-related Senecio aethnensis and S. chrysanthemifolius, and their homoploid hybrid species, S. squalidus. The two former species represent a likely case of recent (<200 ky) speciation with gene flow driven by adaptation to contrasting conditions of high- and low-elevations on Mount Etna, Sicily. As these species form viable and fertile hybrids, it remains unclear whether they have started to evolve reproductive incompatibility. Our analysis represents the first study of phenotypic variation and hybrid breakdown involving multiple Senecio hybrid families. It revealed wide range of variation in multiple traits, including the traits previously unrecorded in synthetic hybrids. Leaf shape, highly distinct between S. aethnensis and S. chrysanthemifolius, was extremely variable in F2 hybrids, but more consistent in S. squalidus. Our study demonstrates that interspecific incompatibilities can evolve rapidly despite on-going gene flow between the species. Further work is necessary to understand the genetic bases of these incompatibilities and their role in speciation with gene flow.
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Affiliation(s)
- Edgar L. Y. Wong
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,grid.507705.0Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
| | - Bruno Nevado
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,grid.9983.b0000 0001 2181 4263Centre for Ecology, Evolution and Environmental Changes, University of Lisbon, Lisbon, Portugal
| | - Simon J. Hiscock
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,Oxford Botanic Garden and Arboretum, Oxford, UK
| | - Dmitry A. Filatov
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK
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9
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Barone G, Domina G, Bartolucci F, Galasso G, Peruzzi L. A Nomenclatural and Taxonomic Revision of the Senecio squalidus Group (Asteraceae). PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11192597. [PMID: 36235463 PMCID: PMC9572006 DOI: 10.3390/plants11192597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 05/27/2023]
Abstract
Senecio squalidus (Asteraceae) currently includes nine subspecies distributed in North and Central Europe and in the Mediterranean basin. Within this taxonomic aggregate, many species have been described, but research on their nomenclatural types is incomplete. A complete nomenclatural survey of 19 names belonging to this taxonomically critical group was carried out. Fourteen lectotypes are here designated. The nomenclatural analysis, complemented by field investigations in the type localities of the taxa described in the Central Mediterranean, allowed us to accept 10 species. Accordingly, we proposed here a new name and a new missing combination at a specific level: S. aknoulensis and S. calabrus.
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Affiliation(s)
- Giulio Barone
- Department of Architecture, University of Palermo, Viale delle Scienze, bldg. 14., I-90128 Palermo, Italy
| | - Gianniantonio Domina
- Department of Agricultural, Food and Forest Sciences, University of Palermo, Viale delle Scienze, bldg. 4., I-90128 Palermo, Italy
| | - Fabrizio Bartolucci
- Floristic Research Center of the Apennines, University of Camerino—Gran Sasso and Monti della Laga National Park, San Colombo, Barisciano, I-67021 L’Aquila, Italy
| | - Gabriele Galasso
- Section of Botany, Natural History Museum of Milan, Corso Venezia 55, I-20121 Milano, Italy
| | - Lorenzo Peruzzi
- PLANTSEED Lab, Department of Biology, University of Pisa, Via Luca Ghini 13., I-56126 Pisa, Italy
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10
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Wong ELY, Hiscock SJ, Filatov DA. The Role of Interspecific Hybridisation in Adaptation and Speciation: Insights From Studies in Senecio. FRONTIERS IN PLANT SCIENCE 2022; 13:907363. [PMID: 35812981 PMCID: PMC9260247 DOI: 10.3389/fpls.2022.907363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/03/2022] [Indexed: 05/08/2023]
Abstract
Hybridisation is well documented in many species, especially plants. Although hybrid populations might be short-lived and do not evolve into new lineages, hybridisaiton could lead to evolutionary novelty, promoting adaptation and speciation. The genus Senecio (Asteraceae) has been actively used to unravel the role of hybridisation in adaptation and speciation. In this article, we first briefly describe the process of hybridisation and the state of hybridisation research over the years. We then discuss various roles of hybridisation in plant adaptation and speciation illustrated with examples from different Senecio species, but also mention other groups of organisms whenever necessary. In particular, we focus on the genomic and transcriptomic consequences of hybridisation, as well as the ecological and physiological aspects from the hybrids' point of view. Overall, this article aims to showcase the roles of hybridisation in speciation and adaptation, and the research potential of Senecio, which is part of the ecologically and economically important family, Asteraceae.
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Affiliation(s)
- Edgar L. Y. Wong
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
- *Correspondence: Edgar L. Y. Wong,
| | - Simon J. Hiscock
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
- Oxford Botanic Garden and Arboretum, Oxford, United Kingdom
| | - Dmitry A. Filatov
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
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11
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12
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Ottenburghs J. The genic view of hybridization in the Anthropocene. Evol Appl 2021; 14:2342-2360. [PMID: 34745330 PMCID: PMC8549621 DOI: 10.1111/eva.13223] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 12/24/2022] Open
Abstract
Human impact is noticeable around the globe, indicating that a new era might have begun: the Anthropocene. Continuing human activities, including land-use changes, introduction of non-native species and rapid climate change, are altering the distributions of countless species, often giving rise to human-mediated hybridization events. While the interbreeding of different populations or species can have detrimental effects, such as genetic extinction, it can be beneficial in terms of adaptive introgression or an increase in genetic diversity. In this paper, I first review the different mechanisms and outcomes of anthropogenic hybridization based on literature from the last five years (2016-2020). The most common mechanisms leading to the interbreeding of previously isolated taxa include habitat change (51% of the studies) and introduction of non-native species (34% intentional and 19% unintentional). These human-induced hybridization events most often result in introgression (80%). The high incidence of genetic exchange between the hybridizing taxa indicates that the application of a genic view of speciation (and introgression) can provide crucial insights on how to address hybridization events in the Anthropocene. This perspective considers the genome as a dynamic collection of genetic loci with distinct evolutionary histories, giving rise to a heterogenous genomic landscape in terms of genetic differentiation and introgression. First, understanding this genomic landscape can lead to a better selection of diagnostic genetic markers to characterize hybrid populations. Second, describing how introgression patterns vary across the genome can help to predict the likelihood of negative processes, such as demographic and genetic swamping, as well as positive outcomes, such as adaptive introgression. It is especially important to not only quantify how much genetic material introgressed, but also what has been exchanged. Third, comparing introgression patterns in pre-Anthropocene hybridization events with current human-induced cases might provide novel insights into the likelihood of genetic swamping or species collapse during an anthropogenic hybridization event. However, this comparative approach remains to be tested before it can be applied in practice. Finally, the genic view of introgression can be combined with conservation genomic studies to determine the legal status of hybrids and take appropriate measures to manage anthropogenic hybridization events. The interplay between evolutionary and conservation genomics will result in the constant exchange of ideas between these fields which will not only improve our knowledge on the origin of species, but also how to conserve and protect them.
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Affiliation(s)
- Jente Ottenburghs
- Wildlife Ecology and ConservationWageningen University & ResearchWageningenThe Netherlands
- Forest Ecology and Forest ManagementWageningen University & ResearchWageningenThe Netherlands
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Gao Y, Harris AJ, Li H, Gao X. Hybrid Speciation and Introgression Both Underlie the Genetic Structures and Evolutionary Relationships of Three Morphologically Distinct Species of Lilium (Liliaceae) Forming a Hybrid Zone Along an Elevational Gradient. FRONTIERS IN PLANT SCIENCE 2020; 11:576407. [PMID: 33365039 PMCID: PMC7750405 DOI: 10.3389/fpls.2020.576407] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 11/02/2020] [Indexed: 05/28/2023]
Abstract
We studied hybrid interactions of Lilium meleagrinum, Lilium gongshanense, and Lilium saluenense using an integrative approach combining population genetics, fieldwork, and phenological research. These three species occur along an elevational gradient, with L. meleagrinum occurring at lower elevations, L. saluenense at higher elevations, and L. gongshanense between them. The species show strong morphological differentiation despite there being no clear environmental barriers to gene flow among them. Lilium gongshanense is likely to have a hybrid origin based on our prior work, but its progenitors remain uncertain. We sought to determine whether gene flow occurs among these three parapatric species, and, if so, whether L. gongshanense is a hybrid of L. meleagrinum and/or L. saluenense. We analyzed data from multiple chloroplast genes and spacers, nuclear internal transcribed spacer (ITS), and 18 nuclear Expressed Sequence Tag-Simple Sequence Repeat (EST-SSR) microsatellites for accessions of the three species representing dense population-level sampling. We also inferred phenology by examining species in the field and using herbarium specimens. We found that there are only two types of chloroplast genomes shared among the three species and that L. gongshanense forms two distinct groups with closest links to other species of Lilium based on ITS. Taken together, L. gongshanense is unlikely to be a hybrid species resulting from a cross between L. meleagrinum and L. saluenense, but gene flow is occurring among the three species. The gene flow is likely to be rare according to evidence from all molecular datasets, and this is corroborated by detection of only one putative hybrid individual in the field and asynchronous phenology. We suspect that the rarity of hybridization events among the species facilitates their continued genetic separation.
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Affiliation(s)
- Yundong Gao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - AJ Harris
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Huaicheng Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- Institut für Biologie, Freie Universität Berlin, Berlin, Germany
| | - Xinfen Gao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
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