1
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Fukutani K, Matsui M, Nishikawa K. Population genetic structure and hybrid zone analyses for species delimitation in the Japanese toad ( Bufo japonicus). PeerJ 2023; 11:e16302. [PMID: 37901459 PMCID: PMC10607272 DOI: 10.7717/peerj.16302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 09/25/2023] [Indexed: 10/31/2023] Open
Abstract
Hybridization following secondary contact may produce different outcomes depending on the extent to which genetic diversity and reproductive barriers have accumulated during isolation. The Japanese toad, Bufo japonicus, is distributed on the main islands of Japan. In the present study, we applied multiplexed inter-simple sequence repeat genotyping by sequencing to achieve the fine-scale resolution of the genetic cluster in B. j. japonicus and B. j. formosus. We also elucidated hybridization patterns and gene flow degrees across contact zones between the clusters identified. Using SNP data, we found four genetic clusters in B. j. japonicus and B. j. formosus and three contact zones of the cluster pairs among these four clusters. The two oldest diverged lineages, B. j. japonicus and B. j. formosus, formed a narrow contact zone consistent with species distinctiveness. Therefore, we recommend that these two subspecies be elevated to the species level. In contrast, the less diverged pairs of two clusters in B. j. japonicus and B. j. formosus, respectively, admixed over a hundred kilometers, suggesting that they have not yet developed strong reproductive isolation and need to be treated as conspecifics. These results will contribute to resolving taxonomic confusion in Japanese toads.
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Affiliation(s)
- Kazumi Fukutani
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Masafumi Matsui
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Kanto Nishikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
- Graduate School of Global Environmental Studies, Kyoto University, Kyoto, Japan
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2
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van Riemsdijk I, Arntzen JW, Bucciarelli GM, McCartney-Melstad E, Rafajlović M, Scott PA, Toffelmier E, Shaffer HB, Wielstra B. Two transects reveal remarkable variation in gene flow on opposite ends of a European toad hybrid zone. Heredity (Edinb) 2023:10.1038/s41437-023-00617-6. [PMID: 37106116 DOI: 10.1038/s41437-023-00617-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 03/27/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
Speciation entails a reduction in gene flow between lineages. The rates at which genomic regions become isolated varies across space and time. Barrier markers are linked to putative genes involved in (processes of) reproductive isolation, and, when observed over two transects, indicate species-wide processes. In contrast, transect-specific putative barrier markers suggest local processes. We studied two widely separated transects along the 900 km hybrid zone between Bufo bufo and B. spinosus, in northern and southern France, for ~1200 RADseq markers. We used genomic and geographic cline analyses to identify barrier markers based on their restricted introgression, and found that some markers are transect-specific, while others are shared between transects. Twenty-six barrier markers were shared across both transects, of which some are clustered in the same chromosomal region, suggesting that their associated genes are involved in reduced gene flow across the entire hybrid zone. Transect-specific barrier markers were twice as numerous in the southern than in the northern transect, suggesting that the overall barrier effect is weaker in northern France. We hypothesize that this is consistent with a longer period of secondary contact in southern France. The smaller number of introgressed genes in the northern transect shows considerably more gene flow towards the southern (B. spinosus) than the northern species (B. bufo). We hypothesize that hybrid zone movement in northern France and hybrid zone stability in southern France explain this pattern. The Bufo hybrid zone provides an excellent opportunity to separate a general barrier effect from localized gene flow-reducing conditions.
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Affiliation(s)
- I van Riemsdijk
- Naturalis Biodiversity Center, Leiden, the Netherlands.
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands.
- Institute for Evolution and Ecology, Plant Evolutionary Ecology, Tübingen University, Tübingen, Germany.
| | - J W Arntzen
- Naturalis Biodiversity Center, Leiden, the Netherlands
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands
| | - G M Bucciarelli
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA
- Institute of the Environment, UC Davis, Davis, CA, USA
- Department of Wildlife, Fish, and Conservation Biology, UC Davis, Davis, CA, USA
| | - E McCartney-Melstad
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA
| | - M Rafajlović
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
| | - P A Scott
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- Natural Sciences Collegium, Eckerd College, 4200 54 Ave S, St Petersburg, FL, 33711, USA
| | - E Toffelmier
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA
| | - H B Shaffer
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA
| | - B Wielstra
- Naturalis Biodiversity Center, Leiden, the Netherlands
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands
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3
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Dursun C, Özdemir N, Gül S. Easternmost distribution of Bufo bufo (Linnaeus, 1758) in Türkiye: implications for the putative contact zone between B. bufo and B. verrucosissimus. Genetica 2023; 151:11-27. [PMID: 36418607 DOI: 10.1007/s10709-022-00175-5] [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: 07/17/2022] [Accepted: 11/09/2022] [Indexed: 11/25/2022]
Abstract
The geographic range of a species is crucial for obtaining information on the exact distribution of the species. The geographic data are important for delimiting distinct species or exploring the degree of differentiation among different populations of a species. The local details of species boundaries facilitate the study of the importance of phylogeographic background, secondary contacts, and hybrid zones, along with the relations between the species and its extrinsic environmental factors. In the present study, the range boundaries of Bufo bufo and Bufo verrucosissimus in the north-eastern region of Türkiye were delineated using an integrative taxonomic approach that utilized a combination of molecular and morphological data. According to the mtDNA results of the present study, B. bufo inhabits a single distribution from İyidere town to Çayeli town in Rize, while B. verrucosissimus is distributed from Şavşat town of Artvin to Ardeşen town in Rize. In addition, the two species coexist in Pazar, Hemşin, and Çamlıhemşin towns in Rize. The demographic analyses indicated a distinct population expansion for the B. verrucosissimus species after the Last Glacial Maximum, while the same did not occur for B. bufo. The univariate and multivariate statistical analyses conducted for the morphological data of the two species corroborated the presence of a putative contact zone between B. bufo and B. verrucosissimus. In summary, the present study resolved the non-distinct geographic boundaries between B. bufo and B. verrucosissimus species and also revealed the easternmost distribution of B. bufo in Türkiye. In addition, important evidence on the putative contact zone between the two species was indicated using an integrative taxonomic approach.
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Affiliation(s)
- Cantekin Dursun
- Department of Biology, Faculty of Arts and Sciences, Recep Tayyip Erdogan University, Fener Mah., 53100, Rize, Turkey.
| | - Nurhayat Özdemir
- Department of Biology, Faculty of Arts and Sciences, Recep Tayyip Erdogan University, Fener Mah., 53100, Rize, Turkey
| | - Serkan Gül
- Department of Biology, Faculty of Arts and Sciences, Recep Tayyip Erdogan University, Fener Mah., 53100, Rize, Turkey
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4
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Sequeira F, Arntzen JW, van Gulik D, Hajema S, Diaz RL, Wagt M, van Riemsdijk I. Genetic traces of hybrid zone movement across a fragmented habitat. J Evol Biol 2022; 35:400-412. [PMID: 35043504 DOI: 10.1111/jeb.13982] [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: 06/02/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 11/27/2022]
Abstract
Theoretical and empirical studies suggest that the structure and position of hybrid zones can change over time. Evidence for moving hybrid zones has been directly inferred by repeated sampling over time, or indirectly through the detection of genetic footprints left by the receding species and the resulting asymmetric patterns of introgression across markers. We here investigate a hybrid zone formed by two subspecies of the Iberian golden-striped salamander, Chioglossa lusitanica, using a panel of 35 nuclear loci (31 SNPs and 4 allozymes) and one mitochondrial locus in a transect in central Portugal. We found concordant and coincident clines for most of the nuclear loci (n=22, 63%), defining a narrow hybrid zone of ca. 6 km wide, with the centre positioned ca. 15 km south of the Mondego river. Asymmetric introgression was observed at another 14 loci. Their clines are displaced towards the north, with positions located either close to the Mondego river (n=6), or further northwards (n=8). We interpret these profiles as genetic traces of the southward displacement of C. lusitanica lusitanica by C. l. longipes over the wider Mondego river valley. We noted the absence of significant linkage disequilibrium and we inferred low levels of effective selection per locus against hybrids, suggesting that introgression in the area of species replacement occurred under a neutral diffusion process. A species distribution model suggests that the C. lusitanica hybrid zone coincides with a narrow corridor of fragmented habitat. From the position of the displaced clines, we infer that patches of locally suitable habitat trapped some genetic variants that became disassociated from the southward moving hybrid zone. This study highlights the influence of habitat availability on hybrid zone movement.
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Affiliation(s)
- Fernando Sequeira
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Campus de Vairão, 4485-661, Vairão, Portugal.,BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661, Vairão, Portugal
| | - Jan W Arntzen
- Institute of Biology, Leiden University, Leiden, The Netherlands.,Naturalis Biodiversity Centre, P. O. Box 9517, 2300 RA, Leiden, The Netherlands
| | - Davy van Gulik
- Hogeschool Leiden, P. O. Box 382, 2300 AJ, Leiden, The Netherlands
| | - Steven Hajema
- Hogeschool Leiden, P. O. Box 382, 2300 AJ, Leiden, The Netherlands
| | - Ruben Lopez Diaz
- Hogeschool Leiden, P. O. Box 382, 2300 AJ, Leiden, The Netherlands
| | - Mattijn Wagt
- Hogeschool Leiden, P. O. Box 382, 2300 AJ, Leiden, The Netherlands
| | - Isolde van Riemsdijk
- Naturalis Biodiversity Centre, P. O. Box 9517, 2300 RA, Leiden, The Netherlands.,Hogeschool Leiden, P. O. Box 382, 2300 AJ, Leiden, The Netherlands
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5
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Dufresnes C, Litvinchuk SN, Rozenblut-Kościsty B, Rodrigues N, Perrin N, Crochet PA, Jeffries DL. Hybridization and introgression between toads with different sex chromosome systems. Evol Lett 2020; 4:444-456. [PMID: 33014420 PMCID: PMC7523563 DOI: 10.1002/evl3.191] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 01/26/2023] Open
Abstract
The growing interest in the lability of sex determination in non‐model vertebrates such as amphibians and fishes has revealed high rates of sex chromosome turnovers among closely related species of the same clade. Can such lineages hybridize and admix with different sex‐determining systems, or could the changes have precipitated their speciation? We addressed these questions in incipient species of toads (Bufonidae), where we identified a heterogametic transition and characterized their hybrid zone with genome‐wide markers (RADseq). Adult and sibship data confirmed that the common toad B. bufo is female heterogametic (ZW), while its sister species the spined toad B. spinosus is male heterogametic (XY). Analysis of a fine scale transect across their parapatric ranges in southeastern France unveiled a narrow tension zone (∼10 km), with asymmetric mitochondrial and nuclear admixture over hundreds of kilometers southward and northward, respectively. The geographic extent of introgression is consistent with an expansion of B. spinosus across B. bufo’s former ranges in Mediterranean France, as also suggested by species distribution models. However, widespread cyto‐nuclear discordances (B. spinosus backrosses carrying B. bufo mtDNA) run against predictions from the dominance effects of Haldane's rule, perhaps because Y and W heterogametologs are not degenerated. Common and spined toads can thus successfully cross‐breed despite fundamental differences in their sex determination mechanisms, but remain partially separated by reproductive barriers. Whether and how the interactions of their XY and ZW genes contribute to these barriers shall provide novel insights on the debated role of labile sex chromosomes in speciation.
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Affiliation(s)
- Christophe Dufresnes
- LASER College of Biology and the Environment Nanjing Forestry University Nanjing People's Republic of China.,Department of Animal and Plant Sciences University of Sheffield Sheffield United Kingdom
| | - Spartak N Litvinchuk
- Institute of Cytology Russian Academy of Sciences Saint Petersburg Russia.,Dagestan State University Makhachkala Russia
| | - Beata Rozenblut-Kościsty
- Department of Evolutionary Biology and Conservation of Vertebrates Faculty of Biological Sciences University of Wrocław Wrocław Poland
| | - Nicolas Rodrigues
- Department of Ecology & Evolution University of Lausanne Lausanne Switzerland
| | - Nicolas Perrin
- Department of Ecology & Evolution University of Lausanne Lausanne Switzerland
| | - Pierre-André Crochet
- CEFE Univ. Montpellier, CNRS, EPHE, IRD Univ Paul Valéry Montpellier 3 Montpellier France
| | - Daniel L Jeffries
- Department of Ecology & Evolution University of Lausanne Lausanne Switzerland
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6
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Toyama KS, Crochet P, Leblois R. Sampling schemes and drift can bias admixture proportions inferred by
structure. Mol Ecol Resour 2020; 20:1769-1785. [DOI: 10.1111/1755-0998.13234] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 07/17/2020] [Accepted: 07/24/2020] [Indexed: 11/27/2022]
Affiliation(s)
- Ken S. Toyama
- Department of Ecology and Evolutionary Biology University of Toronto Toronto ON Canada
| | - Pierre‐André Crochet
- CEFE CNRS University of Montpellier Université Paul Valéry Montpellier 3 EPHE IRD Montpellier France
| | - Raphaël Leblois
- CBGP INRAE CIRAD IRD Montpellier SupAgro University of Montpellier Montpellier France
- Institut de Biologie Computationnelle University of Montpellier Montpellier France
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7
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McEntee JP, Burleigh JG, Singhal S. Dispersal Predicts Hybrid Zone Widths across Animal Diversity: Implications for Species Borders under Incomplete Reproductive Isolation. Am Nat 2020; 196:9-28. [PMID: 32552108 DOI: 10.1086/709109] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hybrid zones occur as range boundaries for many animal taxa. One model for how hybrid zones form and stabilize is the tension zone model, a version of which predicts that hybrid zone widths are determined by a balance between random dispersal into hybrid zones and selection against hybrids. Here, we examine whether random dispersal and proxies for selection against hybrids (genetic distances between hybridizing pairs) can explain variation in hybrid zone widths across 131 hybridizing pairs of animals. We show that these factors alone can explain ∼40% of the variation in zone width among animal hybrid zones, with dispersal explaining far more of the variation than genetic distances. Patterns within clades were idiosyncratic. Genetic distances predicted hybrid zone widths particularly well for reptiles, while this relationship was opposite tension zone predictions in birds. Last, the data suggest that dispersal and molecular divergence set lower bounds on hybrid zone widths in animals, indicating that there are geographic restrictions on hybrid zone formation. Overall, our analyses reinforce the fundamental importance of dispersal in hybrid zone formation and more generally in the ecology of range boundaries.
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8
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Arntzen JW. An amphibian species pushed out of Britain by a moving hybrid zone. Mol Ecol 2019; 28:5145-5154. [PMID: 31643124 PMCID: PMC6900066 DOI: 10.1111/mec.15285] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 02/06/2023]
Abstract
Classical theory states that hybrid zones will be stable in troughs of low population density where dispersal is hampered. Yet, evidence for moving hybrid zones is mounting. One possible reason that moving zones have been underappreciated is that they may drive themselves into oblivion and with just the superseding species remaining, morphological and genetic signals of past species replacement may be difficult to appreciate. Using genetic data (32 diagnostic single nucleotide polymorphisms) from a clinal hybrid zone of the common toad (Bufo bufo) and the spined toad (Bufo spinosus) in France for comparison, alleles of the latter species were documented in common toads in the south of Great Britain, at frequencies in excess of 10%. Because long distance dispersal across the Channel is unlikely, the conclusion reached was that the continental toad hybrid zone which previously extended into Britain, moved southwards and extirpated B. spinosus. Species distribution models for the mid-Holocene and the present support that climate has locally changed in favour of B. bufo. The system bears resemblance with the demise of Homo neanderthalensis and the rise of Homo sapiens and provides an example that some paleoanthropologists demanded in support of a hominin "leaky replacement" scenario. The toad example is informative just because surviving pure B. spinosus and an extant slowly moving interspecific hybrid zone are available for comparison.
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9
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van Riemsdijk I, Butlin RK, Wielstra B, Arntzen JW. Testing an hypothesis of hybrid zone movement for toads in France. Mol Ecol 2019; 28:1070-1083. [PMID: 30609055 DOI: 10.1111/mec.15005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/08/2018] [Accepted: 12/19/2018] [Indexed: 02/06/2023]
Abstract
Hybrid zone movement may result in substantial unidirectional introgression of selectively neutral material from the local to the advancing species, leaving a genetic footprint. This genetic footprint is represented by a trail of asymmetric tails and displaced cline centres in the wake of the moving hybrid zone. A peak of admixture linkage disequilibrium is predicted to exist ahead of the centre of the moving hybrid zone. We test these predictions of the movement hypothesis in a hybrid zone between common (Bufo bufo) and spined toads (B. spinosus), using 31 nuclear and one mtDNA SNPs along a transect in the northwest of France. Average effective selection in Bufo hybrids is low and clines vary in shape and centre. A weak pattern of asymmetric introgression is inferred from cline discordance of seven nuclear markers. The dominant direction of gene flow is from B. spinosus to B. bufo and is in support of southward movement of the hybrid zone. Conversely, a peak of admixture linkage disequilibrium north of the hybrid zone suggests northward movement. These contrasting results can be explained by reproductive isolation of the B. spinosus and B. bufo gene pools at the southern (B. spinosus) side of the hybrid zone. The joint occurrence of asymmetric introgression and admixture linkage disequilibrium can also be explained by the combination of low dispersal and random genetic drift due to low effective population sizes.
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Affiliation(s)
- Isolde van Riemsdijk
- Taxonomy and Systematics, Naturalis Biodiversity Center, Leiden, The Netherlands.,Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Roger K Butlin
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.,Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Ben Wielstra
- Taxonomy and Systematics, Naturalis Biodiversity Center, Leiden, The Netherlands.,Institute of Biology Leiden, Leiden University, Leiden, The Netherlands.,Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.,Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California
| | - Jan W Arntzen
- Taxonomy and Systematics, Naturalis Biodiversity Center, Leiden, The Netherlands
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10
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Sequeira F, Bessa-Silva A, Tarroso P, Sousa-Neves T, Vallinoto M, Gonçalves H, Martínez-Solano I. Discordant patterns of introgression across a narrow hybrid zone between two cryptic lineages of an Iberian endemic newt. J Evol Biol 2019; 33:202-216. [PMID: 31677317 DOI: 10.1111/jeb.13562] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 10/15/2019] [Accepted: 10/25/2019] [Indexed: 11/30/2022]
Abstract
The study of natural hybrid zones can illuminate aspects of lineage divergence and speciation in morphologically cryptic taxa. We studied a hybrid zone between two highly divergent but morphologically similar lineages (south-western and south-eastern) of the Iberian endemic Bosca's newt (Lissotriton boscai) in SW Iberia with a multilocus dataset (microsatellites, nuclear and mitochondrial genes). STRUCTURE and NEWHYBRIDS analyses retrieved few admixed individuals, which classified as backcrosses involving parental individuals of the south-western lineage. Our results show asymmetric introgression of mtDNA beyond the contact from this lineage into the south-eastern lineage. Analysis of nongeographic introgression patterns revealed asymmetries in the direction of introgression, but except for mtDNA, we did not find evidence for nonconcordant introgression patterns across nuclear loci. Analysis of a 150-km transect across the hybrid zone showed broadly coincident cline widths (ca. 3.2-27.9 km), and concordant cline centres across all markers, except for mtDNA that is displaced ca. 60 km northward. Results from ecological niche modelling show that the hybrid zone is in a climatically homogenous area with suitable habitat for the species, suggesting that contact between the two lineages is unlikely to occur further south as their distributions are currently separated by an extensive area of unfavourable habitat. Taken together, our findings suggest the genetic structure of this hybrid zone results from the interplay of historical (biogeographic) and population-level processes. The narrowness and coincidence of genetic clines can be explained by weak selection against hybrids and reflect a degree of reproductive isolation that is consistent with cryptic speciation.
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Affiliation(s)
- Fernando Sequeira
- Laboratorio Associado, CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Universidade do Porto, Vairão, Portugal
| | - Adam Bessa-Silva
- Laboratório de Evolução (LEVO), Instituto de Estudos Costeiros (IECOS), Universidade Federal do Pará, Pará, Brasil
| | - Pedro Tarroso
- Laboratorio Associado, CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Universidade do Porto, Vairão, Portugal
| | - Tiago Sousa-Neves
- Laboratorio Associado, CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Universidade do Porto, Vairão, Portugal.,Museu Paraense Emílio Goeldi, Coordenação de Zoologia, Pará, Brasil
| | - Marcelo Vallinoto
- Laboratorio Associado, CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Universidade do Porto, Vairão, Portugal.,Laboratório de Evolução (LEVO), Instituto de Estudos Costeiros (IECOS), Universidade Federal do Pará, Pará, Brasil
| | - Helena Gonçalves
- Laboratorio Associado, CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Universidade do Porto, Vairão, Portugal.,Museu de História Natural e da Ciência, Universidade do Porto, Porto, Portugal
| | - Iñigo Martínez-Solano
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, CSIC (MNCN-CSIC), Madrid, Spain
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11
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Pinto BJ, Titus-McQuillan J, Daza JD, Gamble T. Persistence of a Geographically-Stable Hybrid Zone in Puerto Rican Dwarf Geckos. J Hered 2019; 110:523-534. [PMID: 30859222 DOI: 10.1093/jhered/esz015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 03/08/2019] [Indexed: 12/14/2022] Open
Abstract
Determining the mechanisms that create and maintain biodiversity is a central question in ecology and evolution. Speciation is the process that creates biodiversity. Speciation is mediated by incompatibilities that lead to reproductive isolation between divergent populations and these incompatibilities can be observed in hybrid zones. Gecko lizards are a speciose clade possessing an impressive diversity of behavioral and morphological traits. In geckos, however, our understanding of the speciation process is negligible. To address this gap, we used genetic sequence data (both mitochondrial and nuclear markers) to revisit a putative hybrid zone between Sphaerodactylus nicholsi and Sphaerodactylus townsendi in Puerto Rico, initially described in 1984. First, we addressed discrepancies in the literature on the validity of both species. Second, we sampled a 10-km-wide transect across the putative hybrid zone and tested explicit predictions about its dynamics using cline models. Third, we investigated potential causes for the hybrid zone using species distribution modeling and simulations; namely, whether unique climatic variables within the hybrid zone might elicit selection for intermediate phenotypes. We find strong support for the species-level status of each species and no evidence of movement, or unique climatic variables near the hybrid zone. We suggest that this narrow hybrid zone is geographically stable and is maintained by a combination of dispersal and selection. Thus, this work has identified an extant model system within geckos that that can be used for future investigations detailing genetic mechanisms of reproductive isolation in an understudied vertebrate group.
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Affiliation(s)
- Brendan J Pinto
- Department of Biological Sciences, Marquette University, Milwaukee, WI
| | | | - Juan D Daza
- Department of Biological Sciences, Sam Houston State University, Huntsville, TX
| | - Tony Gamble
- Department of Biological Sciences, Marquette University, Milwaukee, WI.,Bell Museum of Natural History, University of Minnesota, Saint Paul, MN.,Milwaukee Public Museum, Milwaukee, WI
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12
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Dufresnes C, Beddek M, Skorinov DV, Fumagalli L, Perrin N, Crochet PA, Litvinchuk SN. Diversification and speciation in tree frogs from the Maghreb (Hyla meridionalis sensu lato), with description of a new African endemic. Mol Phylogenet Evol 2019; 134:291-299. [PMID: 30776435 DOI: 10.1016/j.ympev.2019.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/27/2019] [Accepted: 02/09/2019] [Indexed: 01/27/2023]
Abstract
Comparative molecular studies emphasized a new biogeographic paradigm for the terrestrial fauna of North Africa, one of the last uncharted ecoregions of the Western Palearctic: two independent east-west divisions across the Maghreb. Through a comprehensive phylogeography, we assessed how this model suits the genetic diversification documented for the tree frog Hyla meridionalis sensu lato. Analyses of mtDNA variation and thousands of nuclear loci confirmed the old split (low-Pliocene) between Tunisian and Algerian populations. These lineages meet but barely admix in the eastern Maghreb (Algerian-Tunisian border), a sign of putatively advanced reproductive isolation. In the western Maghreb, we report a Pleistocene divergence between Moroccan and Algerian populations. Tree frogs thus follow both predictions: a double east-west break that gave rise to two suture zones characteristic of North-African phylogeography. Moreover, some intraspecific mtDNA variation is not mirrored by the nuclear data, emphasizing that evolutionary units should always be designated by multilocus approaches. Last but not least, we describe the Tunisian lineage as a new species endemic to Africa.
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Affiliation(s)
- Christophe Dufresnes
- Hintermann & Weber SA, Montreux, Switzerland; Laboratory for Conservation Biology, University of Lausanne, Biophore Building, Lausanne, Switzerland; Department of Animal and Plant Sciences, University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - Menad Beddek
- CEFE, CNRS, University Paul Valéry Montpellier 3, EPHE, Montpellier, France; Naturalia Environnement, Site Agroparc, Avignon, France
| | - Dmitriy V Skorinov
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg, Russia
| | - Luca Fumagalli
- Laboratory for Conservation Biology, University of Lausanne, Biophore Building, Lausanne, Switzerland
| | - Nicolas Perrin
- Department of Ecology & Evolution, University of Lausanne, Biophore Building, Lausanne, Switzerland
| | | | - Spartak N Litvinchuk
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg, Russia; Dagestan State University, Makhachkala, Russia
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Arntzen JW, McAtear J, Butôt R, Martínez-Solano I. A common toad hybrid zone that runs from the Atlantic to the Mediterranean. AMPHIBIA-REPTILIA 2018. [DOI: 10.1163/15685381-00003145] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We document the distribution of the common toadBufo bufoand the spined toadB. spinosusat their contact zone across France with data from a mitochondrial DNA RFLP assay, complementing similar work including nuclear markers in the northwest and southeast of France and in Italy. We also reconstruct geographical clines across the species’ contact zone in central France.Bufo bufois found in the north-eastern half of France.Bufo spinosusis found in the south-western complement. The contact zone they form runs from the Atlantic coast near Caen, France, to the Mediterranean coast near Savona, Italy, and has a length of over 900 km. In central FranceB. bufoandB. spinosusengage in a hybrid zone with a unimodal genetic signature. Hybrid zone width is ca. 10 km at mitochondrial DNA and averages at 61 km for four nuclear loci. The hybrid zone is distinctly asymmetric with a signature ofB. spinosusinB. bufoand not the other way round. We attribute this observation toB. bufomoving southwards at the expense ofB. spinosus, with introgression in the direction of the advancing species. We noted substantial geographic variation in characters for species identification. Morphological species identification performs well in France, but breaks down in Italy. Mitochondrial DNA is inconclusive in south-eastern France and Italy. The nuclear genetic markers perform consistently well but have not yet been applied to the zone in full. Possible, but surely heterogeneous ecological correlates for the position of the hybrid zone are mountains and rivers.
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Affiliation(s)
- Jan W. Arntzen
- Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands
| | - Jacob McAtear
- Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands
| | - Roland Butôt
- Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands
| | - Iñigo Martínez-Solano
- Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands
- Evolution and Development Group, Department of Wetland Ecology, Doñana Biological Station, CSIC, c/ Americo Vespucio s/n, 41092 Seville, Spain
- Present address: Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, CSIC, c/ José Gutiérrez Abascal 2, 28006 Madrid, Spain
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Introgressive replacement of natives by invading Arion pest slugs. Sci Rep 2017; 7:14908. [PMID: 29097725 PMCID: PMC5668256 DOI: 10.1038/s41598-017-14619-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 10/09/2017] [Indexed: 11/09/2022] Open
Abstract
Hybridization with invasive species is one of the major threats to the phenotypic and genetic persistence of native organisms worldwide. Arion vulgaris (syn. lusitanicus) is a major agricultural pest slug that successfully invaded many European countries in recent decades, but its impact on closely related native species remains unclear. Here, we hypothesized that the regional decline of native A. rufus is connected with the spread of invasive A. vulgaris, and tested whether this can be linked to hybridization between the two species by analyzing 625 Arion sp. along altitudinal transects in three regions in Switzerland. In each region, we observed clear evidence of different degrees of genetic admixture, suggesting recurrent hybridization beyond the first generation. We found spatial differences in admixture patterns that might reflect distinct invasion histories among the regions. Our analyses provide a landscape level perspective for the genetic interactions between invasive and native animals during the invasion. We predict that without specific management action, A. vulgaris will further expand its range, which might lead to local extinction of A. rufus and other native slugs in the near future. Similar processes are likely occurring in other regions currently invaded by A. vulgaris.
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15
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Arntzen JW, de Vries W, Canestrelli D, Martínez-Solano I. Hybrid zone formation and contrasting outcomes of secondary contact over transects in common toads. Mol Ecol 2017; 26:5663-5675. [PMID: 28752635 DOI: 10.1111/mec.14273] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 07/21/2017] [Accepted: 07/24/2017] [Indexed: 01/05/2023]
Abstract
Much progress in speciation research stems from documenting patterns of morphological and genetic variation in hybrid zones. Contrasting patterns of marker introgression in different sections of the contact can provide valuable insights on the relative importance of various evolutionary mechanisms maintaining species differences in the face of hybridization and gene flow and on hybrid zone temporal and spatial dynamics. We studied species interactions in the common toads Bufo bufo and B. spinosus in France and northwestern Italy using morphological and molecular data from the mitochondrial and nuclear genomes in an extensive survey, including two independent transects west and east of the Alps. At both, we found sharp, coincident and concordant nuclear genetic transitions. However, morphological clines were wider or absent and mtDNA introgression was asymmetric. We discuss alternative, nonexclusive hypotheses about evolutionary processes generating these patterns, including drift, selection, long-distance dispersal and spatial shifts in hybrid zone location and structure. The distribution of intraspecific mtDNA lineages supports a scenario in which B. bufo held a local refugium during the last glacial maximum. Present-day genetic profiles are best explained by an advance of B. spinosus from a nearby Iberian refugium, largely superseding the local B. bufo population, followed by an advance of B. bufo from the Balkans, with prongs north and south of the Alps, driving B. spinosus southwards. A pendulum moving hybrid zone, first northwards and then southwards, explains the wide areas of introgression at either side of the current position of the contact zones.
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Affiliation(s)
- Jan W Arntzen
- Naturalis Biodiversity Center, Leiden, The Netherlands
| | | | - Daniele Canestrelli
- Department of Ecological and Biological Science, Largo dell'Università s.n.c., Viterbo, Italy
| | - Iñigo Martínez-Solano
- Naturalis Biodiversity Center, Leiden, The Netherlands.,Evolution and Development Group, Department of Wetland Ecology, Doñana Biological Station, CSIC, Seville, Spain
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