1
|
Potter S, Moritz C, Piggott MP, Bragg JG, Afonso Silva AC, Bi K, McDonald-Spicer C, Turakulov R, Eldridge MDB. Museum Skins Enable Identification of Introgression Associated with Cytonuclear Discordance. Syst Biol 2024; 73:579-593. [PMID: 38577768 PMCID: PMC11377193 DOI: 10.1093/sysbio/syae016] [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: 03/10/2022] [Revised: 03/14/2024] [Accepted: 04/03/2024] [Indexed: 04/06/2024] Open
Abstract
Increased sampling of genomes and populations across closely related species has revealed that levels of genetic exchange during and after speciation are higher than previously thought. One obvious manifestation of such exchange is strong cytonuclear discordance, where the divergence in mitochondrial DNA (mtDNA) differs from that for nuclear genes more (or less) than expected from differences between mtDNA and nuclear DNA (nDNA) in population size and mutation rate. Given genome-scale data sets and coalescent modeling, we can now confidently identify cases of strong discordance and test specifically for historical or recent introgression as the cause. Using population sampling, combining exon capture data from historical museum specimens and recently collected tissues we showcase how genomic tools can resolve complex evolutionary histories in the brachyotis group of rock-wallabies (Petrogale). In particular, applying population and phylogenomic approaches we can assess the role of demographic processes in driving complex evolutionary patterns and assess a role of ancient introgression and hybridization. We find that described species are well supported as monophyletic taxa for nDNA genes, but not for mtDNA, with cytonuclear discordance involving at least 4 operational taxonomic units across 4 species which diverged 183-278 kya. ABC modeling of nDNA gene trees supports introgression during or after speciation for some taxon pairs with cytonuclear discordance. Given substantial differences in body size between the species involved, this evidence for gene flow is surprising. Heterogenous patterns of introgression were identified but do not appear to be associated with chromosome differences between species. These and previous results suggest that dynamic past climates across the monsoonal tropics could have promoted reticulation among related species.
Collapse
Affiliation(s)
- Sally Potter
- School of Natural Sciences, 14 Eastern Road, Macquarie University, Macquarie Park, NSW 2109, Australia
- Division of Ecology and Evolution, Research School of Biology, 134 Linnaeus Way, The Australian National University, Acton, ACT 2601, Australia
- Australian Museum Research Institute, Australian Museum, 1 William St, Sydney, NSW 2010, Australia
| | - Craig Moritz
- Division of Ecology and Evolution, Research School of Biology, 134 Linnaeus Way, The Australian National University, Acton, ACT 2601, Australia
| | - Maxine P Piggott
- Division of Ecology and Evolution, Research School of Biology, 134 Linnaeus Way, The Australian National University, Acton, ACT 2601, Australia
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, NT 0811, Australia
| | - Jason G Bragg
- National Herbarium of New South Wales, The Royal Botanical Gardens and Domain Trust, Mrs Macquaries Road, Sydney, NSW 2000, Australia
| | | | - Ke Bi
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Christiana McDonald-Spicer
- Division of Ecology and Evolution, Research School of Biology, 134 Linnaeus Way, The Australian National University, Acton, ACT 2601, Australia
| | - Rustamzhon Turakulov
- Australian Genome Research Facility, Victorian Comprehensive Cancer Centre, 305 Grattan Street, Melbourne, VIC 3000, Australia
- Earth Sciences, College of Science and Engineering, Flinders University GPO Box 2100, Adelaide, SA 5001, Australia
| | - Mark D B Eldridge
- Australian Museum Research Institute, Australian Museum, 1 William St, Sydney, NSW 2010, Australia
| |
Collapse
|
2
|
DeRaad DA, McCullough JM, DeCicco LH, Hime PM, Joseph L, Andersen MJ, Moyle RG. Mitonuclear discordance results from incomplete lineage sorting, with no detectable evidence for gene flow, in a rapid radiation of Todiramphus kingfishers. Mol Ecol 2023; 32:4844-4862. [PMID: 37515525 DOI: 10.1111/mec.17080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/15/2023] [Accepted: 06/19/2023] [Indexed: 07/31/2023]
Abstract
Many organisms possess multiple discrete genomes (i.e. nuclear and organellar), which are inherited separately and may have unique and even conflicting evolutionary histories. Phylogenetic reconstructions from these discrete genomes can yield different patterns of relatedness, a phenomenon known as cytonuclear discordance. In many animals, mitonuclear discordance (i.e. discordant evolutionary histories between the nuclear and mitochondrial genomes) has been widely documented, but its causes are often considered idiosyncratic and inscrutable. We show that a case of mitonuclear discordance in Todiramphus kingfishers can be explained by extensive genome-wide incomplete lineage sorting (ILS), likely a result of the explosive diversification history of this genus. For these kingfishers, quartet frequencies reveal that the nuclear genome is dominated by discordant topologies, with none of the internal branches in our consensus nuclear tree recovered in >50% of genome-wide gene trees. Meanwhile, a lack of inter-species shared ancestry, non-significant pairwise tests for gene flow, and little evidence for meaningful migration edges between species, leads to the conclusion that gene flow cannot explain the mitonuclear discordance we observe. This lack of evidence for gene flow combined with evidence for extensive genome-wide gene tree discordance, a hallmark of ILS, leads us to conclude that the mitonuclear discordance we observe likely results from ILS, specifically deep coalescence of the mitochondrial genome. Based on this case study, we hypothesize that similar demographic histories in other 'great speciator' taxa across the Indo-Pacific likely predispose these groups to high levels of ILS and high likelihoods of mitonuclear discordance.
Collapse
Affiliation(s)
- Devon A DeRaad
- Biodiversity Institute and Natural History Museum, University of Kansas, Lawrence, Kansas, USA
| | - Jenna M McCullough
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Lucas H DeCicco
- Biodiversity Institute and Natural History Museum, University of Kansas, Lawrence, Kansas, USA
| | - Paul M Hime
- Biodiversity Institute and Natural History Museum, University of Kansas, Lawrence, Kansas, USA
| | - Leo Joseph
- Australian National Wildlife Collection, CSIRO National Research Collections Australia, Canberra, Australian Capital Territory, Australia
| | - Michael J Andersen
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Robert G Moyle
- Biodiversity Institute and Natural History Museum, University of Kansas, Lawrence, Kansas, USA
| |
Collapse
|
3
|
Diversity of Land Snail Tribe Helicini (Gastropoda: Stylommatophora: Helicidae): Where Do We Stand after 20 Years of Sequencing Mitochondrial Markers? DIVERSITY 2021. [DOI: 10.3390/d14010024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sequences of mitochondrial genes revolutionized the understanding of animal diversity and continue to be an important tool in biodiversity research. In the tribe Helicini, a prominent group of the western Palaearctic land snail fauna, mitochondrial data accumulating since the 2000s helped to newly delimit genera, inform species-level taxonomy and reconstruct past range dynamics. We combined the published data with own unpublished sequences and provide a detailed overview of what they revealed about the diversity of the group. The delimitation of Helix is revised by placing Helix godetiana back in the genus and new synonymies are suggested within the genera Codringtonia and Helix. The spatial distribution of intraspecific mitochondrial lineages of several species is shown for the first time. Comparisons between species reveal considerable variation in distribution patterns of intraspecific lineages, from broad postglacial distributions to regions with a fine-scale pattern of allopatric lineage replacement. To provide a baseline for further research and information for anyone re-using the data, we thoroughly discuss the gaps in the current dataset, focusing on both taxonomic and geographic coverage. Thanks to the wealth of data already amassed and the relative ease with which they can be obtained, mitochondrial sequences remain an important source of information on intraspecific diversity over large areas and taxa.
Collapse
|
4
|
Dong X, Yi W, Zheng C, Zhu X, Wang S, Xue H, Ye Z, Bu W. Species delimitation of rice seed bugs complex: Insights from mitochondrial genomes and ddRAD‐seq data. ZOOL SCR 2021. [DOI: 10.1111/zsc.12523] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Xue Dong
- Institute of Entomology College of Life Sciences Nankai University Tianjin China
| | - Wenbo Yi
- Department of Biology Xinzhou Teachers University Xinzhou China
| | - Chenguang Zheng
- Institute of Entomology College of Life Sciences Nankai University Tianjin China
| | - Xiuxiu Zhu
- Institute of Entomology College of Life Sciences Nankai University Tianjin China
| | - Shujing Wang
- Institute of Entomology College of Life Sciences Nankai University Tianjin China
| | - Huaijun Xue
- Institute of Entomology College of Life Sciences Nankai University Tianjin China
| | - Zhen Ye
- Institute of Entomology College of Life Sciences Nankai University Tianjin China
| | - Wenjun Bu
- Institute of Entomology College of Life Sciences Nankai University Tianjin China
| |
Collapse
|
5
|
Rivera D, Prates I, Firneno TJ, Rodrigues MT, Caldwell JP, Fujita MK. Phylogenomics, introgression, and demographic history of South American true toads (Rhinella). Mol Ecol 2021; 31:978-992. [PMID: 34784086 DOI: 10.1111/mec.16280] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 10/24/2021] [Accepted: 11/11/2021] [Indexed: 11/28/2022]
Abstract
The effects of genetic introgression on species boundaries and how they affect species' integrity and persistence over evolutionary time have received increased attention. The increasing availability of genomic data has revealed contrasting patterns of gene flow across genomic regions, which impose challenges to inferences of evolutionary relationships and of patterns of genetic admixture across lineages. By characterizing patterns of variation across thousands of genomic loci in a widespread complex of true toads (Rhinella), we assess the true extent of genetic introgression across species thought to hybridize to extreme degrees based on natural history observations and multi-locus analyses. Comprehensive geographic sampling of five large-ranged Neotropical taxa revealed multiple distinct evolutionary lineages that span large geographic areas and, at times, distinct biomes. The inferred major clades and genetic clusters largely correspond to currently recognized taxa; however, we also found evidence of cryptic diversity within taxa. While previous phylogenetic studies revealed extensive mito-nuclear discordance, our genetic clustering analyses uncovered several admixed individuals within major genetic groups. Accordingly, historical demographic analyses supported that the evolutionary history of these toads involved cross-taxon gene flow both at ancient and recent times. Lastly, ABBA-BABA tests revealed widespread allele sharing across species boundaries, a pattern that can be confidently attributed to genetic introgression as opposed to incomplete lineage sorting. These results confirm previous assertions that the evolutionary history of Rhinella was characterized by various levels of hybridization even across environmentally heterogeneous regions, posing exciting questions about what factors prevent complete fusion of diverging yet highly interdependent evolutionary lineages.
Collapse
Affiliation(s)
- Danielle Rivera
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.,Amphibian and Reptile Diversity Research Center, University of Texas at Arlington, TX, USA
| | - Ivan Prates
- Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, MI, USA
| | - Thomas J Firneno
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.,Amphibian and Reptile Diversity Research Center, University of Texas at Arlington, TX, USA
| | - Miguel Trefaut Rodrigues
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Janalee P Caldwell
- Sam Noble Museum & Department of Biology, University of Oklahoma, Norman, Oklahoma, 73072-7029, USA
| | - Matthew K Fujita
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.,Amphibian and Reptile Diversity Research Center, University of Texas at Arlington, TX, USA
| |
Collapse
|
6
|
Yang W, Feiner N, Salvi D, Laakkonen H, Jablonski D, Pinho C, Carretero MA, Sacchi R, Zuffi MAL, Scali S, Plavos K, Pafilis P, Poulakakis N, Lymberakis P, Jandzik D, Schulte U, Aubret F, Badiane A, Perez I de Lanuza G, Abalos J, While GM, Uller T. Population genomics of wall lizards reflects the dynamic history of the Mediterranean Basin. Mol Biol Evol 2021; 39:6413643. [PMID: 34718699 PMCID: PMC8760935 DOI: 10.1093/molbev/msab311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The Mediterranean Basin has experienced extensive change in geology and climate over the past six million years. Yet, the relative importance of key geological events for the distribution and genetic structure of the Mediterranean fauna remains poorly understood. Here, we use population genomic and phylogenomic analyses to establish the evolutionary history and genetic structure of common wall lizards (Podarcis muralis). This species is particularly informative because, in contrast to other Mediterranean lizards, it is widespread across the Iberian, Italian, and Balkan Peninsulas, and in extra-Mediterranean regions. We found strong support for six major lineages within P. muralis, which were largely discordant with the phylogenetic relationship of mitochondrial DNA. The most recent common ancestor of extant P. muralis was likely distributed in the Italian Peninsula, and experienced an “Out-of-Italy” expansion following the Messinian salinity crisis (∼5 Mya), resulting in the differentiation into the extant lineages on the Iberian, Italian, and Balkan Peninsulas. Introgression analysis revealed that both inter- and intraspecific gene flows have been pervasive throughout the evolutionary history of P. muralis. For example, the Southern Italy lineage has a hybrid origin, formed through admixture between the Central Italy lineage and an ancient lineage that was the sister to all other P. muralis. More recent genetic differentiation is associated with the onset of the Quaternary glaciations, which influenced population dynamics and genetic diversity of contemporary lineages. These results demonstrate the pervasive role of Mediterranean geology and climate for the evolutionary history and population genetic structure of extant species.
Collapse
Affiliation(s)
- Weizhao Yang
- Department of Biology, Lund University, Lund, 223 62, Sweden
| | - Nathalie Feiner
- Department of Biology, Lund University, Lund, 223 62, Sweden
| | - Daniele Salvi
- Department of Health, Life and Environmental Sciences, University of L'Aquila, 67100, Italy Coppito L'Aquila
| | - Hanna Laakkonen
- Department of Biology, Lund University, Lund, 223 62, Sweden
| | - Daniel Jablonski
- Department of Zoology, Comenius University, Ilkovičova 6, 842 15, Slovakia in Bratislava, Bratislava
| | - Catarina Pinho
- CIBIO/InBIO Research Centre in Biodiversity and Genetic Resources, Universidade do Porto, Campus de Vairão, 4485-661, Vairão, Portugal
| | - Miguel A Carretero
- CIBIO/InBIO Research Centre in Biodiversity and Genetic Resources, Universidade do Porto, Campus de Vairão, 4485-661, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, R. Campo Alegre, s/n, Porto, 4169 - 007, Portugal
| | - Roberto Sacchi
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, 27100, Italy
| | - Marco A L Zuffi
- Museum Natural History, University of Pisa, Pisa, 56011, Italy
| | - Stefano Scali
- Museum of Natural History of Milan, Milano, 20121, Italy
| | | | - Panayiotis Pafilis
- National & Kapodistrian University of Athens, School of Science, Faculty of Biology, Panepistimiopolis 15701, Athens, Greece
| | - Nikos Poulakakis
- Natural History Museum of Crete, School of Sciences and Engineering, University of Crete, Knossos Avenue, Heraklion, 71409, Greece.,Biology Department, School of Sciences and Engineering, University of Crete, Voutes University Campus, Heraklion, 70013, Greece.,Institute of Molecular Biology and Biotechnology (IMBB), Heraklion, 70013, GreeceFoundation for Research and Technology-Hellas (FORTH)
| | - Petros Lymberakis
- Natural History Museum of Crete, School of Sciences and Engineering, University of Crete, Knossos Avenue, Heraklion, 71409, Greece
| | - David Jandzik
- Department of Zoology, Comenius University, Ilkovičova 6, 842 15, Slovakia in Bratislava, Bratislava
| | - Ulrich Schulte
- Büro für Faunistische Gutachten-Dr. Ulrich Schulte, Kaiserstraße 2, Borgholzhausen, 33829, Germany
| | - Fabien Aubret
- Station d'Ecologie Théorique et Expérimentale, CNRS, 09200, Moulis, France.,School of Molecular and Life Sciences, Curtin University, WA, 6102, Australia
| | - Arnaud Badiane
- IMBE, Aix-Marseille Université, Avignon Université, CNRS, IRD, Marseille, France
| | - Guillem Perez I de Lanuza
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Valencia, APT. 22085, 46071, Spain
| | - Javier Abalos
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Valencia, APT. 22085, 46071, Spain
| | - Geoffrey M While
- School of Natural Sciences, University of Tasmania, Sandy Bay, Tasmania, 7005, Australia
| | - Tobias Uller
- Department of Biology, Lund University, Lund, 223 62, Sweden
| |
Collapse
|
7
|
Xu L, Yu R, Lin X, Zhang B, Li N, Lin K, Zhang D, Bai W. Different rates of pollen and seed gene flow cause branch-length and geographic cytonuclear discordance within Asian butternuts. THE NEW PHYTOLOGIST 2021; 232:388-403. [PMID: 34143496 PMCID: PMC8519134 DOI: 10.1111/nph.17564] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 06/13/2021] [Indexed: 05/03/2023]
Abstract
Topological cytonuclear discordance is commonly observed in plant phylogenetic and phylogeographic studies, yet few studies have attempted to detect two other forms of cytonuclear discordance (branch length and geographical) and to uncover the causes of the discordance. We used the whole nuclear and chloroplast genome data from 80 individual Asian butternuts to reveal the pattern and processes of cytonuclear discordance. Our findings indicate that the chloroplast genome had substantially deeper divergence (branch-length discordance) and a steeper cline in the contact zone (geographic discordance) compared with the nuclear genome. After various hypothesis have been tested, the results suggest that incomplete lineage sorting, positive selection and cytonuclear incompatibility are probably insufficient to explain this pattern. However, isolation-by-distance analysis and gene flow estimation point to a much higher level of gene flow by pollen compared with by seeds, which may have slowed down lineage divergence and mediated wider contact for nuclear genome compared with the chloroplast genome. Altogether, this study highlights a critical role of sex-biased dispersal in causing discordance between the nuclear and plastid genome of Asian butternuts. Given its ubiquity among plants, asymmetric gene flow should be given a high priority in future studies of cytonuclear discordance.
Collapse
Affiliation(s)
- Lin‐Lin Xu
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijing100875China
| | - Rui‐Min Yu
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijing100875China
| | - Xin‐Rui Lin
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijing100875China
| | - Bo‐Wen Zhang
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijing100875China
- Centre for Individualised Infection Medicine (CiiM) & TWINCOREJoint ventures between the Helmholtz‐Centre for Infection Research (HZI) and the Hannover Medical School (MHH)Hannover30625Germany
| | - Nan Li
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijing100875China
| | - Kui Lin
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijing100875China
| | - Da‐Yong Zhang
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijing100875China
| | - Wei‐Ning Bai
- State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijing100875China
| |
Collapse
|
8
|
Firneno TJ, O’Neill JR, Itgen MW, Kihneman TA, Townsend JH, Fujita MK. Delimitation despite discordance: Evaluating the species limits of a confounding species complex in the face of mitonuclear discordance. Ecol Evol 2021; 11:12739-12753. [PMID: 34594535 PMCID: PMC8462145 DOI: 10.1002/ece3.8018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 07/28/2021] [Accepted: 07/30/2021] [Indexed: 11/24/2022] Open
Abstract
The delimitation of species is an essential pursuit of biology, and proper taxonomies are crucial for the assessment and conservation management of organismal diversity. However, delimiting species can be hindered by a number of factors including highly conserved morphologies (e.g., cryptic species), differences in criteria of species concepts, lineages being in the early stages of the speciation or divergence process, and discordance between gene topologies (e.g., mitonuclear discordance). Here we use a taxonomically confounded species complex of toads in Central America that exhibits extensive mitonuclear discordance to test delimitation hypotheses. Our investigation integrates mitochondrial sequences, nuclear SNPs, morphology, and macroecological data to determine which taxonomy best explains the divergence and evolutionary relationships among these toads. We found that a three species taxonomy following the distributions of the nuclear SNP haplotypes offers the best explanation of the species in this complex based off of the integrated data types. Due to the taxonomic instability of this group, we also discuss conservation concerns in the face of improper taxonomic delimitation. Our study provides an empirical and integrative hypothesis testing framework to assess species delimitation hypotheses in the face of cryptic morphology and mitonuclear discordance and highlights the importance that a stable taxonomy has over conservation-related actions.
Collapse
Affiliation(s)
- Thomas J. Firneno
- Department of BiologyUniversity of Texas at ArlingtonArlingtonTXUSA
- Department of Biology, Amphibian and Reptile Diversity Research CenterUniversity of Texas at ArlingtonArlingtonTXUSA
| | | | | | | | - Josiah H. Townsend
- Department of BiologyIndiana University of PennsylvaniaIndianaPAUSA
- Departamento de Ambiente y DesarrolloCentro Zamorano de BiodiversidadEscuela Agrícola Panamericana ZamoranoMunicipalidad de San Antonio de OrienteFrancisco MorazánHonduras
| | - Matthew K. Fujita
- Department of BiologyUniversity of Texas at ArlingtonArlingtonTXUSA
- Department of Biology, Amphibian and Reptile Diversity Research CenterUniversity of Texas at ArlingtonArlingtonTXUSA
| |
Collapse
|
9
|
Caeiro-Dias G, Rocha S, Couto A, Pereira C, Brelsford A, Crochet PA, Pinho C. Nuclear phylogenies and genomics of a contact zone establish the species rank of Podarcis lusitanicus (Squamata, Lacertidae). Mol Phylogenet Evol 2021; 164:107270. [PMID: 34352374 DOI: 10.1016/j.ympev.2021.107270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 05/19/2021] [Accepted: 07/26/2021] [Indexed: 11/27/2022]
Abstract
Unravelling when divergent lineages constitute distinct species can be challenging, particularly in complex scenarios combining cryptic diversity and phylogenetic discordances between different types of molecular markers. Combining a phylogenetic approach with the study of contact zones can help to overcome such difficulties. The Podarcis hispanicus species complex has proven to be prosperous in independent evolutionary units, sometimes associated with cryptic diversity. Previous studies have revealed that one of the species of this complex, P. guadarramae, comprises two deeply divergent yet morphologically indistinguishable evolutionary units, currently regarded as subspecies (P. g. guadarramae and P. g. lusitanicus). In this study we used molecular data to address the systematics of the two lineages of Podarcis guadarramae and the closely related P. bocagei. Firstly, we reconstructed the species tree of these three and two additional taxa based on 30 nuclear loci using the multispecies coalescent with and without gene flow. Secondly, we used SNPs obtained from RADseq data to analyze the population structure across the distribution limits P. g. lusitanicus and P. g. guadarramae, and for comparison, a contact zone between P. bocagei and P. g. lusitanicus. Nuclear phylogenetic relationships between these three taxa are clearly difficult to determine due to the influence of gene flow, but our results give little support to the monophyly of P. guadarramae, potentially due to a nearly simultaneous divergence between them. Genetic structure and geographic cline analysis revealed that the two lineages of P. guadarramae replace each other abruptly across the sampled region and that gene flow is geographically restricted, implying the existence of strong reproductive isolation. Podarcis bocagei and P. g. lusitanicus show a similar degree of genetic differentiation and reproductive isolation, with very low levels of admixture in syntopy. These results support that all three forms are equally differentiated and reproductively isolated. In consequence, we conclude that the two former subspecies of Podarcis guadarramae constitute valid, yet cryptic species, that should be referred to as P. lusitanicus and P. guadarramae.
Collapse
Affiliation(s)
- Guilherme Caeiro-Dias
- Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBio, Vairão, Portugal.
| | - Sara Rocha
- CINBIO, Universidade de Vigo, 36310 Vigo, España; Instituto de Investigación Sanitaria Galicia Sur, Hospital Álvaro Cunqueiro, 36213 Vigo, España
| | - Alvarina Couto
- Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBio, Vairão, Portugal
| | - Carolina Pereira
- Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBio, Vairão, Portugal
| | - Alan Brelsford
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland; Biology Department, University of California Riverside, CA, USA
| | | | - Catarina Pinho
- Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBio, Vairão, Portugal
| |
Collapse
|
10
|
Holding ML, Sovic MG, Colston TJ, Gibbs HL. The scales of coevolution: comparative phylogeography and genetic demography of a locally adapted venomous predator and its prey. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa192] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Abstract
Coevolutionary theory predicts that differences in the genetic demography of interacting species can influence patterns of local adaptation by affecting the potential of local populations to respond to selection. We conducted a comparative phylogeographical study of venomous rattlesnakes and their venom-resistant ground squirrel prey across California, and assessed how effective population size (Ne) estimates correspond with a previously documented pattern of rattlesnake local adaptation. Using RAD sequencing markers, we detected lineage relationships among both the rattlesnakes (Crotalus oreganus ssp.) and ground squirrels (Otospermophilus sp.) that are incongruent with previous phylogenetic hypotheses. Both rattlesnakes and squirrels share a deep divergence at the Sacramento–San Joaquin River Delta. At this broad phylogeographical scale, we found that the locally adapted rattlesnakes had higher Ne than squirrels. At the population scale, snakes also had larger Ne accompanied by larger values of several metrics of population genetic diversity. However, the specific magnitude of local adaptation of venom activity to ground squirrel venom resistance was not significantly correlated with local differences in Ne or other diversity statistics between predator and prey populations, suggesting that other factors in the geographic mosaic of coevolution contribute to the specific local-scale outcomes of this interaction. These results suggest an evolutionary mechanism that may explain some (but clearly not all) of rattlesnake local adaptation in this coevolutionary interaction – larger population sizes raise the adaptive potential of rattlesnakes compared to ground squirrels.
Collapse
Affiliation(s)
- Matthew L Holding
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH, USA
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Michael G Sovic
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH, USA
| | - Timothy J Colston
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - H Lisle Gibbs
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH, USA
| |
Collapse
|
11
|
Streicher JW, Day JJ. The toad's warts: Discordance creates bumpy expectations of mitochondrial-nuclear evolution between species. Mol Ecol 2020; 29:3400-3402. [PMID: 32743830 DOI: 10.1111/mec.15568] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 07/27/2020] [Indexed: 11/30/2022]
Abstract
Discordance between the mitochondrial and nuclear genomes is a prevalent phenomenon in nature, in which the underlying processes responsible are considered to be important in shaping genetic variation in natural populations. Among the evolutionary processes that best explain such genomic mismatches incomplete lineage sorting and introgression are commonly identified, however, many studies are unable to distinguish between these hypotheses, which has become a major challenge in the field. In this issue of Molecular Ecology, Firneno et al. (2020) present an elegant exploration of mitochondrial-nuclear discordance in Mesoamerican toads. Integrating genome-scale and spatial data to test between these hypotheses within an empirical model testing framework, they find strong support that incomplete lineage sorting explains the observed discordance. Their work, along with many previous articles in Molecular Ecology, highlights the commonality of mito-nuclear discordance among species despite the expectations of tightly concerted mitochondrial and nuclear genome evolution. It is increasingly clear that the nuclear genomes of many species are (at least for short periods of evolutionary time) functionally compatible with multiple, divergent mitochondrial haplotypes. As such, we suggest future research not only seeks to understand the processes causing spatial mito-nuclear discordance (e.g. incomplete lineage sorting, introgression), but also explores those that maintain discordance through time and space (e.g. relaxed selection on mito-nuclear interactions, heterozygosity, population demographics). We also discuss the vital role that taxonomy plays in interpreting patterns of mito-nuclear discordance when data-consistent yet differing taxonomies are used, such as treating allopatrically distributed taxa as multiple isolated populations versus multiple micro-endemic species.
Collapse
Affiliation(s)
| | - Julia J Day
- Department of Genetics, Evolution and Environment, University College London, London, UK
| |
Collapse
|
12
|
Firneno TJ, O'Neill JR, Portik DM, Emery AH, Townsend JH, Fujita MK. Finding complexity in complexes: Assessing the causes of mitonuclear discordance in a problematic species complex of Mesoamerican toads. Mol Ecol 2020; 29:3543-3559. [PMID: 32500624 DOI: 10.1111/mec.15496] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/18/2020] [Accepted: 05/26/2020] [Indexed: 12/22/2022]
Abstract
Mitonuclear discordance is a frequently encountered pattern in phylogeographic studies and occurs when mitochondrial and nuclear DNA display conflicting signals. Discordance among these genetic markers can be caused by several factors including confounded taxonomies, gene flow, and incomplete lineage sorting. In this study, we present a strong case of mitonuclear discordance in a species complex of toads (Bufonidae: Incilius coccifer complex) found in the Chortís Block of Central America. To determine the cause of mitonuclear discordance in this complex, we used spatially explicit genetic data to test species limits and relationships, characterize demographic history, and quantify gene flow. We found extensive mitonuclear discordance among the three recognized species within this group, especially in populations within the Chortís Highlands of Honduras. Our data reveal nuclear introgression within the Chortís Highlands populations that was most probably driven by cyclical range expansions due to climatic fluctuations. Though we determined introgression occurred within the nuclear genome, our data suggest that it is not the key factor in driving mitonuclear discordance in the entire species complex. Rather, due to a lack of discernible geographic pattern between mitochondrial and nuclear DNA, as well as a relatively recent divergence time of this complex, we concluded that mitonuclear discordance has been caused by incomplete lineage sorting. Our study provides a framework to test sources of mitonuclear discordance and highlights the importance of using multiple marker types to test species boundaries in cryptic species.
Collapse
Affiliation(s)
- Thomas J Firneno
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.,Amphibian and Reptile Diversity Research Center, Department of Biology, University of Texas at Arlington, Arlington, TX, USA
| | - Justin R O'Neill
- Department of Biology, Indiana University of Pennsylvania, Indiana, PA, USA
| | | | - Alyson H Emery
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA
| | - Josiah H Townsend
- Department of Biology, Indiana University of Pennsylvania, Indiana, PA, USA.,Centro Zamorano de Biodiversidad, Departamento de Ambiente y Desarrollo, Escuela Agrícola Panamericana Zamorano, Municipalidad de San Antonio de Oriente, Francisco Morazán, Honduras
| | - Matthew K Fujita
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.,Amphibian and Reptile Diversity Research Center, Department of Biology, University of Texas at Arlington, Arlington, TX, USA
| |
Collapse
|
13
|
Mao X, Rossiter SJ. Genome-wide data reveal discordant mitonuclear introgression in the intermediate horseshoe bat (Rhinolophus affinis). Mol Phylogenet Evol 2020; 150:106886. [PMID: 32534185 DOI: 10.1016/j.ympev.2020.106886] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 06/01/2020] [Accepted: 06/03/2020] [Indexed: 10/24/2022]
Abstract
Closely related taxa often exhibit mitonuclear discordance attributed to introgression of mitochondrial DNA (mtDNA), yet few studies have considered the underlying causes of mtDNA introgression. Here we test for demographic versus adaptive processes as explanations for mtDNA introgression in three subspecies of the intermediate horseshoe bat (Rhinolophus affinis). We generated sequences of 1692 nuclear genes and 13 mitochondrial protein-coding genes for 48 individuals. Phylogenetic reconstructions based on 320 exon sequences and 2217 single nucleotide polymorphisms (SNPs) both revealed conflicts between the species tree and mtDNA tree. These results, together with geographic patterns of mitonuclear discordance, and shared identical or near-identical mtDNA sequences, suggest extensive introgression of mtDNA between the two parapatric mainland subspecies. Under demographic hypotheses, we would also expect to uncover traces of ncDNA introgression, however, population structure and gene flow analyses revealed little nuclear admixture. Furthermore, we found inconsistent estimates of the timing of population expansion and that of the most recent common ancestor for the clade containing introgressed haplotypes. Without a clear demographic explanation, we also examined whether introgression likely arises from adaptation. We found that five mtDNA genes contained fixed amino acid differences between introgressed and non-introgressed individuals, including putative positive selection found in one codon, although this did not show introgression. While our evidence for rejecting demographic hypotheses is arguably stronger than that for rejecting adaptation, we find no definitive support for either explanation. Future efforts will focus on larger-scale resequencing to decipher the underlying causes of discordant mitonuclear introgression in this system.
Collapse
Affiliation(s)
- Xiuguang Mao
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200062, China; Institute of Eco-Chongming (IEC), East China Normal University, Shanghai 200062, China.
| | - Stephen J Rossiter
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK.
| |
Collapse
|
14
|
Bagley JC, Heming NM, Gutiérrez EE, Devisetty UK, Mock KE, Eckert AJ, Strauss SH. Genotyping-by-sequencing and ecological niche modeling illuminate phylogeography, admixture, and Pleistocene range dynamics in quaking aspen ( Populus tremuloides). Ecol Evol 2020; 10:4609-4629. [PMID: 32551047 PMCID: PMC7297775 DOI: 10.1002/ece3.6214] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/23/2020] [Accepted: 02/24/2020] [Indexed: 01/01/2023] Open
Abstract
Populus tremuloides is the widest-ranging tree species in North America and an ecologically important component of mesic forest ecosystems displaced by the Pleistocene glaciations. Using phylogeographic analyses of genome-wide SNPs (34,796 SNPs, 183 individuals) and ecological niche modeling, we inferred population structure, ploidy levels, admixture, and Pleistocene range dynamics of P. tremuloides, and tested several historical biogeographical hypotheses. We found three genetic lineages located mainly in coastal-Cascades (cluster 1), east-slope Cascades-Sierra Nevadas-Northern Rockies (cluster 2), and U.S. Rocky Mountains through southern Canadian (cluster 3) regions of the P. tremuloides range, with tree graph relationships of the form ((cluster 1, cluster 2), cluster 3). Populations consisted mainly of diploids (86%) but also small numbers of triploids (12%) and tetraploids (1%), and ploidy did not adversely affect our genetic inferences. The main vector of admixture was from cluster 3 into cluster 2, with the admixture zone trending northwest through the Rocky Mountains along a recognized phenotypic cline (Utah to Idaho). Clusters 1 and 2 provided strong support for the "stable-edge hypothesis" that unglaciated southwestern populations persisted in situ since the last glaciation. By contrast, despite a lack of clinal genetic variation, cluster 3 exhibited "trailing-edge" dynamics from niche suitability predictions signifying complete northward postglacial expansion. Results were also consistent with the "inland dispersal hypothesis" predicting postglacial assembly of Pacific Northwestern forest ecosystems, but rejected the hypothesis that Pacific-coastal populations were colonized during outburst flooding from glacial Lake Missoula. Overall, congruent patterns between our phylogeographic and ecological niche modeling results and fossil pollen data demonstrate complex mixtures of stable-edge, refugial locations, and postglacial expansion within P. tremuloides. These findings confirm and refine previous genetic studies, while strongly supporting a distinct Pacific-coastal genetic lineage of quaking aspen.
Collapse
Affiliation(s)
- Justin C. Bagley
- Plant Evolutionary Genomics LaboratoryDepartment of BiologyVirginia Commonwealth UniversityRichmondVAUSA
- Departamento de ZoologiaInstituto de Ciências BiológicasUniversidade de BrasíliaBrasíliaBrazil
| | - Neander M. Heming
- Departamento de ZoologiaInstituto de Ciências BiológicasUniversidade de BrasíliaBrasíliaBrazil
| | - Eliécer E. Gutiérrez
- Departamento de ZoologiaInstituto de Ciências BiológicasUniversidade de BrasíliaBrasíliaBrazil
- Programa de Pos‐Graduação em Biodiversidade AnimalCentro de Ciências Naturais e ExatasUniversidade Federal de Santa MariaSanta MariaBrazil
| | | | - Karen E. Mock
- Department of Wildland Resources and Ecology CenterUtah State UniversityLoganUTUSA
| | - Andrew J. Eckert
- Plant Evolutionary Genomics LaboratoryDepartment of BiologyVirginia Commonwealth UniversityRichmondVAUSA
| | - Steven H. Strauss
- Department of Forest Ecosystems and SocietyOregon State UniversityCorvallisORUSA
| |
Collapse
|
15
|
Dufresnes C, Nicieza AG, Litvinchuk SN, Rodrigues N, Jeffries DL, Vences M, Perrin N, Martínez-Solano Í. Are glacial refugia hotspots of speciation and cytonuclear discordances? Answers from the genomic phylogeography of Spanish common frogs. Mol Ecol 2020; 29:986-1000. [PMID: 32012388 DOI: 10.1111/mec.15368] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 12/16/2022]
Abstract
Subdivided Pleistocene glacial refugia, best known as "refugia within refugia", provided opportunities for diverging populations to evolve into incipient species and/or to hybridize and merge following range shifts tracking the climatic fluctuations, potentially promoting extensive cytonuclear discordances and "ghost" mtDNA lineages. Here, we tested which of these opposing evolutionary outcomes prevails in northern Iberian areas hosting multiple historical refugia of common frogs (Rana cf. temporaria), based on a genomic phylogeography approach (mtDNA barcoding and RAD-sequencing). We found evidence for both incipient speciation events and massive cytonuclear discordances. On the one hand, populations from northwestern Spain (Galicia and Asturias, assigned to the regional endemic R. parvipalmata), are deeply-diverged at mitochondrial and nuclear genomes (~4 My of independent evolution), and barely admix with northeastern populations (assigned to R. temporaria sensu stricto) across a narrow hybrid zone (~25 km) located in the Cantabrian Mountains, suggesting that they represent distinct species. On the other hand, the most divergent mtDNA clade, widespread in Cantabria and the Basque country, shares its nuclear genome with other R. temporaria s. s. lineages. Patterns of population expansions and isolation-by-distance among these populations are consistent with past mitochondrial capture and/or drift in generating and maintaining this ghost mitochondrial lineage. This remarkable case study emphasizes the complex evolutionary history that shaped the present genetic diversity of refugial populations, and stresses the need to revisit their phylogeography by genomic approaches, in order to make informed taxonomic inferences.
Collapse
Affiliation(s)
- Christophe Dufresnes
- LASER, College of Biology and the Environment, Nanjing Forestry University, Nanjing, China.,Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Alfredo G Nicieza
- Department of Organisms and Systems Biology, University of Oviedo, Oviedo, Spain.,Research Unit of Biodiversity (UMIB, CSIC-UO-PA), Mieres, Spain
| | - Spartak N Litvinchuk
- Institute of Cytology, Russian Academy of Sciences, Saint Petersburg, Russia.,Dagestan State University, Makhachkala, Russia
| | - Nicolas Rodrigues
- Department of Ecology & Evolution, University of Lausanne, Lausanne, Switzerland
| | - Daniel L Jeffries
- Department of Ecology & Evolution, University of Lausanne, Lausanne, Switzerland
| | - Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Nicolas Perrin
- Department of Ecology & Evolution, University of Lausanne, Lausanne, Switzerland
| | - Íñigo Martínez-Solano
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
| |
Collapse
|
16
|
Dufresnes C, Mazepa G, Jablonski D, Oliveira RC, Wenseleers T, Shabanov DA, Auer M, Ernst R, Koch C, Ramírez-Chaves HE, Mulder KP, Simonov E, Tiutenko A, Kryvokhyzha D, Wennekes PL, Zinenko OI, Korshunov OV, Al-Johany AM, Peregontsev EA, Masroor R, Betto-Colliard C, Denoël M, Borkin LJ, Skorinov DV, Pasynkova RA, Mazanaeva LF, Rosanov JM, Dubey S, Litvinchuk S. Fifteen shades of green: The evolution of Bufotes toads revisited. Mol Phylogenet Evol 2019; 141:106615. [DOI: 10.1016/j.ympev.2019.106615] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/14/2019] [Accepted: 09/10/2019] [Indexed: 01/01/2023]
|
17
|
Larsen PA, Matocq MD. Emerging genomic applications in mammalian ecology, evolution, and conservation. J Mammal 2019. [DOI: 10.1093/jmammal/gyy184] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Peter A Larsen
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, MN, USA
| | - Marjorie D Matocq
- Department of Natural Resources and Environmental Science; Program in Ecology, Evolution, and Conservation Biology, University of Nevada, Reno, NV, USA
| |
Collapse
|
18
|
McCartney-Melstad E, Gidiş M, Shaffer HB. Population genomic data reveal extreme geographic subdivision and novel conservation actions for the declining foothill yellow-legged frog. Heredity (Edinb) 2018; 121:112-125. [PMID: 29941996 PMCID: PMC6039490 DOI: 10.1038/s41437-018-0097-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 04/17/2018] [Accepted: 05/13/2018] [Indexed: 12/25/2022] Open
Abstract
Genomic data have the potential to inform high resolution landscape genetic and biological conservation studies that go far beyond recent mitochondrial and microsatellite analyses. We characterize the relationships of populations of the foothill yellow-legged frog, Rana boylii, a declining, "sentinel" species for stream ecosystems throughout its range in California and Oregon. We generated RADseq data and applied phylogenetic methods, hierarchical Bayesian clustering, PCA and population differentiation with admixture analyses to characterize spatial genetic structure across the species range. To facilitate direct comparison with previous analyses, we included many localities and individuals from our earlier work based on mitochondrial DNA. The results are striking, and emphasize the power of our landscape genomic approach. We recovered five extremely differentiated primary clades that indicate that R. boylii may be the most genetically differentiated anuran yet studied. Our results provide better resolution and more spatially consistent patterns than our earlier work, confirming the increased resolving power of genomic data compared to single-locus studies. Genomic structure is not equal across the species distribution. Approximately half the range of R. boylii consists of a single, relatively uniform population, while Sierra Nevada and coastal California clades are deeply, hierarchically substructured with biogeographic breaks observed in other codistributed taxa. Our results indicate that clades should serve as management units for R. boylii rather than previously suggested watershed boundaries, and that the near-extinct population from southwestern California is particularly diverged, exhibits the lowest genetic diversity, and is a critical conservation target for species recovery.
Collapse
Affiliation(s)
- Evan McCartney-Melstad
- Department of Ecology and Evolutionary Biology, La Kretz Center for California Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA, USA.
| | - Müge Gidiş
- Department of Ecology and Evolutionary Biology, La Kretz Center for California Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA, USA
- Kütahya School of Health, Dumlupınar University, Kütahya, Turkey
| | - H Bradley Shaffer
- Department of Ecology and Evolutionary Biology, La Kretz Center for California Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA, USA
| |
Collapse
|
19
|
Li X, Shen X, Chen X, Xiang D, Murphy RW, Shen Y. Detection of Potential Problematic Cytb Gene Sequences of Fishes in GenBank. Front Genet 2018; 9:30. [PMID: 29467794 PMCID: PMC5808227 DOI: 10.3389/fgene.2018.00030] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/22/2018] [Indexed: 02/05/2023] Open
Abstract
Fishes are, by far, the most diverse group of vertebrates. Their classification relies heavily on morphology. In practice, the correct morphological identification of species often depends on personal experience because many species vary in their body shape, color and other external characters. Thus, the identification of a species may be prone to errors. Due to the rapid development of molecular biology, the number of sequences of fishes deposited in GenBank has grown explosively. These published data likely contain errors owing to invalid or incorrectly identified species. The erroneous data can lead to downstream problems. Thus, it is critical that such errors get identified and corrected. A strategy based on DNA barcoding can detect potentially erroneous data, especially when intraspecific K2P variation exceeds interspecific K2P divergence. Analyses of the most used DNA marker for fishes (mitochondrial Cytb) discovers that intraspecific differences of fishes are generally less than 1%, while interspecific differences are generally higher than 10%. Based on this ruler, our analyses identify 1,303 potential problematic Cytb sequences of fishes in GenBank and point to taxonomic problems, errors in identification, genetic introgression and other concerns. Care must be taken to avoid the perpetuation of errors when using these available data.
Collapse
Affiliation(s)
- Xiaobing Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xuejuan Shen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xiao Chen
- College of Marine Sciences, South China Agricultural University, Guangzhou, China
| | - Dan Xiang
- Joint Influenza Research Centre (SUMC/HKU), Shantou University Medical College, Shantou, China
| | - Robert W. Murphy
- Centre for Biodiversity and Conservation Biology, Royal Ontario Museum, Toronto, ON, Canada
| | - Yongyi Shen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Joint Influenza Research Centre (SUMC/HKU), Shantou University Medical College, Shantou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
- *Correspondence: Yongyi Shen
| |
Collapse
|