1
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Opatova V, Bourguignon K, Bond JE. Species delimitation with limited sampling: An example from rare trapdoor spider genus Cyclocosmia (Mygalomorphae, Halonoproctidae). Mol Ecol Resour 2024; 24:e13894. [PMID: 37971187 DOI: 10.1111/1755-0998.13894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/24/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023]
Abstract
The outcome of species delimitation depends on many factors, including conceptual framework, study design, data availability, methodology employed and subjective decision making. Obtaining sufficient taxon sampling in endangered or rare taxa might be difficult, particularly when non-lethal tissue collection cannot be utilized. The need to avoid overexploitation of the natural populations may thus limit methodological framework available for downstream data analyses and bias the results. We test species boundaries in rare North American trapdoor spider genus Cyclocosmia Ausserer (1871) inhabiting the Southern Coastal Plain biodiversity hotspot with the use of genomic data and two multispecies coalescent model methods. We evaluate the performance of each methodology within a limited sampling framework. To mitigate the risk of species over splitting, common in taxa with highly structured populations, we subsequently implement a species validation step via genealogical diversification index (gdi), which accounts for both genetic isolation and gene flow. We delimited eight geographically restricted lineages within sampled North American Cyclocosmia, suggesting that major river drainages in the region are likely barriers to dispersal. Our results suggest that utilizing BPP in the species discovery step might be a good option for datasets comprising hundreds of loci, but fewer individuals, which may be a common scenario for rare taxa. However, we also show that such results should be validated via gdi, in order to avoid over splitting.
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Affiliation(s)
- Vera Opatova
- Department of Zoology, Faculty of Sciences, Charles University, Prague 2, Czech Republic
| | - Kellie Bourguignon
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Jason E Bond
- Department of Entomology and Nematology, University of California, Davis, California, USA
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2
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Pang XX, Zhang DY. Detection of Ghost Introgression Requires Exploiting Topological and Branch Length Information. Syst Biol 2024:syad077. [PMID: 38224495 DOI: 10.1093/sysbio/syad077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Indexed: 01/17/2024] Open
Abstract
In recent years, the study of hybridization and introgression has made significant progress, with ghost introgression-the transfer of genetic material from extinct or unsampled lineages to extant species-emerging as a key area for research. Accurately identifying ghost introgression, however, presents a challenge. To address this issue, we focused on simple cases involving three species with a known phylogenetic tree. Using mathematical analyses and simulations, we evaluated the performance of popular phylogenetic methods, including HyDe and PhyloNet/MPL, and the full-likelihood method, Bayesian Phylogenetics and Phylogeography (BPP), in detecting ghost introgression. Our findings suggest that heuristic approaches relying on site-pattern counts or gene-tree topologies struggle to differentiate ghost introgression from introgression between sampled non-sister species, frequently leading to incorrect identification of donor and recipient species. The full-likelihood method BPP using multilocus sequence alignments directly-hence taking into account both gene-tree topologies and branch lengths, by contrast, is capable of detecting ghost introgression in phylogenomic datasets. We analyzed a real-world phylogenomic dataset of 14 species of Jaltomata (Solanaceae) to showcase the potential of full-likelihood methods for accurate inference of introgression.
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Affiliation(s)
- Xiao-Xu Pang
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Da-Yong Zhang
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, China
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3
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Thawornwattana Y, Seixas F, Yang Z, Mallet J. Major patterns in the introgression history of Heliconius butterflies. eLife 2023; 12:RP90656. [PMID: 38108819 PMCID: PMC10727504 DOI: 10.7554/elife.90656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023] Open
Abstract
Gene flow between species, although usually deleterious, is an important evolutionary process that can facilitate adaptation and lead to species diversification. It also makes estimation of species relationships difficult. Here, we use the full-likelihood multispecies coalescent (MSC) approach to estimate species phylogeny and major introgression events in Heliconius butterflies from whole-genome sequence data. We obtain a robust estimate of species branching order among major clades in the genus, including the 'melpomene-silvaniform' group, which shows extensive historical and ongoing gene flow. We obtain chromosome-level estimates of key parameters in the species phylogeny, including species divergence times, present-day and ancestral population sizes, as well as the direction, timing, and intensity of gene flow. Our analysis leads to a phylogeny with introgression events that differ from those obtained in previous studies. We find that Heliconius aoede most likely represents the earliest-branching lineage of the genus and that 'silvaniform' species are paraphyletic within the melpomene-silvaniform group. Our phylogeny provides new, parsimonious histories for the origins of key traits in Heliconius, including pollen feeding and an inversion involved in wing pattern mimicry. Our results demonstrate the power and feasibility of the full-likelihood MSC approach for estimating species phylogeny and key population parameters despite extensive gene flow. The methods used here should be useful for analysis of other difficult species groups with high rates of introgression.
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Affiliation(s)
| | - Fernando Seixas
- Department of Organismic and Evolutionary Biology, Harvard UniversityCambridgeUnited States
| | - Ziheng Yang
- Department of Genetics, Evolution and Environment, University College LondonLondonUnited Kingdom
| | - James Mallet
- Department of Organismic and Evolutionary Biology, Harvard UniversityCambridgeUnited States
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4
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Flouri T, Jiao X, Huang J, Rannala B, Yang Z. Efficient Bayesian inference under the multispecies coalescent with migration. Proc Natl Acad Sci U S A 2023; 120:e2310708120. [PMID: 37871206 PMCID: PMC10622872 DOI: 10.1073/pnas.2310708120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 08/15/2023] [Indexed: 10/25/2023] Open
Abstract
Analyses of genome sequence data have revealed pervasive interspecific gene flow and enriched our understanding of the role of gene flow in speciation and adaptation. Inference of gene flow using genomic data requires powerful statistical methods. Yet current likelihood-based methods involve heavy computation and are feasible for small datasets only. Here, we implement the multispecies-coalescent-with-migration model in the Bayesian program bpp, which can be used to test for gene flow and estimate migration rates, as well as species divergence times and population sizes. We develop Markov chain Monte Carlo algorithms for efficient sampling from the posterior, enabling the analysis of genome-scale datasets with thousands of loci. Implementation of both introgression and migration models in the same program allows us to test whether gene flow occurred continuously over time or in pulses. Analyses of genomic data from Anopheles mosquitoes demonstrate rich information in typical genomic datasets about the mode and rate of gene flow.
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Affiliation(s)
- Tomáš Flouri
- Department of Genetics, Evolution, and Environment, University College London, LondonWC1E 6BT, United Kingdom
| | - Xiyun Jiao
- Department of Statistics and Data Science, China Southern University of Science and Technology, Shenzhen518055, China
| | - Jun Huang
- Department of Intelligent Medical Engineering, School of Biomedical Engineering, Capital Medical University, Beijing100069, China
| | - Bruce Rannala
- Department of Evolution and Ecology, University of California, Davis, CA95616
| | - Ziheng Yang
- Department of Genetics, Evolution, and Environment, University College London, LondonWC1E 6BT, United Kingdom
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5
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Ma N, Ma D, Liu X, Zhao L, Ma L, Ma D, Dong S. Bisphenol P exposure in C57BL/6 mice caused gut microbiota dysbiosis and induced intestinal barrier disruption via LPS/TLR4/NF-κB signaling pathway. Environ Int 2023; 175:107949. [PMID: 37126915 DOI: 10.1016/j.envint.2023.107949] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/30/2023] [Accepted: 04/20/2023] [Indexed: 05/03/2023]
Abstract
Despite being one of the most world's widely used and mass-produced compounds, bisphenol A (BPA) has a wide range of toxic effects. Bisphenol P (BPP), an alternative to BPA, has been detected in many foods. The effects of BPP dietary exposure on gut microbiota and the intestinal barrier were unclear. We designed three batches of animal experiments: The first studied mice were exposed to BPP (30 µg/kg BW/day) for nine weeks and found that they gained weight and developed dysbiosis of the gut microbiota. The second, using typical human exposure levels (L, 0.3 µg/kg BW/day BPP) and higher concentrations (M, 30 µg/kg BW/day BPP; H, 3000 µg/kg BW/day BPP), caused gut microbiota dysbiosis in mice, activated the Lipopolysaccharide (LPS) /TLR4/NF-κB signaling pathway, triggered an inflammatory response, increased intestinal permeability, and promoted bacterial translocation leading to intestinal barrier disruption. The third treatment used a combination of antibiotics and alleviated intestinal inflammation and injury. This study demonstrated the mechanism of injury and concentration effects of intestinal damage caused by BPP exposure, providing reference data for BPP use and control and yielding new insights for human disease prevention.
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Affiliation(s)
- Nana Ma
- College of Life Science, Hebei University, Baoding, Hebei 071002, China
| | - Diao Ma
- College of Life Science, Hebei University, Baoding, Hebei 071002, China
| | - Xia Liu
- College of Life Science, Hebei University, Baoding, Hebei 071002, China
| | - Lining Zhao
- College of Life Science, Hebei University, Baoding, Hebei 071002, China
| | - Lei Ma
- College of Life Science, Hebei University, Baoding, Hebei 071002, China
| | - Dan Ma
- College of Life Science, Hebei University, Baoding, Hebei 071002, China
| | - Sijun Dong
- College of Life Science, Hebei University, Baoding, Hebei 071002, China.
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Vieira JPS, Selbach-Schnadelbach A, Braz M, Ribeiro PL, van den Berg C, Oliveira RP. Coalescent-Based Species Delimitation in Herbaceous Bamboos (Bambusoideae, Olyreae) from Eastern Brazil: Implications for Taxonomy and Conservation in a Group with Weak Morphological Divergence Coupled with Low Genetic Diversity. Plants (Basel) 2022; 12:107. [PMID: 36616235 PMCID: PMC9824829 DOI: 10.3390/plants12010107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
Species delimitation in herbaceous bamboos has been complex and, in some genera, a great part of its diversity has been confirmed only based on genetic information, as is the case of the genus Raddia. It includes nine species, all occurring in Brazil, but only R. portoi predominates in dry forests of the Northeast associated with the Caatinga phytogeographic domain. This species is morphologically close to R. angustifolia, which is known for a single location in the Atlantic Forest in Southern Bahia, and is considered to be threatened by extinction. Besides problems with taxonomic focus, actions for its conservation are complicated because it is not certain if it must be considered an independent species or included in the more widespread R. portoi. In this study, we used coalescent multispecies (MSC) theory approaches combined with genetic structure analyses in an attempt to delimit these two species. Different analyses were congruent and the species delimitation using MSC inferred distinct lineages supporting their recognition as two species. These results solved the taxonomic doubts and also showed the power of these approaches to delimit species as lineages, even in groups with weak morphological divergence and low genetic variability, and also impacting our knowledge for conservation purposes.
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Affiliation(s)
- João Paulo S. Vieira
- Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana, Av. Transnordestina s.n., Novo Horizonte, Feira de Santana 44031-460, Bahia, Brazil
| | - Alessandra Selbach-Schnadelbach
- Instituto de Biologia, Universidade Federal da Bahia, Av. Barão de Jeremoabo s.n., Ondina, Salvador 40150-170, Bahia, Brazil
| | - Marcos Braz
- Instituto de Biologia, Universidade Federal da Bahia, Av. Barão de Jeremoabo s.n., Ondina, Salvador 40150-170, Bahia, Brazil
| | - Patrícia L. Ribeiro
- Centro de Ciências Agrárias, Ambientais e Biológicas, Universidade Federal do Recôncavo da Bahia, Cruz das Almas 44380-000, Bahia, Brazil
| | - Cássio van den Berg
- Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana, Av. Transnordestina s.n., Novo Horizonte, Feira de Santana 44031-460, Bahia, Brazil
| | - Reyjane P. Oliveira
- Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana, Av. Transnordestina s.n., Novo Horizonte, Feira de Santana 44031-460, Bahia, Brazil
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7
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Yang Z, Flouri T. Estimation of Cross-Species Introgression Rates using Genomic Data Despite Model Unidentifiability. Mol Biol Evol 2022; 39:6568285. [PMID: 35417543 PMCID: PMC9087891 DOI: 10.1093/molbev/msac083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Full-likelihood implementations of the multispecies coalescent with introgression (MSci) model treat genealogical fluctuations across the genome as a major source of information to infer the history of species divergence and gene flow using multilocus sequence data. However, MSci models are known to have unidentifiability issues, whereby different models or parameters make the same predictions about the data and cannot be distinguished by the data. Previous studies of unidentifiability have focused on heuristic methods based on gene trees and do not make an efficient use of the information in the data. Here we study the unidentifiability of MSci models under the full-likelihood methods. We characterize the unidentifiability of the bidirectional introgression (BDI) model, which assumes that gene flow occurs in both directions. We derive simple rules for arbitrary BDI models, which create unidentifiability of the label-switching type. In general, an MSci model with k BDI events has 2k unidentifiable modes or towers in the posterior, with each BDI event between sister species creating within-model parameter unidentifiability and each BDI event between nonsister species creating between-model unidentifiability. We develop novel algorithms for processing Markov chain Monte Carlo samples to remove label-switching problems and implement them in the bpp program. We analyze real and synthetic data to illustrate the utility of the BDI models and the new algorithms. We discuss the unidentifiability of heuristic methods and provide guidelines for the use of MSci models to infer gene flow using genomic data.
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Affiliation(s)
- Ziheng Yang
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E6BT, UK
| | - Tomáš Flouri
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E6BT, UK
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8
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Magalhães FDM, Camurugi F, Lyra ML, Baldo D, Gehara M, Haddad CFB, Garda AA. Ecological divergence and synchronous Pleistocene diversification in the widespread South American butter frog complex. Mol Phylogenet Evol 2022; 169:107398. [PMID: 35031468 DOI: 10.1016/j.ympev.2022.107398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/31/2021] [Accepted: 11/15/2021] [Indexed: 11/19/2022]
Abstract
Phylogeographic studies primarily focus on the major role of landscape topography in driving lineage diversification. However, populational phylogeographic breaks may also occur as a result of either niche conservatism or divergence, in the absence of geographic barriers to gene flow. Furthermore, these two factors are not mutually exclusive and can act in concert, making it challenging to evaluate their relative importance on explaining genetic variation in nature. Herein, we use sequences of two mitochondrial and four nuclear genes to investigate the timing and diversification patterns of species pertaining to the Leptodactylus latrans complex, which harbors four morphologically cryptic species with broad distributions across environmental gradients in eastern South America. The origin of this species complex dates back to the late Miocene (ca. 5.5 Mya), but most diversification events occurred synchronically during the late Pleistocene likely as the result of ecological divergence driven by Quaternary climatic oscillations. Further, significant patterns of environmental niche divergences among species in the L. latrans complex imply that ecological isolation is the primary mode of genetic diversification, mostly because phylogenetic breaks are associated with environmental transitions rather than topographic barriers at both species and populational scale. We provided new insights about diversification patterns and processes within a species complex of broadly and continuously distributed group of frogs along South America.
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Affiliation(s)
- Felipe de M Magalhães
- Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal da Paraíba-UFPB, Centro de Ciências Exatas e da Natureza, Cidade Universitária, 58000-000 João Pessoa, Paraiba, Brazil; Earth and Environmental Sciences, Ecology and Evolution, Rutgers University-Newark 195 University Ave, Newark, NJ 07102, USA.
| | - Felipe Camurugi
- Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Cidade Universitária, 79070-900, Campo Grande, Mato Grosso do Sul, Brazil
| | - Mariana L Lyra
- Instituto de Biociências, Universidade Estadual Paulista, Campus Rio Claro, Departamento de Biodiversidade e Centro de Aquicultura (CAUNESP), Laboratório de Herpetologia, Cx. Postal 199, 13506-900 Rio Claro, São Paulo, Brazil
| | - Diego Baldo
- Instituto de Biología Subtropical (IBS, CONICET-UNaM), Laboratorio de Genética Evolutiva, Facultad de Ciencias Exactas, Universidad Nacional de Misiones, Félix de Azara 1552, CPA N3300LQF Posadas, Misiones, Argentina
| | - Marcelo Gehara
- Earth and Environmental Sciences, Ecology and Evolution, Rutgers University-Newark 195 University Ave, Newark, NJ 07102, USA
| | - Célio F B Haddad
- Instituto de Biociências, Universidade Estadual Paulista, Campus Rio Claro, Departamento de Biodiversidade e Centro de Aquicultura (CAUNESP), Laboratório de Herpetologia, Cx. Postal 199, 13506-900 Rio Claro, São Paulo, Brazil
| | - Adrian A Garda
- Laboratório de Anfíbios e Répteis (LAR), Departamento de Botânica e Zoologia da Universidade Federal do Rio Grande do Norte, Campus Universitário. Lagoa Nova, 59078-900 Natal, Rio Grande do Norte, Brazil
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9
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Jiao X, Flouri T, Yang Z. Multispecies coalescent and its applications to infer species phylogenies and cross-species gene flow. Natl Sci Rev 2022; 8:nwab127. [PMID: 34987842 PMCID: PMC8692950 DOI: 10.1093/nsr/nwab127] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/10/2021] [Accepted: 07/11/2021] [Indexed: 02/06/2023] Open
Abstract
Multispecies coalescent (MSC) is the extension of the single-population coalescent model to multiple species. It integrates the phylogenetic process of species divergences and the population genetic process of coalescent, and provides a powerful framework for a number of inference problems using genomic sequence data from multiple species, including estimation of species divergence times and population sizes, estimation of species trees accommodating discordant gene trees, inference of cross-species gene flow and species delimitation. In this review, we introduce the major features of the MSC model, discuss full-likelihood and heuristic methods of species tree estimation and summarize recent methodological advances in inference of cross-species gene flow. We discuss the statistical and computational challenges in the field and research directions where breakthroughs may be likely in the next few years.
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Affiliation(s)
- Xiyun Jiao
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Tomáš Flouri
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Ziheng Yang
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
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10
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Huang J, Bennett J, Flouri T, Leaché AD, Yang Z. Phase Resolution of Heterozygous Sites in Diploid Genomes is Important to Phylogenomic Analysis under the Multispecies Coalescent Model. Syst Biol 2021; 71:334-352. [PMID: 34143216 PMCID: PMC8977997 DOI: 10.1093/sysbio/syab047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 06/03/2021] [Accepted: 06/21/2021] [Indexed: 01/01/2023] Open
Abstract
Genome sequencing projects routinely generate haploid consensus sequences from diploid
genomes, which are effectively chimeric sequences with the phase at heterozygous sites
resolved at random. The impact of phasing errors on phylogenomic analyses under the
multispecies coalescent (MSC) model is largely unknown. Here, we conduct a computer
simulation to evaluate the performance of four phase-resolution strategies (the true phase
resolution, the diploid analytical integration algorithm which averages over all phase
resolutions, computational phase resolution using the program PHASE, and random
resolution) on estimation of the species tree and evolutionary parameters in analysis of
multilocus genomic data under the MSC model. We found that species tree estimation is
robust to phasing errors when species divergences were much older than average coalescent
times but may be affected by phasing errors when the species tree is shallow. Estimation
of parameters under the MSC model with and without introgression is affected by phasing
errors. In particular, random phase resolution causes serious overestimation of population
sizes for modern species and biased estimation of cross-species introgression probability.
In general, the impact of phasing errors is greater when the mutation rate is higher, the
data include more samples per species, and the species tree is shallower with recent
divergences. Use of phased sequences inferred by the PHASE program produced small biases
in parameter estimates. We analyze two real data sets, one of East Asian brown frogs and
another of Rocky Mountains chipmunks, to demonstrate that heterozygote phase-resolution
strategies have similar impacts on practical data analyses. We suggest that genome
sequencing projects should produce unphased diploid genotype sequences if fully phased
data are too challenging to generate, and avoid haploid consensus sequences, which have
heterozygous sites phased at random. In case the analytical integration algorithm is
computationally unfeasible, computational phasing prior to population genomic analyses is
an acceptable alternative. [BPP; introgression; multispecies coalescent; phase; species
tree.]
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Affiliation(s)
- Jun Huang
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK.,Department of Mathematics, Beijing Jiaotong University, Beijing, 100044, P.R. China
| | - Jeremy Bennett
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK.,Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road, Unit 3043, Storrs, CT 06269-3043, USA
| | - Tomáš Flouri
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Adam D Leaché
- Department of Biology & Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98195-1800, USA
| | - Ziheng Yang
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
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11
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Martinsson S, Klinth M, Erséus C. Testing species hypotheses for Fridericia magna, an enchytraeid worm (Annelida: Clitellata) with great mitochondrial variation. BMC Evol Biol 2020; 20:116. [PMID: 32928097 PMCID: PMC7488859 DOI: 10.1186/s12862-020-01678-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 08/20/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Deep mitochondrial divergences were observed in Scandinavian populations of the terrestrial to semi-aquatic annelid Fridericia magna (Clitellata: Enchytraeidae). This raised the need for testing whether the taxon is a single species or a complex of cryptic species. RESULTS A total of 62 specimens from 38 localities were included in the study, 44 of which were used for species delimitation. First, the 44 specimens were divided into clusters using ABGD (Automatic Barcode Gap Discovery) on two datasets, consisting of sequences of the mitochondrial markers COI and 16S. For each dataset, the worms were divided into six not completely congruent clusters. When they were combined, a maximum of seven clusters, or species hypotheses, were obtained, and the seven clusters were used as input in downstream analyses. We tested these hypotheses by constructing haplowebs for two nuclear markers, H3 and ITS, and in both haplowebs the specimens appeared as a single species. Multi-locus species delimitation analyses performed with the Bayesian BPP program also mainly supported a single species. Furthermore, no apparent morphological differences were found between the clusters. Two of the clusters were partially separated from each other and the other clusters, but not strongly enough to consider them as separate species. All 62 specimens were used to visualise the Scandinavian distribution, of the species, and to compare with published COI data from other Fridericia species. CONCLUSION We show that the morphospecies Fridericia magna is a single species, harbouring several distinct mitochondrial clusters. There is partial genetic separation between some of them, which may be interpreted as incipient speciation. The study shows the importance of rigorous species delimitation using several independent markers when deep mitochondrial divergences might give the false impression of cryptic speciation.
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Affiliation(s)
- Svante Martinsson
- Systematics and Biodiversity, Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE-405 30, Göteborg, Sweden.
| | - Mårten Klinth
- Systematics and Biodiversity, Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE-405 30, Göteborg, Sweden
| | - Christer Erséus
- Systematics and Biodiversity, Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE-405 30, Göteborg, Sweden
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12
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Pozzi L, Penna A, Bearder SK, Karlsson J, Perkin A, Disotell TR. Cryptic diversity and species boundaries within the Paragalago zanzibaricus species complex. Mol Phylogenet Evol 2020; 150:106887. [PMID: 32534184 DOI: 10.1016/j.ympev.2020.106887] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 05/04/2020] [Accepted: 06/03/2020] [Indexed: 11/17/2022]
Abstract
The recently described genus Paragalago is a complex of several nocturnal and morphologically cryptic species distributed in the forests of eastern Africa. Species diversity within this genus has been mainly described using species-specific differences in their loud calls. However, molecular data are still lacking for this group and species boundaries remain unclear. In this study, we explore species diversity within the zanzibaricus-complex using a combination of mitochondrial and nuclear data and comparing multiple species delimitation methods. Our results consistently support the existence of three independent lineages, P. cocos, P. zanzibaricus, and P. granti, confirming previous hypotheses based on vocal data. We conclude that these three lineages represent valid cryptic species and we hypothesize that speciation within this complex was characterized by cycles of forest expansion and contraction in the Plio-Pleistocene.
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Affiliation(s)
- Luca Pozzi
- Department of Anthropology, University of Texas at San Antonio, San Antonio, TX, USA.
| | - Anna Penna
- Department of Anthropology, University of Texas at San Antonio, San Antonio, TX, USA
| | - Simon K Bearder
- Nocturnal Primate Research Group, Oxford Brookes University, Oxford, UK
| | - Johan Karlsson
- Nocturnal Primate Research Group, Oxford Brookes University, Oxford, UK
| | - Andrew Perkin
- Nocturnal Primate Research Group, Oxford Brookes University, Oxford, UK
| | - Todd R Disotell
- Department of Anthropology, New York University, New York, NY, USA; Department of Anthropology, University of Massachusetts, Amherst, MA, USA
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13
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Leman R, Tubeuf H, Raad S, Tournier I, Derambure C, Lanos R, Gaildrat P, Castelain G, Hauchard J, Killian A, Baert-Desurmont S, Legros A, Goardon N, Quesnelle C, Ricou A, Castera L, Vaur D, Le Gac G, Ka C, Fichou Y, Bonnet-Dorion F, Sevenet N, Guillaud-Bataille M, Boutry-Kryza N, Schultz I, Caux-Moncoutier V, Rossing M, Walker LC, Spurdle AB, Houdayer C, Martins A, Krieger S. Assessment of branch point prediction tools to predict physiological branch points and their alteration by variants. BMC Genomics 2020; 21:86. [PMID: 31992191 PMCID: PMC6988378 DOI: 10.1186/s12864-020-6484-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 01/10/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Branch points (BPs) map within short motifs upstream of acceptor splice sites (3'ss) and are essential for splicing of pre-mature mRNA. Several BP-dedicated bioinformatics tools, including HSF, SVM-BPfinder, BPP, Branchpointer, LaBranchoR and RNABPS were developed during the last decade. Here, we evaluated their capability to detect the position of BPs, and also to predict the impact on splicing of variants occurring upstream of 3'ss. RESULTS We used a large set of constitutive and alternative human 3'ss collected from Ensembl (n = 264,787 3'ss) and from in-house RNAseq experiments (n = 51,986 3'ss). We also gathered an unprecedented collection of functional splicing data for 120 variants (62 unpublished) occurring in BP areas of disease-causing genes. Branchpointer showed the best performance to detect the relevant BPs upstream of constitutive and alternative 3'ss (99.48 and 65.84% accuracies, respectively). For variants occurring in a BP area, BPP emerged as having the best performance to predict effects on mRNA splicing, with an accuracy of 89.17%. CONCLUSIONS Our investigations revealed that Branchpointer was optimal to detect BPs upstream of 3'ss, and that BPP was most relevant to predict splicing alteration due to variants in the BP area.
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Affiliation(s)
- Raphaël Leman
- Laboratoire de Biologie Clinique et Oncologique, Centre François Baclesse, Caen, France. .,Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France. .,Université Caen-Normandie, Caen, France.
| | - Hélène Tubeuf
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France.,Interactive Biosoftware, Rouen, France
| | - Sabine Raad
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Isabelle Tournier
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Céline Derambure
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Raphaël Lanos
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Pascaline Gaildrat
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Gaia Castelain
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Julie Hauchard
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Audrey Killian
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Stéphanie Baert-Desurmont
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Angelina Legros
- Laboratoire de Biologie Clinique et Oncologique, Centre François Baclesse, Caen, France
| | - Nicolas Goardon
- Laboratoire de Biologie Clinique et Oncologique, Centre François Baclesse, Caen, France.,Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Céline Quesnelle
- Laboratoire de Biologie Clinique et Oncologique, Centre François Baclesse, Caen, France
| | - Agathe Ricou
- Laboratoire de Biologie Clinique et Oncologique, Centre François Baclesse, Caen, France.,Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Laurent Castera
- Laboratoire de Biologie Clinique et Oncologique, Centre François Baclesse, Caen, France.,Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Dominique Vaur
- Laboratoire de Biologie Clinique et Oncologique, Centre François Baclesse, Caen, France.,Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Gérald Le Gac
- Inserm UMR1078, Genetics, Functional Genomics and Biotechnology, Université de Bretagne Occidentale, Brest, France
| | - Chandran Ka
- Inserm UMR1078, Genetics, Functional Genomics and Biotechnology, Université de Bretagne Occidentale, Brest, France
| | - Yann Fichou
- Inserm UMR1078, Genetics, Functional Genomics and Biotechnology, Université de Bretagne Occidentale, Brest, France
| | - Françoise Bonnet-Dorion
- Inserm U916, Département de Pathologie, Laboratoire de Génétique Constitutionnelle, Institut Bergonié, Bordeaux, France
| | - Nicolas Sevenet
- Inserm U916, Département de Pathologie, Laboratoire de Génétique Constitutionnelle, Institut Bergonié, Bordeaux, France
| | | | - Nadia Boutry-Kryza
- Lyon Neuroscience Research Center-CRNL, Inserm U1028, CNRS UMR 5292, University of Lyon, Lyon, France
| | - Inès Schultz
- Laboratoire d'Oncogénétique, Centre Paul Strauss, Strasbourg, France
| | | | - Maria Rossing
- Centre for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Logan C Walker
- Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Amanda B Spurdle
- Department of Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Claude Houdayer
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Alexandra Martins
- Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France
| | - Sophie Krieger
- Laboratoire de Biologie Clinique et Oncologique, Centre François Baclesse, Caen, France. .,Inserm U1245, Normandy Center for Genomic and Personalized Medicine, Rouen, UNIROUEN, Normandy University, Caen, France. .,Université Caen-Normandie, Caen, France. .,Present address: Laboratoire de biologie et génétique des cancers, Centre François Baclesse, Caen, France.
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14
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Chan KO, Grismer LL. To split or not to split? Multilocus phylogeny and molecular species delimitation of southeast Asian toads (family: Bufonidae). BMC Evol Biol 2019; 19:95. [PMID: 31023232 PMCID: PMC6485082 DOI: 10.1186/s12862-019-1422-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/12/2019] [Indexed: 11/10/2022] Open
Abstract
Background Recent studies have demonstrated that Bayesian species delimitation based on the multispecies coalescent model can produce inaccurate results by misinterpreting population splits as species divergences. An approach based on the genealogical divergence index (gdi) was shown to be a viable alternative, especially for delimiting allopatric populations where gene flow is low. We implemented these analyses to assess species boundaries in Southeast Asian toads, a group that is understudied and characterized by numerous unresolved species complexes. Results Multilocus phylogenetic analyses showed that deep evolutionary relationships including the genera Sigalegalephrynus, Ghatophryne, Parapelophryne, Leptophryne, Pseudobufo, Rentapia, and Phrynoides remain unresolved. Comparison of genetic divergences revealed that intraspecific divergences among allopatric populations of Pelophyrne signata (Borneo vs. Peninsular Malaysia), Ingerophrynus parvus (Peninsular Malaysia vs. Myanmar), and Leptophryne borbonica (Peninsular Malaysia, Java, Borneo, and Sumatra) are consistent with interspecific divergences of other Southeast Asian bufonid taxa. Conversely, interspecific divergences between Pelophryne guentheri/P. api, Ansonia latiffi/A. leptopus, and I. gollum/I. divergens were low (< 3%) and consistent with intraspecific divergences of other closely related taxa. The BPP analysis produced variable results depending on prior settings and priors estimated from empirical data produced the best results that were also congruent with the gdi analysis. Conclusions This study showed that the evolutionary history of Southeast Asian toads is difficult to resolve and numerous relationships remain ambiguous. Although some results from the species delimitation analyses were inconclusive, they were nevertheless efficacious at identifying potential new species and taxonomic incompatibilities for future in-depth investigation. We also demonstrated the sensitivity of BPP to different priors and that careful selection priors based on empirical data can greatly improve the analysis. Finally, the gdi can be a robust tool to complement other species delimitation methods. Electronic supplementary material The online version of this article (10.1186/s12862-019-1422-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kin Onn Chan
- Lee Kong Chian Natural History Museum, National University of Singapore, 2 Conservatory Drive, Singapore, 117377, Singapore.
| | - L Lee Grismer
- Herpetology Laboratory, Department of Biology, La Sierra University, 4500 Riverwalk Parkway, Riverside, CA, 92515, USA
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15
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Singh G, Ptroot A, Ico VJ, Tte J, Pradeep K Divakar, Crespo A, Cáceres MEDS, H Thorsten Lumbsch, Schmitt I. Neoprotoparmelia gen. nov. and Maronina (Lecanorales, Protoparmelioideae): species description and generic delimitation using DNA barcodes and phenotypical characters. MycoKeys 2018:19-50. [PMID: 30595656 PMCID: PMC6303283 DOI: 10.3897/mycokeys.44.29904] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/12/2018] [Indexed: 11/12/2022] Open
Abstract
Multilocus phylogenetic studies revealed a high level of cryptic diversity within the lichen-forming fungal genus Maronina (Protoparmelioideae, Parmeliaceae). Coalescent-based species delimitation suggested that most of the cryptic molecular lineages warranted recognition as separate species. Here we study the morphology and chemistry of these taxa and formally describe eight new species based on phenotypical and molecular characters. Further, we evaluate the use of ITS rDNA as a DNA barcode for identifying species in this genus. For the first time, we obtained an ITS sequence of Maroninaaustraliensis, the type species of the genus and showed that it is phylogenetically not closely related to species currently placed in Maronina or Protoparmelia. We assembled a dataset of 66 ITS sequences to assess the interspecies genetic distances amongst the twelve Maronina species using ITS as DNA barcode. We found that Maronina and Protoparmelia form a supported monophyletic group whereas M.australiensis is sister to both. We therefore propose a new genus Neoprotoparmelia to accommodate the tropical-subtropical species within Protoparmelioideae, with Neoprotoparmeliacorallifera as the type, N.amerisidiata, N.australisidiata, N.brasilisidiata, N.capensis, N.crassa, N.pauli, N.plurisporibadia and N.siamisidiata as new species and N.capitata, N.isidiata, N.multifera, N.orientalis and N.pulchra as new proposed combinations. We provide a key to Neoprotoparmelia and confirm the use of ITS for accurately identifying species in this group.
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Affiliation(s)
- Garima Singh
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - André Ptroot
- Laboratório de Botânica/Liquenologia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de Mato Grosso do Sul, Caixa Postal 549, CEP 79070-900, Campo Grande, Mato Grosso do Sul, Brazil
| | - Víctor J Ico
- Departamento de Farmacología, Farmacognosia y Botánica, U.D. Botánica, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal s/n, E-28040 Madrid, Spain
| | - Jürgen Tte
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Pradeep K Divakar
- Departamento de Farmacología, Farmacognosia y Botánica, U.D. Botánica, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal s/n, E-28040 Madrid, Spain
| | - Ana Crespo
- Departamento de Farmacología, Farmacognosia y Botánica, U.D. Botánica, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal s/n, E-28040 Madrid, Spain
| | | | - H Thorsten Lumbsch
- Science & Education, Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, IL, 60605, United States of America
| | - Imke Schmitt
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.,Department of Biological Sciences, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
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16
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Galen SC, Nunes R, Sweet PR, Perkins SL. Integrating coalescent species delimitation with analysis of host specificity reveals extensive cryptic diversity despite minimal mitochondrial divergence in the malaria parasite genus Leucocytozoon. BMC Evol Biol 2018; 18:128. [PMID: 30165810 PMCID: PMC6117968 DOI: 10.1186/s12862-018-1242-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 08/15/2018] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Coalescent methods that use multi-locus sequence data are powerful tools for identifying putatively reproductively isolated lineages, though this approach has rarely been used for the study of microbial groups that are likely to harbor many unrecognized species. Among microbial symbionts, integrating genetic species delimitation methods with trait data that could indicate reproductive isolation, such as host specificity data, has rarely been used despite its potential to inform species limits. Here we test the ability of an integrative approach combining genetic and host specificity data to delimit species within the avian malaria parasite genus Leucocytozoon in central Alaska. RESULTS We sequenced seven nuclear loci for 69 Leucocytozoon samples and used multiple species delimitation methods (GMYC and BPP models), tested for differences in host infection patterns among putative species based on 406 individual infections, and characterized parasite morphology. We found that cryptic morphology has masked a highly diverse Leucocytozoon assemblage, with most species delimitation methods recovering support for at least 21 separate species that occur sympatrically and have divergent host infection patterns. Reproductive isolation among putative species appears to have evolved despite low mtDNA divergence, and in one instance two Leucocytozoon cytb haplotypes that differed by a single base pair (~ 0.2% divergence) were supported as separate species. However, there was no consistent association between mtDNA divergence and species limits. Among cytb haplotypes that differed by one to three base pairs we observed idiosyncratic patterns of nuclear and ecological divergence, with cytb haplotype pairs found to be either conspecific, reproductively isolated with no divergence in host specificity, or reproductively isolated with divergent patterns of host specialization. CONCLUSION Integrating multi-locus genetic species delimitation methods and non-traditional ecological data types such as host specificity provide a novel view of the diversity of avian malaria parasites that has been missed previously using morphology and mtDNA barcodes. Species delimitation methods show that Leucocytozoon is highly species-rich in Alaska, and the genus is likely to harbor extraordinary species-level diversity worldwide. Integrating genetic and ecological data will be an important approach for understanding the diversity and evolutionary history of microbial symbionts moving forward.
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Affiliation(s)
- Spencer C. Galen
- Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 USA
- Richard Gilder Graduate School, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 USA
| | - Renato Nunes
- Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 USA
| | - Paul R. Sweet
- Department of Ornithology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 USA
| | - Susan L. Perkins
- Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 USA
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17
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Damm M, Hempel BF, Nalbantsoy A, Süssmuth RD. Comprehensive Snake Venomics of the Okinawa Habu Pit Viper, Protobothrops flavoviridis, by Complementary Mass Spectrometry-Guided Approaches. Molecules 2018; 23:molecules23081893. [PMID: 30060607 PMCID: PMC6222445 DOI: 10.3390/molecules23081893] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 07/24/2018] [Accepted: 07/27/2018] [Indexed: 11/16/2022] Open
Abstract
The Asian world is home to a multitude of venomous and dangerous snakes, which are used to induce various medical effects in the preparation of traditional snake tinctures and alcoholics, like the Japanese snake wine, named Habushu. The aim of this work was to perform the first quantitative proteomic analysis of the Protobothrops flavoviridis pit viper venom. Accordingly, the venom was analyzed by complimentary bottom-up and top-down mass spectrometry techniques. The mass spectrometry-based snake venomics approach revealed that more than half of the venom is composed of different phospholipases A2 (PLA₂). The combination of this approach and an intact mass profiling led to the identification of the three main Habu PLA₂s. Furthermore, nearly one-third of the total venom consists of snake venom metalloproteinases and disintegrins, and several minor represented toxin families were detected: C-type lectin-like proteins (CTL), cysteine-rich secretory proteins (CRISP), snake venom serine proteases (svSP), l-amino acid oxidases (LAAO), phosphodiesterase (PDE) and 5'-nucleotidase. Finally, the venom of P. flavoviridis contains certain bradykinin-potentiating peptides and related peptides, like the svMP inhibitors, pEKW, pEQW, pEEW and pENW. In preliminary MTT cytotoxicity assays, the highest cancerous-cytotoxicity of crude venom was measured against human neuroblastoma SH-SY5Y cells and shows disintegrin-like effects in some fractions.
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Affiliation(s)
- Maik Damm
- Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany.
| | | | - Ayse Nalbantsoy
- Department of Bioengineering, Ege University, 35100 Izmir, Turkey.
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18
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Sciani JM, Pimenta DC. The modular nature of bradykinin-potentiating peptides isolated from snake venoms. J Venom Anim Toxins Incl Trop Dis 2017; 23:45. [PMID: 29090005 PMCID: PMC5657115 DOI: 10.1186/s40409-017-0134-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 09/21/2017] [Indexed: 01/18/2023] Open
Abstract
Bradykinin-potentiating peptides (BPPs) are molecules discovered by Sergio Ferreira – who found them in the venom of Bothrops jararaca in the 1960s – that literally potentiate the action of bradykinin in vivo by, allegedly, inhibiting the angiotensin-converting enzymes. After administration, the global physiological effect of BPP is the decrease of the blood pressure. Due to this interesting effect, one of these peptides was used by David Cushman and Miguel Ondetti to develop a hypotensive drug, the widely known captopril, vastly employed on hypertension treatment. From that time on, many studies on BPPs have been conducted, basically describing new peptides and assaying their pharmacological effects, mostly in comparison to captopryl. After compiling most of these data, we are proposing that snake BPPs are ‘modular’ peptidic molecules, in which the combination of given amino acid ‘blocks’ results in the different existing peptides (BPPs), commonly found in snake venom. We have observed that there would be mandatory modules (present in all snake BPPs), such as the N-terminal pyroglutamic acid and C-terminal QIPP, and optional modules (amino acid blocks present in some of them), such as AP or WAQ. Scattered between these modules, there might be other amino acids that would ‘complete’ the peptide, without disrupting the signature of the classical BPP. This modular arrangement would represent an important evolutionary advantage in terms of biological diversity that might have its origins either at the genomic or at the post-translational modification levels. Regardless of the modules’ origin, the increase in the diversity of peptides has definitely been essential for snakes’ success on nature.
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Affiliation(s)
- Juliana Mozer Sciani
- Laboratory of Biochemistry and Biophysics, Butantan Institute, Av. Vital Brasil, 1500, São Paulo, SP CEP 05503-900 Brazil
| | - Daniel Carvalho Pimenta
- Laboratory of Biochemistry and Biophysics, Butantan Institute, Av. Vital Brasil, 1500, São Paulo, SP CEP 05503-900 Brazil
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Xu B, Yang Z. Challenges in Species Tree Estimation Under the Multispecies Coalescent Model. Genetics 2016; 204:1353-68. [PMID: 27927902 DOI: 10.1534/genetics.116.190173] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 09/25/2016] [Indexed: 11/18/2022] Open
Abstract
The multispecies coalescent (MSC) model has emerged as a powerful framework for inferring species phylogenies while accounting for ancestral polymorphism and gene tree-species tree conflict. A number of methods have been developed in the past few years to estimate the species tree under the MSC. The full likelihood methods (including maximum likelihood and Bayesian inference) average over the unknown gene trees and accommodate their uncertainties properly but involve intensive computation. The approximate or summary coalescent methods are computationally fast and are applicable to genomic datasets with thousands of loci, but do not make an efficient use of information in the multilocus data. Most of them take the two-step approach of reconstructing the gene trees for multiple loci by phylogenetic methods and then treating the estimated gene trees as observed data, without accounting for their uncertainties appropriately. In this article we review the statistical nature of the species tree estimation problem under the MSC, and explore the conceptual issues and challenges of species tree estimation by focusing mainly on simple cases of three or four closely related species. We use mathematical analysis and computer simulation to demonstrate that large differences in statistical performance may exist between the two classes of methods. We illustrate that several counterintuitive behaviors may occur with the summary methods but they are due to inefficient use of information in the data by summary methods and vanish when the data are analyzed using full-likelihood methods. These include (i) unidentifiability of parameters in the model, (ii) inconsistency in the so-called anomaly zone, (iii) singularity on the likelihood surface, and (iv) deterioration of performance upon addition of more data. We discuss the challenges and strategies of species tree inference for distantly related species when the molecular clock is violated, and highlight the need for improving the computational efficiency and model realism of the likelihood methods as well as the statistical efficiency of the summary methods.
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20
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Fossen EI, Ekrem T, Nilsson AN, Bergsten J. Species delimitation in northern European water scavenger beetles of the genus Hydrobius (Coleoptera, Hydrophilidae). Zookeys 2016; 564:71-120. [PMID: 27081333 PMCID: PMC4820092 DOI: 10.3897/zookeys.564.6558] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 12/23/2015] [Indexed: 12/18/2022] Open
Abstract
The chiefly Holarctic Hydrobius species complex (Coleoptera, Hydrophilidae) currently consists of Hydrobius arcticus Kuwert, 1890, and three morphological variants of Hydrobius fuscipes (Linnaeus, 1758): var. fuscipes, var. rottenbergii and var. subrotundus in northern Europe. Here molecular and morphological data are used to test the species boundaries in this species complex. Three gene segments (COI, H3 and ITS2) were sequenced and analyzed with Bayesian methods to infer phylogenetic relationships. The Generalized Mixed Yule Coalescent (GMYC) model and two versions of the Bayesian species delimitation method BPP, with or without an a priori defined guide tree (v2.2 & v3.0), were used to evaluate species limits. External and male genital characters of primarily Fennoscandian specimens were measured and statistically analyzed to test for significant differences in quantitative morphological characters. The four morphotypes formed separate genetic clusters on gene trees and were delimited as separate species by GMYC and by both versions of BPP, despite specimens of Hydrobius fuscipes var. fuscipes and Hydrobius fuscipes var. subrotundus being sympatric. Hydrobius arcticus and Hydrobius fuscipes var. rottenbergii could only be separated genetically with ITS2, and were delimited statistically with GMYC on ITS2 and with BPP on the combined data. In addition, six or seven potentially cryptic species of the Hydrobius fuscipes complex from regions outside northern Europe were delimited genetically. Although some overlap was found, the mean values of six male genital characters were significantly different between the morphotypes (p < 0.001). Morphological characters previously presumed to be diagnostic were less reliable to separate Hydrobius fuscipes var. fuscipes from Hydrobius fuscipes var. subrotundus, but characters in the literature for Hydrobius arcticus and Hydrobius fuscipes var. rottenbergii were diagnostic. Overall, morphological and molecular evidence strongly suggest that Hydrobius arcticus and the three morphological variants of Hydrobius fuscipes are separate species and Hydrobius rottenbergii Gerhardt, 1872, stat. n. and Hydrobius subrotundus Stephens, 1829, stat. n. are elevated to valid species. An identification key to northern European species of Hydrobius is provided.
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Affiliation(s)
- Erlend I. Fossen
- Department of Biology, Centre for Biodiversity Dynamics, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway
- Department of Natural History, NTNU University Museum, 7491 Trondheim, Norway
| | - Torbjørn Ekrem
- Department of Natural History, NTNU University Museum, 7491 Trondheim, Norway
| | - Anders N. Nilsson
- Department of Ecology and Environmental Science, University of Umeå, S-901 87 Umeå, Sweden
| | - Johannes Bergsten
- Department of Zoology, Swedish Museum of Natural History, Box 50007, SE-10405 Stockholm, Sweden
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