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Diamantidis D, Fan WTL, Birkner M, Wakeley J. Bursts of coalescence within population pedigrees whenever big families occur. Genetics 2024; 227:iyae030. [PMID: 38408329 DOI: 10.1093/genetics/iyae030] [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: 01/23/2024] [Revised: 01/23/2024] [Accepted: 02/18/2024] [Indexed: 02/28/2024] Open
Abstract
We consider a simple diploid population-genetic model with potentially high variability of offspring numbers among individuals. Specifically, against a backdrop of Wright-Fisher reproduction and no selection, there is an additional probability that a big family occurs, meaning that a pair of individuals has a number of offspring on the order of the population size. We study how the pedigree of the population generated under this model affects the ancestral genetic process of a sample of size two at a single autosomal locus without recombination. Our population model is of the type for which multiple-merger coalescent processes have been described. We prove that the conditional distribution of the pairwise coalescence time given the random pedigree converges to a limit law as the population size tends to infinity. This limit law may or may not be the usual exponential distribution of the Kingman coalescent, depending on the frequency of big families. But because it includes the number and times of big families, it differs from the usual multiple-merger coalescent models. The usual multiple-merger coalescent models are seen as describing the ancestral process marginal to, or averaging over, the pedigree. In the limiting ancestral process conditional on the pedigree, the intervals between big families can be modeled using the Kingman coalescent but each big family causes a discrete jump in the probability of coalescence. Analogous results should hold for larger samples and other population models. We illustrate these results with simulations and additional analysis, highlighting their implications for inference and understanding of multilocus data.
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Affiliation(s)
| | - Wai-Tong Louis Fan
- Department of Mathematics, Indiana University, Bloomington, IN 47405, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Matthias Birkner
- Institut für Mathematik, Johannes-Gutenberg-Universität, 55099 Mainz, Germany
| | - John Wakeley
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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Yan H, Hu Z, Thomas GWC, Edwards SV, Sackton TB, Liu JS. PhyloAcc-GT: A Bayesian Method for Inferring Patterns of Substitution Rate Shifts on Targeted Lineages Accounting for Gene Tree Discordance. Mol Biol Evol 2023; 40:msad195. [PMID: 37665177 PMCID: PMC10540510 DOI: 10.1093/molbev/msad195] [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: 12/23/2022] [Revised: 08/15/2023] [Accepted: 09/01/2023] [Indexed: 09/05/2023] Open
Abstract
An important goal of evolutionary genomics is to identify genomic regions whose substitution rates differ among lineages. For example, genomic regions experiencing accelerated molecular evolution in some lineages may provide insight into links between genotype and phenotype. Several comparative genomics methods have been developed to identify genomic accelerations between species, including a Bayesian method called PhyloAcc, which models shifts in substitution rate in multiple target lineages on a phylogeny. However, few methods consider the possibility of discordance between the trees of individual loci and the species tree due to incomplete lineage sorting, which might cause false positives. Here, we present PhyloAcc-GT, which extends PhyloAcc by modeling gene tree heterogeneity. Given a species tree, we adopt the multispecies coalescent model as the prior distribution of gene trees, use Markov chain Monte Carlo (MCMC) for inference, and design novel MCMC moves to sample gene trees efficiently. Through extensive simulations, we show that PhyloAcc-GT outperforms PhyloAcc and other methods in identifying target lineage-specific accelerations and detecting complex patterns of rate shifts, and is robust to specification of population size parameters. PhyloAcc-GT is usually more conservative than PhyloAcc in calling convergent rate shifts because it identifies more accelerations on ancestral than on terminal branches. We apply PhyloAcc-GT to two examples of convergent evolution: flightlessness in ratites and marine mammal adaptations, and show that PhyloAcc-GT is a robust tool to identify shifts in substitution rate associated with specific target lineages while accounting for incomplete lineage sorting.
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Affiliation(s)
- Han Yan
- Department of Statistics, Harvard University, Cambridge, MA, USA
| | - Zhirui Hu
- Department of Statistics, Harvard University, Cambridge, MA, USA
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA
| | | | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | | | - Jun S Liu
- Department of Statistics, Harvard University, Cambridge, MA, USA
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3
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Ecological speciation of Japanese hedgehog mushroom: Hydnum subalpinum sp. nov. is distinguished from its sister species H. repando-orientale by means of integrative taxonomy. Mycol Prog 2022. [DOI: 10.1007/s11557-022-01844-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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4
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Peng J, Swofford DL, Kubatko L. Estimation of speciation times under the multispecies coalescent. Bioinformatics 2022; 38:5182-5190. [PMID: 36227122 DOI: 10.1093/bioinformatics/btac679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 06/02/2022] [Accepted: 10/10/2022] [Indexed: 12/24/2022] Open
Abstract
MOTIVATION The multispecies coalescent model is now widely accepted as an effective model for incorporating variation in the evolutionary histories of individual genes into methods for phylogenetic inference from genome-scale data. However, because model-based analysis under the coalescent can be computationally expensive for large datasets, a variety of inferential frameworks and corresponding algorithms have been proposed for estimation of species-level phylogenies and associated parameters, including speciation times and effective population sizes. RESULTS We consider the problem of estimating the timing of speciation events along a phylogeny in a coalescent framework. We propose a maximum a posteriori estimator based on composite likelihood (MAPCL) for inferring these speciation times under a model of DNA sequence evolution for which exact site-pattern probabilities can be computed under the assumption of a constant θ throughout the species tree. We demonstrate that the MAPCL estimates are statistically consistent and asymptotically normally distributed, and we show how this result can be used to estimate their asymptotic variance. We also provide a more computationally efficient estimator of the asymptotic variance based on the non-parametric bootstrap. We evaluate the performance of our method using simulation and by application to an empirical dataset for gibbons. AVAILABILITY AND IMPLEMENTATION The method has been implemented in the PAUP* program, freely available at https://paup.phylosolutions.com for Macintosh, Windows and Linux operating systems. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Jing Peng
- Division of Biostatistics, The Ohio State University, Columbus, OH 43210, USA
| | - David L Swofford
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Laura Kubatko
- Department of Statistics, The Ohio State University, Columbus, OH 43210, USA.,Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA.,Mathematical Biosciences Institute, The Ohio State University, Columbus, OH 43210, USA
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5
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Kolbasova G, Schmidt-Rhaesa A, Syomin V, Bredikhin D, Morozov T, Neretina T. Cryptic species complex or an incomplete speciation? Phylogeographic analysis reveals an intricate Pleistocene history of Priapulus caudatus Lamarck, 1816. ZOOL ANZ 2022. [DOI: 10.1016/j.jcz.2022.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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Cui H, Li H, Zhang M, Li H, Wang X, Wang Z, Zhai W, Chen X, Cheng H, Xu J, Zhao X, Ding Z. Molecular Characterization, Expression, Evolutionary Selection, and Biological Activity Analysis of CD68 Gene from Megalobrama amblycephala. Int J Mol Sci 2022; 23:13133. [PMID: 36361921 PMCID: PMC9656401 DOI: 10.3390/ijms232113133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 11/24/2022] Open
Abstract
CD68 is a highly glycosylated transmembrane glycoprotein that belongs to the lysosome-associated membrane glycoprotein family and is involved in various immune processes. In this study, Megalobrama amblycephala CD68 (MaCD68) was cloned and characterized, and its expression patterns and evolutionary characteristics were analyzed. The coding region of MaCD68 was 987 bp, encoding 328 amino acids, and the predicted protein molecular weight was 34.9 kDa. MaCD68 contained two transmembrane helical structures and 18 predicted N-glycosylation sites. Multiple sequence alignments showed that the MaCD68 protein had high homology with other fish, and their functional sites were also highly conserved. Phylogenetic analysis revealed that MaCD68 and other cypriniformes fish clustered into one branch. Adaptive evolution analysis identified several positively selected sites of teleost CD68 using site and branch-site models, indicating that it was under positive selection pressure during evolution. Quantitative real-time reverse transcription polymerase chain reaction analysis showed that MaCD68 was highly expressed in the head kidney, spleen, and heart. After Aeromonas hydrophila infection, MaCD68 was significantly upregulated in all tested tissues, peaking at 12 h post-infection (hpi) in the kidney and head kidney and at 120 hpi in the liver and spleen, suggesting that MaCD68 participated in the innate immune response of the host against bacterial infection. Immunohistochemical and immunofluorescence analyses also showed that positive signals derived from the MaCD68 protein were further enhanced after bacterial and lipopolysaccharide treatment, which suggested that MaCD68 is involved in the immune response and could be used as a macrophage marker. Biological activity analysis indicated that recombinant MaCD68 (rMaCD68) protein had no agglutination or bactericidal effects on A. hydrophila but did have these effects on Escherichia coli. In conclusion, these results suggest that MaCD68 plays a vital role in the immune response against pathogens, which is helpful in understanding the immune responses and mechanisms of M. amblycephala.
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Affiliation(s)
- Hujun Cui
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Hong Li
- Hunan Fisheries Science Institute, Changsha 410153, China
| | - Minying Zhang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Hongping Li
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xu Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Zirui Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Wei Zhai
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xiangning Chen
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Hanliang Cheng
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Jianhe Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xiaoheng Zhao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
| | - Zhujin Ding
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Key Laboratory of Marine Biotechnology, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
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Cui H, Shen X, Zheng Y, Guo P, Gu Z, Gao Y, Zhao X, Cheng H, Xu J, Chen X, Ding Z. Identification, expression patterns, evolutionary characteristics and recombinant protein activities analysis of CD209 gene from Megalobrama amblycephala. FISH & SHELLFISH IMMUNOLOGY 2022; 126:47-56. [PMID: 35568142 DOI: 10.1016/j.fsi.2022.04.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
CD209 is a type II transmembrane protein in the C-type lectin family, which is involved in the regulation of innate and adaptive immune system. Although it has been widely studied in mammals, but little has been reported about fish CD209 genes. In the present study, Megalobrama amblycephala CD209 (MaCD209) gene was cloned and characterized, its expression patterns, evolutionary characteristics, agglutinative and bacteriostatic activities were analyzed. These results showed that the open reading frame (ORF) of MaCD209 gene was 795 bp, encoding 264 aa, and the calculated molecular weight of the encoded protein was 29.7 kDa. MaCD209 was predicted to contain 2 N-glycosylation sites, 1 functional domain (C-LECT-DC-SIGN-like) and 1 transmembrane domain. Multiple sequence alignment showed that the amino acid sequence of MaCD209 was highly homologous with that of partial fishes, especially the highly conserved C-LECT-DC-SIGN-like domain and functional sites of CD209. Phylogenetic analysis showed that the CD209 genes from M. amblycephala and other cypriniformes fishes were clustered into one group, which was reliable and could be used for evolutionary analysis. Then, adaptive evolutionary analysis of teleost CD209 was conducted, and several positively selected sites were identified using site and branch-site models. Quantitative real-time PCR analysis showed that MaCD209 gene was highly expressed in the liver and heart. Moreover, the expression of MaCD209 was significantly induced upon Aeromonas hydrophila infection, with the peak levels at 4 h or 12 h post infection. The immunohistochemical analysis also revealed increased distribution of MaCD209 protein post bacterial infection. In addition, recombinant MaCD209 (rMaCD209) protein was prepared using a pET32a expression system, which showed excellent bacterial binding and agglutinative activities in a Ca2+-independent manner. However, rMaCD209 could only inhibit the proliferation of Escherichia coli rather than A. hydrophila. In conclusion, this study identified the MaCD209 gene, detected its expression and evolutionary characteristics, and evaluated the biological activities of rMaCD209 protein, which would provide a theoretical basis for understanding the evolution and functions of fish CD209 genes.
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Affiliation(s)
- Hujun Cui
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Xiaoxue Shen
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Yancui Zheng
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Peng Guo
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Zhaotian Gu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Yanan Gao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Xiaoheng Zhao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Hanliang Cheng
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Jianhe Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Xiangning Chen
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Zhujin Ding
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China; School of Marine Science and Fisheries, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, 222005, China.
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Zhu T, Flouri T, Yang Z. A simulation study to examine the impact of recombination on phylogenomic inferences under the multispecies coalescent model. Mol Ecol 2022; 31:2814-2829. [PMID: 35313033 PMCID: PMC9321900 DOI: 10.1111/mec.16433] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 01/25/2022] [Accepted: 02/28/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Tianqi Zhu
- Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China
- Key Laboratory of Random Complex Structures and Data Science, Academy of Mathematics and Systems Science, Chinese Academy of Sciences Beijing 100190 China
| | - 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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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: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [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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Thawornwattana Y, Seixas FA, Yang Z, Mallet J. OUP accepted manuscript. Syst Biol 2022; 71:1159-1177. [PMID: 35169847 PMCID: PMC9366460 DOI: 10.1093/sysbio/syac009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 02/01/2022] [Accepted: 02/08/2022] [Indexed: 11/21/2022] Open
Abstract
Introgressive hybridization plays a key role in adaptive evolution and species diversification in many groups of species. However, frequent hybridization and gene flow between species make estimation of the species phylogeny and key population parameters challenging. Here, we show that by accounting for phasing and using full-likelihood methods, introgression histories and population parameters can be estimated reliably from whole-genome sequence data. We employ the multispecies coalescent (MSC) model with and without gene flow to infer the species phylogeny and cross-species introgression events using genomic data from six members of the erato-sara clade of Heliconius butterflies. The methods naturally accommodate random fluctuations in genealogical history across the genome due to deep coalescence. To avoid heterozygote phasing errors in haploid sequences commonly produced by genome assembly methods, we process and compile unphased diploid sequence alignments and use analytical methods to average over uncertainties in heterozygote phase resolution. There is robust evidence for introgression across the genome, both among distantly related species deep in the phylogeny and between sister species in shallow parts of the tree. We obtain chromosome-specific estimates of key population parameters such as introgression directions, times and probabilities, as well as species divergence times and population sizes for modern and ancestral species. We confirm ancestral gene flow between the sara clade and an ancestral population of Heliconius telesiphe, a likely hybrid speciation origin for Heliconius hecalesia, and gene flow between the sister species Heliconius erato and Heliconius himera. Inferred introgression among ancestral species also explains the history of two chromosomal inversions deep in the phylogeny of the group. This study illustrates how a full-likelihood approach based on the MSC makes it possible to extract rich historical information of species divergence and gene flow from genomic data. [3s; bpp; gene flow; Heliconius; hybrid speciation; introgression; inversion; multispecies coalescent]
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Affiliation(s)
- Yuttapong Thawornwattana
- Correspondence to be sent to: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; E-mail: ; (Y.T. and J.M.); Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK; E-mail: (Z.Y.)
| | - Fernando A Seixas
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Ziheng Yang
- Correspondence to be sent to: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; E-mail: ; (Y.T. and J.M.); Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK; E-mail: (Z.Y.)
| | - James Mallet
- Correspondence to be sent to: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; E-mail: ; (Y.T. and J.M.); Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK; E-mail: (Z.Y.)
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11
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Borges LMS, Treneman NC, Haga T, Shipway JR, Raupach MJ, Altermark B, Carlton JT. Out of taxonomic crypsis: A new trans-arctic cryptic species pair corroborated by phylogenetics and molecular evidence. Mol Phylogenet Evol 2021; 166:107312. [PMID: 34530118 DOI: 10.1016/j.ympev.2021.107312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 08/06/2021] [Accepted: 09/09/2021] [Indexed: 01/17/2023]
Abstract
Cryptic species are a common phenomenon in cosmopolitan marine species. The use of molecular tools has often uncovered cryptic species occupying a fraction of the geographic range of the original morphospecies. Shipworms (Teredinidae) are marine bivalves, living in drift and fixed wood, many of which have a conserved morphology across cosmopolitan distributions. Herein novel and GenBank mitochondrial (cytochrome c oxidase subunit I) and nuclear (18S rRNA) DNA sequences are employed to produce a phylogeny of the Teredinidae and delimit a cryptic species pair in the Psiloteredo megotara complex. The anatomy, biogeography, and ecology of P. megotara, Psiloteredo sp. and Nototeredo edax are compared based on private and historic museum collections and a thorough literature review. Morphological and anatomical characters of P. megotara from the North Atlantic and Psiloteredo sp. from Japan were morphologically indistinguishable, and differ in pallet architecture and soft tissue anatomy from N. edax. The two Psiloteredo species were then delimited as genetically distinct species using four molecular-based methods. Consequently, the Northwest Pacific species, Psiloteredo pentagonalis, first synonymized with N. edax and then with P. megotara, is resurrected. Nototeredo edax, P. megotara and P. pentagonalis are redescribed based upon morphological and molecular characters. Phylogenetic analysis further revealed cryptic species complexes within the cosmopolitan species Bankia carinata and possibly additional cryptic lineages within the cosmopolitan Lyrodus pedicellatus.
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Affiliation(s)
- Luísa M S Borges
- L(3) Scientific Solutions, Runder Berg 7e, 21502 Geesthacht, Germany.
| | - Nancy C Treneman
- Oregon Institute of Marine Biology, P.O. Box 5389, Charleston, OR 97420, USA.
| | - Takuma Haga
- National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan.
| | - J Reuben Shipway
- Institute of Marine Sciences, University of Portsmouth, Ferry Rd, Portsmouth, UK. & Microbiology Department, University of Massachusetts, Amherst, MA, USA.
| | - Michael J Raupach
- Sektion Hemiptera, Bavarian State Collection of Zoology (SNSB - ZSM), Münchhausenstraße 21, 81247 München, Germany.
| | - Bjørn Altermark
- Department of Chemistry, Faculty of Science and Technology, UiT- The Arctic University of Norway, PB 6050 Langnes, 9037 Tromsø, Norway.
| | - James T Carlton
- Ocean & Coastal Studies Program, Williams College-Mystic Seaport, Mystic, CT 06355, USA.
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Forthman M, Braun EL, Kimball RT. Gene tree quality affects empirical coalescent branch length estimation. ZOOL SCR 2021. [DOI: 10.1111/zsc.12512] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Michael Forthman
- Department of Entomology & Nematology University of Florida Gainesville FL USA
- California State Collection of Arthropods Plant Pest Diagnostics Branch California Department of Food & Agriculture Sacramento CA USA
| | - Edward L. Braun
- Department of Biology University of Florida Gainesville FL USA
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13
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Korunes KL, Machado CA, Noor MAF. Inversions shape the divergence of Drosophila pseudoobscura and Drosophila persimilis on multiple timescales. Evolution 2021; 75:1820-1834. [PMID: 34041743 DOI: 10.1111/evo.14278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/03/2021] [Accepted: 05/17/2021] [Indexed: 02/02/2023]
Abstract
By shaping meiotic recombination, chromosomal inversions can influence genetic exchange between hybridizing species. Despite the recognized importance of inversions in evolutionary processes such as divergence and speciation, teasing apart the effects of inversions over time remains challenging. For example, are their effects on sequence divergence primarily generated through creating blocks of linkage disequilibrium prespeciation or through preventing gene flux after speciation? We provide a comprehensive look into the influence of inversions on gene flow throughout the evolutionary history of a classic system: Drosophila pseudoobscura and Drosophila persimilis. We use extensive whole-genome sequence data to report patterns of introgression and divergence with respect to chromosomal arrangements. Overall, we find evidence that inversions have contributed to divergence patterns between D. pseudoobscura and D. persimilis over three distinct timescales: (1) segregation of ancestral polymorphism early in the speciation process, (2) gene flow after the split of D. pseudoobscura and D. persimilis, but prior to the split of D. pseudoobscura subspecies, and (3) recent gene flow between sympatric D. pseudoobscura and D. persimilis, after the split of D. pseudoobscura subspecies. We discuss these results in terms of our understanding of evolution in this classic system and provide cautions for interpreting divergence measures in other systems.
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Affiliation(s)
- Katharine L Korunes
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, 27708
| | - Carlos A Machado
- Department of Biology, University of Maryland, College Park, Maryland, 20742
| | - Mohamed A F Noor
- Department of Biology, Duke University, Durham, North Carolina, 27708
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14
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Silliman K, Indorf JL, Knowlton N, Browne WE, Hurt C. Base-substitution mutation rate across the nuclear genome of Alpheus snapping shrimp and the timing of isolation by the Isthmus of Panama. BMC Ecol Evol 2021; 21:104. [PMID: 34049492 PMCID: PMC8164322 DOI: 10.1186/s12862-021-01836-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 04/06/2021] [Indexed: 11/17/2022] Open
Abstract
Background The formation of the Isthmus of Panama and final closure of the Central American Seaway (CAS) provides an independent calibration point for examining the rate of DNA substitutions. This vicariant event has been widely used to estimate the substitution rate across mitochondrial genomes and to date evolutionary events in other taxonomic groups. Nuclear sequence data is increasingly being used to complement mitochondrial datasets for phylogenetic and evolutionary investigations; these studies would benefit from information regarding the rate and pattern of DNA substitutions derived from the nuclear genome. Results To estimate the genome-wide neutral mutation rate (µ), genotype-by-sequencing (GBS) datasets were generated for three transisthmian species pairs in Alpheus snapping shrimp. A range of bioinformatic filtering parameters were evaluated in order to minimize potential bias in mutation rate estimates that may result from SNP filtering. Using a Bayesian coalescent approach (G-PhoCS) applied to 44,960 GBS loci, we estimated µ to be 2.64E−9 substitutions/site/year, when calibrated with the closure of the CAS at 3 Ma. Post-divergence gene flow was detected in one species pair. Failure to account for this post-split migration inflates our substitution rate estimates, emphasizing the importance of demographic methods that can accommodate gene flow. Conclusions Results from our study, both parameter estimates and bioinformatic explorations, have broad-ranging implications for phylogeographic studies in other non-model taxa using reduced representation datasets. Our best estimate of µ that accounts for coalescent and demographic processes is remarkably similar to experimentally derived mutation rates in model arthropod systems. These results contradicted recent suggestions that the closure of the Isthmus was completed much earlier (around 10 Ma), as mutation rates based on an early calibration resulted in uncharacteristically low genomic mutation rates. Also, stricter filtering parameters resulted in biased datasets that generated lower mutation rate estimates and influenced demographic parameters, serving as a cautionary tale for the adherence to conservative bioinformatic strategies when generating reduced-representation datasets at the species level. To our knowledge this is the first use of transisthmian species pairs to calibrate the rate of molecular evolution from GBS data. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01836-3.
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Affiliation(s)
- Katherine Silliman
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA. .,Committee on Evolutionary Biology, University of Chicago, Chicago, IL, 60637, USA.
| | - Jane L Indorf
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Nancy Knowlton
- National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - William E Browne
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Carla Hurt
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA.,Department of Biology, Tennessee Tech University, Cookeville, TN, 38505, USA
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15
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Inference of gene flow in the process of speciation: Efficient maximum-likelihood implementation of a generalised isolation-with-migration model. Theor Popul Biol 2021; 140:1-15. [PMID: 33736959 DOI: 10.1016/j.tpb.2021.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 02/28/2021] [Accepted: 03/01/2021] [Indexed: 11/21/2022]
Abstract
The 'isolation with migration' (IM) model has been extensively used in the literature to detect gene flow during the process of speciation. In this model, an ancestral population split into two or more descendant populations which subsequently exchanged migrants at a constant rate until the present. Of course, the assumption of constant gene flow until the present is often over-simplistic in the context of speciation. In this paper, we consider a 'generalised IM' (GIM) model: a two-population IM model in which migration rates and population sizes are allowed to change at some point in the past. By developing a maximum-likelihood implementation of this model, we enable inference on both historical and contemporary rates of gene flow between two closely related populations or species. The GIM model encompasses both the standard two-population IM model and the 'isolation with initial migration' (IIM) model as special cases, as well as a model of secondary contact. We examine for simulated data how our method can be used, by means of likelihood ratio tests or AIC scores, to distinguish between the following scenarios of population divergence: (a) divergence in complete isolation; (b) divergence with a period of gene flow followed by isolation; (c) divergence with a period of isolation followed by secondary contact; (d) divergence with ongoing gene flow. Our method is based on the coalescent and is suitable for data sets consisting of the number of nucleotide differences between one pair of DNA sequences at each of a large number of independent loci. As our method relies on an explicit expression for the likelihood, it is computationally very fast.
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16
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Zhu T, Yang Z. Complexity of the simplest species tree problem. Mol Biol Evol 2021; 38:3993-4009. [PMID: 33492385 PMCID: PMC8382899 DOI: 10.1093/molbev/msab009] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 01/04/2021] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
The multispecies coalescent model provides a natural framework for species tree estimation accounting for gene-tree conflicts. Although a number of species tree methods under the multispecies coalescent have been suggested and evaluated using simulation, their statistical properties remain poorly understood. Here, we use mathematical analysis aided by computer simulation to examine the identifiability, consistency, and efficiency of different species tree methods in the case of three species and three sequences under the molecular clock. We consider four major species-tree methods including concatenation, two-step, independent-sites maximum likelihood, and maximum likelihood. We develop approximations that predict that the probit transform of the species tree estimation error decreases linearly with the square root of the number of loci. Even in this simplest case, major differences exist among the methods. Full-likelihood methods are considerably more efficient than summary methods such as concatenation and two-step. They also provide estimates of important parameters such as species divergence times and ancestral population sizes,whereas these parameters are not identifiable by summary methods. Our results highlight the need to improve the statistical efficiency of summary methods and the computational efficiency of full likelihood methods of species tree estimation.
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Affiliation(s)
- Tianqi Zhu
- Institute of Applied Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Random Complex Structures and Data Science, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, China
| | - Ziheng Yang
- Institute of Applied Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, China.,Department of Genetics, University College London, Gower Street, London WC1E 6BT, UK
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17
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Pinacho-Pinacho CD, Sereno-Uribe AL, Hernández-Orts JS, García-Varela M, Pérez-Ponce de León G. Integrative taxonomy reveals an even greater diversity within the speciose genus Phyllodistomum (Platyhelminthes:Trematoda:Gorgoderidae), parasitic in the urinary bladder of Middle American freshwater fishes, with descriptions of five new species. INVERTEBR SYST 2021. [DOI: 10.1071/is21007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Phyllodistomum is one of the most species-rich genera of parasitic platyhelminths, with 120 species described worldwide; they infect the urinary bladder of marine and freshwater fishes. As the number of new species within the genus has increased, morphological conservatism, and the lack of reliable diagnostic traits make the separation of species a challenging task. The increase of genetic data for Phyllodistomum species has permitted the use of an integrative taxonomy approach as a framework for species discovery and delimitation. DNA sequences (28S rRNA and COI mtDNA) were obtained from individuals of Phyllodistomum sampled in 29 locations across Middle America, and used in combination with morphology, host association and geographic distribution to uncover five new congeneric species. Morphologically, the new species are relatively similar; there are no unique morphological traits to readily distinguish them. We first investigated species boundaries through phylogenetic analyses of the independent and concatenated datasets; analyses recognised five candidate species showing reciprocal monophyly and strong clade support, particularly for COI data. The interspecific 28S rRNA and COI sequence divergence among the new species from 0.4 to 18.4% and from 5.1 to 27% respectively. These results were further validated by a Bayesian species delimitation approach. The five new species are well supported by molecular data used in combination with other sources of information such as host association and geographical distribution and are described herein as Phyllodistomum romualdae sp. nov., P. virmantasi sp. nov., P. isabelae sp. nov., P. scotti sp. nov., and P. simonae sp. nov.
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18
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Rosas-Valdez R, Morrone JJ, Pinacho-Pinacho CD, Domínguez-Domínguez O, García-Varela M. Genetic diversification of acanthocephalans of the genus Floridosentis Ward 1953 (Acanthocephala: Neoechinorhynchidae), parasites of mullets from the Americas. INFECTION GENETICS AND EVOLUTION 2020; 85:104535. [PMID: 32920194 DOI: 10.1016/j.meegid.2020.104535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 01/05/2023]
Abstract
Adult worms of the genus Floridosentis are endoparasites of marine fishes of the genus Mugil and are broadly distributed in the Americas. Currently, Floridosentis includes two species, F. mugilis, distributed in the Gulf of Mexico and along the Atlantic Ocean coast, and F. pacifica, restricted to the Pacific Ocean coast. The aim of this study was to explore the species limit of both species of the genus Floridosentis, collected in 37 localities in eight countries: Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Ecuador and Venezuela. We sequenced 253 specimens to build a comprehensive dataset for three genes: the cytochrome c oxidase subunit I (cox 1) from mitochondrial DNA, the internal transcribed spacers ITS1 and ITS2 including the 5.8S gene (ITS region), and the D2 + D3 domains of the large subunit (LSU) of nuclear DNA. Maximum likelihood and Bayesian analyses with the cox 1 and concatenated (cox 1 + ITS+LSU) datasets were conducted. Two species delimitation methods were implemented, the Automatic Barcode Gap Discovery (ABGD), and Bayesian species delimitation (BPP), plus a haplotype network inferred with 253 specimens, allowing us to validate two nominal species of Floridosentis., F. mugilis, plus one linage distributed in the Gulf of Mexico and along the Atlantic Ocean coast, and F. pacifica, plus two additional lineages distributed along the Pacific Ocean coast. All these lineages are shared by both species of mullet (Mugil curema and M. cephalus). The currents in the Atlantic Ocean, Pacific Ocean and Gulf of Mexico, in combination with the biology of the definitive hosts, have played a key role in the distribution of the two nominal species and of the three lineages of Floridosentis across the Americas.
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Affiliation(s)
- Rogelio Rosas-Valdez
- Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Av. Preparatoria s/n. Col. Agronómica, 98066 Zacatecas, Mexico
| | - Juan José Morrone
- Museo de Zoología "Alfonso L. Herrera", Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), Apartado postal 70-399, 04510 Mexico City, Mexico
| | - Carlos Daniel Pinacho-Pinacho
- Cátedras CONACyT, Instituto de Ecología, A.C., Red de Estudios Moleculares Avanzados, Carretera antigua a Coatepec 351, El Haya, Xalapa, 91070 Veracruz, Mexico
| | - Omar Domínguez-Domínguez
- Laboratorio de Biología Acuática, Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Martín García-Varela
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), Circuito exterior s/n, Ciudad Universitaria, 04510 Mexico City, Mexico.
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19
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Košuthová A, Bergsten J, Westberg M, Wedin M. Species delimitation in the cyanolichen genus Rostania. BMC Evol Biol 2020; 20:115. [PMID: 32912146 PMCID: PMC7488055 DOI: 10.1186/s12862-020-01681-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 08/31/2020] [Indexed: 11/24/2022] Open
Abstract
Background In this study, we investigate species limits in the cyanobacterial lichen genus Rostania (Collemataceae, Peltigerales, Lecanoromycetes). Four molecular markers (mtSSU rDNA, β-tubulin, MCM7, RPB2) were sequenced and analysed with two coalescent-based species delimitation methods: the Generalized Mixed Yule Coalescent model (GMYC) and a Bayesian species delimitation method (BPP) using a multispecies coalescence model (MSC), the latter with or without an a priori defined guide tree. Results Species delimitation analyses indicate the presence of eight strongly supported candidate species. Conclusive correlation between morphological/ecological characters and genetic delimitation could be found for six of these. Of the two additional candidate species, one is represented by a single sterile specimen and the other currently lacks morphological or ecological supporting evidence. Conclusions We conclude that Rostania includes a minimum of six species: R. ceranisca, R. multipunctata, R. occultata 1, R. occultata 2, R. occultata 3, and R. occultata 4,5,6. Three distinct Nostoc morphotypes occur in Rostania, and there is substantial correlation between these morphotypes and Rostania thallus morphology.
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Affiliation(s)
- Alica Košuthová
- Department of Botany, Swedish Museum of Natural History, P.O. Box 50007, SE-104 05, Stockholm, Sweden.
| | - Johannes Bergsten
- Department of Zoology, Swedish Museum of Natural History, P.O. Box 50007, SE-104 05, Stockholm, Sweden
| | - Martin Westberg
- Museum of Evolution, Uppsala University, Norbyvägen 16, SE-752 36, Uppsala, Sweden
| | - Mats Wedin
- Department of Botany, Swedish Museum of Natural History, P.O. Box 50007, SE-104 05, Stockholm, Sweden
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20
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Repeated species radiations in the recent evolution of the key marine phytoplankton lineage Gephyrocapsa. Nat Commun 2019; 10:4234. [PMID: 31530807 PMCID: PMC6748936 DOI: 10.1038/s41467-019-12169-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/22/2019] [Indexed: 11/10/2022] Open
Abstract
Phytoplankton account for nearly half of global primary productivity and strongly affect the global carbon cycle, yet little is known about the forces that drive the evolution of these keystone microscopic organisms. Here we combine morphometric data from the fossil record of the ubiquitous coccolithophore genus Gephyrocapsa with genomic analyses of extant species to assess the genetic processes underlying Pleistocene palaeontological patterns. We demonstrate that all modern diversity in Gephyrocapsa (including Emiliania huxleyi) originated in a rapid species radiation during the last 0.6 Ma, coincident with the latest of the three pulses of Gephyrocapsa diversification and extinction documented in the fossil record. Our evolutionary genetic analyses indicate that new species in this genus have formed in sympatry or parapatry, with occasional hybridisation between species. This sheds light on the mode of speciation during evolutionary radiation of marine phytoplankton and provides a model of how new plankton species form. The phytoplankton Gephyrocapsa have gone through repeated macroevolutionary shifts in size. Here, Bendif et al. combine fossil and genomic data to show the latest shift was coincident with a species radiation and suggest that previous shifts have also resulted from cycles of radiation and extinction.
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21
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Pie MR, Bornschein MR, Ribeiro LF, Faircloth BC, McCormack JE. Phylogenomic species delimitation in microendemic frogs of the Brazilian Atlantic Forest. Mol Phylogenet Evol 2019; 141:106627. [PMID: 31539606 DOI: 10.1016/j.ympev.2019.106627] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/17/2019] [Accepted: 09/17/2019] [Indexed: 10/26/2022]
Abstract
The advent of next-generation sequencing allows researchers to use large-scale datasets for species delimitation analyses, yet one can envision an inflection point where the added accuracy of including more loci does not offset the increased computational burden. One alternative to including all loci could be to prioritize the analysis of loci for which there is an expectation of high informativeness. Here, we explore the issue of species delimitation and locus selection with montane species from two anuran genera that have been isolated in sky islands across the southern Brazilian Atlantic Forest: Melanophryniscus (Bufonidae) and Brachycephalus (Brachycephalidae). To delimit species, we obtained genetic data using target enrichment of ultraconserved elements from 32 populations (13 for Melanophryniscus and 19 for Brachycephalus), and we were able to create datasets that included over 800 loci with no missing data. We ranked loci according to their number of parsimony-informative sites, and we performed species delimitation analyses using BPP with the most informative 10, 20, 40, 80, 160, 320, and 640 loci. We identified three types of phylogenetic node: nodes with either consistently high or low support regardless of the number of loci or their informativeness and nodes that were initially poorly supported where support became stronger as we included more data. When viewed across all sensitivity analyses, our results suggest that the current species richness in both genera is likely underestimated. In addition, our results show the effects of different sampling strategies on species delimitation using phylogenomic datasets.
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Affiliation(s)
- Marcio R Pie
- Departamento de Zoologia, Universidade Federal do Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; Mater Natura - Instituto de Estudos Ambientais, CEP 80250-020 Curitiba, Paraná, Brazil.
| | - Marcos R Bornschein
- Mater Natura - Instituto de Estudos Ambientais, CEP 80250-020 Curitiba, Paraná, Brazil; Instituto de Biociências, Universidade Estadual Paulista, Praça Infante Dom Henrique s/no, Parque Bitaru, CEP 11330-900 São Vicente, São Paulo, Brazil
| | - Luiz F Ribeiro
- Mater Natura - Instituto de Estudos Ambientais, CEP 80250-020 Curitiba, Paraná, Brazil; Escola de Ciências da Vida, Pontifícia Universidade Católica do Paraná, CEP 80215-901 Curitiba, Paraná, Brazil
| | - Brant C Faircloth
- Department of Biological Sciences and Museum of Natural Science, Louisiana State University, Baton Rouge, LA 70803, USA
| | - John E McCormack
- Moore Laboratory of Zoology, Occidental College, 1600 Campus Road, Los Angeles, CA 90041, USA
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22
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Zhou C, Tu H, Yu H, Zheng S, Dai B, Price M, Wu Y, Yang N, Yue B, Meng Y. The Draft Genome of the Endangered Sichuan Partridge ( Arborophila rufipectus) with Evolutionary Implications. Genes (Basel) 2019; 10:E677. [PMID: 31491910 PMCID: PMC6770966 DOI: 10.3390/genes10090677] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/30/2019] [Accepted: 09/02/2019] [Indexed: 12/17/2022] Open
Abstract
The Sichuan partridge (Arborophila rufipectus, Phasianidae, Galliformes) is distributed in south-west China, and classified as endangered grade. To examine the evolution and genomic features of Sichuan partridge, we de novo assembled the Sichuan partridge reference genome. The final draft assembly consisted of approximately 1.09 Gb, and had a scaffold N50 of 4.57 Mb. About 1.94 million heterozygous single-nucleotide polymorphisms (SNPs) were detected, 17,519 protein-coding genes were predicted, and 9.29% of the genome was identified as repetitive elements. A total of 56 olfactory receptor (OR) genes were found in Sichuan partridge, and conserved motifs were detected. Comparisons between the Sichuan partridge genome and chicken genome revealed a conserved genome structure, and phylogenetic analysis demonstrated that Arborophila possessed a basal phylogenetic position within Phasianidae. Gene Ontology (GO) enrichment analysis of positively selected genes (PSGs) in Sichuan partridge showed over-represented GO functions related to environmental adaptation, such as energy metabolism and behavior. Pairwise sequentially Markovian coalescent analysis revealed the recent demographic trajectory for the Sichuan partridge. Our data and findings provide valuable genomic resources not only for studying the evolutionary adaptation, but also for facilitating the long-term conservation and genetic diversity for this endangered species.
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Affiliation(s)
- Chuang Zhou
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, China.
| | - Hongmei Tu
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, China.
| | - Haoran Yu
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, China.
| | - Shuai Zheng
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, China.
| | - Bo Dai
- College of Life Sciences, Leshan Normal University, Leshan 614004, China.
| | - Megan Price
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, China.
| | - Yongjie Wu
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, China.
| | - Nan Yang
- Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu 610064, China.
| | - Bisong Yue
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, China.
| | - Yang Meng
- Key Laboratory of Bioresources and Ecoenvironment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, China.
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23
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Zhou C, James JG, Xu Y, Tu H, He X, Wen Q, Price M, Yang N, Wu Y, Ran J, Meng Y, Yue B. Genome-wide analysis sheds light on the high-altitude adaptation of the buff-throated partridge (Tetraophasis szechenyii). Mol Genet Genomics 2019; 295:31-46. [PMID: 31414227 DOI: 10.1007/s00438-019-01601-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/30/2019] [Indexed: 12/23/2022]
Abstract
The buff-throated partridge (Tetraophasis szechenyii) is a hypoxia-tolerant bird living in an extremely inhospitable high-altitude environment, which has high ultraviolet (UV) radiation as well as a low oxygen supply when compared with low-altitude areas. To further understand the molecular genetic mechanisms of the high-altitude adaptation of the buff-throated partridges, we de novo assembled the complete genome of the buff-throated partridge. Comparative genomics revealed that positively selected hypoxia-related genes in the buff-throated partridge were distributed in the HIF-1 signaling pathway (map04066), response to hypoxia (GO:0001666), response to oxygen-containing compound (GO:1901700), ATP binding (GO:0005524), and angiogenesis (GO:0001525). Of these positively selected hypoxia-related genes, one positively selected gene (LONP1) had one buff-throated partridge-specific missense mutation which was classified as deleterious by PolyPhen-2. Moreover, positively selected genes in the buff-throated partridge were enriched in cellular response to DNA damage stimulus (corrected P value: 0.028006) and DNA repair (corrected P value: 0.044549), which was related to the increased exposure of the buff-throated partridge to UV radiation. Compared with other avian genomes, the buff-throated partridge showed expansion in genes associated with steroid hormone receptor activity and contractions in genes related to immune and olfactory perception. Furthermore, comparisons between the buff-throated partridge genome and red junglefowl genome revealed a conserved genome structure and provided strong evidence of the sibling relationship between Tetraophasis and Lophophorus. Our data and analysis contributed to the study of Phasianidae evolutionary history and provided new insights into the potential adaptation mechanisms to the high altitude employed by the buff-throated partridge.
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Affiliation(s)
- Chuang Zhou
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Jake George James
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Yu Xu
- School of Life Sciences, Guizhou Normal University, Guiyang, 550001, People's Republic of China
| | - Hongmei Tu
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Xingcheng He
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Qinchao Wen
- Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Megan Price
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Nan Yang
- Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu, People's Republic of China
| | - Yongjie Wu
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Jianghong Ran
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Yang Meng
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China.
| | - Bisong Yue
- Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China.
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The Interplay between Incipient Species and Social Polymorphism in the Desert Ant Cataglyphis. Sci Rep 2019; 9:9495. [PMID: 31263177 PMCID: PMC6603034 DOI: 10.1038/s41598-019-45950-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 06/19/2019] [Indexed: 11/22/2022] Open
Abstract
In social insects, due to considerable polyphenism as well as high level of hybridization, the delimitation of species can be challenging. The genus Cataglyphis presents a high level of diversification, making it an excellent model with which to study evolutionary paths. Israel appears to be a “hot spot” for recent speciation in this genus. Although previous studies have described multiple species of Cataglyphis in Israel, a recent genetic study has questioned the existence of some of these historically described species. The present study focuses on an apparent species complex, the C. niger species complex which includes C. niger, C. savigyi, and C. drusus that are distinguishable by their mitochondrial DNA (and therefore named mitotypes) but not by their nuclear DNA. Using a multi-method approach (genetics, chemistry and behavior), we show that these mitotypes also differ in their social structures and are readily distinguishable by their cuticular hydrocarbons profiles. While most populations of the different mitotypes are allopatric, at our study site they are sympatric, but nonetheless maintain the observed differences between them. This raises the evolutionary question: Are these incipient species that have diverged with gene flow, or is this a case of social and chemical polymorphism that is maintained within a single species? Unveiling the interplay between social polyphenism and species segregation is at the core of evolutionary biology.
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25
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Flouri T, Jiao X, Rannala B, Yang Z. Species Tree Inference with BPP Using Genomic Sequences and the Multispecies Coalescent. Mol Biol Evol 2019; 35:2585-2593. [PMID: 30053098 PMCID: PMC6188564 DOI: 10.1093/molbev/msy147] [Citation(s) in RCA: 189] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The multispecies coalescent provides a natural framework for accommodating ancestral genetic polymorphism and coalescent processes that can cause different genomic regions to have different genealogical histories. The Bayesian program BPP includes a full-likelihood implementation of the multispecies coalescent, using transmodel Markov chain Monte Carlo to calculate the posterior probabilities of different species trees. BPP is suitable for analyzing multilocus sequence data sets and it accommodates the heterogeneity of gene trees (both the topology and branch lengths) among loci and gene tree uncertainties due to limited phylogenetic information at each locus. Here, we provide a practical guide to the use of BPP in species tree estimation. BPP is a command-line program that runs on linux, macosx, and windows. This protocol shows how to use both BPP 3.4 (http://abacus.gene.ucl.ac.uk/software/) and BPP 4.0 (https://github.com/bpp/).
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Affiliation(s)
- Tomáš Flouri
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Xiyun Jiao
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Bruce Rannala
- Department of Ecology and Evolution, University of California, Davis, CA
| | - Ziheng Yang
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
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26
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Thawornwattana Y, Dalquen D, Yang Z. Coalescent Analysis of Phylogenomic Data Confidently Resolves the Species Relationships in the Anopheles gambiae Species Complex. Mol Biol Evol 2019; 35:2512-2527. [PMID: 30102363 PMCID: PMC6188554 DOI: 10.1093/molbev/msy158] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Deep coalescence and introgression make it challenging to infer phylogenetic relationships among closely related species that arose through radiative speciation events. Despite numerous phylogenetic analyses and the availability of whole genomes, the phylogeny in the Anopheles gambiae species complex has not been confidently resolved. Here we extract over 80, 000 coding and noncoding short segments (called loci) from the genomes of six members of the species complex and use a Bayesian method under the multispecies coalescent model to infer the species tree, which takes into account genealogical heterogeneity across the genome and uncertainty in the gene trees. We obtained a robust estimate of the species tree from the distal region of the X chromosome: (A. merus, ((A. melas, (A. arabiensis, A. quadriannulatus)), (A. gambiae, A. coluzzii))), with A. merus to be the earliest branching species. This species tree agrees with the chromosome inversion phylogeny and provides a parsimonious interpretation of inversion and introgression events. Simulation informed by the real data suggest that the coalescent approach is reliable while the sliding-window analysis used in a previous phylogenomic study generates artifactual species trees. Likelihood ratio test of gene flow revealed strong evidence of autosomal introgression from A. arabiensis into A. gambiae (at the average rate of ∼0.2 migrants per generation), but not in the opposite direction, and introgression of the 3 L chromosomal region from A. merus into A. quadriannulatus. Our results highlight the importance of accommodating incomplete lineage sorting and introgression in phylogenomic analyses of species that arose through recent radiative speciation events.
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Affiliation(s)
- Yuttapong Thawornwattana
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom.,Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Daniel Dalquen
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Ziheng Yang
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom.,Radcliffe Institute for Advanced Studies, Harvard University, Cambridge, MA
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27
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Mello B, Schrago CG. The Estimated Pacemaker for Great Apes Supports the Hominoid Slowdown Hypothesis. Evol Bioinform Online 2019; 15:1176934319855988. [PMID: 31223232 PMCID: PMC6566470 DOI: 10.1177/1176934319855988] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/17/2019] [Indexed: 11/16/2022] Open
Abstract
The recent surge of genomic data has prompted the investigation of substitution rate variation across the genome, as well as among lineages. Evolutionary trees inferred from distinct genomic regions may display branch lengths that differ between loci by simple proportionality constants, indicating that rate variation follows a pacemaker model, which may be attributed to lineage effects. Analyses of genes from diverse biological clades produced contrasting results, supporting either this model or alternative scenarios where multiple pacemakers exist. So far, an evaluation of the pacemaker hypothesis for all great apes has never been carried out. In this work, we tested whether the evolutionary rates of hominids conform to pacemakers, which were inferred accounting for gene tree/species tree discordance. For higher precision, substitution rates in branches were estimated with a calibration-free approach, the relative rate framework. A predominant evolutionary trend in great apes was evidenced by the recovery of a large pacemaker, encompassing most hominid genomic regions. In addition, the majority of genes followed a pace of evolution that was closely related to the strict molecular clock. However, slight rate decreases were recovered in the internal branches leading to humans, corroborating the hominoid slowdown hypothesis. Our findings suggest that in great apes, life history traits were the major drivers of substitution rate variation across the genome.
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Affiliation(s)
- Beatriz Mello
- Department of Genetics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos G Schrago
- Department of Genetics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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28
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Cohen P, Privman E. Speciation and hybridization in invasive fire ants. BMC Evol Biol 2019; 19:111. [PMID: 31142287 PMCID: PMC6542140 DOI: 10.1186/s12862-019-1437-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 05/13/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND A major focus of evolutionary biology is the formation of reproductive barriers leading to divergence and ultimately, speciation. Often, it is not clear whether the separation of populations is complete or if there still is ongoing gene flow in the form of rare cases of admixture, known as isolation with migration. Here, we studied the speciation of two fire ant species, Solenopsis invicta and Solenopsis richteri, both native to South America, both inadvertently introduced to North America in the early twentieth century. While the two species are known to admix in the introduced range, in the native range no hybrids were found. RESULTS We conducted a population genomic survey of native and introduced populations of the two species using reduced representation genomic sequencing of 337 samples. Using maximum likelihood analysis over native range samples, we found no evidence of any gene flow between the species since they diverged. We estimated their time of divergence to 190,000 (100,000-350,000) generations ago. Modelling the demographic history of native and introduced S. invicta populations, we evaluated their divergence times and historic and contemporary population sizes, including the original founder population in North America, which was estimated at 26 (10-93) unrelated singly-mated queens. CONCLUSIONS We provide evidence for complete genetic isolation maintained between two invasive species in their natïve range, based, for the first time, on large scale genomic data analysis. The results lay the foundations for further studies into different stages in the formation of genetic barriers in dynamic, invasive populations.
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Affiliation(s)
- Pnina Cohen
- Department of Evolution and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, Israel
| | - Eyal Privman
- Department of Evolution and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, Israel
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29
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Shi CM, Yang Z. Coalescent-Based Analyses of Genomic Sequence Data Provide a Robust Resolution of Phylogenetic Relationships among Major Groups of Gibbons. Mol Biol Evol 2019; 35:159-179. [PMID: 29087487 PMCID: PMC5850733 DOI: 10.1093/molbev/msx277] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The phylogenetic relationships among extant gibbon species remain unresolved despite numerous efforts using morphological, behavorial, and genetic data and the sequencing of whole genomes. A major challenge in reconstructing the gibbon phylogeny is the radiative speciation process, which resulted in extremely short internal branches in the species phylogeny and extensive incomplete lineage sorting with extensive gene-tree heterogeneity across the genome. Here, we analyze two genomic-scale data sets, with ∼10,000 putative noncoding and exonic loci, respectively, to estimate the species tree for the major groups of gibbons. We used the Bayesian full-likelihood method bpp under the multispecies coalescent model, which naturally accommodates incomplete lineage sorting and uncertainties in the gene trees. For comparison, we included three heuristic coalescent-based methods (mp-est, SVDQuartets, and astral) as well as concatenation. From both data sets, we infer the phylogeny for the four extant gibbon genera to be (Hylobates, (Nomascus, (Hoolock, Symphalangus))). We used simulation guided by the real data to evaluate the accuracy of the methods used. Astral, while not as efficient as bpp, performed well in estimation of the species tree even in presence of excessive incomplete lineage sorting. Concatenation, mp-est and SVDQuartets were unreliable when the species tree contains very short internal branches. Likelihood ratio test of gene flow suggests a small amount of migration from Hylobates moloch to H. pileatus, while cross-genera migration is absent or rare. Our results highlight the utility of coalescent-based methods in addressing challenging species tree problems characterized by short internal branches and rampant gene tree-species tree discordance.
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Affiliation(s)
- Cheng-Min Shi
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.,Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Ziheng Yang
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom.,Radcliffe Institute for Advanced Studies, Harvard University, Cambridge, MA 02138, USA
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30
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Dutheil JY, Hobolth A. Ancestral Population Genomics. Methods Mol Biol 2019; 1910:555-589. [PMID: 31278677 DOI: 10.1007/978-1-4939-9074-0_18] [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] [Indexed: 06/09/2023]
Abstract
Borrowing both from population genetics and phylogenetics, the field of population genomics emerged as full genomes of several closely related species were available. Providing we can properly model sequence evolution within populations undergoing speciation events, this resource enables us to estimate key population genetics parameters such as ancestral population sizes and split times. Furthermore we can enhance our understanding of the recombination process and investigate various selective forces. With the advent of resequencing technologies, genome-wide patterns of diversity in extant populations have now come to complement this picture, offering an increasing power to study more recent genetic history.We discuss the basic models of genomes in populations, including speciation models for closely related species. A major point in our discussion is that only a few complete genomes contain much information about the whole population. The reason being that recombination unlinks genomic regions, and therefore a few genomes contain many segments with distinct histories. The challenge of population genomics is to decode this mosaic of histories in order to infer scenarios of demography and selection. We survey modeling strategies for understanding genetic variation in ancestral populations and species. The underlying models build on the coalescent with recombination process and introduce further assumptions to scale the analyses to genomic data sets.
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Affiliation(s)
- Julien Y Dutheil
- Department of Evolutionary Genetics, Max Planck Institute of Evolutionary Biology, Plön, Germany.
| | - Asger Hobolth
- Bioinformatics Research Center (BiRC), Aarhus University, Aarhus, Denmark
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31
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Leaché AD, Zhu T, Rannala B, Yang Z. The Spectre of Too Many Species. Syst Biol 2019; 68:168-181. [PMID: 29982825 PMCID: PMC6292489 DOI: 10.1093/sysbio/syy051] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 06/29/2018] [Accepted: 06/29/2018] [Indexed: 11/21/2022] Open
Abstract
Recent simulation studies examining the performance of Bayesian species delimitation as implemented in the bpp program have suggested that bpp may detect population splits but not species divergences and that it tends to over-split when data of many loci are analyzed. Here, we confirm these results and provide the mathematical justifications. We point out that the distinction between population and species splits made in the protracted speciation model (PSM) has no influence on the generation of gene trees and sequence data, which explains why no method can use such data to distinguish between population splits and speciation. We suggest that the PSM is unrealistic as its mechanism for assigning species status assumes instantaneous speciation, contradicting prevailing taxonomic practice. We confirm the suggestion, based on simulation, that in the case of speciation with gene flow, Bayesian model selection as implemented in bpp tends to detect population splits when the amount of data (the number of loci) increases. We discuss the use of a recently proposed empirical genealogical divergence index (gdi) for species delimitation and illustrate that parameter estimates produced by a full likelihood analysis as implemented in bpp provide much more reliable inference under the gdi than the approximate method phrapl. We distinguish between Bayesian model selection and parameter estimation and suggest that the model selection approach is useful for identifying sympatric cryptic species, while the parameter estimation approach may be used to implement empirical criteria for determining species status among allopatric populations.
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Affiliation(s)
- Adam D Leaché
- Department of Biology & Burke Museum of Natural History and Culture, University of Washington, Seattle, USA
| | - Tianqi Zhu
- National Center for Mathematics and Interdisciplinary Sciences, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, China
- Key Laboratory of Random Complex Structures and Data Science, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, China
| | - Bruce Rannala
- Department of Evolution and Ecology, University of California Davis, One Shields Avenue, Davis, USA
| | - Ziheng Yang
- National Center for Mathematics and Interdisciplinary Sciences, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, China
- Department of Genetics, University College London, London, UK
- Radcliffe Institute for Advanced Studies, Harvard University, Cambridge, USA
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32
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Zhou C, Zheng S, Jiang X, Liang W, Price M, Fan Z, Meng Y, Yue B. First complete genome sequence in Arborophila and comparative genomics reveals the evolutionary adaptation of Hainan Partridge (Arborophila ardens). AVIAN RESEARCH 2018; 9:45. [DOI: 10.1186/s40657-018-0136-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 12/05/2018] [Indexed: 08/30/2023]
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33
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Tang Q, Edwards SV, Rheindt FE. Rapid diversification and hybridization have shaped the dynamic history of the genus Elaenia. Mol Phylogenet Evol 2018; 127:522-533. [DOI: 10.1016/j.ympev.2018.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 04/11/2018] [Accepted: 05/08/2018] [Indexed: 01/04/2023]
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34
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Beeravolu CR, Hickerson MJ, Frantz LAF, Lohse K. ABLE: blockwise site frequency spectra for inferring complex population histories and recombination. Genome Biol 2018; 19:145. [PMID: 30253810 PMCID: PMC6156964 DOI: 10.1186/s13059-018-1517-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 08/22/2018] [Indexed: 01/08/2023] Open
Abstract
We introduce ABLE (Approximate Blockwise Likelihood Estimation), a novel simulation-based composite likelihood method that uses the blockwise site frequency spectrum to jointly infer past demography and recombination. ABLE is explicitly designed for a wide variety of data from unphased diploid genomes to genome-wide multi-locus data (for example, RADSeq) and can also accommodate arbitrarily large samples. We use simulations to demonstrate the accuracy of this method to infer complex histories of divergence and gene flow and reanalyze whole genome data from two species of orangutan. ABLE is available for download at https://github.com/champost/ABLE.
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Affiliation(s)
- Champak R Beeravolu
- Biology Department, The City College of New York, New York, 10031, NY, USA. .,Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, 8057, Switzerland.
| | - Michael J Hickerson
- Biology Department, The City College of New York, New York, 10031, NY, USA.,The Graduate Center, The City University of New York, New York, 10016, NY, USA.,Division of Invertebrate Zoology, American Museum of Natural History, New York, 10024, NY, USA
| | - Laurent A F Frantz
- Paleogenomics and Bio-Archaeology Research Network, Research Laboratory for Archeology and History of Art, University of Oxford, Oxford, OX1 3QY, UK.,School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Konrad Lohse
- Institute of Evolutionary Biology, University of Edinburgh, King's Buildings, Edinburgh, EH9 3FL, UK
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35
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Taheri S, James S, Roy V, Decaëns T, Williams B, Anderson F, Rougerie R, Chang CH, Brown G, Cunha L, Stanton D, Da Silva E, Chen JH, Lemmon A, Moriarty Lemmon E, Bartz M, Baretta D, Barois I, Lapied E, Coulis M, Dupont L. Complex taxonomy of the ‘brush tail’ peregrine earthworm Pontoscolex corethrurus. Mol Phylogenet Evol 2018; 124:60-70. [DOI: 10.1016/j.ympev.2018.02.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 02/20/2018] [Accepted: 02/20/2018] [Indexed: 01/19/2023]
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36
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Fuller ZL, Leonard CJ, Young RE, Schaeffer SW, Phadnis N. Ancestral polymorphisms explain the role of chromosomal inversions in speciation. PLoS Genet 2018; 14:e1007526. [PMID: 30059505 PMCID: PMC6085072 DOI: 10.1371/journal.pgen.1007526] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/09/2018] [Accepted: 06/29/2018] [Indexed: 01/28/2023] Open
Abstract
Understanding the role of chromosomal inversions in speciation is a fundamental problem in evolutionary genetics. Here, we perform a comprehensive reconstruction of the evolutionary histories of the chromosomal inversions in Drosophila persimilis and D. pseudoobscura. We provide a solution to the puzzling origins of the selfish Sex-Ratio arrangement in D. persimilis and uncover surprising patterns of phylogenetic discordance on this chromosome. These patterns show that, contrary to widely held views, all fixed chromosomal inversions between D. persimilis and D. pseudoobscura were already present in their ancestral population long before the species split. Our results suggest that patterns of higher genomic divergence and an association of reproductive isolation genes with chromosomal inversions may be a direct consequence of incomplete lineage sorting of ancestral polymorphisms. These findings force a reconsideration of the role of chromosomal inversions in speciation, not as protectors of existing hybrid incompatibilities, but as fertile grounds for their formation.
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Affiliation(s)
- Zachary L. Fuller
- Department of Biology, Erwin W. Mueller Laboratories, The Pennsylvania State University, University Park, PA, United States of America
| | | | - Randee E. Young
- Department of Biology, University of Utah, Salt Lake City, UT, United States of America
| | - Stephen W. Schaeffer
- Department of Biology, Erwin W. Mueller Laboratories, The Pennsylvania State University, University Park, PA, United States of America
| | - Nitin Phadnis
- Department of Biology, University of Utah, Salt Lake City, UT, United States of America
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37
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Pinacho-Pinacho CD, García-Varela M, Sereno-Uribe AL, Pérez-Ponce de León G. A hyper-diverse genus of acanthocephalans revealed by tree-based and non-tree-based species delimitation methods: Ten cryptic species of Neoechinorhynchus in Middle American freshwater fishes. Mol Phylogenet Evol 2018; 127:30-45. [PMID: 29783021 DOI: 10.1016/j.ympev.2018.05.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/12/2018] [Accepted: 05/17/2018] [Indexed: 12/20/2022]
Abstract
The genus Neoechinorhynchus represents a hyper-diverse group of acanthocephalans, parasites of fresh and brackish water fish and freshwater turtles, with approximately 116 species described worldwide. Forty-nine species have been recorded in the Americas, nine of them in Middle America. Even though species delimitation methods using DNA sequences have been rarely used for parasitic helminths, the genetic library for species of Neoechinorhynchus has grown in the past few years, enhancing the possibility of using these methods for inferring evolutionary relationships and for establishing more robust species boundaries. In this study, we used non-tree-based and tree-based methods through a coalescent approach to explore the species limits of specimens of Neoechinorhynchus collected in 57 localities across Middle America. We sequenced a large number of individuals to build a comprehensive dataset for three genes: the mitochondrial cytochrome c oxidase subunit I (352 individuals), the internal transcribed spacers (330 individuals), and the D2 + D3 domains of the large subunit (278 individuals). Several species delimitation methods were implemented, i.e., Automatic Barcode Gap Discovery (ABGD), General Mixed Yule-Coalescent Model (GMYC), Bayesian species delimitation (BPP) and species tree (∗BEAST). Additionally, we conducted a detailed morphological study of the diagnostic traits associated with the proboscis of 184 males and 169 females. Overall, our analyses allowed us to validate nine nominal species of Neoechinorhynchus and to identify 10 additional genetic lineages herein regarded as candidate species. This unexpected genetic diversity and the lack of reliable morphological traits show that the genus Neoechinorhynchus includes a group of cryptic species, at least in Middle America.
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Affiliation(s)
- Carlos Daniel Pinacho-Pinacho
- Investigador Cátedra CONACyT, Instituto de Ecología, A.C., Red de Estudios Moleculares Avanzados, Km 2.5 Ant. Carretera a Coatepec, Xalapa, Veracruz 91070, Mexico.
| | - Martín García-Varela
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, C.P. 04510, Ap. Postal 70-153, Ciudad Universitaria, Ciudad de México, Mexico.
| | - Ana L Sereno-Uribe
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, C.P. 04510, Ap. Postal 70-153, Ciudad Universitaria, Ciudad de México, Mexico.
| | - Gerardo Pérez-Ponce de León
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, C.P. 04510, Ap. Postal 70-153, Ciudad Universitaria, Ciudad de México, Mexico.
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38
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Rannala B, Yang Z. Efficient Bayesian Species Tree Inference under the Multispecies Coalescent. Syst Biol 2018; 66:823-842. [PMID: 28053140 PMCID: PMC8562347 DOI: 10.1093/sysbio/syw119] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 12/10/2016] [Indexed: 11/12/2022] Open
Abstract
We develop a Bayesian method for inferring the species phylogeny under the multispecies coalescent (MSC) model. To improve the mixing properties of the Markov chain Monte Carlo (MCMC) algorithm that traverses the space of species trees, we implement two efficient MCMC proposals: the first is based on the Subtree Pruning and Regrafting (SPR) algorithm and the second is based on a node-slider algorithm. Like the Nearest-Neighbor Interchange (NNI) algorithm we implemented previously, both new algorithms propose changes to the species tree, while simultaneously altering the gene trees at multiple genetic loci to automatically avoid conflicts with the newly proposed species tree. The method integrates over gene trees, naturally taking account of the uncertainty of gene tree topology and branch lengths given the sequence data. A simulation study was performed to examine the statistical properties of the new method. The method was found to show excellent statistical performance, inferring the correct species tree with near certainty when 10 loci were included in the dataset. The prior on species trees has some impact, particularly for small numbers of loci. We analyzed several previously published datasets (both real and simulated) for rattlesnakes and Philippine shrews, in comparison with alternative methods. The results suggest that the Bayesian coalescent-based method is statistically more efficient than heuristic methods based on summary statistics, and that our implementation is computationally more efficient than alternative full-likelihood methods under the MSC. Parameter estimates for the rattlesnake data suggest drastically different evolutionary dynamics between the nuclear and mitochondrial loci, even though they support largely consistent species trees. We discuss the different challenges facing the marginal likelihood calculation and transmodel MCMC as alternative strategies for estimating posterior probabilities for species trees. [Bayes factor; Bayesian inference; MCMC; multispecies coalescent; nodeslider; species tree; SPR.].
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Affiliation(s)
- Bruce Rannala
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Ziheng Yang
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
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39
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Dalquen DA, Zhu T, Yang Z. Maximum Likelihood Implementation of an Isolation-with-Migration Model for Three Species. Syst Biol 2018; 66:379-398. [PMID: 27486180 DOI: 10.1093/sysbio/syw063] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 07/08/2016] [Indexed: 01/03/2023] Open
Abstract
We develop a maximum likelihood (ML) method for estimating migration rates between species using genomic sequence data. A species tree is used to accommodate the phylogenetic relationships among three species, allowing for migration between the two sister species, while the third species is used as an out-group. A Markov chain characterization of the genealogical process of coalescence and migration is used to integrate out the migration histories at each locus analytically, whereas Gaussian quadrature is used to integrate over the coalescent times on each genealogical tree numerically. This is an extension of our early implementation of the symmetrical isolation-with-migration model for three species to accommodate arbitrary loci with two or three sequences per locus and to allow asymmetrical migration rates. Our implementation can accommodate tens of thousands of loci, making it feasible to analyze genome-scale data sets to test for gene flow. We calculate the posterior probabilities of gene trees at individual loci to identify genomic regions that are likely to have been transferred between species due to gene flow. We conduct a simulation study to examine the statistical properties of the likelihood ratio test for gene flow between the two in-group species and of the ML estimates of model parameters such as the migration rate. Inclusion of data from a third out-group species is found to increase dramatically the power of the test and the precision of parameter estimation. We compiled and analyzed several genomic data sets from the Drosophila fruit flies. Our analyses suggest no migration from D. melanogaster to D. simulans, and a significant amount of gene flow from D. simulans to D. melanogaster, at the rate of ~0.02 migrant individuals per generation. We discuss the utility of the multispecies coalescent model for species tree estimation, accounting for incomplete lineage sorting and migration.
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Affiliation(s)
- Daniel A Dalquen
- Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Tianqi Zhu
- Center for Computational Genomics, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Ziheng Yang
- Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK.,Center for Computational Genomics, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
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40
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Savary R, Masclaux FG, Wyss T, Droh G, Cruz Corella J, Machado AP, Morton JB, Sanders IR. A population genomics approach shows widespread geographical distribution of cryptic genomic forms of the symbiotic fungus Rhizophagus irregularis. THE ISME JOURNAL 2018; 12:17-30. [PMID: 29027999 PMCID: PMC5739010 DOI: 10.1038/ismej.2017.153] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 07/20/2017] [Accepted: 08/21/2017] [Indexed: 11/26/2022]
Abstract
Arbuscular mycorrhizal fungi (AMF; phylum Gomeromycota) associate with plants forming one of the most successful microbe-plant associations. The fungi promote plant diversity and have a potentially important role in global agriculture. Plant growth depends on both inter- and intra-specific variation in AMF. It was recently reported that an unusually large number of AMF taxa have an intercontinental distribution, suggesting long-distance gene flow for many AMF species, facilitated by either long-distance natural dispersal mechanisms or human-assisted dispersal. However, the intercontinental distribution of AMF species has been questioned because the use of very low-resolution markers may be unsuitable to detect genetic differences among geographically separated AMF, as seen with some other fungi. This has been untestable because of the lack of population genomic data, with high resolution, for any AMF taxa. Here we use phylogenetics and population genomics to test for intra-specific variation in Rhizophagus irregularis, an AMF species for which genome sequence information already exists. We used ddRAD sequencing to obtain thousands of markers distributed across the genomes of 81 R. irregularis isolates and related species. Based on 6 888 variable positions, we observed significant genetic divergence into four main genetic groups within R. irregularis, highlighting that previous studies have not captured underlying genetic variation. Despite considerable genetic divergence, surprisingly, the variation could not be explained by geographical origin, thus also supporting the hypothesis for at least one AMF species of widely dispersed AMF genotypes at an intercontinental scale. Such information is crucial for understanding AMF ecology, and how these fungi can be used in an environmentally safe way in distant locations.
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Affiliation(s)
- Romain Savary
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - Frédéric G Masclaux
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Tania Wyss
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - Germain Droh
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
- Laboratoire de Génétique, Unité de Formation et de Recherche en Biosciences, Université Félix Houphouet Boigny, Abidjan, Ivory Coast
| | - Joaquim Cruz Corella
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - Ana Paula Machado
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - Joseph B Morton
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA
| | - Ian R Sanders
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
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41
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Janko K, Pačes J, Wilkinson‐Herbots H, Costa RJ, Roslein J, Drozd P, Iakovenko N, Rídl J, Hroudová M, Kočí J, Reifová R, Šlechtová V, Choleva L. Hybrid asexuality as a primary postzygotic barrier between nascent species: On the interconnection between asexuality, hybridization and speciation. Mol Ecol 2018; 27:248-263. [PMID: 28987005 PMCID: PMC6849617 DOI: 10.1111/mec.14377] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/25/2017] [Accepted: 09/05/2017] [Indexed: 12/30/2022]
Abstract
Although sexual reproduction is ubiquitous throughout nature, the molecular machinery behind it has been repeatedly disrupted during evolution, leading to the emergence of asexual lineages in all eukaryotic phyla. Despite intensive research, little is known about what causes the switch from sexual reproduction to asexuality. Interspecific hybridization is one of the candidate explanations, but the reasons for the apparent association between hybridization and asexuality remain unclear. In this study, we combined cross-breeding experiments with population genetic and phylogenomic approaches to reveal the history of speciation and asexuality evolution in European spined loaches (Cobitis). Contemporary species readily hybridize in hybrid zones, but produce infertile males and fertile but clonally reproducing females that cannot mediate introgressions. However, our analysis of exome data indicates that intensive gene flow between species has occurred in the past. Crossings among species with various genetic distances showed that, while distantly related species produced asexual females and sterile males, closely related species produce sexually reproducing hybrids of both sexes. Our results suggest that hybridization leads to sexual hybrids at the initial stages of speciation, but as the species diverge further, the gradual accumulation of reproductive incompatibilities between species could distort their gametogenesis towards asexuality. Interestingly, comparative analysis of published data revealed that hybrid asexuality generally evolves at lower genetic divergences than hybrid sterility or inviability. Given that hybrid asexuality effectively restricts gene flow, it may establish a primary reproductive barrier earlier during diversification than other "classical" forms of postzygotic incompatibilities. Hybrid asexuality may thus indirectly contribute to the speciation process.
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Affiliation(s)
- Karel Janko
- Institute of Animal Physiology and GeneticsLaboratory of Fish GeneticsThe Czech Academy of SciencesLibechovCzech Republic
- Department of Biology and EcologyFaculty of ScienceUniversity of OstravaOstravaCzech Republic
| | - Jan Pačes
- Institute of Animal Physiology and GeneticsLaboratory of Fish GeneticsThe Czech Academy of SciencesLibechovCzech Republic
- Institute of Molecular GeneticsLaboratory of Genomics and BioinformaticsThe Czech Academy of SciencesPragueCzech Republic
| | | | - Rui J. Costa
- Department of Statistical ScienceUniversity College LondonLondonUK
| | - Jan Roslein
- Institute of Animal Physiology and GeneticsLaboratory of Fish GeneticsThe Czech Academy of SciencesLibechovCzech Republic
- Department of Biology and EcologyFaculty of ScienceUniversity of OstravaOstravaCzech Republic
- Department of Fish EcologyInstitute of Vertebrate BiologyThe Czech Academy of SciencesBrnoCzech Republic
| | - Pavel Drozd
- Department of Biology and EcologyFaculty of ScienceUniversity of OstravaOstravaCzech Republic
| | - Nataliia Iakovenko
- Institute of Animal Physiology and GeneticsLaboratory of Fish GeneticsThe Czech Academy of SciencesLibechovCzech Republic
- Department of Biology and EcologyFaculty of ScienceUniversity of OstravaOstravaCzech Republic
- Schmalhausen Institute of Zoology of NAS of UkraineKyivUkraine
| | - Jakub Rídl
- Institute of Molecular GeneticsLaboratory of Genomics and BioinformaticsThe Czech Academy of SciencesPragueCzech Republic
| | - Miluše Hroudová
- Institute of Molecular GeneticsLaboratory of Genomics and BioinformaticsThe Czech Academy of SciencesPragueCzech Republic
| | - Jan Kočí
- Institute of Animal Physiology and GeneticsLaboratory of Fish GeneticsThe Czech Academy of SciencesLibechovCzech Republic
- Department of Biology and EcologyFaculty of ScienceUniversity of OstravaOstravaCzech Republic
| | - Radka Reifová
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | - Věra Šlechtová
- Institute of Animal Physiology and GeneticsLaboratory of Fish GeneticsThe Czech Academy of SciencesLibechovCzech Republic
| | - Lukáš Choleva
- Institute of Animal Physiology and GeneticsLaboratory of Fish GeneticsThe Czech Academy of SciencesLibechovCzech Republic
- Department of Biology and EcologyFaculty of ScienceUniversity of OstravaOstravaCzech Republic
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42
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Roos C, Liedigk R, Thinh VN, Nadler T, Zinner D. The Hybrid Origin of the Indochinese Gray Langur Trachypithecus crepusculus. INT J PRIMATOL 2017. [DOI: 10.1007/s10764-017-0008-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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43
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Sproul JS, Maddison DR. Cryptic species in the mountaintops: species delimitation and taxonomy of the Bembidion breve species group (Coleoptera: Carabidae) aided by genomic architecture of a century-old type specimen. Zool J Linn Soc 2017. [DOI: 10.1093/zoolinnean/zlx076] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- John S Sproul
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - David R Maddison
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
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44
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Ruane S, Myers EA, Lo K, Yuen S, Welt RS, Juman M, Futterman I, Nussbaum RA, Schneider G, Burbrink FT, Raxworthy CJ. Unrecognized species diversity and new insights into colour pattern polymorphism within the widespread Malagasy snake Mimophis (Serpentes: Lamprophiidae). SYST BIODIVERS 2017. [DOI: 10.1080/14772000.2017.1375046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Sara Ruane
- Department of Biological Sciences, 206 Boyden Hall, Rutgers University, 195 University Ave, Newark, NJ 07102, USA
- Department of Herpetology, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
| | - Edward A. Myers
- Department of Herpetology, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
| | - Kahmun Lo
- Science Research Mentoring Program, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
| | - Sara Yuen
- Science Research Mentoring Program, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
| | - Rachel S. Welt
- Department of Herpetology, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
| | - Maya Juman
- Science Research Mentoring Program, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
| | - India Futterman
- Science Research Mentoring Program, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
| | - Ronald A. Nussbaum
- Division of Reptiles and Amphibians, Museum of Zoology, Research Museums Center, 3600 Varsity Drive, University of Michigan, Ann Arbor, MI 48108, USA
| | - Gregory Schneider
- Division of Reptiles and Amphibians, Museum of Zoology, Research Museums Center, 3600 Varsity Drive, University of Michigan, Ann Arbor, MI 48108, USA
| | - Frank T. Burbrink
- Department of Herpetology, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
| | - Christopher J. Raxworthy
- Department of Herpetology, American Museum of Natural History, Central Park West and 79th St., NY, NY 10024, USA
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45
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Challenges in Species Tree Estimation Under the Multispecies Coalescent Model. Genetics 2017; 204:1353-1368. [PMID: 27927902 DOI: 10.1534/genetics.116.190173] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [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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46
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Yang M, He Z, Shi S, Wu CI. Can genomic data alone tell us whether speciation happened with gene flow? Mol Ecol 2017; 26:2845-2849. [PMID: 28345182 DOI: 10.1111/mec.14117] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 03/08/2017] [Accepted: 03/20/2017] [Indexed: 01/02/2023]
Abstract
The allopatric model, which requires a period of geographical isolation for speciation to complete, has been the standard model in the modern era. Recently, "speciation with gene flow" has been widely discussed in relation to the model of "strict allopatry" and the level of DNA divergence across genomic regions. We wish to caution that genomic data by themselves may only permit the rejection of the simplest form of allopatry. Even a slightly more complex and realistic model that starts with subdivided populations would be impossible to reject by the genomic data alone. To resolve this central issue of speciation, other forms of observations such as the sequencing of reproductive isolation genes or the identification of geographical barrier(s) will be necessary.
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Affiliation(s)
- Ming Yang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ziwen He
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Suhua Shi
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Chung-I Wu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
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47
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Yang Z, Rannala B. Bayesian species identification under the multispecies coalescent provides significant improvements to DNA barcoding analyses. Mol Ecol 2017; 26:3028-3036. [DOI: 10.1111/mec.14093] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 02/15/2017] [Accepted: 02/16/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Ziheng Yang
- Department of Genetics, Evolution and Environment; University College London; Gower Street London WC1E 6BT UK
- College of Life Sciences; Beijing Normal University; Beijing 100875 China
| | - Bruce Rannala
- College of Life Sciences; Beijing Normal University; Beijing 100875 China
- Department of Evolution and Ecology; University of California at Davis; One Shields Avenue Davis CA 95616 USA
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48
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Costa RJ, Wilkinson-Herbots H. Inference of Gene Flow in the Process of Speciation: An Efficient Maximum-Likelihood Method for the Isolation-with-Initial-Migration Model. Genetics 2017; 205:1597-1618. [PMID: 28193727 PMCID: PMC5378116 DOI: 10.1534/genetics.116.188060] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 01/25/2017] [Indexed: 12/03/2022] Open
Abstract
The isolation-with-migration (IM) model is commonly used to make inferences about gene flow during speciation, using polymorphism data. However, it has been reported that the parameter estimates obtained by fitting the IM model are very sensitive to the model's assumptions-including the assumption of constant gene flow until the present. This article is concerned with the isolation-with-initial-migration (IIM) model, which drops precisely this assumption. In the IIM model, one ancestral population divides into two descendant subpopulations, between which there is an initial period of gene flow and a subsequent period of isolation. We derive a very fast method of fitting an extended version of the IIM model, which also allows for asymmetric gene flow and unequal population sizes. This is a maximum-likelihood method, applicable to data on the number of segregating sites between pairs of DNA sequences from a large number of independent loci. In addition to obtaining parameter estimates, our method can also be used, by means of likelihood-ratio tests, to distinguish between alternative models representing the following divergence scenarios: (a) divergence with potentially asymmetric gene flow until the present, (b) divergence with potentially asymmetric gene flow until some point in the past and in isolation since then, and (c) divergence in complete isolation. We illustrate the procedure on pairs of Drosophila sequences from ∼30,000 loci. The computing time needed to fit the most complex version of the model to this data set is only a couple of minutes. The R code to fit the IIM model can be found in the supplementary files of this article.
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Affiliation(s)
- Rui J Costa
- Department of Statistical Science, University College London, WC1E 6BT, United Kingdom
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49
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Oswald JA, Overcast I, Mauck WM, Andersen MJ, Smith BT. Isolation with asymmetric gene flow during the nonsynchronous divergence of dry forest birds. Mol Ecol 2017; 26:1386-1400. [PMID: 28100029 DOI: 10.1111/mec.14013] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/30/2016] [Accepted: 12/29/2016] [Indexed: 01/17/2023]
Abstract
Dry forest bird communities in South America are often fragmented by intervening mountains and rainforests, generating high local endemism. The historical assembly of dry forest communities likely results from dynamic processes linked to numerous population histories among codistributed species. Nevertheless, species may diversify in the same way through time if landscape and environmental features, or species ecologies, similarly structure populations. Here we tested whether six co-distributed taxon pairs that occur in the dry forests of the Tumbes and Marañón Valley of northwestern South America show concordant patterns and modes of diversification. We employed a genome reduction technique, double-digest restriction site-associated DNA sequencing, and obtained 4407-7186 genomewide SNPs. We estimated demographic history in each taxon pair and inferred that all pairs had the same best-fit demographic model: isolation with asymmetric gene flow from the Tumbes into the Marañón Valley, suggesting a common diversification mode. Overall, we also observed congruence in effective population size (Ne ) patterns where ancestral Ne were 2.9-11.0× larger than present-day Marañón Valley populations and 0.3-2.0× larger than Tumbesian populations. Present-day Marañón Valley Ne was smaller than Tumbes. In contrast, we found simultaneous population isolation due to a single event to be unlikely as taxon pairs diverged over an extended period of time (0.1-2.9 Ma) with multiple nonoverlapping divergence periods. Our results show that even when populations of codistributed species asynchronously diverge, the mode of their differentiation can remain conserved over millions of years. Divergence by allopatric isolation due to barrier formation does not explain the mode of differentiation between these two bird assemblages; rather, migration of individuals occurred before and after geographic isolation.
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Affiliation(s)
- Jessica A Oswald
- Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611-7800, USA.,Museum of Natural Science, Louisiana State University, 119 Foster Hall, Baton Rouge, LA, 70803, USA
| | - Isaac Overcast
- Subprogram in Ecology, Evolution and Behavior, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - William M Mauck
- Department of Ornithology, American Museum of Natural History, Central Park West at 79th Street, New York, NY, 10024, USA
| | - Michael J Andersen
- Department of Ornithology, American Museum of Natural History, Central Park West at 79th Street, New York, NY, 10024, USA.,Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Brian Tilston Smith
- Department of Ornithology, American Museum of Natural History, Central Park West at 79th Street, New York, NY, 10024, USA
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50
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Freilich X, Anadón JD, Bukala J, Calderon O, Chakraborty R, Boissinot S. Comparative Phylogeography of Ethiopian anurans: impact of the Great Rift Valley and Pleistocene climate change. BMC Evol Biol 2016; 16:206. [PMID: 27724843 PMCID: PMC5057412 DOI: 10.1186/s12862-016-0774-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/28/2016] [Indexed: 11/29/2022] Open
Abstract
Background The Ethiopian highlands are a biodiversity hotspot, split by the Great Rift Valley into two distinct systems of plateaus and mountains. The Rift Valley is currently hot and dry and acts as a barrier to gene flow for highland-adapted species. It is however unlikely that the conditions in the Rift were inhospitable to highland species during the entire Pleistocene. To assess the significance of the Ethiopian Rift as a biogeographic barrier as well as the impact Pleistocene climatic changes have had on the evolution of Ethiopian organisms, we performed phylogeographic analyses and developed present and past niche models on seven anuran species with different elevational and ecological preferences. Results We found that highland species on the east and the west sides of the Rift are genetically differentiated and have not experienced any detectable gene flow for at least 0.4 my. In contrast, species found at elevations lower than 2500 m do not show any population structure. We also determined that highland species have lower effective population sizes than lowland species, which have experienced a large, yet gradual, demographic expansion, starting approximately half a million year ago. Conclusions The pattern we report here is consistent with the increasingly warmer and drier conditions of the Pleistocene in East Africa, which resulted in the expansion of savanna, the fragmentation of forests and the shrinking of highland habitats. Climatic niche models indicated that the Rift is currently non suitable for most of the studied species, but it could have been a more permeable barrier during the Last Glacial Maximum. However, considering the strong genetic structure of highland species, we hypothesize that the barrier mechanisms at the Rift are not only climatic but also topographical. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0774-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xenia Freilich
- Department of Biology, Queens College, City University of New York, Flushing, NY, USA.,Ecology, Evolution and Behavior Program, Graduate Center, City University of New York, New York, NY, USA
| | - José D Anadón
- Department of Biology, Queens College, City University of New York, Flushing, NY, USA.,Ecology, Evolution and Behavior Program, Graduate Center, City University of New York, New York, NY, USA
| | - Jolanta Bukala
- Department of Biology, Queens College, City University of New York, Flushing, NY, USA
| | - Ordaliza Calderon
- Department of Biology, Queens College, City University of New York, Flushing, NY, USA
| | - Ronveer Chakraborty
- Department of Biology, Queens College, City University of New York, Flushing, NY, USA
| | - Stéphane Boissinot
- New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates.
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