1
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Innes PA, Goebl AM, Smith CCR, Rosenberger K, Kane NC. Gene expression and alternative splicing contribute to adaptive divergence of ecotypes. Heredity (Edinb) 2024; 132:120-132. [PMID: 38071268 PMCID: PMC10924094 DOI: 10.1038/s41437-023-00665-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 11/23/2023] [Accepted: 11/24/2023] [Indexed: 03/10/2024] Open
Abstract
Regulation of gene expression is a critical link between genotype and phenotype explaining substantial heritable variation within species. However, we are only beginning to understand the ways that specific gene regulatory mechanisms contribute to adaptive divergence of populations. In plants, the post-transcriptional regulatory mechanism of alternative splicing (AS) plays an important role in both development and abiotic stress response, making it a compelling potential target of natural selection. AS allows organisms to generate multiple different transcripts/proteins from a single gene and thus may provide a source of evolutionary novelty. Here, we examine whether variation in alternative splicing and gene expression levels might contribute to adaptation and incipient speciation of dune-adapted prairie sunflowers in Great Sand Dunes National Park, Colorado, USA. We conducted a common garden experiment to assess transcriptomic variation among ecotypes and analyzed differential expression, differential splicing, and gene coexpression. We show that individual genes are strongly differentiated for both transcript level and alternative isoform proportions, even when grown in a common environment, and that gene coexpression networks are disrupted between ecotypes. Furthermore, we examined how genome-wide patterns of sequence divergence correspond to divergence in transcript levels and isoform proportions and find evidence for both cis and trans-regulation. Together, our results emphasize that alternative splicing has been an underappreciated mechanism providing source material for natural selection at short evolutionary time scales.
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Affiliation(s)
- Peter A Innes
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA.
| | - April M Goebl
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA
- Research and Conservation Department, Denver Botanic Gardens, Denver, CO, USA
| | - Chris C R Smith
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, USA
| | - Kaylee Rosenberger
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA
| | - Nolan C Kane
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA
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2
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Abstract
Vertebrates exhibit a wide range of color patterns, which play critical roles in mediating intra- and interspecific communication. Because of their diversity and visual accessibility, color patterns offer a unique and fascinating window into the processes underlying biological organization. In this review, we focus on describing many of the general principles governing the formation and evolution of color patterns in different vertebrate groups. We characterize the types of patterns, review the molecular and developmental mechanisms by which they originate, and discuss their role in constraining or facilitating evolutionary change. Lastly, we outline outstanding questions in the field and discuss different approaches that can be used to address them. Overall, we provide a unifying conceptual framework among vertebrate systems that may guide research into naturally evolved mechanisms underlying color pattern formation and evolution.
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Affiliation(s)
| | - Ricardo Mallarino
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA;
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3
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Zhang Q, Cao L, Song H, Lin K, Pang E. MkcDBGAS: a reference-free approach to identify comprehensive alternative splicing events in a transcriptome. Brief Bioinform 2023; 24:bbad367. [PMID: 37833843 PMCID: PMC10576019 DOI: 10.1093/bib/bbad367] [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: 07/21/2023] [Revised: 08/31/2023] [Accepted: 09/26/2023] [Indexed: 10/15/2023] Open
Abstract
Alternative splicing (AS) is an essential post-transcriptional mechanism that regulates many biological processes. However, identifying comprehensive types of AS events without guidance from a reference genome is still a challenge. Here, we proposed a novel method, MkcDBGAS, to identify all seven types of AS events using transcriptome alone, without a reference genome. MkcDBGAS, modeled by full-length transcripts of human and Arabidopsis thaliana, consists of three modules. In the first module, MkcDBGAS, for the first time, uses a colored de Bruijn graph with dynamic- and mixed- kmers to identify bubbles generated by AS with precision higher than 98.17% and detect AS types overlooked by other tools. In the second module, to further classify types of AS, MkcDBGAS added the motifs of exons to construct the feature matrix followed by the XGBoost-based classifier with the accuracy of classification greater than 93.40%, which outperformed other widely used machine learning models and the state-of-the-art methods. Highly scalable, MkcDBGAS performed well when applied to Iso-Seq data of Amborella and transcriptome of mouse. In the third module, MkcDBGAS provides the analysis of differential splicing across multiple biological conditions when RNA-sequencing data is available. MkcDBGAS is the first accurate and scalable method for detecting all seven types of AS events using the transcriptome alone, which will greatly empower the studies of AS in a wider field.
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Affiliation(s)
- Quanbao Zhang
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Lei Cao
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Hongtao Song
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Kui Lin
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Erli Pang
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China
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4
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Elkin J, Martin A, Courtier-Orgogozo V, Santos ME. Analysis of the genetic loci of pigment pattern evolution in vertebrates. Biol Rev Camb Philos Soc 2023; 98:1250-1277. [PMID: 37017088 DOI: 10.1111/brv.12952] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/08/2023] [Accepted: 03/14/2023] [Indexed: 04/06/2023]
Abstract
Vertebrate pigmentation patterns are amongst the best characterised model systems for studying the genetic basis of adaptive evolution. The wealth of available data on the genetic basis for pigmentation evolution allows for analysis of trends and quantitative testing of evolutionary hypotheses. We employed Gephebase, a database of genetic variants associated with natural and domesticated trait variation, to examine trends in how cis-regulatory and coding mutations contribute to vertebrate pigmentation phenotypes, as well as factors that favour one mutation type over the other. We found that studies with lower ascertainment bias identified higher proportions of cis-regulatory mutations, and that cis-regulatory mutations were more common amongst animals harbouring a higher number of pigment cell classes. We classified pigmentation traits firstly according to their physiological basis and secondly according to whether they affect colour or pattern, and identified that carotenoid-based pigmentation and variation in pattern boundaries are preferentially associated with cis-regulatory change. We also classified genes according to their developmental, cellular, and molecular functions. We found a greater proportion of cis-regulatory mutations in genes implicated in upstream developmental processes compared to those involved in downstream cellular functions, and that ligands were associated with a higher proportion of cis-regulatory mutations than their respective receptors. Based on these trends, we discuss future directions for research in vertebrate pigmentation evolution.
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Affiliation(s)
- Joel Elkin
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
| | - Arnaud Martin
- Department of Biological Sciences, The George Washington University, 800 22nd St. NW, Suite 6000, Washington, DC, 20052, USA
| | | | - M Emília Santos
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
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5
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MacDonald BT, Elowe NH, Garvie CW, Kaushik VK, Ellinor PT. Identification of a new Corin atrial natriuretic peptide-converting enzyme substrate: Agouti-signaling protein (ASIP). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538495. [PMID: 37162877 PMCID: PMC10168342 DOI: 10.1101/2023.04.26.538495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Corin is a transmembrane tethered enzyme best known for processing the hormone atrial natriuretic peptide (ANP) in cardiomyocytes to control electrolyte balance and blood pressure. Loss of function mutations in Corin prevent ANP processing and lead to hypertension. Curiously, Corin loss of function variants also result in lighter coat color pigmentation in multiple species. Corin pigmentation effects are dependent on a functional Agouti locus encoding the agouti-signaling protein (ASIP) based on a genetic interaction. However, the nature of this conserved role of Corin has not been defined. Here we report that ASIP is a direct proteolytic substrate of the Corin enzyme.
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Affiliation(s)
- Bryan T. MacDonald
- Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Nadine H. Elowe
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Colin W. Garvie
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Virendar K. Kaushik
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Patrick T. Ellinor
- Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA
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6
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An enhancer of Agouti contributes to parallel evolution of cryptically colored beach mice. Proc Natl Acad Sci U S A 2022; 119:e2202862119. [PMID: 35776547 PMCID: PMC9271204 DOI: 10.1073/pnas.2202862119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Identifying the genetic basis of repeatedly evolved traits provides a way to reconstruct their evolutionary history and ultimately investigate the predictability of evolution. Here, we focus on the oldfield mouse (Peromyscus polionotus), which occurs in the southeastern United States, where it exhibits considerable color variation. Dorsal coats range from dark brown in mainland mice to near white in mice inhabiting sandy beaches; this light pelage has evolved independently on Florida's Gulf and Atlantic coasts as camouflage from predators. To facilitate genomic analyses, we first generated a chromosome-level genome assembly of Peromyscus polionotus subgriseus. Next, in a uniquely variable mainland population (Peromyscus polionotus albifrons), we scored 23 pigment traits and performed targeted resequencing in 168 mice. We find that pigment variation is strongly associated with an ∼2-kb region ∼5 kb upstream of the Agouti signaling protein coding region. Using a reporter-gene assay, we demonstrate that this regulatory region contains an enhancer that drives expression in the dermis of mouse embryos during the establishment of pigment prepatterns. Moreover, extended tracts of homozygosity in this Agouti region indicate that the light allele experienced recent and strong positive selection. Notably, this same light allele appears fixed in both Gulf and Atlantic coast beach mice, despite these populations being separated by >1,000 km. Together, our results suggest that this identified Agouti enhancer allele has been maintained in mainland populations as standing genetic variation and from there, has spread to and been selected in two independent beach mouse lineages, thereby facilitating their rapid and parallel evolution.
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7
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Sherman TJ, Petty D, Schountz T, Hodges N, Hawkinson AC. Increased Ifng and Il10 Expression Correlate with Disease in Rodent Models Experimentally Infected with Modoc Virus. Viruses 2022; 14:v14051026. [PMID: 35632766 PMCID: PMC9146023 DOI: 10.3390/v14051026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 11/28/2022] Open
Abstract
Flaviviruses present an ongoing threat to global public health, although the factors that contribute to the disease remain incompletely understood. We examined an acute Modoc virus (MODV) infection of two rodent models. Viral RNA was detected in the kidneys, spleen, liver, brain, urine, and sera of experimentally infected deer mice, a reservoir host of MODV, and Syrian hamsters, a known disease model. As expected, clinical outcomes differed between species, and the levels of viral RNA recovered from various tissues demonstrated signs of differential replication and tissue tropism. Multivariate analysis indicated significance in the profile of expressed genes between species when analyzed across tissues and over time (p = 0.02). Between-subject effects with corrected models revealed a significance specific to the expression of Ifng (p = 0.01). the expression of Ifng was elevated in hamsters as compared to deer mice in brain tissues at all timepoints. As the over-expression of Ifng has been shown to correlate with decreased vascular integrity, the findings presented here offer a potential mechanism for viral dissemination into the CNS. The expression of IL10 also differed significantly between species at certain timepoints in brain tissues; however, it is uncertain how increased expression of this cytokine may influence the outcome of MODV-induced pathology.
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Affiliation(s)
- Tyler J. Sherman
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine, Colorado State University, Fort Collins, CO 80523, USA; (D.P.); (T.S.); (N.H.)
- Correspondence:
| | - Douglas Petty
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine, Colorado State University, Fort Collins, CO 80523, USA; (D.P.); (T.S.); (N.H.)
| | - Tony Schountz
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine, Colorado State University, Fort Collins, CO 80523, USA; (D.P.); (T.S.); (N.H.)
| | - Natasha Hodges
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine, Colorado State University, Fort Collins, CO 80523, USA; (D.P.); (T.S.); (N.H.)
| | - Ann C. Hawkinson
- School of Biological Sciences, College of Natural and Health Sciences, University of Northern Colorado, Greeley, CO 80524, USA;
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8
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Verta JP, Jacobs A. The role of alternative splicing in adaptation and evolution. Trends Ecol Evol 2021; 37:299-308. [PMID: 34920907 DOI: 10.1016/j.tree.2021.11.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/26/2021] [Accepted: 11/19/2021] [Indexed: 01/02/2023]
Abstract
Regulation of gene expression plays a central role in adaptive divergence and evolution. Although the role of gene regulation in microevolutionary processes is gaining wide acceptance, most studies have only investigated the evolution of transcript levels, ignoring the potentially significant role of transcript structures. We argue that variation in alternative splicing plays an important and widely unexplored role in adaptation (e.g., by increasing transcriptome and/or proteome diversity, or buffering potentially deleterious genetic variation). New studies increasingly highlight the potential for independent evolution in alternative splicing and transcript level, providing alternative paths for selection to act upon. We propose that alternative splicing and transcript levels can provide contrasting, nonredundant mechanisms of equal importance for adaptive diversification of gene function and regulation.
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Affiliation(s)
- Jukka-Pekka Verta
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Viikinkaari 9, 00790, Helsinki, Finland.
| | - Arne Jacobs
- Institute of Biodiversity, Animal Health, and Comparative Medicine, University of Glasgow, G12 8QQ, Glasgow, UK.
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9
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Takeishi T, Fujiwara K, Osada N, Mita A, Takada T, Shiroishi T, Suzuki H. Phylogeographic study using nuclear genome sequences of <i>Asip</i> to infer the origins of ventral fur color variation in the house mouse <i>Mus musculus</i>. Genes Genet Syst 2021; 96:271-284. [DOI: 10.1266/ggs.21-00075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Toki Takeishi
- Laboratory of Ecology and Genetics Graduate School of Environmental Science, Hokkaido University
| | - Kazumichi Fujiwara
- Graduate School of Information Science and Technology, Hokkaido University
| | - Naoki Osada
- Graduate School of Information Science and Technology, Hokkaido University
| | | | - Toyoyuki Takada
- Integrated Bioresource Information Division, RIKEN BioResource Research Center
| | | | - Hitoshi Suzuki
- Laboratory of Ecology and Genetics Graduate School of Environmental Science, Hokkaido University
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10
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Anello M, Daverio MS, Rodríguez SS, Romero SR, Renieri C, Vidal Rioja L, Di Rocco F. The ASIP gene in the llama (Lama glama): Alternative transcripts, expression and relation with color phenotypes. Gene 2021; 809:146018. [PMID: 34655720 DOI: 10.1016/j.gene.2021.146018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 07/15/2021] [Accepted: 10/11/2021] [Indexed: 11/27/2022]
Abstract
The Agouti gene (ASIP) is one of the most important genes for coat color determination in mammals. It has a complex structure with several promoters and alternative non-coding first exons that are transcribed into mRNAs with different 5'UTR. These mRNA isoforms regulate the temporal and spatial expression of the gene, producing diverse pigmentation patterns. Here, we studied ASIP transcriptional variants and their expression in the skin of llamas with different coat color phenotypes. We also described the ASIP locus, including promoter usage and the splicing events that originate each transcript variant. Using 5'RACE-PCR we isolated seven ASIP transcripts with alternative 5'UTR, where exons 1A, 1A', 1C, 1D, and a novel non-coding exon 1A" were identified. Additionally, new alternative spliced forms were found. The diversity of ASIP 5'UTRs is originated by a complex pattern of alternative promoter usage, multiple transcription start sites and splicing events that include exon skipping and alternative 3' splicing site selection. We found that ASIP was highly expressed in llamas with white and brown phenotypes while black animals presented very low expression. The main responsible for this difference was a fusion transcript between ASIP and NCOA6 genes, which was present in the skin of white and brown llamas but not in the black ones. The rest of ASIP transcripts presented very low expression in the skin, indicating that the main regulation point for ASIP gene expression is at the transcriptional level. Nevertheless, the characteristics of the 5'UTRs sequences suggest that alternative transcripts could be regulated differently at the protein synthesis level.
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Affiliation(s)
- M Anello
- Instituto Multidisciplinario de Biología Celular (IMBICE), CONICET-UNLP-CIC, La Plata, Buenos Aires, Argentina
| | - M S Daverio
- Instituto Multidisciplinario de Biología Celular (IMBICE), CONICET-UNLP-CIC, La Plata, Buenos Aires, Argentina; Cátedra de Biología, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
| | - S S Rodríguez
- Instituto Multidisciplinario de Biología Celular (IMBICE), CONICET-UNLP-CIC, La Plata, Buenos Aires, Argentina
| | - S R Romero
- Instituto de Investigaciones y Desarrollo Tecnológico para la Agricultura Familiar- Región NOA (IPAF NOA) INTA - Posta de Hornillos, Maimara, Jujuy, Argentina
| | - C Renieri
- School of Pharmacy, University of Camerino, Camerino, Marche, Italia
| | - L Vidal Rioja
- Instituto Multidisciplinario de Biología Celular (IMBICE), CONICET-UNLP-CIC, La Plata, Buenos Aires, Argentina
| | - F Di Rocco
- Instituto Multidisciplinario de Biología Celular (IMBICE), CONICET-UNLP-CIC, La Plata, Buenos Aires, Argentina.
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11
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Jin Y, Tong H, Shao G, Li J, Lv Y, Wo Y, Brown RP, Fu C. Dorsal Pigmentation and Its Association with Functional Variation in MC1R in a Lizard from Different Elevations on the Qinghai-Tibetan Plateau. Genome Biol Evol 2021; 12:2303-2313. [PMID: 33095228 PMCID: PMC7719228 DOI: 10.1093/gbe/evaa225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2020] [Indexed: 12/27/2022] Open
Abstract
Identification of the role of the MC1R gene has provided major insights into variation in skin pigmentation in several organisms, including humans, but the evolutionary genetics of this variation is less well established. Variation in this gene and its relationship with degree of melanism was analyzed in one of the world’s highest-elevation lizards, Phrynocephalus theobaldi from the Qinghai–Tibetan Plateau. Individuals from the low-elevation group were shown to have darker dorsal pigmentation than individuals from a high-elevation group. The existence of climatic variation across these elevations was quantified, with lower elevations exhibiting higher air pressure, temperatures, and humidity, but less wind and insolation. Analysis of the MC1R gene in 214 individuals revealed amino acid differences at five sites between intraspecific sister lineages from different elevations, with two sites showing distinct fixed residues at low elevations. Three of the four single-nucleotide polymorphisms that underpinned these amino acid differences were highly significant outliers, relative to the generalized MC1R population structuring, suggestive of selection. Transfection of cells with an MC1R allele from a lighter high-elevation population caused a 43% reduction in agonist-induced cyclic AMP accumulation, and hence lowered melanin synthesis, relative to transfection with an allele from a darker low-elevation population. The high-elevation allele led to less efficient integration of the MC1R protein into melanocyte membranes. Our study identifies variation in the degree of melanism that can be explained by four or fewer MC1R substitutions. We establish a functional link between these substitutions and melanin synthesis and demonstrate elevation-associated shifts in their frequencies.
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Affiliation(s)
- Yuanting Jin
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Haojie Tong
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Gang Shao
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Jiasheng Li
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Yudie Lv
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Yubin Wo
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Richard P Brown
- College of Life Sciences, China Jiliang University, Hangzhou, China.,School of Biological & Environmental Sciences, Liverpool John Moores University, United Kingdom
| | - Caiyun Fu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
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12
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Jacobs A, Elmer KR. Alternative splicing and gene expression play contrasting roles in the parallel phenotypic evolution of a salmonid fish. Mol Ecol 2021; 30:4955-4969. [PMID: 33502030 PMCID: PMC8653899 DOI: 10.1111/mec.15817] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/06/2021] [Accepted: 01/18/2021] [Indexed: 12/25/2022]
Abstract
Understanding the contribution of different molecular processes to evolution and development is crucial for identifying the mechanisms of adaptation. Here, we used RNA-sequencing data to test the importance of alternative splicing and differential gene expression in a case of parallel adaptive evolution, the replicated postglacial divergence of the salmonid fish Arctic charr (Salvelinus alpinus) into sympatric benthic and pelagic ecotypes across multiple independent lakes. We found that genes differentially spliced between ecotypes were mostly not differentially expressed (<6% overlap) and were involved in different biological processes. Differentially spliced genes were primarily enriched for muscle development and functioning, while differentially expressed genes were involved in metabolism, immunity and growth. Furthermore, alternative splicing and gene expression were mostly controlled by independent cis-regulatory quantitative trait loci (<3.4% overlap). Cis-regulatory regions were associated with the parallel divergence in splicing (16.5% of intron clusters) and expression (6.7%-10.1% of differentially expressed genes), indicating shared regulatory variation across ecotype pairs. Contrary to theoretical expectation, we found that differentially spliced genes tended to be highly central in regulatory networks ("hub genes") and were annotated to significantly more gene ontology terms compared to nondifferentially spliced genes, consistent with a higher level of pleiotropy. Together, our results suggest that the concerted regulation of alternative splicing and differential gene expression through different regulatory regions leads to the divergence of complementary processes important for local adaptation. This provides novel insights into the importance of contrasting but putatively complementary molecular processes in rapid parallel adaptive evolution.
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Affiliation(s)
- Arne Jacobs
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary & Life SciencesUniversity of GlasgowGlasgowUK
- Department of Natural ResourcesCornell UniversityIthacaNYUSA
| | - Kathryn R. Elmer
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary & Life SciencesUniversity of GlasgowGlasgowUK
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13
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Smith CCR, Rieseberg LH, Hulke BS, Kane NC. Aberrant RNA splicing due to genetic incompatibilities in sunflower hybrids. Evolution 2021; 75:2747-2758. [PMID: 34533836 DOI: 10.1111/evo.14360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 06/27/2021] [Accepted: 09/01/2021] [Indexed: 01/18/2023]
Abstract
Genome-scale studies have revealed divergent mRNA splicing patterns between closely related species or populations. However, it is unclear whether splicing differentiation is a simple byproduct of population divergence, or whether it also acts as a mechanism for reproductive isolation. We examined mRNA splicing in wild × domesticated sunflower hybrids and observed 45 novel splice forms that were not found in the wild or domesticated parents, in addition to 16 high-expression parental splice forms that were absent in one or more hybrids. We identify loci associated with variation in the levels of these splice forms, finding that many aberrant transcripts were regulated by multiple alleles with nonadditive interactions. We identified particular spliceosome components that were associated with 21 aberrant isoforms, more than half of which were located in or near regulatory QTL. These incompatibilities often resulted in alteration in the protein-coding regions of the novel transcripts in the form of frameshifts and truncations. By associating the splice variation in these genes with size and growth rate measurements, we found that the cumulative expression of all aberrant transcripts was correlated with a significant reduction in growth rate. Our results lead us to propose a model where divergent splicing regulatory loci could act as incompatibility loci that contribute to the evolution of reproductive isolation.
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Affiliation(s)
- Chris C R Smith
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, Colorado, 80309
| | - Loren H Rieseberg
- Department of Botany, University of British Columbia, Vancouver, BC, VCR 2A5, Canada
| | - Brent S Hulke
- Edward T. Schafer Agricultural Research Center, USDA-ARS, Fargo, North Dakota, 58102
| | - Nolan C Kane
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, Colorado, 80309
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14
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Huang Y, Feulner PGD, Eizaguirre C, Lenz TL, Bornberg-Bauer E, Milinski M, Reusch TBH, Chain FJJ. Genome-Wide Genotype-Expression Relationships Reveal Both Copy Number and Single Nucleotide Differentiation Contribute to Differential Gene Expression between Stickleback Ecotypes. Genome Biol Evol 2020; 11:2344-2359. [PMID: 31298693 PMCID: PMC6735750 DOI: 10.1093/gbe/evz148] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2019] [Indexed: 12/11/2022] Open
Abstract
Repeated and independent emergence of trait divergence that matches habitat differences is a sign of parallel evolution by natural selection. Yet, the molecular underpinnings that are targeted by adaptive evolution often remain elusive. We investigate this question by combining genome-wide analyses of copy number variants (CNVs), single nucleotide polymorphisms (SNPs), and gene expression across four pairs of lake and river populations of the three-spined stickleback (Gasterosteus aculeatus). We tested whether CNVs that span entire genes and SNPs occurring in putative cis-regulatory regions contribute to gene expression differences between sticklebacks from lake and river origins. We found 135 gene CNVs that showed a significant positive association between gene copy number and gene expression, suggesting that CNVs result in dosage effects that can fuel phenotypic variation and serve as substrates for habitat-specific selection. Copy number differentiation between lake and river sticklebacks also contributed to expression differences of two immune-related genes in immune tissues, cathepsin A and GIMAP7. In addition, we identified SNPs in cis-regulatory regions (eSNPs) associated with the expression of 1,865 genes, including one eSNP upstream of a carboxypeptidase gene where both the SNP alleles differentiated and the gene was differentially expressed between lake and river populations. Our study highlights two types of mutations as important sources of genetic variation involved in the evolution of gene expression and in potentially facilitating repeated adaptation to novel environments.
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Affiliation(s)
- Yun Huang
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany.,Biodiversity Research Center, Academia Sinica, Taipei, Taiwan, ROC
| | - Philine G D Feulner
- Department of Fish Ecology and Evolution, Centre of Ecology, Evolution and Biogeochemistry, EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.,Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Switzerland
| | - Christophe Eizaguirre
- School of Biological and Chemical Sciences, Queen Mary University of London, United Kingdom
| | - Tobias L Lenz
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Erich Bornberg-Bauer
- Evolutionary Bioinformatics, Institute for Evolution and Biodiversity, Westfälische Wilhelms University, Münster, Germany
| | - Manfred Milinski
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Thorsten B H Reusch
- Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
| | - Frédéric J J Chain
- Department of Biological Sciences, University of Massachusetts Lowell, USA
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15
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Kratochwil CF, Liang Y, Urban S, Torres-Dowdall J, Meyer A. Evolutionary Dynamics of Structural Variation at a Key Locus for Color Pattern Diversification in Cichlid Fishes. Genome Biol Evol 2019; 11:3452-3465. [PMID: 31821504 PMCID: PMC6916709 DOI: 10.1093/gbe/evz261] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2019] [Indexed: 02/07/2023] Open
Abstract
Color patterns in African cichlid fishes vary spectacularly. Although phylogenetic analysis showed already 30 years ago that many color patterns evolved repeatedly in these adaptive radiations, only recently have we begun to understand the genomic basis of color variation. Horizontal stripe patterns evolved and were lost several times independently across the adaptive radiations of Lake Victoria, Malawi, and Tanganyika and regulatory evolution of agouti-related peptide 2 (agrp2/asip2b) has been linked to this phenotypically labile trait. Here, we asked whether the agrp2 locus exhibits particular characteristics that facilitate divergence in color patterns. Based on comparative genomic analyses, we discovered several recent duplications, insertions, and deletions. Interestingly, one of these events resulted in a tandem duplication of the last exon of agrp2. The duplication likely precedes the East African radiations that started 8-12 Ma, is not fixed within any of the radiations, and is found to vary even within some species. Moreover, we also observed variation in copy number (two to five copies) and secondary loss of the duplication, illustrating a surprising dynamic at this locus that possibly promoted functional divergence of agrp2. Our work suggests that such instances of exon duplications are a neglected mechanism potentially involved in the repeated evolution and diversification that deserves more attention.
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Affiliation(s)
- Claudius F Kratochwil
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Germany
- International Max Planck Research School for Organismal Biology (IMPRS), Max Planck Institute for Ornithology, Radolfzell, Germany
- Zukunftskolleg, University of Konstanz, Germany
| | - Yipeng Liang
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Germany
| | - Sabine Urban
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Germany
- International Max Planck Research School for Organismal Biology (IMPRS), Max Planck Institute for Ornithology, Radolfzell, Germany
| | - Julián Torres-Dowdall
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Germany
- Zukunftskolleg, University of Konstanz, Germany
| | - Axel Meyer
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Germany
- International Max Planck Research School for Organismal Biology (IMPRS), Max Planck Institute for Ornithology, Radolfzell, Germany
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16
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Yoon Y, Klomp J, Martin-Martin I, Criscione F, Calvo E, Ribeiro J, Schmidt-Ott U. Embryo polarity in moth flies and mosquitoes relies on distinct old genes with localized transcript isoforms. eLife 2019; 8:e46711. [PMID: 31591963 PMCID: PMC6783274 DOI: 10.7554/elife.46711] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 09/06/2019] [Indexed: 01/07/2023] Open
Abstract
Unrelated genes establish head-to-tail polarity in embryos of different fly species, raising the question of how they evolve this function. We show that in moth flies (Clogmia, Lutzomyia), a maternal transcript isoform of odd-paired (Zic) is localized in the anterior egg and adopted the role of anterior determinant without essential protein change. Additionally, Clogmia lost maternal germ plasm, which contributes to embryo polarity in fruit flies (Drosophila). In culicine (Culex, Aedes) and anopheline mosquitoes (Anopheles), embryo polarity rests on a previously unnamed zinc finger gene (cucoid), or pangolin (dTcf), respectively. These genes also localize an alternative transcript isoform at the anterior egg pole. Basal-branching crane flies (Nephrotoma) also enrich maternal pangolin transcript at the anterior egg pole, suggesting that pangolin functioned as ancestral axis determinant in flies. In conclusion, flies evolved an unexpected diversity of anterior determinants, and alternative transcript isoforms with distinct expression can adopt fundamentally distinct developmental roles.
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Affiliation(s)
- Yoseop Yoon
- Department of Organismal Biology and AnatomyUniversity of ChicagoChicagoUnited States
| | - Jeff Klomp
- Department of Organismal Biology and AnatomyUniversity of ChicagoChicagoUnited States
| | - Ines Martin-Martin
- Laboratory of Malaria and Vector ResearchNational Institute of Allergy and Infectious DiseasesRockvilleUnited States
| | - Frank Criscione
- Laboratory of Malaria and Vector ResearchNational Institute of Allergy and Infectious DiseasesRockvilleUnited States
| | - Eric Calvo
- Laboratory of Malaria and Vector ResearchNational Institute of Allergy and Infectious DiseasesRockvilleUnited States
| | - Jose Ribeiro
- Laboratory of Malaria and Vector ResearchNational Institute of Allergy and Infectious DiseasesRockvilleUnited States
| | - Urs Schmidt-Ott
- Department of Organismal Biology and AnatomyUniversity of ChicagoChicagoUnited States
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17
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Xu W, Long L, Zhao Y, Stevens L, Felipe I, Munoz J, Ellis RE, McGrath PT. Evolution of Yin and Yang isoforms of a chromatin remodeling subunit precedes the creation of two genes. eLife 2019; 8:e48119. [PMID: 31498079 PMCID: PMC6752949 DOI: 10.7554/elife.48119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/05/2019] [Indexed: 12/13/2022] Open
Abstract
Genes can encode multiple isoforms, broadening their functions and providing a molecular substrate to evolve phenotypic diversity. Evolution of isoform function is a potential route to adapt to new environments. Here we show that de novo, beneficial alleles in the nurf-1 gene became fixed in two laboratory lineages of C. elegans after isolation from the wild in 1951, before methods of cryopreservation were developed. nurf-1 encodes an ortholog of BPTF, a large (>300 kD) multidomain subunit of the NURF chromatin remodeling complex. Using CRISPR-Cas9 genome editing and transgenic rescue, we demonstrate that in C. elegans, nurf-1 has split into two, largely non-overlapping isoforms (NURF-1.D and NURF-1.B, which we call Yin and Yang, respectively) that share only two of 26 exons. Both isoforms are essential for normal gametogenesis but have opposite effects on male/female gamete differentiation. Reproduction in hermaphrodites, which involves production of both sperm and oocytes, requires a balance of these opposing Yin and Yang isoforms. Transgenic rescue and genetic position of the fixed mutations suggest that different isoforms are modified in each laboratory strain. In a related clade of Caenorhabditis nematodes, the shared exons have duplicated, resulting in the split of the Yin and Yang isoforms into separate genes, each containing approximately 200 amino acids of duplicated sequence that has undergone accelerated protein evolution following the duplication. Associated with this duplication event is the loss of two additional nurf-1 transcripts, including the long-form transcript and a newly identified, highly expressed transcript encoded by the duplicated exons. We propose these lost transcripts are non-functional side products necessary to transcribe the Yin and Yang transcripts in the same cells. Our work demonstrates how gene sharing, through the production of multiple isoforms, can precede the creation of new, independent genes.
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Affiliation(s)
- Wen Xu
- School of Biological SciencesGeorgia Institute of TechnologyAtlantaUnited States
| | - Lijiang Long
- School of Biological SciencesGeorgia Institute of TechnologyAtlantaUnited States
- Interdisciplinary Graduate Program in Quantitative BiosciencesGeorgia Institute of TechnologyAtlantaUnited States
| | - Yuehui Zhao
- School of Biological SciencesGeorgia Institute of TechnologyAtlantaUnited States
| | - Lewis Stevens
- Institute of Evolutionary Biology, Ashworth Laboratories, School of Biological SciencesUniversity of EdinburghEdinburghUnited Kingdom
| | - Irene Felipe
- Epithelial Carcinogenesis GroupSpanish National Cancer Research Center-CNIOMadridSpain
| | - Javier Munoz
- Proteomics Unit-ProteoRed-ISCIIISpanish National Cancer Research Center-CNIOMadridSpain
| | - Ronald E Ellis
- Department of Molecular BiologyRowan University School of Osteopathic MedicineStratfordUnited States
| | - Patrick T McGrath
- School of Biological SciencesGeorgia Institute of TechnologyAtlantaUnited States
- Parker H. Petit Institute of Bioengineering and BioscienceGeorgia Institute of TechnologyAtlantaUnited States
- School of PhysicsGeorgia Institute of TechnologyAtlantaUnited States
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18
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Tong H, Li J, Wo Y, Shao G, Zhao W, Aguilar‐Gómez D, Jin Y. Effects of substrate color on intraspecific body color variation in the toad-headed lizard, Phrynocephalus versicolor. Ecol Evol 2019; 9:10253-10262. [PMID: 31624549 PMCID: PMC6787858 DOI: 10.1002/ece3.5545] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 12/19/2022] Open
Abstract
Diversity in animal coloration is generally associated with adaptation to their living habitats, ranging from territorial display and sexual selection to predation or predation avoidance, and thermoregulation. However, the mechanism underlying color variation in toad-headed Phrynocephalus lizards remains poorly understood. In this study, we investigated the population color variation of Phrynocephalus versicolor. We found that lizards distributed in dark substrate have darker dorsal coloration (melanic lizards) than populations living in light substrates. This characteristic may improve their camouflage effectiveness. A reciprocal substrate translocation experiment was conducted to clarify the potential role of morphological adaptation and physiological plasticity of this variation. Spectrometry technology and digital photography were used to quantify the color variation of the above-mentioned melanic and nonmelanic P. versicolor populations and their native substrate. Additionally, substrate color preference in both populations was investigated with choice experiments. Our results indicate that the melanic and nonmelanic populations with remarkable habitat color difference were significantly different on measured reflectance, luminance, and RGB values. Twenty-four hours, 30 days, and 60 days of substrate translocation treatment had little effects on dorsal color change. We also found that melanic lizards choose to live in dark substrate, while nonmelanic lizards have no preference for substrate color. In conclusion, our results support that the dorsal coloration of P. versicolor, associated with substrate color, is likely a morphological adaptation rather than phenotypic plasticity.
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Affiliation(s)
- Haojie Tong
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Jiasheng Li
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Yubin Wo
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Gang Shao
- College of Life SciencesChina Jiliang UniversityHangzhouChina
| | - Wei Zhao
- School of Life SciencesLanzhou UniversityLanzhouChina
| | | | - Yuanting Jin
- College of Life SciencesChina Jiliang UniversityHangzhouChina
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19
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The population genetics of crypsis in vertebrates: recent insights from mice, hares, and lizards. Heredity (Edinb) 2019; 124:1-14. [PMID: 31399719 PMCID: PMC6906368 DOI: 10.1038/s41437-019-0257-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/16/2019] [Accepted: 07/25/2019] [Indexed: 12/22/2022] Open
Abstract
By combining well-established population genetic theory with high-throughput sequencing data from natural populations, major strides have recently been made in understanding how, why, and when vertebrate populations evolve crypsis. Here, we focus on background matching, a particular facet of crypsis that involves the ability of an organism to conceal itself through matching its color to the surrounding environment. While interesting in and of itself, the study of this phenotype has also provided fruitful population genetic insights into the interplay of strong positive selection with other evolutionary processes. Specifically, and predicated upon the findings of previous candidate gene association studies, a primary focus of this recent literature involves the realization that the inference of selection from DNA sequence data first requires a robust model of population demography in order to identify genomic regions which do not conform to neutral expectations. Moreover, these demographic estimates provide crucial information about the origin and timing of the onset of selective pressures associated with, for example, the colonization of a novel environment. Furthermore, such inference has revealed crypsis to be a particularly useful phenotype for investigating the interplay of migration and selection—with examples of gene flow constraining rates of adaptation, or alternatively providing the genetic variants that may ultimately sweep through the population. Here, we evaluate the underlying evidence, review the strengths and weaknesses of the many population genetic methodologies used in these studies, and discuss how these insights have aided our general understanding of the evolutionary process.
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20
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Pfeifer SP, Laurent S, Sousa VC, Linnen CR, Foll M, Excoffier L, Hoekstra HE, Jensen JD. The Evolutionary History of Nebraska Deer Mice: Local Adaptation in the Face of Strong Gene Flow. Mol Biol Evol 2019; 35:792-806. [PMID: 29346646 PMCID: PMC5905656 DOI: 10.1093/molbev/msy004] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The interplay of gene flow, genetic drift, and local selective pressure is a dynamic process that has been well studied from a theoretical perspective over the last century. Wright and Haldane laid the foundation for expectations under an island-continent model, demonstrating that an island-specific beneficial allele may be maintained locally if the selection coefficient is larger than the rate of migration of the ancestral allele from the continent. Subsequent extensions of this model have provided considerably more insight. Yet, connecting theoretical results with empirical data has proven challenging, owing to a lack of information on the relationship between genotype, phenotype, and fitness. Here, we examine the demographic and selective history of deer mice in and around the Nebraska Sand Hills, a system in which variation at the Agouti locus affects cryptic coloration that in turn affects the survival of mice in their local habitat. We first genotyped 250 individuals from 11 sites along a transect spanning the Sand Hills at 660,000 single nucleotide polymorphisms across the genome. Using these genomic data, we found that deer mice first colonized the Sand Hills following the last glacial period. Subsequent high rates of gene flow have served to homogenize the majority of the genome between populations on and off the Sand Hills, with the exception of the Agouti pigmentation locus. Furthermore, mutations at this locus are strongly associated with the pigment traits that are strongly correlated with local soil coloration and thus responsible for cryptic coloration.
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Affiliation(s)
- Susanne P Pfeifer
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,School of Life Sciences, Center for Evolution & Medicine, Arizona State University, Tempe, AZ
| | - Stefan Laurent
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Vitor C Sousa
- Institute of Ecology & Evolution, University of Berne, Berne, Switzerland.,Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | | | - Matthieu Foll
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Laurent Excoffier
- Institute of Ecology & Evolution, University of Berne, Berne, Switzerland
| | - Hopi E Hoekstra
- Department of Organismic & Evolutionary Biology and Molecular & Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, Cambridge, MA
| | - Jeffrey D Jensen
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,School of Life Sciences, Center for Evolution & Medicine, Arizona State University, Tempe, AZ
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21
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Sanger TJ, Rajakumar R. How a growing organismal perspective is adding new depth to integrative studies of morphological evolution. Biol Rev Camb Philos Soc 2019; 94:184-198. [PMID: 30009397 DOI: 10.1111/brv.12442] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 01/24/2023]
Abstract
Over the past half century, the field of Evolutionary Developmental Biology, or Evo-devo, has integrated diverse fields of biology into a more synthetic understanding of morphological diversity. This has resulted in numerous insights into how development can evolve and reciprocally influence morphological evolution, as well as generated several novel theoretical areas. Although comparative by default, there remains a great gap in our understanding of adaptive morphological diversification and how developmental mechanisms influence the shape and pattern of phenotypic variation. Herein we highlight areas of research that are in the process of filling this void, and areas, if investigated more fully, that will add new insights into the diversification of morphology. At the centre of our discussion is an explicit awareness of organismal biology. Here we discuss an organismal framework that is supported by three distinct pillars. First, there is a need for Evo-devo to adopt a high-resolution phylogenetic approach in the study of morphological variation and its developmental underpinnings. Secondly, we propose that to understand the dynamic nature of morphological evolution, investigators need to give more explicit attention to the processes that generate evolutionarily relevant variation at the population level. Finally, we emphasize the need to address more thoroughly the processes that structure variation at micro- and macroevolutionary scales including modularity, morphological integration, constraint, and plasticity. We illustrate the power of these three pillars using numerous examples from both invertebrates and vertebrates to emphasize that many of these approaches are already present within the field, but have yet to be formally integrated into many research programs. We feel that the most exciting new insights will come where the traditional experimental approaches to Evo-devo are integrated more thoroughly with the principles of this organismal framework.
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Affiliation(s)
- Thomas J Sanger
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, U.S.A
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22
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Sakuma Y, Matsunami M, Takada T, Suzuki H. Multiple Conserved Elements Structuring Inverted Repeats in the Mammalian Coat Color-Related Gene Asip. Zoolog Sci 2019; 36:23-30. [PMID: 31116535 DOI: 10.2108/zs180081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 09/17/2018] [Indexed: 11/17/2022]
Abstract
In the agouti signaling gene protein (Asip) of the house mouse (Mus musculus), inverted repeat (IR) arrays are known to exist in a non-coding region adjacent to the ventral-specific promoter region and the accompanying two exons (exons 1A and 1A'), which are around 100 kb upstream from the amino acid coding regions of exons 2, 3, and 4. To determine the gene structure of mammalian Asip and to elucidate trends in its evolution, non-coding sequences of six rodent (mouse, rat, Chinese hamster, squirrel, guinea pig, and naked mole rat) and three non-rodent (rabbit, human, and cow) species were retrieved from databases and compared. Our homology search analyses revealed the presence of three to five highly conserved non-coding elements (CNE). These CNEs were found to form IRs in rodents and lagomorphs. Combinations of IRs were further shown to build symmetric, long IR arrays. Intra- and inter-specific comparisons of the sequences of three universal CNEs showed homogeneity between CNE pairs within species. This implies that certain evolutionary constraints maintained the IR structure in the rodent and rabbit species.
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Affiliation(s)
- Yuki Sakuma
- Laboratory of Ecology and Genetics, Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo 060-0810, Japan
| | - Masatoshi Matsunami
- Laboratory of Ecology and Genetics, Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo 060-0810, Japan, .,Graduate School of Medicine, University of the Ryukyus, Nishihara-cho 903-0215, Japan,
| | - Toyoyuki Takada
- Mammalian Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Hitoshi Suzuki
- Laboratory of Ecology and Genetics, Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo 060-0810, Japan
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23
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Rhoné B, Mariac C, Couderc M, Berthouly-Salazar C, Ousseini IS, Vigouroux Y. No Excess of Cis-Regulatory Variation Associated with Intraspecific Selection in Wild Pearl Millet (Cenchrus americanus). Genome Biol Evol 2017; 9:388-397. [PMID: 28137746 PMCID: PMC5381623 DOI: 10.1093/gbe/evx004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2017] [Indexed: 12/15/2022] Open
Abstract
Several studies suggest that cis-regulatory mutations are the favorite target of evolutionary changes, one reason being that cis-regulatory mutations might have fewer deleterious pleiotropic effects than protein-coding mutations. A review of the process also suggests that this bias towards adaptive cis-regulatory variation might be less pronounced at the intraspecific level compared with the interspecific level. In this study, we assessed the contribution of cis-regulatory variation to adaptation at the intraspecific level using populations of wild pearl millet (Cenchrus americanus ssp. monodii) sampled along an environmental gradient in Niger. From RNA sequencing of hybrids to assess allele-specific expression, we identified genes with cis-regulatory divergence between two parental accessions collected in contrasted environmental conditions. This revealed that ∼15% of transcribed genes showed cis-regulatory variation. Intersecting the gene set exhibiting cis-regulatory variation with the gene set identified as targets of selection revealed no excess of cis-acting mutations among the selected genes. We additionally found no excess of cis-regulatory variation among genes associated with adaptive traits. As our approach relied on methods identifying mainly genes submitted to strong selection pressure or with high phenotypic effect, the contribution of cis-regulatory changes to soft selection or polygenic adaptive traits remains to be tested. However our results favor the hypothesis that enrichment of adaptive cis-regulatory divergence builds up over time. For short evolutionary time-scales, cis-acting mutations are not predominantly involved in adaptive evolution associated with strong selective signal.
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Affiliation(s)
- Bénédicte Rhoné
- Unité Mixte de Recherche Diversité Adaptation et Développement des Plantes (UMR DIADE), Institut de Recherche pour le Développement, Montpellier, France.,Laboratoire de Biométrie et Biologie Evolutive, Université Lyon 1, CNRS, Lyon, France
| | - Cédric Mariac
- Unité Mixte de Recherche Diversité Adaptation et Développement des Plantes (UMR DIADE), Institut de Recherche pour le Développement, Montpellier, France
| | - Marie Couderc
- Unité Mixte de Recherche Diversité Adaptation et Développement des Plantes (UMR DIADE), Institut de Recherche pour le Développement, Montpellier, France
| | - Cécile Berthouly-Salazar
- Unité Mixte de Recherche Diversité Adaptation et Développement des Plantes (UMR DIADE), Institut de Recherche pour le Développement, Montpellier, France.,Laboratoire Mixte International Adaptation des Plantes et Microorganismes Associés aux Stress Environnementaux (LMI LAPSE), Centre de Recherche de Bel Air, Dakar, Sénégal
| | - Issaka Salia Ousseini
- Unité Mixte de Recherche Diversité Adaptation et Développement des Plantes (UMR DIADE), Institut de Recherche pour le Développement, Montpellier, France.,Laboratoire Mixte International Adaptation des Plantes et Microorganismes Associés aux Stress Environnementaux (LMI LAPSE), Centre de Recherche de Bel Air, Dakar, Sénégal.,Biology Department, Unité Mixte de Recherche Diversité Adaptation et Développement des plantes (UMR DIADE), Université Montpellier, France.,Université Abdou Moumouni de Niamey, Niger
| | - Yves Vigouroux
- Unité Mixte de Recherche Diversité Adaptation et Développement des Plantes (UMR DIADE), Institut de Recherche pour le Développement, Montpellier, France.,Laboratoire Mixte International Adaptation des Plantes et Microorganismes Associés aux Stress Environnementaux (LMI LAPSE), Centre de Recherche de Bel Air, Dakar, Sénégal.,Biology Department, Unité Mixte de Recherche Diversité Adaptation et Développement des plantes (UMR DIADE), Université Montpellier, France
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24
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Singh P, Börger C, More H, Sturmbauer C. The Role of Alternative Splicing and Differential Gene Expression in Cichlid Adaptive Radiation. Genome Biol Evol 2017; 9:2764-2781. [PMID: 29036566 PMCID: PMC5737861 DOI: 10.1093/gbe/evx204] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2017] [Indexed: 12/11/2022] Open
Abstract
Species diverge eco-morphologically through the continuous action of natural selection on functionally important structures, producing alternative adaptive morphologies. In cichlid fishes, the oral and pharyngeal jaws are such key structures. Adaptive variation in jaw morphology contributes to trophic specialization, which is hypothesized to fuel their rapid speciation in the East African Great Lakes. Much is known about the genes involved in cichlid jaw and craniofacial development. However, it is still unclear what salient sources of variation gave rise to trophic-niche specialization, facilitating adaptive radiation. Here, we explore two sources of transcriptional variation that may underlie species-specific disparities in jaw morphology. Using whole transcriptome RNA-sequencing, we analyze differences in gene expression and alternative splicing, at the end of postlarval development, in fully functional jaws of six species of cichlids from the Lake Tanganyika tribe Tropheini. Our data reveal a surprisingly high degree of alternative splicing events compared with gene expression differences among species and trophic types. This suggests that differential trophic adaptation of the jaw apparatus may have been shaped by transcriptional rewiring of splicing as well as gene expression variation during the rapid radiation of the Tropheini. Specifically, genes undergoing splicing across most species were found to be enriched for pharyngeal jaw gene ontology terms. Overall, jaw transcriptional patterns at postlarval developmental stage were highly dynamic and species-specific. In conclusion, this work indicates that shifts in alternative splicing could have played a more important role in cichlid adaptive radiation, and possibly adaptive radiation in general, than currently recognized.
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Affiliation(s)
- Pooja Singh
- Department of Zoology, University of Graz, Austria
- Department of Biology, University of Konstanz, Germany
| | | | - Heather More
- Department of Zoology, University of Graz, Austria
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
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25
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Passow CN, Brown AP, Arias-Rodriguez L, Yee MC, Sockell A, Schartl M, Warren WC, Bustamante C, Kelley JL, Tobler M. Complexities of gene expression patterns in natural populations of an extremophile fish (Poecilia mexicana, Poeciliidae). Mol Ecol 2017; 26:4211-4225. [PMID: 28598519 PMCID: PMC5731456 DOI: 10.1111/mec.14198] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/18/2017] [Accepted: 05/24/2017] [Indexed: 12/31/2022]
Abstract
Variation in gene expression can provide insights into organismal responses to environmental stress and physiological mechanisms mediating adaptation to habitats with contrasting environmental conditions. We performed an RNA-sequencing experiment to quantify gene expression patterns in fish adapted to habitats with different combinations of environmental stressors, including the presence of toxic hydrogen sulphide (H2 S) and the absence of light in caves. We specifically asked how gene expression varies among populations living in different habitats, whether population differences were consistent among organs, and whether there is evidence for shared expression responses in populations exposed to the same stressors. We analysed organ-specific transcriptome-wide data from four ecotypes of Poecilia mexicana (nonsulphidic surface, sulphidic surface, nonsulphidic cave and sulphidic cave). The majority of variation in gene expression was correlated with organ type, and the presence of specific environmental stressors elicited unique expression differences among organs. Shared patterns of gene expression between populations exposed to the same environmental stressors increased with levels of organismal organization (from transcript to gene to physiological pathway). In addition, shared patterns of gene expression were more common between populations from sulphidic than populations from cave habitats, potentially indicating that physiochemical stressors with clear biochemical consequences can constrain the diversity of adaptive solutions that mitigate their adverse effects. Overall, our analyses provided insights into transcriptional variation in a unique system, in which adaptation to H2 S and darkness coincide. Functional annotations of differentially expressed genes provide a springboard for investigating physiological mechanisms putatively underlying adaptation to extreme environments.
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Affiliation(s)
| | - Anthony P. Brown
- Department of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, México
| | - Muh-Ching Yee
- Department of Genetics, Stanford University, Stanford, CA, USA
| | | | - Manfred Schartl
- Physiological Chemistry, Biozentrum, University of Würzburg, Würzburg, Germany
- Comprehensive Cancer Center Mainfranken, University Clinic Würzburg, Würzburg, Germany
- Texas A&M Institute for Advanced Study and Department of Biology, Texas A&M University, College Station, TX, USA
| | - Wesley C. Warren
- McDonnell Genome Institute, Washington University in St. Louis, St. Louis, MO, USA
| | | | - Joanna L. Kelley
- Department of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, USA
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26
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Boratyński Z, Brito JC, Campos JC, Cunha JL, Granjon L, Mappes T, Ndiaye A, Rzebik-Kowalska B, Serén N. Repeated evolution of camouflage in speciose desert rodents. Sci Rep 2017; 7:3522. [PMID: 28615685 PMCID: PMC5471182 DOI: 10.1038/s41598-017-03444-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 05/05/2017] [Indexed: 11/09/2022] Open
Abstract
There are two main factors explaining variation among species and the evolution of characters along phylogeny: adaptive change, including phenotypic and genetic responses to selective pressures, and phylogenetic inertia, or the resemblance between species due to shared phylogenetic history. Phenotype-habitat colour match, a classic Darwinian example of the evolution of camouflage (crypsis), offers the opportunity to test the importance of historical versus ecological mechanisms in shaping phenotypes among phylogenetically closely related taxa. To assess it, we investigated fur (phenotypic data) and habitat (remote sensing data) colourations, along with phylogenetic information, in the species-rich Gerbillus genus. Overall, we found a strong phenotype-habitat match, once the phylogenetic signal is taken into account. We found that camouflage has been acquired and lost repeatedly in the course of the evolutionary history of Gerbillus. Our results suggest that fur colouration and its covariation with habitat is a relatively labile character in mammals, potentially responding quickly to selection. Relatively unconstrained and substantial genetic basis, as well as structural and functional independence from other fitness traits of mammalian colouration might be responsible for that observation.
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Affiliation(s)
- Zbyszek Boratyński
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal.
| | - José C Brito
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal.,Department of Biology, Faculty of Science, University of Porto, Rua Campo Alegre, 4169-007, Porto, Portugal
| | - João C Campos
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal.,Department of Biology, Faculty of Science, University of Porto, Rua Campo Alegre, 4169-007, Porto, Portugal
| | - José L Cunha
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal
| | - Laurent Granjon
- IRD, UMR CBGP, Campus International de Baillarguet, CS 30016, 34988, Montferrier-sur-Lez cedex, France
| | - Tapio Mappes
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, P.O. Box 35, 40014, Finland
| | - Arame Ndiaye
- Department of Animal Biology, Faculty of Sciences and Technologies, University Cheikh Anta Diop, BP 5005, Dakar, Senegal
| | - Barbara Rzebik-Kowalska
- Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31-016, Kraków, Poland
| | - Nina Serén
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal
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27
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Rogers SM, Xu S, Schlüter PM. Introduction: integrative molecular ecology is rapidly advancing the study of adaptation and speciation. Mol Ecol 2017; 26:1-6. [DOI: 10.1111/mec.13947] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 11/30/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Sean M. Rogers
- Department of Biological Sciences; University of Calgary; Calgary Alberta Canada T3L 2R9
| | - Shuqing Xu
- Max Planck Institute for Chemical Ecology; Hans-Knöll-Straße 8 D-07745 Jena Germany
| | - Philipp M. Schlüter
- Department of Systematic and Evolutionary Botany; University of Zurich; Zollikerstrasse 107 CH-8008 Zurich Switzerland
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28
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Byers KJRP, Xu S, Schlüter PM. Molecular mechanisms of adaptation and speciation: why do we need an integrative approach? Mol Ecol 2016; 26:277-290. [DOI: 10.1111/mec.13678] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/18/2016] [Accepted: 04/21/2016] [Indexed: 01/06/2023]
Affiliation(s)
- Kelsey J. R. P. Byers
- Department of Systematic and Evolutionary Botany; University of Zurich; Zollikerstrasse 107 CH-8008 Zurich Switzerland
| | - Shuqing Xu
- Max Planck Institute for Chemical Ecology; Hans-Knöll-Straße 8 D-07745 Jena Germany
| | - Philipp M. Schlüter
- Department of Systematic and Evolutionary Botany; University of Zurich; Zollikerstrasse 107 CH-8008 Zurich Switzerland
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