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Filatov DA, Kirkpatrick M. How does evolution work in superabundant microbes? Trends Microbiol 2024:S0966-842X(24)00024-6. [PMID: 38360431 DOI: 10.1016/j.tim.2024.01.009] [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: 10/13/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024]
Abstract
Marine phytoplankton play crucial roles in the Earth's ecological, chemical, and geological processes. They are responsible for about half of global primary production and drive the ocean biological carbon pump. Understanding how plankton species may adapt to the Earth's rapidly changing environments is evidently an urgent priority. This problem requires evolutionary genetic approaches as evolution occurs at the level of allele frequency change within populations driven by genetic drift and natural selection (microevolution). Plankters such as the coccolithophore Gephyrocapsa huxleyi and the cyanobacterium Prochlorococcus 'marinus' are among Earth's most abundant organisms. In this opinion paper we discuss how evolution in astronomically large populations of superabundant microbes (SAMs) may act fundamentally differently than it does in the populations of more modest size found in well-studied organisms. This offers exciting opportunities to study evolution in the conditions that have yet to be explored and also leads to unique challenges. Exploring these opportunities and challenges is the goal of this article.
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Affiliation(s)
- Dmitry A Filatov
- Department of Biology, University of Oxford, Oxford, OX1 3RB, UK.
| | - Mark Kirkpatrick
- Department of Integrative Biology, University of Texas, Austin, TX 78712, USA
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2
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Wang JJT, Steenwyk JL, Brem RB. Natural trait variation across Saccharomycotina species. FEMS Yeast Res 2024; 24:foae002. [PMID: 38218591 PMCID: PMC10833146 DOI: 10.1093/femsyr/foae002] [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: 06/27/2023] [Revised: 10/13/2023] [Accepted: 01/12/2024] [Indexed: 01/15/2024] Open
Abstract
Among molecular biologists, the group of fungi called Saccharomycotina is famous for its yeasts. These yeasts in turn are famous for what they have in common-genetic, biochemical, and cell-biological characteristics that serve as models for plants and animals. But behind the apparent homogeneity of Saccharomycotina species lie a wealth of differences. In this review, we discuss traits that vary across the Saccharomycotina subphylum. We describe cases of bright pigmentation; a zoo of cell shapes; metabolic specialties; and species with unique rules of gene regulation. We discuss the genetics of this diversity and why it matters, including insights into basic evolutionary principles with relevance across Eukarya.
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Affiliation(s)
- Johnson J -T Wang
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jacob L Steenwyk
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Rachel B Brem
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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3
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Tarkhnishvili D, Yanchukov A, Böhne A. Editorial: Advantages, limitations, and evolutionary constraints of asexual reproduction: An empirical approach. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1184306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023] Open
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4
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Insights into the differentiation and adaptation within Circaeasteraceae from Circaeaster agrestis genome sequencing and resequencing. iScience 2023; 26:106159. [PMID: 36895650 PMCID: PMC9988679 DOI: 10.1016/j.isci.2023.106159] [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: 09/20/2022] [Revised: 01/26/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
Circaeaster agrestis and Kingdonia uniflora are sister species that reproduce sexually and mainly asexually respectively, providing a good system for comparative genome evolution between taxa with different reproductive models. Comparative genome analyses revealed the two species have similar genome size, but C. agrestis encodes many more genes. The gene families specific to C. agrestis show significant enrichment of genes associated with defense response, while those gene families specific to K. uniflora are enriched in genes regulating root system development. Collinearity analyses revealed C. agrestis experienced two rounds of whole-genome duplication. Fst outlier test across 25 C. agrestis populations uncovered a close inter-relationship between abiotic stress and genetic variability. Genetic feature comparisons showed K. uniflora presents much higher genome heterozygosity, transposable element load, linkage disequilibrium degree, and πN/πS ratio. This study provides new insights into understanding the genetic differentiation and adaptation within ancient lineages characterized by multiple reproductive models.
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5
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Population Genomic Analyses Suggest a Hybrid Origin, Cryptic Sexuality, and Decay of Genes Regulating Seed Development for the Putatively Strictly Asexual Kingdonia uniflora (Circaeasteraceae, Ranunculales). Int J Mol Sci 2023; 24:ijms24021451. [PMID: 36674965 PMCID: PMC9866071 DOI: 10.3390/ijms24021451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023] Open
Abstract
Asexual lineages are perceived to be short-lived on evolutionary timescales. Hence, reports for exceptional cases of putative 'ancient asexuals' usually raise questions about the persistence of such species. So far, there have been few studies to solve the mystery in plants. The monotypic Kingdonia dating to the early Eocene, contains only K. uniflora that has no known definitive evidence for sexual reproduction nor records for having congeneric sexual species, raising the possibility that the species has persisted under strict asexuality for a long period of time. Here, we analyze whole genome polymorphism and divergence in K. uniflora. Our results show that K. uniflora is characterized by high allelic heterozygosity and elevated πN/πS ratio, in line with theoretical expectations under asexual evolution. Allele frequency spectrum analysis reveals the origin of asexuality in K. uniflora occurred prior to lineage differentiation of the species. Although divergence within K. uniflora individuals exceeds that between populations, the topologies of the two haplotype trees, however, fail to match each other, indicating long-term asexuality is unlikely to account for the high allele divergence and K. uniflora may have a recent hybrid origin. Phi-test shows a statistical probability of recombination for the conflicting phylogenetic signals revealed by the split network, suggesting K. uniflora engages in undetected sexual reproduction. Detection of elevated genetic differentiation and premature stop codons (in some populations) in genes regulating seed development indicates mutational degradation of sexuality-specific genes in K. uniflora. This study unfolds the origin and persistence mechanism of a plant lineage that has been known to reproduce asexually and presents the genomic consequences of lack of sexuality.
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6
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Martinossi-Allibert I, Ament-Velásquez SL, Saupe SJ, Johannesson H. To self or not to self? Absence of mate choice despite costly outcrossing in the fungus Podospora anserina. J Evol Biol 2023; 36:238-250. [PMID: 36263943 PMCID: PMC10092876 DOI: 10.1111/jeb.14108] [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: 03/10/2022] [Revised: 09/16/2022] [Accepted: 09/20/2022] [Indexed: 01/11/2023]
Abstract
Fungi have a large potential for flexibility in their mode of sexual reproduction, resulting in mating systems ranging from haploid selfing to outcrossing. However, we know little about which mating strategies are used in nature, and why, even in well-studied model organisms. Here, we explored the fitness consequences of alternative mating strategies in the ascomycete fungus Podospora anserina. We measured and compared fitness proxies of nine genotypes in either diploid selfing or outcrossing events, over two generations, and with or without environmental stress. We showed that fitness was consistently lower in outcrossing events, irrespective of the environment. The cost of outcrossing was partly attributed to non-self recognition genes with pleiotropic effects on fertility. We then predicted that when presented with options to either self or outcross, individuals would perform mate choice in favour of the reproductive strategy that yields higher fitness. Contrary to our prediction, individuals did not seem to avoid outcrossing when a choice was offered, in spite of the fitness cost incurred. Our results suggest that, although functionally diploid, P. anserina does not benefit from outcrossing in most cases. We outline different explanations for the apparent lack of mate choice in face of high fitness costs associated with outcrossing, including a new perspective on the pleiotropic effect of non-self recognition genes.
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Affiliation(s)
- Ivain Martinossi-Allibert
- Systematic Biology, Department of Organismal Biology, Uppsala University, Uppsala, Sweden.,Institut de Biochimie et de Génétique Cellulaire, UMR 5095 CNRS, Université de Bordeaux, Bordeaux CEDEX, France.,Department of Biology, Realfagbygget, Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Sven J Saupe
- Institut de Biochimie et de Génétique Cellulaire, UMR 5095 CNRS, Université de Bordeaux, Bordeaux CEDEX, France
| | - Hanna Johannesson
- Systematic Biology, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
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7
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Repeat sequences limit the effectiveness of lateral gene transfer and favored the evolution of meiotic sex in early eukaryotes. Proc Natl Acad Sci U S A 2022; 119:e2205041119. [PMID: 35994648 PMCID: PMC9436333 DOI: 10.1073/pnas.2205041119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The transition from prokaryotic lateral gene transfer to eukaryotic meiotic sex is poorly understood. Phylogenetic evidence suggests that it was tightly linked to eukaryogenesis, which involved an unprecedented rise in both genome size and the density of genetic repeats. Expansion of genome size raised the severity of Muller's ratchet, while limiting the effectiveness of lateral gene transfer (LGT) at purging deleterious mutations. In principle, an increase in recombination length combined with higher rates of LGT could solve this problem. Here, we show using a computational model that this solution fails in the presence of genetic repeats prevalent in early eukaryotes. The model demonstrates that dispersed repeat sequences allow ectopic recombination, which leads to the loss of genetic information and curtails the capacity of LGT to prevent mutation accumulation. Increasing recombination length in the presence of repeat sequences exacerbates the problem. Mutational decay can only be resisted with homology along extended sequences of DNA. We conclude that the transition to homologous pairing along linear chromosomes was a key innovation in meiotic sex, which was instrumental in the expansion of eukaryotic genomes and morphological complexity.
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8
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Stetsenko R, Roze D. The evolution of recombination in self-fertilizing organisms. Genetics 2022; 222:6656355. [PMID: 35929790 PMCID: PMC9434187 DOI: 10.1093/genetics/iyac114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cytological data from flowering plants suggest that the evolution of recombination rates is affected by the mating system of organisms, as higher chiasma frequencies are often observed in self-fertilizing species compared with their outcrossing relatives. Understanding the evolutionary cause of this effect is of particular interest, as it may shed light on the selective forces favoring recombination in natural populations. While previous models showed that inbreeding may have important effects on selection for recombination, existing analytical treatments are restricted to the case of loosely linked loci and weak selfing rates, and ignore the stochastic effect of genetic interference (Hill-Robertson effect), known to be an important component of selection for recombination in randomly mating populations. In this article, we derive general expressions quantifying the stochastic and deterministic components of selection acting on a mutation affecting the genetic map length of a whole chromosome along which deleterious mutations occur, valid for arbitrary selfing rates. The results show that selfing generally increases selection for recombination caused by interference among mutations as long as selection against deleterious alleles is sufficiently weak. While interference is often the main driver of selection for recombination under tight linkage or high selfing rates, deterministic effects can play a stronger role under intermediate selfing rates and high recombination, selecting against recombination in the absence of epistasis, but favoring recombination when epistasis is negative. Individual-based simulation results indicate that our analytical model often provides accurate predictions for the strength of selection on recombination under partial selfing.
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Affiliation(s)
- Roman Stetsenko
- CNRS, IRL 3614 Evolutionary Biology and Ecology of Algae, 29688 Roscoff, France.,Sorbonne Université, Station Biologique de Roscoff, 29688 Roscoff, France
| | - Denis Roze
- CNRS, IRL 3614 Evolutionary Biology and Ecology of Algae, 29688 Roscoff, France.,Sorbonne Université, Station Biologique de Roscoff, 29688 Roscoff, France
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9
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McElroy KE, Bankers L, Soper D, Hehman G, Boore JL, Logsdon JM, Neiman M. Patterns of gene expression in ovaries of sexual vs. asexual lineages of a freshwater snail. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.845640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Why sexual reproduction is so common when asexual reproduction should be much more efficient and less costly remains an open question in evolutionary biology. Comparisons between otherwise similar sexual and asexual taxa allow us to characterize the genetic architecture underlying asexuality, which can, in turn, illuminate how this reproductive mode transition occurred and the mechanisms by which it is maintained or disrupted. Here, we used transcriptome sequencing to compare patterns of ovarian gene expression between actively reproducing obligately sexual and obligately asexual females from multiple lineages of Potamopyrgus antipodarum, a freshwater New Zealand snail characterized by frequent separate transitions to asexuality and coexistence of otherwise similar sexual and asexual lineages. We also used these sequence data to evaluate whether population history accounts for variation in patterns of gene expression. We found that source population was a major source of gene expression variation, and likely more influential than reproductive mode. This outcome for these common garden-raised snails is strikingly similar to earlier results from field-collected snails. While we did not identify a likely set of candidate genes from expression profiles that could plausibly explain how transitions to asexuality occurred, we identified around 1,000 genes with evidence of differential expression between sexual and asexual reproductive modes, and 21 genes that appear to exhibit consistent expression differences between sexuals and asexuals across genetic backgrounds. This second smaller set of genes provides a good starting point for further exploration regarding a potential role in the transition to asexual reproduction. These results mark the first effort to characterize the causes of asexuality in P. antipodarum, demonstrate the apparently high heritability of gene expression patterns in this species, and hint that for P. antipodarum, transitions to asexuality might not necessarily be strongly associated with broad changes in gene expression.
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10
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Protacio RU, Davidson MK, Wahls WP. Adaptive Control of the Meiotic Recombination Landscape by DNA Site-dependent Hotspots With Implications for Evolution. Front Genet 2022; 13:947572. [PMID: 35812747 PMCID: PMC9257126 DOI: 10.3389/fgene.2022.947572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/01/2022] [Indexed: 02/04/2023] Open
Abstract
Meiosis is an essential component of the sexual life cycle in eukaryotes. The independent assortment of chromosomes in meiosis increases genetic diversity at the level of whole chromosomes and meiotic recombination increases genetic diversity within chromosomes. The resulting variability fuels evolution. Interestingly, global mapping of recombination in diverse taxa revealed dramatic changes in its frequency distribution between closely related species, subspecies, and even isolated populations of the same species. New insight into mechanisms for these evolutionarily rapid changes has come from analyses of environmentally induced plasticity of recombination in fission yeast. Many different DNA sites, and where identified their binding/activator proteins, control the positioning of recombination at hotspots. Each different class of hotspots functions as an independently controlled rheostat that modulates rates of recombination over a broad dynamic range in response to changing conditions. Together, this independent modulation can rapidly and dramatically alter the global frequency distribution of recombination. This process likely contributes substantially to (i.e., can largely explain) evolutionarily rapid, Prdm9-independent changes in the recombination landscape. Moreover, the precise control mechanisms allow cells to dynamically favor or disfavor newly arising combinations of linked alleles in response to changing extracellular and intracellular conditions, which has striking implications for the impacts of meiotic recombination on evolution.
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11
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Normark BB. The clones are all right. Science 2022; 376:1052-1053. [PMID: 35653466 DOI: 10.1126/science.abq3024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Parthenogenetic grasshoppers confound predictions by showing no signs of decline.
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Affiliation(s)
- Benjamin B Normark
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
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12
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Bever BW, Dietz ZP, Sullins JA, Montoya AM, Bergthorsson U, Katju V, Estes S. Mitonuclear Mismatch is Associated With Increased Male Frequency, Outcrossing, and Male Sperm Size in Experimentally-Evolved C. elegans. Front Genet 2022; 13:742272. [PMID: 35360860 PMCID: PMC8961728 DOI: 10.3389/fgene.2022.742272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
We provide a partial test of the mitonuclear sex hypothesis with the first controlled study of how male frequencies and rates of outcrossing evolve in response to mitonuclear mismatch by allowing replicate lineages of C. elegans nematodes containing either mitochondrial or nuclear mutations of electron transport chain (ETC) genes to evolve under three sexual systems: facultatively outcrossing (wildtype), obligately selfing, and obligately outcrossing. Among facultatively outcrossing lines, we found evolution of increased male frequency in at least one replicate line of all four ETC mutant backgrounds tested—nuclear isp-1, mitochondrial cox-1 and ctb-1, and an isp-1 IV; ctb-1M mitonuclear double mutant—and confirmed for a single line set (cox-1) that increased male frequency also resulted in successful outcrossing. We previously found the same result for lines evolved from another nuclear ETC mutant, gas-1. For several lines in the current experiment, however, male frequency declined to wildtype levels (near 0%) in later generations. Male frequency did not change in lines evolved from a wildtype control strain. Additional phenotypic assays of lines evolved from the mitochondrial cox-1 mutant indicated that evolution of high male frequency was accompanied by evolution of increased male sperm size and mating success with tester females, but that it did not translate into increased mating success with coevolved hermaphrodites. Rather, hermaphrodites’ self-crossed reproductive fitness increased, consistent with sexually antagonistic coevolution. In accordance with evolutionary theory, males and sexual outcrossing may be most beneficial to populations evolving from a state of low ancestral fitness (gas-1, as previously reported) and less beneficial or deleterious to those evolving from a state of higher ancestral fitness (cox-1). In support of this idea, the obligately outcrossing fog-2 V; cox-1 M lines exhibited no fitness evolution compared to their ancestor, while facultatively outcrossing lines showed slight upward evolution of fitness, and all but one of the obligately selfing xol-1 X; cox-1 M lines evolved substantially increased fitness—even beyond wildtype levels. This work provides a foundation to directly test the effect of reproductive mode on the evolutionary dynamics of mitonuclear genomes, as well as whether compensatory mutations (nuclear or mitochondrial) can rescue populations from mitochondrial dysfunction.
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Affiliation(s)
- Brent W. Bever
- Department of Biology, Portland State University, Portland, OR, United States
| | - Zachary P. Dietz
- Department of Biology, Portland State University, Portland, OR, United States
| | - Jennifer A. Sullins
- Department of Biology, Portland State University, Portland, OR, United States
| | - Ariana M. Montoya
- Department of Biology, Portland State University, Portland, OR, United States
| | - Ulfar Bergthorsson
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - Vaishali Katju
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - Suzanne Estes
- Department of Biology, Portland State University, Portland, OR, United States
- *Correspondence: Suzanne Estes,
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13
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Jaron KS, Parker DJ, Anselmetti Y, Tran Van P, Bast J, Dumas Z, Figuet E, François CM, Hayward K, Rossier V, Simion P, Robinson-Rechavi M, Galtier N, Schwander T. Convergent consequences of parthenogenesis on stick insect genomes. SCIENCE ADVANCES 2022; 8:eabg3842. [PMID: 35196080 PMCID: PMC8865771 DOI: 10.1126/sciadv.abg3842] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The shift from sexual reproduction to parthenogenesis has occurred repeatedly in animals, but how the loss of sex affects genome evolution remains poorly understood. We generated reference genomes for five independently evolved parthenogenetic species in the stick insect genus Timema and their closest sexual relatives. Using these references and population genomic data, we show that parthenogenesis results in an extreme reduction of heterozygosity and often leads to genetically uniform populations. We also find evidence for less effective positive selection in parthenogenetic species, suggesting that sex is ubiquitous in natural populations because it facilitates fast rates of adaptation. Parthenogenetic species did not show increased transposable element (TE) accumulation, likely because there is little TE activity in the genus. By using replicated sexual-parthenogenetic comparisons, our study reveals how the absence of sex affects genome evolution in natural populations, providing empirical support for the negative consequences of parthenogenesis as predicted by theory.
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Affiliation(s)
- Kamil S. Jaron
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
- Corresponding author. (D.J.P.); (K.S.J.); (T.S.)
| | - Darren J. Parker
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Corresponding author. (D.J.P.); (K.S.J.); (T.S.)
| | | | - Patrick Tran Van
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Jens Bast
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Zoé Dumas
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Emeric Figuet
- ISEM—Institut des Sciences de l’Evolution, Montpellier, France
| | | | - Keith Hayward
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Victor Rossier
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Paul Simion
- ISEM—Institut des Sciences de l’Evolution, Montpellier, France
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Nicolas Galtier
- ISEM—Institut des Sciences de l’Evolution, Montpellier, France
| | - Tanja Schwander
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Corresponding author. (D.J.P.); (K.S.J.); (T.S.)
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14
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Kreiner JM, Sandler G, Stern AJ, Tranel PJ, Weigel D, Stinchcombe J, Wright SI. Repeated origins, widespread gene flow, and allelic interactions of target-site herbicide resistance mutations. eLife 2022; 11:70242. [PMID: 35037853 PMCID: PMC8798060 DOI: 10.7554/elife.70242] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 01/16/2022] [Indexed: 11/13/2022] Open
Abstract
Causal mutations and their frequency in agricultural fields are well-characterized for herbicide resistance. However, we still lack understanding of their evolutionary history: the extent of parallelism in the origins of target-site resistance (TSR), how long these mutations persist, how quickly they spread, and allelic interactions that mediate their selective advantage. We addressed these questions with genomic data from 19 agricultural populations of common waterhemp (Amaranthus tuberculatus), which we show to have undergone a massive expansion over the past century, with a contemporary effective population size estimate of 8 x 107. We found variation at seven characterized TSR loci, two of which had multiple amino acid substitutions, and three of which were common. These three common resistance variants show extreme parallelism in their mutational origins, with gene flow having shaped their distribution across the landscape. Allele age estimates supported a strong role of adaptation from de novo mutations, with a median age of 30 suggesting that most resistance alleles arose soon after the onset of herbicide use. However, resistant lineages varied in both their age and evidence for selection over two different timescales, implying considerable heterogeneity in the forces that govern their persistence. Two such forces are intra- and inter-locus allelic interactions; we report a signal of extended haplotype competition between two common TSR alleles, and extreme linkage with genome-wide alleles with known functions in resistance adaptation. Together, this work reveals a remarkable example of spatial parallel evolution in a metapopulation, with important implications for the management of herbicide resistance.
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Affiliation(s)
- Julia M Kreiner
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - George Sandler
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - Aaron J Stern
- Graduate Group in Computational Biology, University of California, Berkeley, Berkeley, United States
| | - Patrick J Tranel
- Department of Crop Sciences, University of Illinois Urbana-Champaign, Urbana, United States
| | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - John Stinchcombe
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - Stephen Isaac Wright
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
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15
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Evolution via somatic genetic variation in modular species. Trends Ecol Evol 2021; 36:1083-1092. [PMID: 34538501 DOI: 10.1016/j.tree.2021.08.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/14/2021] [Accepted: 08/20/2021] [Indexed: 01/10/2023]
Abstract
Somatic genetic variation (SoGV) may play a consequential yet underappreciated role in long-lived, modular species among plants, animals, and fungi. Recent genomic data identified two levels of genetic heterogeneity, between cell lines and between modules, that are subject to multilevel selection. Because SoGV can transfer into gametes when germlines are sequestered late in ontogeny (plants, algae, and fungi and some basal animals), sexual and asexual processes provide interdependent routes of mutational input and impact the accumulation of genetic load and molecular evolution rates of the integrated asexual/sexual life cycle. Avenues for future research include possible fitness effects of SoGV, the identification and implications of multilevel selection, and modeling of asexual selective sweeps using approaches from tumor evolution.
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16
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Brandt A, Tran Van P, Bluhm C, Anselmetti Y, Dumas Z, Figuet E, François CM, Galtier N, Heimburger B, Jaron KS, Labédan M, Maraun M, Parker DJ, Robinson-Rechavi M, Schaefer I, Simion P, Scheu S, Schwander T, Bast J. Haplotype divergence supports long-term asexuality in the oribatid mite Oppiella nova. Proc Natl Acad Sci U S A 2021; 118:e2101485118. [PMID: 34535550 PMCID: PMC8463897 DOI: 10.1073/pnas.2101485118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2021] [Indexed: 12/05/2022] Open
Abstract
Sex strongly impacts genome evolution via recombination and segregation. In the absence of these processes, haplotypes within lineages of diploid organisms are predicted to accumulate mutations independently of each other and diverge over time. This so-called "Meselson effect" is regarded as a strong indicator of the long-term evolution under obligate asexuality. Here, we present genomic and transcriptomic data of three populations of the asexual oribatid mite species Oppiella nova and its sexual relative Oppiella subpectinata We document strikingly different patterns of haplotype divergence between the two species, strongly supporting Meselson effect-like evolution and long-term asexuality in O. nova: I) variation within individuals exceeds variation between populations in O. nova but vice versa in O. subpectinata; II) two O. nova sublineages feature a high proportion of lineage-specific heterozygous single-nucleotide polymorphisms (SNPs), indicating that haplotypes continued to diverge after lineage separation; III) the deepest split in gene trees generally separates the two haplotypes in O. nova, but populations in O. subpectinata; and IV) the topologies of the two haplotype trees match each other. Our findings provide positive evidence for the absence of canonical sex over evolutionary time in O. nova and suggest that asexual oribatid mites can escape the dead-end fate usually associated with asexual lineages.
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Affiliation(s)
- Alexander Brandt
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, University of Goettingen, 37073 Goettingen, Germany;
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Patrick Tran Van
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Christian Bluhm
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, University of Goettingen, 37073 Goettingen, Germany
- Abteilung Boden und Umwelt, Forstliche Versuchs- und Forschungsanstalt Baden-Wuerttemberg, 79100 Freiburg, Germany
| | - Yoann Anselmetti
- Group Phylogeny and Molecular Evolution, Institut des Sciences de l'Evolution de Montpellier, 34090 Montpellier, France
- CoBIUS Lab, Department of Computer Science, University of Sherbrooke, Sherbrooke, QC J1K2R1, Canada
| | - Zoé Dumas
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Emeric Figuet
- Group Phylogeny and Molecular Evolution, Institut des Sciences de l'Evolution de Montpellier, 34090 Montpellier, France
| | - Clémentine M François
- Group Phylogeny and Molecular Evolution, Institut des Sciences de l'Evolution de Montpellier, 34090 Montpellier, France
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, École Nationale des Travaux Publics de l'État, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France
| | - Nicolas Galtier
- Group Phylogeny and Molecular Evolution, Institut des Sciences de l'Evolution de Montpellier, 34090 Montpellier, France
| | - Bastian Heimburger
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, University of Goettingen, 37073 Goettingen, Germany
| | - Kamil S Jaron
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
- Group Evolutionary Bioinformatics, Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom
| | - Marjorie Labédan
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Mark Maraun
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, University of Goettingen, 37073 Goettingen, Germany
| | - Darren J Parker
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
- Group Evolutionary Bioinformatics, Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
- Group Evolutionary Bioinformatics, Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Ina Schaefer
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, University of Goettingen, 37073 Goettingen, Germany
| | - Paul Simion
- Group Phylogeny and Molecular Evolution, Institut des Sciences de l'Evolution de Montpellier, 34090 Montpellier, France
- Laboratory of Evolutionary Genetics and Ecology, Unit in Environmental and Evolutionary Biology, Université de Namur, 5000 Namur, Belgium
| | - Stefan Scheu
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, University of Goettingen, 37073 Goettingen, Germany
- Section Biodiversity and Ecology, Centre of Biodiversity and Sustainable Land Use, 37073 Goettingen, Germany
| | - Tanja Schwander
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Jens Bast
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
- Institute for Zoology, University of Cologne, 50674 Cologne, Germany
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Oldrieve G, Verney M, Jaron KS, Hébert L, Matthews KR. Monomorphic Trypanozoon: towards reconciling phylogeny and pathologies. Microb Genom 2021; 7. [PMID: 34397347 PMCID: PMC8549356 DOI: 10.1099/mgen.0.000632] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Trypanosoma brucei evansi and T. brucei equiperdum are animal infective trypanosomes conventionally classified by their clinical disease presentation, mode of transmission, host range, kinetoplast DNA (kDNA) composition and geographical distribution. Unlike other members of the subgenus Trypanozoon, they are non-tsetse transmitted and predominantly morphologically uniform (monomorphic) in their mammalian host. Their classification as independent species or subspecies has been long debated and genomic studies have found that isolates within T. brucei evansi and T. brucei equiperdum have polyphyletic origins. Since current taxonomy does not fully acknowledge these polyphyletic relationships, we re-analysed publicly available genomic data to carefully define each clade of monomorphic trypanosome. This allowed us to identify, and account for, lineage-specific variation. We included a recently published isolate, IVM-t1, which was originally isolated from the genital mucosa of a horse with dourine and typed as T. equiperdum. Our analyses corroborate previous studies in identifying at least four distinct monomorphic T. brucei clades. We also found clear lineage-specific variation in the selection efficacy and heterozygosity of the monomorphic lineages, supporting their distinct evolutionary histories. The inferred evolutionary position of IVM-t1 suggests its reassignment to the T. brucei evansi type B clade, challenging the relationship between the Trypanozoon species, the infected host, mode of transmission and the associated pathological phenotype. The analysis of IVM-t1 also provides, to our knowledge, the first evidence of the expansion of T. brucei evansi type B, or a fifth monomorphic lineage represented by IVM-t1, outside of Africa, with important possible implications for disease diagnosis.
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Affiliation(s)
- Guy Oldrieve
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Mylène Verney
- Unité PhEED, Laboratoire de Santé Animale, Site de Normandie, ANSES, RD675, 1443012 Goustranville, France
| | - Kamil S Jaron
- Institute of Evolutionary Biology, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Laurent Hébert
- Unité PhEED, Laboratoire de Santé Animale, Site de Normandie, ANSES, RD675, 1443012 Goustranville, France
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
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18
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Tran Van P, Anselmetti Y, Bast J, Dumas Z, Galtier N, Jaron KS, Martens K, Parker DJ, Robinson-Rechavi M, Schwander T, Simion P, Schön I. First annotated draft genomes of nonmarine ostracods (Ostracoda, Crustacea) with different reproductive modes. G3 (BETHESDA, MD.) 2021; 11:jkab043. [PMID: 33591306 PMCID: PMC8049415 DOI: 10.1093/g3journal/jkab043] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/05/2021] [Indexed: 11/14/2022]
Abstract
Ostracods are one of the oldest crustacean groups with an excellent fossil record and high importance for phylogenetic analyses but genome resources for this class are still lacking. We have successfully assembled and annotated the first reference genomes for three species of nonmarine ostracods; two with obligate sexual reproduction (Cyprideis torosa and Notodromas monacha) and the putative ancient asexual Darwinula stevensoni. This kind of genomic research has so far been impeded by the small size of most ostracods and the absence of genetic resources such as linkage maps or BAC libraries that were available for other crustaceans. For genome assembly, we used an Illumina-based sequencing technology, resulting in assemblies of similar sizes for the three species (335-382 Mb) and with scaffold numbers and their N50 (19-56 kb) in the same orders of magnitude. Gene annotations were guided by transcriptome data from each species. The three assemblies are relatively complete with BUSCO scores of 92-96. The number of predicted genes (13,771-17,776) is in the same range as Branchiopoda genomes but lower than in most malacostracan genomes. These three reference genomes from nonmarine ostracods provide the urgently needed basis to further develop ostracods as models for evolutionary and ecological research.
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Affiliation(s)
- Patrick Tran Van
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland
| | - Yoann Anselmetti
- ISEM—Institut des Sciences de l’Evolution, Montpellier 34090, France
| | - Jens Bast
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Zoé Dumas
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Nicolas Galtier
- ISEM—Institut des Sciences de l’Evolution, Montpellier 34090, France
| | - Kamil S Jaron
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Koen Martens
- Royal Belgian Institute of Natural Sciences, OD Nature, Freshwater Biology, Brussels 1000, Belgium
- Department of Biology, University of Ghent, Ghent 9000, Belgium
| | - Darren J Parker
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland
| | - Tanja Schwander
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Paul Simion
- ISEM—Institut des Sciences de l’Evolution, Montpellier 34090, France
- Université de Namur, LEGE, URBE, Namur 5000, Belgium
| | - Isa Schön
- Royal Belgian Institute of Natural Sciences, OD Nature, Freshwater Biology, Brussels 1000, Belgium
- University of Hasselt, Research Group Zoology, Diepenbeek 3590, Belgium
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19
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Jaron KS, Bast J, Nowell RW, Ranallo-Benavidez TR, Robinson-Rechavi M, Schwander T. Genomic Features of Parthenogenetic Animals. J Hered 2021; 112:19-33. [PMID: 32985658 PMCID: PMC7953838 DOI: 10.1093/jhered/esaa031] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 08/17/2020] [Indexed: 12/21/2022] Open
Abstract
Evolution without sex is predicted to impact genomes in numerous ways. Case studies of individual parthenogenetic animals have reported peculiar genomic features that were suggested to be caused by their mode of reproduction, including high heterozygosity, a high abundance of horizontally acquired genes, a low transposable element load, or the presence of palindromes. We systematically characterized these genomic features in published genomes of 26 parthenogenetic animals representing at least 18 independent transitions to asexuality. Surprisingly, not a single feature was systematically replicated across a majority of these transitions, suggesting that previously reported patterns were lineage-specific rather than illustrating the general consequences of parthenogenesis. We found that only parthenogens of hybrid origin were characterized by high heterozygosity levels. Parthenogens that were not of hybrid origin appeared to be largely homozygous, independent of the cellular mechanism underlying parthenogenesis. Overall, despite the importance of recombination rate variation for the evolution of sexual animal genomes, the genome-wide absence of recombination does not appear to have had the dramatic effects which are expected from classical theoretical models. The reasons for this are probably a combination of lineage-specific patterns, the impact of the origin of parthenogenesis, and a survivorship bias of parthenogenetic lineages.
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Affiliation(s)
- Kamil S Jaron
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Jens Bast
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Reuben W Nowell
- Department of Life Sciences, Imperial College London, Ascot, Berkshire, UK
- Reuben W. Nowell is now at the Department of Zoology, University of Oxford, Oxford, UK
| | | | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Tanja Schwander
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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20
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Orive ME, Krueger-Hadfield SA. Sex and Asex: A Clonal Lexicon. J Hered 2020; 112:1-8. [PMID: 33336685 DOI: 10.1093/jhered/esaa058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/15/2020] [Indexed: 01/05/2023] Open
Abstract
Organisms across the tree of life have complex life cycles that include both sexual and asexual reproduction or that are obligately asexual. These organisms include ecologically dominant species that structure many terrestrial and marine ecosystems, as well as many pathogens, pests, and invasive species. We must consider both the evolution and maintenance of these various reproductive modes and how these modes shape the genetic diversity, adaptive evolution, and ability to persist in the species that exhibit them. Thus, having a common framework is a key aspect of understanding the biodiversity that shapes our planet. In the 2019 AGA President's Symposium, Sex and Asex: The genetics of complex life cycles, researchers investigating a wide range of taxonomic models and using a variety of modes of investigation coalesced around a common theme-understanding not only how such complex life cycles may evolve, but how they are shaped by the evolutionary and ecological forces around them. In this introduction to the Special Issue from the symposium, we give an overview of some of the key ideas and areas of investigation (a common clonal lexicon, we might say) and introduce the breadth of work submitted by symposium participants.
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Affiliation(s)
- Maria E Orive
- Department of Ecology and Evolutionary Biology, University of Kansas, 1200 Sunnyside Ave., Lawrence, KS 66045
| | - Stacy A Krueger-Hadfield
- Department of Biology, University of Alabama, Birmingham, 1300 University Blvd., Birmingham, AL 35294
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