1
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Romero H, Aguilar PS, Graña M, Langleib M, Gudiño V, Podbilewicz B. Membrane fusion and fission during eukaryogenesis. Curr Opin Cell Biol 2024; 86:102321. [PMID: 38219525 DOI: 10.1016/j.ceb.2023.102321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 12/22/2023] [Accepted: 12/25/2023] [Indexed: 01/16/2024]
Abstract
All eukaryotes can be traced back to a single shared ancestral lineage that emerged from interactions between different prokaryotic cells. Current models of eukaryogenesis describe various selective forces and evolutionary mechanisms that contributed to the formation of eukaryotic cells. Central to this process were significant changes in cellular structure, resulting in the configuration of a new cell type characterized by internal membrane compartments. Additionally, eukaryogenesis results in a life cycle that relies on cell-cell fusion. We discuss the potential roles of proteins involved in remodeling cellular membranes, highlighting two critical stages in the evolution of eukaryotes: the internalization of symbiotic partners and a scenario wherein the emergence of sexual reproduction is linked to a polyploid ancestor generated by cell-cell fusion.
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Affiliation(s)
- Héctor Romero
- Laboratorio de Genómica Evolutiva, Facultad de Ciencias/CURE, Universidad de la República, Uruguay; Centro Interdisciplinario de Ciencia de Datos y Aprendizaje Automático (CICADA), Espacio Interdisciplinario, Universidad de la República, Uruguay.
| | - Pablo S Aguilar
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-CONICET), Buenos Aires, Argentina.
| | - Martin Graña
- Unidad de Bioinformática, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Mauricio Langleib
- Laboratorio de Genómica Evolutiva, Facultad de Ciencias/CURE, Universidad de la República, Uruguay; Unidad de Bioinformática, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Virginia Gudiño
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-CONICET), Buenos Aires, Argentina
| | - Benjamin Podbilewicz
- Department of Biology, Technion Israel Institute of Technology, Haifa, Israel; Instituto de Fisiología Celular, UNAM, Mexico City, Mexico
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2
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Slowinski SP, Cho J, Penley MJ, Alexander LW, Greenberg AB, Namburar SR, Morran LT. High parasite virulence necessary for the maintenance of host outcrossing via parasite-mediated selection. Evol Lett 2023; 7:371-378. [PMID: 38045726 PMCID: PMC10692999 DOI: 10.1093/evlett/qrad036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 08/09/2023] [Accepted: 08/27/2023] [Indexed: 12/05/2023] Open
Abstract
Biparental sex is widespread in nature, yet costly relative to uniparental reproduction. It is generally unclear why self-fertilizing or asexual lineages do not readily invade outcrossing populations. The Red Queen hypothesis predicts that coevolving parasites can prevent self-fertilizing or asexual lineages from invading outcrossing host populations. However, only highly virulent parasites are predicted to maintain outcrossing, which may limit the general applicability of the Red Queen hypothesis. Here, we tested whether the ability of coevolving parasites to prevent invasion of self-fertilization within outcrossing host populations was dependent on parasite virulence. We introduced wild-type Caenorhabditis elegans hermaphrodites, capable of both self-fertilization and outcrossing, into C. elegans populations fixed for a mutant allele conferring obligate outcrossing. Replicate C. elegans populations were exposed for 24 host generations to one of four strains of Serratia marcescens parasites that varied in virulence, under three treatments: a heat-killed (control, noninfectious) parasite treatment, a fixed-genotype (nonevolving) parasite treatment, and a copassaged (potentially coevolving) parasite treatment. As predicted, self-fertilization invaded C. elegans host populations in the control and fixed-parasite treatments, regardless of parasite virulence. In the copassaged treatment, selfing invaded host populations coevolving with low- to mid-virulence strains, but remained rare in hosts coevolving with highly virulent bacterial strains. Therefore, we found that only highly virulent coevolving parasites can impede the invasion of selfing.
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Affiliation(s)
- Samuel P Slowinski
- Department of Biology, University of Maryland, College Park, MD, United States
| | - JaeHoon Cho
- Department of Biology, Emory University, Atlanta GA, United States
| | - McKenna J Penley
- Department of Biology, Emory University, Atlanta GA, United States
| | - Laura W Alexander
- Department of Integrative Biology, University of California, Berkeley, CA, United States
| | | | | | - Levi T Morran
- Department of Biology, Emory University, Atlanta GA, United States
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3
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Rybnikov SR, Frenkel Z, Hübner S, Weissman DB, Korol AB. Modeling the evolution of recombination plasticity: A prospective review. Bioessays 2023; 45:e2200237. [PMID: 37246937 DOI: 10.1002/bies.202200237] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/17/2023] [Accepted: 05/17/2023] [Indexed: 05/30/2023]
Abstract
Meiotic recombination is one of the main sources of genetic variation, a fundamental factor in the evolutionary adaptation of sexual eukaryotes. Yet, the role of variation in recombination rate and other recombination features remains underexplored. In this review, we focus on the sensitivity of recombination rates to different extrinsic and intrinsic factors. We briefly present the empirical evidence for recombination plasticity in response to environmental perturbations and/or poor genetic background and discuss theoretical models developed to explain how such plasticity could have evolved and how it can affect important population characteristics. We highlight a gap between the evidence, which comes mostly from experiments with diploids, and theory, which typically assumes haploid selection. Finally, we formulate open questions whose solving would help to outline conditions favoring recombination plasticity. This will contribute to answering the long-standing question of why sexual recombination exists despite its costs, since plastic recombination may be evolutionary advantageous even in selection regimes rejecting any non-zero constant recombination.
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Affiliation(s)
- Sviatoslav R Rybnikov
- Institute of Evolution, University of Haifa, Haifa, Israel
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Zeev Frenkel
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Sariel Hübner
- Galilee Research Institute (MIGAL), Tel-Hai College, Kiryat Shmona, Israel
| | | | - Abraham B Korol
- Institute of Evolution, University of Haifa, Haifa, Israel
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
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4
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Wiens JJ. Trait-based species richness: ecology and macroevolution. Biol Rev Camb Philos Soc 2023; 98:1365-1387. [PMID: 37015839 DOI: 10.1111/brv.12957] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/21/2023] [Accepted: 03/27/2023] [Indexed: 04/06/2023]
Abstract
Understanding the origins of species richness patterns is a fundamental goal in ecology and evolutionary biology. Much research has focused on explaining two kinds of species richness patterns: (i) spatial species richness patterns (e.g. the latitudinal diversity gradient), and (ii) clade-based species richness patterns (e.g. the predominance of angiosperm species among plants). Here, I highlight a third kind of richness pattern: trait-based species richness (e.g. the number of species with each state of a character, such as diet or body size). Trait-based richness patterns are relevant to many topics in ecology and evolution, from ecosystem function to adaptive radiation to the paradox of sex. Although many studies have described particular trait-based richness patterns, the origins of these patterns remain far less understood, and trait-based richness has not been emphasised as a general category of richness patterns. Here, I describe a conceptual framework for how trait-based richness patterns arise compared to other richness patterns. A systematic review suggests that trait-based richness patterns are most often explained by when each state originates within a group (i.e. older states generally have higher richness), and not by differences in transition rates among states or faster diversification of species with certain states. This latter result contrasts with the widespread emphasis on diversification rates in species-richness research. I show that many recent studies of spatial richness patterns are actually studies of trait-based richness patterns, potentially confounding the causes of these patterns. Finally, I describe a plethora of unanswered questions related to trait-based richness patterns.
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Affiliation(s)
- John J Wiens
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, USA
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5
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MacPherson B, Scott R, Gras R. Using individual-based modelling to investigate a pluralistic explanation for the prevalence of sexual reproduction in animal species. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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6
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Pierre JS, Stoeckel S, Wajnberg E. The advantage of sex: Reinserting fluctuating selection in the pluralist approach. PLoS One 2022; 17:e0272134. [PMID: 35917359 PMCID: PMC9345338 DOI: 10.1371/journal.pone.0272134] [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: 01/07/2022] [Accepted: 07/13/2022] [Indexed: 11/29/2022] Open
Abstract
The advantage of sex, and its fixation in some clades and species all over the eukaryote tree of life, is considered an evolutionary enigma, especially regarding its assumed two-fold cost. Several likely hypotheses have been proposed such as (1) a better response to the negative frequency-dependent selection imposed by the “Red Queen” hypothesis; (2) the competition between siblings induced by the Tangled Bank hypothesis; (3) the existence of genetic and of (4) ecological factors that can diminish the cost of sex to less than the standard assumed two-fold; and (5) a better maintenance of genetic diversity and its resulting phenotypic variation, providing a selective advantage in randomly fluctuating environments. While these hypotheses have mostly been studied separately, they can also act simultaneously. This was advocated by several studies which presented a pluralist point of view. Only three among the five causes cited above were considered yet in such a framework: the Red Queen hypothesis, the Tangled Bank and the genetic factors lowering the cost of sex. We thus simulated the evolution of a finite mutating population undergoing negative frequency-dependent selection on phenotypes and a two-fold (or less) cost of sexuality, experiencing randomly fluctuating selection along generations. The individuals inherited their reproductive modes, either clonal or sexual. We found that exclusive sexuality begins to fix in populations exposed to environmental variation that exceeds the width of one ecological niche (twice the standard deviation of a Gaussian response to environment). This threshold was lowered by increasing negative frequency-dependent selection and when reducing the two-fold cost of sex. It contributes advocating that the different processes involved in a short-term advantage of sex and recombination can act in combination to favor the fixation of sexual reproduction in populations.
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Affiliation(s)
- Jean-Sébastien Pierre
- UMR 6553 Ecologie Biodiversité Evolution, CNRS INEE, Université de Rennes 1, OSUR, Campus de Beaulieu, Rennes Cedex, France
- * E-mail:
| | - Solenn Stoeckel
- IGEPP, INRAE, Institut Agro, Université de Rennes, Le Rheu, France
| | - Eric Wajnberg
- INRAE, Sophia Antipolis Cedex, France
- Projet Hephaistos, INRIA, Sophia Antipolis Cedex, France
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7
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Using individual-based modeling to investigate whether fluctuating resources help to explain the prevalence of sexual reproduction in animal species. ECOL INFORM 2022. [DOI: 10.1016/j.ecoinf.2021.101499] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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8
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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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9
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MacPherson B, Scott R, Gras R. Using individual-based modelling to investigate the possible role that the Red Tooth effect plays in maintaining sexual reproduction. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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McElroy KE, Müller S, Lamatsch DK, Bankers L, Fields PD, Jalinsky JR, Sharbrough J, Boore JL, Logsdon JM, Neiman M. Asexuality Associated with Marked Genomic Expansion of Tandemly Repeated rRNA and Histone Genes. Mol Biol Evol 2021; 38:3581-3592. [PMID: 33885820 PMCID: PMC8382920 DOI: 10.1093/molbev/msab121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
How does asexual reproduction influence genome evolution? Although is it clear that genomic structural variation is common and important in natural populations, we know very little about how one of the most fundamental of eukaryotic traits-mode of genomic inheritance-influences genome structure. We address this question with the New Zealand freshwater snail Potamopyrgus antipodarum, which features multiple separately derived obligately asexual lineages that coexist and compete with otherwise similar sexual lineages. We used whole-genome sequencing reads from a diverse set of sexual and asexual individuals to analyze genomic abundance of a critically important gene family, rDNA (the genes encoding rRNAs), that is notable for dynamic and variable copy number. Our genomic survey of rDNA in P. antipodarum revealed two striking results. First, the core histone and 5S rRNA genes occur between tandem copies of the 18S-5.8S-28S gene cluster, a unique architecture for these crucial gene families. Second, asexual P. antipodarum harbor dramatically more rDNA-histone copies than sexuals, which we validated through molecular and cytogenetic analysis. The repeated expansion of this genomic region in asexual P. antipodarum lineages following distinct transitions to asexuality represents a dramatic genome structural change associated with asexual reproduction-with potential functional consequences related to the loss of sexual reproduction.
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Affiliation(s)
- Kyle E McElroy
- Ecology, Evolutionary, and Organismal Biology, Iowa State University, Ames, IA, USA
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - Stefan Müller
- Institute of Human Genetics, Munich University Hospital, Ludwig-Maximilians University, Munich, Germany
| | - Dunja K Lamatsch
- Research Department for Limnology, University of Innsbruck, Mondsee, Mondsee, Austria
| | - Laura Bankers
- Division of Infectious Diseases, University of Colorado—Anschutz Medical Campus, Aurora, CO, USA
| | - Peter D Fields
- Department of Environmental Sciences, Zoology, University of Basel, Basel, Switzerland
| | | | - Joel Sharbrough
- Biology Department, New Mexico Institute of Mining and Technology, Socorro, NM, USA
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Jeffrey L Boore
- Providence St. Joseph Health and Institute for Systems Biology, Seattle, WA, USA
| | - John M Logsdon
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, IA, USA
- Department of Gender, Women's, and Sexuality Studies, University of Iowa, Iowa City, IA, USA
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11
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Gowler CD, Rogalski MA, Shaw CL, Hunsberger KK, Duffy MA. Density, parasitism, and sexual reproduction are strongly correlated in lake Daphnia populations. Ecol Evol 2021; 11:10446-10456. [PMID: 34367587 PMCID: PMC8328469 DOI: 10.1002/ece3.7847] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/03/2021] [Accepted: 06/08/2021] [Indexed: 01/06/2023] Open
Abstract
Many organisms can reproduce both asexually and sexually. For cyclical parthenogens, periods of asexual reproduction are punctuated by bouts of sexual reproduction, and the shift from asexual to sexual reproduction has large impacts on fitness and population dynamics. We studied populations of Daphnia dentifera to determine the amount of investment in sexual reproduction as well as the factors associated with variation in investment in sex. To do so, we tracked host density, infections by nine different parasites, and sexual reproduction in 15 lake populations of D. dentifera for 3 years. Sexual reproduction was seasonal, with male and ephippial female production beginning as early as late September and generally increasing through November. However, there was substantial variation in the prevalence of sexual individuals across populations, with some populations remaining entirely asexual throughout the study period and others shifting almost entirely to sexual females and males. We found strong relationships between density, prevalence of infection, parasite species richness, and sexual reproduction in these populations. However, strong collinearity between density, parasitism, and sexual reproduction means that further work will be required to disentangle the causal mechanisms underlying these relationships.
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Affiliation(s)
- Camden D. Gowler
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
| | - Mary A. Rogalski
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
- Biology and Environmental StudiesBowdoin CollegeBrunswickMEUSA
| | - Clara L. Shaw
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
| | | | - Meghan A. Duffy
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
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12
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Chen L, Wiens JJ. Multicellularity and sex helped shape the Tree of Life. Proc Biol Sci 2021; 288:20211265. [PMID: 34315265 PMCID: PMC8316805 DOI: 10.1098/rspb.2021.1265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/06/2021] [Indexed: 12/11/2022] Open
Abstract
Across the Tree of Life, there are dramatic differences in species numbers among groups. However, the factors that explain the differences among the deepest branches have remained unknown. We tested whether multicellularity and sexual reproduction might explain these patterns, since the most species-rich groups share these traits. We found that groups with multicellularity and sexual reproduction have accelerated rates of species proliferation (diversification), and that multicellularity has a stronger effect than sexual reproduction. Patterns of species richness among clades are then strongly related to these differences in diversification rates. Taken together, these results help explain patterns of biodiversity among groups of organisms at the very broadest scales. They may also help explain the mysterious preponderance of sexual reproduction among species (the 'paradox of sex') by showing that organisms with sexual reproduction proliferate more rapidly.
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Affiliation(s)
- Lian Chen
- College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, People's Republic of China
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721-0088, USA
| | - John J. Wiens
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721-0088, USA
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13
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Fujita MK, Singhal S, Brunes TO, Maldonado JA. Evolutionary Dynamics and Consequences of Parthenogenesis in Vertebrates. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2020. [DOI: 10.1146/annurev-ecolsys-011720-114900] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Parthenogenesis is asexual reproduction without any required participation from males and, as such, is a null model for sexual reproduction. In a comparative context, we can expand our understanding of the evolution and ecology of sex by investigating the consequences of parthenogenesis. In this review, we examine the theoretical predictions of and empirical results on the evolution of asexual reproduction in vertebrates, focusing on recent studies addressing the origins and geographic spread of parthenogenetic lineages and the genomic consequences of an asexual life history. With advances in computational methods and genome technologies, researchers are poised to make rapid and significant progress in studying the origin and evolution of parthenogenesis in vertebrates, thus providing an important perspective on understanding biodiversity patterns of both asexual and sexual populations.
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Affiliation(s)
- Matthew K. Fujita
- Amphibian and Reptile Diversity Research Center and Department of Biology, University of Texas at Arlington, Arlington, Texas 76019, USA
| | - Sonal Singhal
- Department of Biology, California State University, Dominguez Hills, Carson, California 90747, USA
| | - Tuliana O. Brunes
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Jose A. Maldonado
- Amphibian and Reptile Diversity Research Center and Department of Biology, University of Texas at Arlington, Arlington, Texas 76019, USA
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14
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Martel SI, Ossa CG, Simon J, Figueroa CC, Bozinovic F. Latitudinal trend in the reproductive mode of the pea aphid Acyrthosiphon pisum invading a wide climatic range. Ecol Evol 2020; 10:8289-8298. [PMID: 32788979 PMCID: PMC7417215 DOI: 10.1002/ece3.6536] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 05/15/2020] [Accepted: 06/08/2020] [Indexed: 11/12/2022] Open
Abstract
The maintenance of sexuality is a puzzling phenomenon in evolutionary biology. Many universal hypotheses have been proposed to explain the prevalence of sex despite its costs, but it has been hypothesized that sex could be also retained by lineage-specific mechanisms that would confer some short-term advantage. Aphids are good models to study the maintenance of sex because they exhibit coexistence of both sexual and asexual populations within the same species and because they invade a large variety of ecosystems. Sex in aphids is thought to be maintained because only sexually produced eggs can persist in cold climates, but whether sex is obligate or facultative depending on climatic conditions remains to be elucidated. In this study, we have inferred the reproductive mode of introduced populations of the pea aphid Acyrthosiphon pisum in Chile along a climatic gradient using phenotypic assays and genetic-based criteria to test the ecological short-term advantage of sex in cold environments. Our results showed a latitudinal trend in the reproductive mode of Chilean pea aphid population from obligate parthenogenesis in the north to an intermediate life cycle producing both parthenogenetic and sexual progeny in the southernmost locality, where harsh winters are usual. These findings are congruent with the hypothesis of the ecological short-term advantage of sex in aphids.
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Affiliation(s)
- Sebastián I. Martel
- Departamento de EcologíaFacultad de Ciencias BiológicasCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiago de ChileChile
| | - Carmen G. Ossa
- Instituto de BiologíaFacultad de CienciasUniversidad de ValparaísoValparaísoChile
| | | | - Christian C. Figueroa
- Instituto de Ciencias BiológicasCenter for Molecular and Functional Ecology in Agroecosystems (CEMF)Universidad de TalcaTalcaChile
| | - Francisco Bozinovic
- Departamento de EcologíaFacultad de Ciencias BiológicasCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiago de ChileChile
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15
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Hörandl E, Hadacek F. Oxygen, life forms, and the evolution of sexes in multicellular eukaryotes. Heredity (Edinb) 2020; 125:1-14. [PMID: 32415185 PMCID: PMC7413252 DOI: 10.1038/s41437-020-0317-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 04/26/2020] [Accepted: 04/26/2020] [Indexed: 12/27/2022] Open
Abstract
The evolutionary advantage of different sexual systems in multicellular eukaryotes is still not well understood, because the differentiation into male and female individuals halves offspring production compared with asexuality. Here we propose that various physiological adaptations to oxidative stress could have forged sessility versus motility, and consequently the evolution of sexual systems in multicellular animals, plants, and fungi. Photosynthesis causes substantial amounts of oxidative stress in photoautotrophic plants and, likewise, oxidative chemistry of polymer breakdown, cellulose and lignin, for saprotrophic fungi. In both cases, its extent precludes motility, an additional source of oxidative stress. Sessile life form and the lack of neuronal systems, however, limit options for mate recognition and adult sexual selection, resulting in inefficient mate-searching systems. Hence, sessility requires that all individuals can produce offspring, which is achieved by hermaphroditism in plants and/or by multiple mating types in fungi. In animals, motility requires neuronal systems, and muscle activity, both of which are highly sensitive to oxidative damage. As a consequence, motility has evolved in animals as heterotrophic organisms that (1) are not photosynthetically active, and (2) are not primary decomposers. Adaptations to motility provide prerequisites for an active mating behavior and efficient mate-searching systems. These benefits compensate for the "cost of males", and may explain the early evolution of sex chromosomes in metazoans. We conclude that different sexual systems evolved under the indirect physiological constraints of lifestyles.
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Affiliation(s)
- Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants, University of Goettingen, Göttingen, Germany.
| | - Franz Hadacek
- Department of Plant Biochemistry, University of Goettingen, Göttingen, Germany
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16
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Dalziel AC, Tirbhowan S, Drapeau HF, Power C, Jonah LS, Gbotsyo YA, Dion‐Côté A. Using asexual vertebrates to study genome evolution and animal physiology: Banded ( Fundulus diaphanus) x Common Killifish ( F. heteroclitus) hybrid lineages as a model system. Evol Appl 2020; 13:1214-1239. [PMID: 32684956 PMCID: PMC7359844 DOI: 10.1111/eva.12975] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/12/2020] [Accepted: 03/16/2020] [Indexed: 12/27/2022] Open
Abstract
Wild, asexual, vertebrate hybrids have many characteristics that make them good model systems for studying how genomes evolve and epigenetic modifications influence animal physiology. In particular, the formation of asexual hybrid lineages is a form of reproductive incompatibility, but we know little about the genetic and genomic mechanisms by which this mode of reproductive isolation proceeds in animals. Asexual lineages also provide researchers with the ability to produce genetically identical individuals, enabling the study of autonomous epigenetic modifications without the confounds of genetic variation. Here, we briefly review the cellular and molecular mechanisms leading to asexual reproduction in vertebrates and the known genetic and epigenetic consequences of the loss of sex. We then specifically discuss what is known about asexual lineages of Fundulus diaphanus x F. heteroclitus to highlight gaps in our knowledge of the biology of these clones. Our preliminary studies of F. diaphanus and F. heteroclitus karyotypes from Porter's Lake (Nova Scotia, Canada) agree with data from other populations, suggesting a conserved interspecific chromosomal arrangement. In addition, genetic analyses suggest that: (a) the same major clonal lineage (Clone A) of F. diaphanus x F. heteroclitus has remained dominant over the past decade, (b) some minor clones have also persisted, (c) new clones may have recently formed, and iv) wild clones still mainly descend from F. diaphanus ♀ x F. heteroclitus ♂ crosses (96% in 2017-2018). These data suggest that clone formation may be a relatively rare, but continuous process, and there are persistent environmental or genetic factors causing a bias in cross direction. We end by describing our current research on the genomic causes and consequences of a transition to asexuality and the potential physiological consequences of epigenetic variation.
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Affiliation(s)
| | - Svetlana Tirbhowan
- Department of BiologySaint Mary's UniversityHalifaxNSCanada
- Département de biologieUniversité de MonctonMonctonNBCanada
| | | | - Claude Power
- Département de biologieUniversité de MonctonMonctonNBCanada
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17
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Pla S, Benvenuto C, Capellini I, Piferrer F. A phylogenetic comparative analysis on the evolution of sequential hermaphroditism in seabreams (Teleostei: Sparidae). Sci Rep 2020; 10:3606. [PMID: 32107416 PMCID: PMC7046777 DOI: 10.1038/s41598-020-60376-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 01/28/2020] [Indexed: 01/25/2023] Open
Abstract
The Sparids are an ideal group of fishes in which to study the evolution of sexual systems since they exhibit a great sexual diversity, from gonochorism (separate sexes) to protandrous (male-first) and protogynous (female-first) sequential hermaphroditism (sex change). According to the size-advantage model (SAM), selection should favour sex change when the second sex achieves greater reproductive success at a larger body size than the first sex. Using phylogenetic comparative methods and a sample of 68 sparid species, we show that protogyny and protandry evolve from gonochorism but evolutionary transitions between these two forms of sequential hermaphroditism are unlikely to happen. Using male gonadosomatic index (GSI) as a measure of investment in gametes and proxy for sperm competition, we find that, while gonochoristic and protogynous species support the predictions of SAM, protandrous species do not, as they exhibit higher GSI values than expected even after considering mating systems and spawning modes. We suggest that small males of protandrous species have to invest disproportionally more in sperm production than predicted not only when spawning in aggregations, with high levels of sperm competition, but also when spawning in pairs due to the need to fertilize highly fecund females, much larger than themselves. We propose that this compensatory mechanism, together with Bateman’s principles in sequential hermaphrodites, should be formally incorporated in the SAM.
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Affiliation(s)
- Susanna Pla
- Institut de Ciències del Mar, Spanish National Research Council (CSIC), Barcelona, Spain
| | - Chiara Benvenuto
- Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Salford, UK
| | - Isabella Capellini
- School of Biological Sciences, Queen's University of Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK
| | - Francesc Piferrer
- Institut de Ciències del Mar, Spanish National Research Council (CSIC), Barcelona, Spain.
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18
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How long do Red Queen dynamics survive under genetic drift? A comparative analysis of evolutionary and eco-evolutionary models. BMC Evol Biol 2020; 20:8. [PMID: 31931696 PMCID: PMC6958710 DOI: 10.1186/s12862-019-1562-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/12/2019] [Indexed: 11/26/2022] Open
Abstract
Background Red Queen dynamics are defined as long term co-evolutionary dynamics, often with oscillations of genotype abundances driven by fluctuating selection in host-parasite systems. Much of our current understanding of these dynamics is based on theoretical concepts explored in mathematical models that are mostly (i) deterministic, inferring an infinite population size and (ii) evolutionary, thus ecological interactions that change population sizes are excluded. Here, we recall the different mathematical approaches used in the current literature on Red Queen dynamics. We then compare models from game theory (evo) and classical theoretical ecology models (eco-evo), that are all derived from individual interactions and are thus intrinsically stochastic. We assess the influence of this stochasticity through the time to the first loss of a genotype within a host or parasite population. Results The time until the first genotype is lost (“extinction time”), is shorter when ecological dynamics, in the form of a changing population size, is considered. Furthermore, when individuals compete only locally with other individuals extinction is even faster. On the other hand, evolutionary models with a fixed population size and competition on the scale of the whole population prolong extinction and therefore stabilise the oscillations. The stabilising properties of intra-specific competitions become stronger when population size is increased and the deterministic part of the dynamics gain influence. In general, the loss of genotype diversity can be counteracted with mutations (or recombination), which then allow the populations to recurrently undergo negative frequency-dependent selection dynamics and selective sweeps. Conclusion Although the models we investigated are equal in their biological motivation and interpretation, they have diverging mathematical properties both in the derived deterministic dynamics and the derived stochastic dynamics. We find that models that do not consider intraspecific competition and that include ecological dynamics by letting the population size vary, lose genotypes – and thus Red Queen oscillations – faster than models with competition and a fixed population size.
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19
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Abstract
In diverse parasite taxa, from scale insects to root-knot nematodes, asexual lineages have exceptionally large host ranges, larger than those of their sexual relatives. Phylogenetic comparative studies of parasite taxa indicate that increases in host range and geographic range increase the probability of establishment of asexual lineages. At first pass, this convergence of traits appears counter-intuitive: intimate, antagonistic association with an enormous range of host taxa correlates with asexual reproduction, which should limit genetic variation within populations. Why would narrow host ranges favor sexual parasites and large host ranges favor asexual parasites? To take on this problem I link theory on ecological specialization to the two predominant hypotheses for the evolution of sex. I argue that both hypotheses predict a positive association between host range and the probability of invasion of asexual parasites, mediated either by variation in population size or in the strength of antagonistic coevolution. I also review hypotheses on colonization and the evolution of niche breadth in asexual lineages. I emphasize parasite taxa, with their diversity of reproductive modes and ecological strategies, as valuable assets in the hunt for solutions to the classic problems of the evolution of sex and geographic parthenogenesis.
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Affiliation(s)
- Amanda K Gibson
- Wissenschaftskolleg zu Berlin, Berlin, Germany.,Department of Biology, University of Virginia, Charlottesville, VA, USA
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20
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Cutter AD, Morran LT, Phillips PC. Males, Outcrossing, and Sexual Selection in Caenorhabditis Nematodes. Genetics 2019; 213:27-57. [PMID: 31488593 PMCID: PMC6727802 DOI: 10.1534/genetics.119.300244] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 06/06/2019] [Indexed: 12/15/2022] Open
Abstract
Males of Caenorhabditis elegans provide a crucial practical tool in the laboratory, but, as the rarer and more finicky sex, have not enjoyed the same depth of research attention as hermaphrodites. Males, however, have attracted the attention of evolutionary biologists who are exploiting the C. elegans system to test longstanding hypotheses about sexual selection, sexual conflict, transitions in reproductive mode, and genome evolution, as well as to make new discoveries about Caenorhabditis organismal biology. Here, we review the evolutionary concepts and data informed by study of males of C. elegans and other Caenorhabditis We give special attention to the important role of sperm cells as a mediator of inter-male competition and male-female conflict that has led to drastic trait divergence across species, despite exceptional phenotypic conservation in many other morphological features. We discuss the evolutionary forces important in the origins of reproductive mode transitions from males being common (gonochorism: females and males) to rare (androdioecy: hermaphrodites and males) and the factors that modulate male frequency in extant androdioecious populations, including the potential influence of selective interference, host-pathogen coevolution, and mutation accumulation. Further, we summarize the consequences of males being common vs rare for adaptation and for trait divergence, trait degradation, and trait dimorphism between the sexes, as well as for molecular evolution of the genome, at both micro-evolutionary and macro-evolutionary timescales. We conclude that C. elegans male biology remains underexploited and that future studies leveraging its extensive experimental resources are poised to discover novel biology and to inform profound questions about animal function and evolution.
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Affiliation(s)
- Asher D Cutter
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario M5S3B2, Canada
| | - Levi T Morran
- Department of Biology, Emory University, Atlanta, Georgia 30322, and
| | - Patrick C Phillips
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon 97403
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21
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Engqvist L, Ramm SA. Promiscuity punishes sexual deviants. Mol Ecol 2019; 26:5359-5361. [PMID: 29080372 DOI: 10.1111/mec.14355] [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: 07/21/2017] [Accepted: 09/05/2017] [Indexed: 11/30/2022]
Abstract
Sex is good for us, but it is a compromise. For the benefit of being able to produce genetically variable offspring, we must pay the cost of passing on only half our genes to each of them. Whilst evolutionary biologists still puzzle over the precise details of why the benefits of sex so frequently seem to outweigh the costs (Neiman, Lively, & Meirmans, ), one major challenge to sexual reproduction is the fact that if we pass on only half our genetic material to each gamete, there is a strong incentive for each individual allele to try to gain an unfair representation during gamete production. Fundamental to stabilizing sex once it evolves is therefore the ability to ensure a fair meiosis. Nevertheless, this system is not perfect, and some selfish genetic elements - so-called meiotic drivers - manage to tip the meiotic scales in their favour and gain a transmission advantage (review in Burt and Trivers, ). In this issue of Molecular Ecology, Manser, Lindholm, Simmons, and Firman () demonstrate that in house mice, the effectiveness of one such harmful transmission distorter is reduced by polyandry and hence that population viability can be somewhat restored by female promiscuity.
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Affiliation(s)
- Leif Engqvist
- Division of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Steven A Ramm
- Evolutionary Biology, Bielefeld University, Bielefeld, Germany
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22
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Maraun M, Caruso T, Hense J, Lehmitz R, Mumladze L, Murvanidze M, Nae I, Schulz J, Seniczak A, Scheu S. Parthenogenetic vs. sexual reproduction in oribatid mite communities. Ecol Evol 2019; 9:7324-7332. [PMID: 31380053 PMCID: PMC6662391 DOI: 10.1002/ece3.5303] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 11/26/2022] Open
Abstract
The dominance of sex in Metazoa is enigmatic. Sexual species allocate resources to the production of males, while potentially facing negative effects such as the loss of well-adapted genotypes due to recombination, and exposure to diseases and predators during mating. Two major hypotheses have been put forward to explain the advantages of parthenogenetic versus sexual reproduction in animals, that is, the Red Queen hypothesis and the Tangled Bank/Structured Resource Theory of Sex. The Red Queen hypothesis assumes that antagonistic predator-prey/ parasite-host interactions favor sex. The Structured Resource Theory of Sex predicts sexual reproduction to be favored if resources are in short supply and aggregated in space. In soil, a remarkable number of invertebrates reproduce by parthenogenesis, and this pattern is most pronounced in oribatid mites (Oribatida, Acari). Oribatid mites are abundant in virtually any soil across very different habitats, and include many sexual and parthenogenetic (thelytokous) species. Thereby, they represent an ideal model group to investigate the role of sexual versus parthenogenetic reproduction across different ecosystems and habitats. Here, we compiled data on oribatid mite communities from different ecosystems and habitats across biomes, including tropical rainforests, temperate forests, grasslands, arable fields, salt marshes, bogs, caves, and deadwood. Based on the compiled dataset, we analyzed if the percentage of parthenogenetic species and the percentage of individuals of parthenogenetic species are related to total oribatid mite density, species number, and other potential driving factors of the reproductive mode including altitude and latitude. We then interpret the results in support of either the Red Queen hypothesis or the Structured Resource Theory of Sex. Overall, the data showed that low density of oribatid mites due to harsh environmental conditions is associated with high frequency of parthenogenesis supporting predictions of the Structured Resource Theory of Sex rather than the Red Queen hypothesis.
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Affiliation(s)
- Mark Maraun
- JFB Institute of Zoology and AnthropologyGeorg August University GöttingenGöttingenGermany
| | - Tancredi Caruso
- School of Biological Sciences and Institute for Global Food SecurityQueen's University of BelfastBelfastNorthern Ireland
| | - Jonathan Hense
- Fachdidaktik Biologie, Nees‐InstitutRheinische Friedrich‐Wilhelms Universität BonnBonnGermany
| | | | - Levan Mumladze
- Institute of Ecology and Institute of ZoologyIlia State UniversityTbilisiGeorgia
| | - Maka Murvanidze
- Institute of Entomology of AgriculturalUniversity of GeorgiaTbilisiGeorgia
| | - Ioana Nae
- Emil Racovita Institute of Speleology of Romanian AcademyBucharestRomania
| | - Julia Schulz
- JFB Institute of Zoology and AnthropologyGeorg August University GöttingenGöttingenGermany
| | - Anna Seniczak
- RealfagbyggetUniversity Museum of Bergen, University of BergenBergenNorway
| | - Stefan Scheu
- JFB Institute of Zoology and AnthropologyGeorg August University GöttingenGöttingenGermany
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23
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Tvedte ES, Logsdon JM, Forbes AA. Sex loss in insects: causes of asexuality and consequences for genomes. CURRENT OPINION IN INSECT SCIENCE 2019; 31:77-83. [PMID: 31109677 DOI: 10.1016/j.cois.2018.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 11/03/2018] [Accepted: 11/20/2018] [Indexed: 06/09/2023]
Abstract
Boasting a staggering diversity of reproductive strategies, insects provide attractive models for the comparative study of the causes and consequences of transitions to asexuality. We provide an overview of some contemporary studies of reproductive systems in insects and compile an initial database of asexual insect genome resources. Insect systems have already yielded some important insights into various mechanisms by which sex is lost, including genetic, endosymbiont-mediated, and hybridization. Studies of mutation and substitution after loss of sex provide the strongest empirical support for hypothesized effects of asexuality, whereas there is mixed evidence for ecological hypotheses such as increased parasite load and altered niche breadth in asexuals. Most hypotheses have been explored in a select few taxa (e.g. stick insects, aphids), such that much of the great taxonomic breadth of insects remain understudied. Given the variation in the proximate causes of asexuality in insects, we argue for expanding the taxonomic breadth of study systems. Despite some challenges for investigating sex in insects, the increasing cost-effectiveness of genomic sequencing makes data generation for closely-related asexual and sexual lineages increasingly feasible.
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Affiliation(s)
- Eric S Tvedte
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States.
| | - John M Logsdon
- Department of Biology, University of Iowa, Iowa City, IA, United States
| | - Andrew A Forbes
- Department of Biology, University of Iowa, Iowa City, IA, United States
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24
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Parker DJ, Bast J, Jalvingh K, Dumas Z, Robinson-Rechavi M, Schwander T. Repeated Evolution of Asexuality Involves Convergent Gene Expression Changes. Mol Biol Evol 2019; 36:350-364. [PMID: 30445505 PMCID: PMC6404633 DOI: 10.1093/molbev/msy217] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Asexual reproduction has evolved repeatedly from sexual ancestors across a wide range of taxa. Whereas the costs and benefits associated with asexuality have received considerable attention, the molecular changes underpinning the evolution of asexual reproduction remain relatively unexplored. In particular, it is completely unknown whether the repeated evolution of asexual phenotypes involves similar molecular changes, as previous studies have focused on changes occurring in single lineages. Here, we investigate the extent of convergent gene expression changes across five independent transitions to asexuality in stick insects. We compared gene expression of asexual females to females of close sexual relatives in whole-bodies, reproductive tracts, and legs. We identified a striking amount of convergent gene expression change (up to 8% of genes), greatly exceeding that expected by chance. Convergent changes were also tissue-specific, and most likely driven by selection for functional changes. Genes showing convergent changes in the reproductive tract were associated with meiotic spindle formation and centrosome organization. These genes are particularly interesting as they can influence the production of unreduced eggs, a key barrier to asexual reproduction. Changes in legs and whole-bodies were likely involved in female sexual trait decay, with enrichment in terms such as sperm-storage and pigmentation. By identifying changes occurring across multiple independent transitions to asexuality, our results provide a rare insight into the molecular basis of asexual phenotypes and suggest that the evolutionary path to asexuality is highly constrained, requiring repeated changes to the same key genes.
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Affiliation(s)
- Darren J Parker
- 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
| | - Kirsten Jalvingh
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Zoé Dumas
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - 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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25
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Kondrashov AS. Through Sex, Nature Is Telling Us Something Important. Trends Genet 2018; 34:352-361. [DOI: 10.1016/j.tig.2018.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/02/2018] [Accepted: 01/05/2018] [Indexed: 11/28/2022]
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26
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Neiman M, Meirmans PG, Schwander T, Meirmans S. Sex in the wild: How and why field-based studies contribute to solving the problem of sex. Evolution 2018; 72:1194-1203. [PMID: 29645091 DOI: 10.1111/evo.13485] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/27/2018] [Indexed: 02/06/2023]
Abstract
Why and how sexual reproduction is maintained in natural populations, the so-called "queen of problems," is a key unanswered question in evolutionary biology. Recent efforts to solve the problem of sex have often emphasized results generated from laboratory settings. Here, we use a survey of representative "sex in the wild" literature to review and synthesize the outcomes of empirical studies focused on natural populations. Especially notable results included relatively strong support for mechanisms involving niche differentiation and a near absence of attention to adaptive evolution. Support for a major role of parasites is largely confined to a single study system, and only three systems contribute most of the support for mutation accumulation hypotheses. This evidence for taxon specificity suggests that outcomes of particular studies should not be more broadly extrapolated without extreme caution. We conclude by suggesting steps forward, highlighting tests of niche differentiation mechanisms in both laboratory and nature, and empirical evaluation of adaptive evolution-focused hypotheses in the wild. We also emphasize the value of leveraging the growing body of genomic resources for nonmodel taxa to address whether the clearance of harmful mutations and spread of beneficial variants in natural populations proceeds as expected under various hypotheses for sex.
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Affiliation(s)
- Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, Iowa 52242
| | - Patrick G Meirmans
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, P.O. Box 94248, 1090GE Amsterdam, The Netherlands
| | - Tanja Schwander
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Stephanie Meirmans
- Academic Medical Center (AMC), University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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