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Mezhzherin SV, Morozov-Leonov SY, Rostovska OV. Nuclear gene introgressions in hybrid populations of water frog Pelophylax esculentus complex: geographical analysis of the phenomenon and its interpretation. Genetica 2024; 152:31-42. [PMID: 38361120 DOI: 10.1007/s10709-024-00203-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/31/2024] [Indexed: 02/17/2024]
Abstract
Reproduction of water frog hybrids Pelophylax esculentus (Pelophylax ridibundus x Pelophylax lessonae) is associated with hemiclonal reproduction and backcrossing. The hemiclonal mode of reproduction occurs within P. esculentus allodiploids. In this case, the unrecombined genome of one parental species is transmitted to the offspring after premeiotic elimination of the chromosome set of the second parental species. Usually, the chromosome set of P. lessonae is eliminated, and the altered genome of P. ridibundus is passed on to the progeny. The hemiclonal inheritance within diploid Pelophylax esculentus hybrids may be accompanied by certain aberrations of premeiotic elimination. As a result, the formation of P. ridibundus specimens with introgressions of the P. lessonae genetic material, or the formation of recombinant hybrids occurs, depending on which of the parental species backcrossing takes place. The aim of our study is to describe the aberration of premeiotic elimination within the water frog P. esculentus complex detected by the nuclear gene Ldh-B inheritance, with an attempt to find out the causes of this phenomenon. It has been established that aberrations of premeiotic elimination are widespread, but only within populations of water frog from the river system of Upper Dnieper within Ukraine. The highest level of introgression takes place in the water frog populations within Kiev metropolis under conditions of expressed anthropogenization, while the maximum frequency of recombinants was detected within populations from the basin of Desna River, that has preserved native ecosystems. It was demonstrated that the frequency of premeiotic aberrations does not correlate with the intensity of interspecific water frog hybridization. Populations with introgressions are more common than populations with recombinants, however, within the latter, the frequency of recombination events is higher. The primary factor of gametogenesis aberrations, most likely, is the genetic characteristics of the local populations of parental species, since unambiguous explanations of this phenomenon based on the action of environmental stress (pollution of water systems) are not obvious.
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Affiliation(s)
- Sergey V Mezhzherin
- Department of Evolutionary Genetic and Fundamentals of Systematics, I.I. Schmalhausen Institute of Zoology, B. Khmel'nitskogo Str., Kiev-30, 01601, Ukraine
| | - Svyatoslav Yu Morozov-Leonov
- Department of Evolutionary Genetic and Fundamentals of Systematics, I.I. Schmalhausen Institute of Zoology, B. Khmel'nitskogo Str., Kiev-30, 01601, Ukraine.
| | - Olga V Rostovska
- Department of Evolutionary Genetic and Fundamentals of Systematics, I.I. Schmalhausen Institute of Zoology, B. Khmel'nitskogo Str., Kiev-30, 01601, Ukraine
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Morozov-Leonov SY. Reproduction and the Evolutionary Potential of the Hybrid Form Pelophylax Esculentus-Bidibundus (Amphibia, Ranidae) within the Drainages of Pripyat, Dniester, and Southern Bug Rivers. CYTOL GENET+ 2023. [DOI: 10.3103/s0095452723010085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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Klabacka RL, Parry HA, Yap KN, Cook RA, Herron VA, Horne LM, Wolak ME, Maldonado JA, Kavazis AN, Fujita MK, Oaks JR, Schwartz TS. Reduced mitochondrial respiration in hybrid asexual lizards. Am Nat 2022; 199:719-728. [DOI: 10.1086/719014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Morozov-Leonov SY. Hybrid Form Pelophylax esculentus-ridibundus (Amphibia, Ranidae) from the Tisa River Drainage: Its Origin and Evolutionary Potential. CYTOL GENET+ 2021. [DOI: 10.3103/s0095452721060098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Morozov-Leonov SY. Evolutionary Potential of the Hybrid Form Pelophylax esculentus-ridibundus (Amphibia, Ranidae) within Dnieper and Desna Drainages: Its Loss Caused by the Hemiclonal Inheritance and the Compensatory Role of Parental Genomes’ Recombination. CYTOL GENET+ 2021. [DOI: 10.3103/s0095452721030063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Capture and return of sexual genomes by hybridogenetic frogs provide clonal genome enrichment in a sexual species. Sci Rep 2021; 11:1633. [PMID: 33452404 PMCID: PMC7810977 DOI: 10.1038/s41598-021-81240-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 01/04/2021] [Indexed: 01/29/2023] Open
Abstract
Hybridogenesis is a reproductive tool for sexual parasitism. Hybridogenetic hybrids use gametes from their sexual host for their own reproduction, but sexual species gain no benefit from such matings as their genome is later eliminated. Here, we examine the presence of sexual parasitism in water frogs through crossing experiments and genome-wide data. We specifically focus on the famous Central-European populations where Pelophylax esculentus males (hybrids of P. ridibundus and P. lessonae) live with P. ridibundus. We identified a system where the hybrids commonly produce two types of clonal gametes (hybrid amphispermy). The haploid lessonae genome is clonally inherited from generation to generation and assures the maintenance of hybrids through a process, in which lessonae sperm fertilize P. ridibundus eggs. The haploid ridibundus genome in hybrids received from P. ridibundus a generation ago, is perpetuated as clonal ridibundus sperm and used to fertilize P. ridibundus eggs, yielding female P. ridibundus progeny. These results imply animal reproduction in which hybridogenetic taxa are not only sexual parasites, but also participate in the formation of a sexual taxon in a remarkable way. This occurs through a process by which sexual gametes are being captured, converted to clones, and returned to sexual populations in one generation.
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Dubey S, Maddalena T, Bonny L, Jeffries DL, Dufresnes C. Population genomics of an exceptional hybridogenetic system of Pelophylax water frogs. BMC Evol Biol 2019; 19:164. [PMID: 31382876 PMCID: PMC6683362 DOI: 10.1186/s12862-019-1482-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 07/16/2019] [Indexed: 12/20/2022] Open
Abstract
Background Hybridogenesis can represent the first stage towards hybrid speciation where the hybrid taxon eventually weans off its parental species. In hybridogenetic water frogs, the hybrid Pelophylax kl. esculentus (genomes RL) usually eliminates one genome from its germline and relies on its parental species P. lessonae (genomes LL) or P. ridibundus (genomes RR) to perpetuate in so-called L-E and R-E systems. But not exclusively: some all-hybrid populations (E-E system) bypass the need for their parental species and fulfill their sexual cycle via triploid hybrid frogs. Genetic surveys are essential to understand the great diversity of these hybridogenetic dynamics and their evolution. Here we conducted such study using RAD-sequencing on Pelophylax from southern Switzerland (Ticino), a geographically-isolated region featuring different assemblages of parental P. lessonae and hybrid P. kl. esculentus. Results We found two types of hybridogenetic systems in Ticino: an L-E system in northern populations and a presumably all-hybrid E-E system in the closely-related southern populations, where P. lessonae was not detected. In the latter, we did not find evidence for triploid individuals from the population genomic data, but identified a few P. ridibundus (RR) as offspring from interhybrid crosses (LR × LR). Conclusions Assuming P. lessonae is truly absent from southern Ticino, the putative maintenance of all-hybrid populations without triploid individuals would require an unusual lability of genome elimination, namely that P. kl. esculentus from both sexes are capable of producing gametes with either L or R genomes. This could be achieved by the co-existence of L- and R- eliminating lineages or by “hybrid amphigamy”, i. e. males and females producing sperm and eggs among which both genomes are represented. These hypotheses imply that polyploidy is not the exclusive evolutionary pathway for hybrids to become reproductively independent, and challenge the classical view that hybridogenetic taxa are necessarily sexual parasites. Electronic supplementary material The online version of this article (10.1186/s12862-019-1482-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sylvain Dubey
- Hintermann & Weber SA, Avenue des Alpes 25, 1820, Montreux, Switzerland.,Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland.,Agrosustain SA, c/o Agroscope, Route de Duillier 60, 1260, Nyon, Switzerland
| | | | - Laura Bonny
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland
| | - Daniel L Jeffries
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland
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Morozov-Leonov SY. Hemiclone Diversity in the Hybrid Form Pelophylax esculentus-ridibundus (Amphibia, Ranidae) from the Prypyat, Dnestr, and Southern Boug River Basins. CYTOL GENET+ 2019. [DOI: 10.3103/s0095452719010092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Morozov-Leonov SY. Hemiclone diversity in the hybrid form Pelophylax esculentus-ridibundus (Amphibia, Ranidae) from the Tisa river drainage. CYTOL GENET+ 2017. [DOI: 10.3103/s0095452717060093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Biriuk OV, Shabanov DA, Korshunov AV, Borkin LJ, Lada GA, Pasynkova RA, Rosanov JM, Litvinchuk SN. Gamete production patterns and mating systems in water frogs of the hybridogenetic Pelophylax esculentus
complex in north-eastern Ukraine. J ZOOL SYST EVOL RES 2016. [DOI: 10.1111/jzs.12132] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Olha V. Biriuk
- V. N. Karazin Kharkiv National University; Kharkiv Ukraine
| | | | | | - Leo J. Borkin
- Zoological Institute; Russian Academy of Sciences; St. Petersburg Russia
| | | | - Rosa A. Pasynkova
- Institute of Cytology; Russian Academy of Sciences; St. Petersburg Russia
| | - Jury M. Rosanov
- Institute of Cytology; Russian Academy of Sciences; St. Petersburg Russia
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Holenweg Peter AK, Reyer HU, Abt Tietje G. Species and sex ratio differences in mixed populations of hybridogenetic water frogs: The influence of pond features. ECOSCIENCE 2016. [DOI: 10.1080/11956860.2002.11682684] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Radojičić JM, Krizmanić I, Kasapidis P, Zouros E. Extensive mitochondrial heteroplasmy in hybrid water frog (Pelophylax spp.) populations from Southeast Europe. Ecol Evol 2015; 5:4529-41. [PMID: 26668720 PMCID: PMC4670067 DOI: 10.1002/ece3.1692] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 08/05/2015] [Accepted: 08/12/2015] [Indexed: 11/30/2022] Open
Abstract
Water frogs of the genus Pelophylax (previous Rana) species have been much studied in Europe for their outstanding reproductive mechanism in which sympatric hybridization between genetically distinct parental species produces diverse genetic forms of viable hybrid animals. The most common hybrid is P. esculentus that carries the genomes of both parental species, P. ridibundus and P. lessonae, but usually transfers the whole genome of only one parent to its offsprings (hybridogenesis). The evolutionary cost of transfer of the intact genome and hence the hemiclonal reproduction is the depletion of heterozygosity in the hybrid populations. Pelophylax esculentus presents an excellent example of the long‐term sustained hybridization and hemiclonal reproduction in which the effects of the low genetic diversity are balanced through the novel mutations and periodic recombinations. In this study, we analyzed the mitochondrial (mt) and microsatellites DNA variations in hybrid Pelophylax populations from southern parts of the Pannonian Basin and a north–south transect of the Balkan Peninsula, which are home for a variety of Pelophylax genetic lineages. The mtDNA haplotypes found in this study corresponded to P. ridibundus and P. epeiroticus of the Balkan – Anatolian lineage (ridibundus–bedriagae) and to P. lessonae and a divergent lessonae haplotype of the lessonae lineage. The mtDNA genomes showed considerable intraspecific variation and geographic differentiation. The Balkan wide distributed P. ridibundus was found in all studied populations and its nuclear genome, along with either the lessonae or the endemic epeiroticus genome, in all hybrids. An unexpected finding was that the hybrid populations were invariably heteroplasmic, that is, they contained the mtDNA of both parental species. We discussed the possibility that such extensive heteroplasmy is a result of hybridization and it comes from regular leakage of the paternal mtDNA from a sperm of one species that fertilizes eggs of another. In this case, the mechanisms that protect the egg from heterospecific fertilization and further from the presence of sperm mtDNA could become compromised due to their differences and divergence at both, mitochondrial and nuclear DNA. The heteroplasmy once retained in the fertilized egg could be transmitted by hybrid backcrossing to the progeny and maintained in a population over generations. The role of interspecies and heteroplasmic hybrid animals due to their genomic diversity and better fitness compare to the parental species might be of the special importance in adaptations to miscellaneous and isolated environments at the Balkan Peninsula.
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Affiliation(s)
- Jelena M Radojičić
- Hellenic Centre for Marine Research Institute of Marine Biology, Biotechnology and Aquaculture Heraklion Greece ; Department of Biology University of Crete Heraklion Greece
| | - Imre Krizmanić
- Faculty of Biology Institute of Zoology University of Belgrade Belgrade Serbia
| | - Panagiotis Kasapidis
- Hellenic Centre for Marine Research Institute of Marine Biology, Biotechnology and Aquaculture Heraklion Greece
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Reyer HU, Arioli-Jakob C, Arioli M. Post-zygotic selection against parental genotypes during larval development maintains all-hybrid populations of the frog Pelophylax esculentus. BMC Evol Biol 2015; 15:131. [PMID: 26141702 PMCID: PMC4491251 DOI: 10.1186/s12862-015-0404-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/02/2015] [Indexed: 11/10/2022] Open
Abstract
Background Hybridization between two species usually leads to inviable or infertile offspring, due to endogenous or exogenous selection pressures. Yet, hybrid taxa are found in several plant and animal genera, and some of these hybrid taxa are ecologically and evolutionarily very successful. One example of such a successful hybrid is the water frog, Pelophylax esculentus which originated from matings between the two species P. ridibundus (genotype RR) and P. lessonae (LL). At the northern border of the distribution all-hybrid populations consisting of diploid (LR) and one or two triploid (LLR, LRR) frog types have been established. Here, the hybrid has achieved reproductive independence from its sexual ancestors and forms a self-sustaining evolutionary unit. Based on the gamete production of these hybrids, certain mating combinations should lead to LL and RR offspring, but these parental forms are absent among the adults. Results In order to investigate the mechanisms that maintain such an all-hybrid system, we performed a field study and a crossing experiment. In the field we sampled several ponds for water frog larvae at different developmental stages. Genotype compositions were then analysed and life-history differences between the genotypes examined. In the experiment we crossed diploid and triploid males and females from different ponds and determined fertilization success as well as development speed and survival rates of the offspring under high, medium and low food availability. In both parts of the study, we found numerous LL and RR offspring during the egg and early larval stages; but the frequency of these parental genotypes decreased drastically during later stages. In natural ponds almost all of them had disappeared already before metamorphosis; under the more benign experimental conditions the last ones died as juveniles during the following year. Conclusions From the combined results we conclude that the absence of parental genotypes in all-hybrid populations is due to post-zygotic selection against them, rather than to pre-zygotic mechanisms that might prevent their formation in the first place. For this post-zygotic selection, genetic mechanisms resulting from low genetic diversity and fixation of deleterious mutations seem to be a more likely explanation than ecological factors.
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Affiliation(s)
- Heinz-Ulrich Reyer
- Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, Zürich, CH-8057, Switzerland.
| | - Christian Arioli-Jakob
- Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, Zürich, CH-8057, Switzerland.
| | - Martina Arioli
- Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, Zürich, CH-8057, Switzerland.
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Abstract
This review summarizes the current status of the known extant genuine polyploid anuran and urodelan species, as well as spontaneously originated and/or experimentally produced amphibian polyploids. The mechanisms by which polyploids can originate, the meiotic pairing configurations, the diploidization processes operating in polyploid genomes, the phenomenon of hybridogenesis, and the relationship between polyploidization and sex chromosome evolution are discussed. The polyploid systems in some important amphibian taxa are described in more detail.
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Quilodrán CS, Montoya-Burgos JI, Currat M. Modelling interspecific hybridization with genome exclusion to identify conservation actions: the case of native and invasive Pelophylax waterfrogs. Evol Appl 2015; 8:199-210. [PMID: 25685194 PMCID: PMC4319866 DOI: 10.1111/eva.12245] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 12/09/2015] [Indexed: 11/27/2022] Open
Abstract
Interspecific hybridization occurs in nature but can also be caused by human actions. It often leads to infertile or fertile hybrids that exclude one parental genome during gametogenesis, escaping genetic recombination and introgression. The threat that genome-exclusion hybridization might represent on parental species is poorly understood, especially when invasive species are involved. Here, we show how to assess the effects of genome-exclusion hybridization and how to elaborate conservation actions by simulating scenarios using a model of nonintrogressive hybridization. We examine the case of the frog Pelophylax ridibundus, introduced in Western Europe, which can hybridize with the native Pelophylax lessonae and the pre-existing hybrid Pelophylax esculentus, maintained by hybridogenesis. If translocated from Southern Europe, P. ridibundus produces new sterile hybrids and we show that it mainly threatens P. esculentus. Translocation from Central Europe leads to new fertile hybrids, threatening all native waterfrogs. Local extinction is demographically mediated via wasted reproductive potential or via demographic flow through generations towards P. ridibundus. We reveal that enlarging the habitat size of the native P. lessonae relative to that of the invader is a promising conservation strategy, avoiding the difficulties of fighting the invader. We finally stress that nonintrogressive hybridization is to be considered in conservation programmes.
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Affiliation(s)
- Claudio S Quilodrán
- Laboratory of vertebrate evolution, Department of Genetics and Evolution, University of Geneva Geneva, Switzerland ; Laboratory of anthropology, genetics and peopling history, Anthropology Unit, Department of Genetics and Evolution, University of Geneva Geneva, Switzerland
| | - Juan I Montoya-Burgos
- Laboratory of vertebrate evolution, Department of Genetics and Evolution, University of Geneva Geneva, Switzerland
| | - Mathias Currat
- Laboratory of anthropology, genetics and peopling history, Anthropology Unit, Department of Genetics and Evolution, University of Geneva Geneva, Switzerland
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Pruvost NBM, Mikulíček P, Choleva L, Reyer HU. Contrasting reproductive strategies of triploid hybrid males in vertebrate mating systems. J Evol Biol 2015; 28:189-204. [PMID: 25411907 DOI: 10.1111/jeb.12556] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 11/17/2014] [Indexed: 11/26/2022]
Abstract
The scarcity of parthenogenetic vertebrates is often attributed to their 'inferior' mode of clonal reproduction, which restricts them to self-reproduce their own genotype lineage and leaves little evolutionary potential with regard to speciation and evolution of sexual reproduction. Here, we show that for some taxa, such uniformity does not hold. Using hybridogenetic water frogs (Pelophylax esculentus) as a model system, we demonstrate that triploid hybrid males from two geographic regions exhibit very different reproductive modes. With an integrative data set combining field studies, crossing experiments, flow cytometry and microsatellite analyses, we found that triploid hybrids from Central Europe are rare, occur in male sex only and form diploid gametes of a single clonal lineage. In contrast, triploid hybrids from north-western Europe are widespread, occur in both sexes and produce recombined haploid gametes. These differences translate into contrasting reproductive roles between regions. In Central Europe, triploid hybrid males sexually parasitize diploid hybrids and just perpetuate their own genotype--which is the usual pattern in parthenogens. In north-western Europe, on the other hand, the triploid males are gamete donors for diploid hybrids, thereby stabilizing the mixed 2n-3n hybrid populations. By demonstrating these contrasting roles in male reproduction, we draw attention to a new significant evolutionary potential for animals with nonsexual reproduction, namely reproductive plasticity.
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Affiliation(s)
- N B M Pruvost
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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18
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Mikulíček P, Kautman M, Kautman J, Pruvost NBM. Mode of hybridogenesis and habitat preferences influence population composition of water frogs (Pelophylax esculentus
complex, Anura: Ranidae) in a region of sympatric occurrence (western Slovakia). J ZOOL SYST EVOL RES 2014. [DOI: 10.1111/jzs.12083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Peter Mikulíček
- Department of Zoology; Faculty of Natural Sciences; Comenius University; Bratislava Slovak Republic
| | - Matej Kautman
- Department of Biology and Wildlife Diseases; Faculty of Veterinary Hygiene and Ecology; University of Veterinary and Pharmaceutical Sciences; Brno Czech Republic
| | - Ján Kautman
- Slovak National Museum; Museum of Natural History; Bratislava Slovak Republic
| | - Nicolas B. M. Pruvost
- Institute of Evolutionary Biology and Environmental Studies; University of Zurich; Zurich Switzerland
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Bove P, Milazzo P, Barbuti R. The role of deleterious mutations in the stability of hybridogenetic water frog complexes. BMC Evol Biol 2014; 14:107. [PMID: 24885008 PMCID: PMC4037432 DOI: 10.1186/1471-2148-14-107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/09/2014] [Indexed: 11/11/2022] Open
Abstract
Background Some species of water frogs originated from hybridization between different species. Such hybrid populations have a particular reproduction system called hybridogenesis. In this paper we consider the two species Pelophylax ridibundus and Pelophylax lessonae, and their hybrids Pelophylax esculentus. P. lessonae and P. esculentus form stable complexes (L-E complexes) in which P. esculentus are hemiclonal. In L-E complexes all the transmitted genomes by P. esculentus carry deleterious mutations which are lethal in homozygosity. Results We analyze, by means of an individual based computational model, L-E complexes. The results of simulations based on the model show that, by eliminating deleterious mutations, L-E complexes collapse. In addition, simulations show that particular female preferences can contribute to the diffusion of deleterious mutations among all P. esculentus frogs. Finally, simulations show how L-E complexes react to the introduction of translocated P. ridibundus. Conclusions The conclusions are the following: (i) deleterious mutations (combined with sexual preferences) strongly contribute to the stability of L-E complexes; (ii) female sexual choice can contribute to the diffusion of deleterious mutations; and (iii) the introduction of P. ridibundus can destabilize L-E complexes.
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Affiliation(s)
| | | | - Roberto Barbuti
- Dipartimento di Informatica, Università di Pisa, Largo B, Pontecorvo, 3, 56127 Pisa, Italy.
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21
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Leuenberger J, Gander A, Schmidt BR, Perrin N. Are invasive marsh frogs (Pelophylax ridibundus) replacing the native P. lessonae/P. esculentus hybridogenetic complex in Western Europe? Genetic evidence from a field study. CONSERV GENET 2014. [DOI: 10.1007/s10592-014-0585-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Mikulíček P, Kautman M, Demovič B, Janko K. When a clonal genome finds its way back to a sexual species: evidence from ongoing but rare introgression in the hybridogenetic water frog complex. J Evol Biol 2014; 27:628-42. [PMID: 26227900 DOI: 10.1111/jeb.12332] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 12/02/2013] [Accepted: 01/06/2014] [Indexed: 11/28/2022]
Abstract
Besides several exceptions, asexual metazoans are usually viewed as ephemeral sinks for genomes, which become 'frozen' in clonal lineages after their emergence from ancestral sexual species. Here, we investigated whether and at what rate the asexuals are able to introgress their genomes back into the parental sexual population, thus more or less importantly affecting the gene pools of sexual species. We focused on hybridogenetic hybrids of western Palaearctic water frogs (Pelophylax esculentus), which originate through hybridization between P. ridibundus and P. lessonae, but transmit only clonal ridibundus genome into their gametes. Although usually mating with P. lessonae, P. esculentus may upon mating with P. ridibundus or another hybrid produce sexually reproducing P. ridibundus offspring with the introgressed ex-clonal genome. We compared the rate of nuclear amplified fragment length polymorphism (AFLP) and mitochondrial introgression in two types of populations, that is, those where P. ridibundus occurs in isolation and those where it lives with the hybridogens. Although significant differentiation (Φpt) between sexual and clonal ridibundus genomes suggested limited gene flow between sexuals and hybridogens, a non-negligible (~5%) proportion of P. ridibundus bore introgressed mtDNA and AFLP markers. Whereas transfer of mtDNA was exclusively unidirectional, introgression of nuclear markers was bidirectional. The proportion of introgressed P. ridibundus was highest in syntopic populations with P. esculentus, proving an ongoing and site-specific interspecific genetic transfer mediated by hybridogenetic hybrids. It turns out that asexual hybrids are not just a sink for genes of sexual species, but may significantly influence the genetic architecture of their sexual counterparts.
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Affiliation(s)
- P Mikulíček
- Department of Zoology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic
| | - M Kautman
- Department of Zoology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.,Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
| | - B Demovič
- Department of Zoology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.,State Nature Conservancy of the Slovak Republic, Administration of the Protected Landscape Area White Carpathians, Nemšová, Slovak Republic
| | - K Janko
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Liběchov, Czech Republic.,Life Science Research Centre, Department of Biology and Ecology, Faculty of Natural Sciences, University of Ostrava, Ostrava, Czech Republic
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Hoffmann A, Reyer HU. Genomic effects on advertisement call structure in diploid and triploid hybrid waterfrogs (Anura, Pelophylax esculentus). BMC Ecol 2013; 13:47. [PMID: 24304922 PMCID: PMC4235041 DOI: 10.1186/1472-6785-13-47] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 11/23/2013] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND In anurans, differences in male mating calls have intensively been studied with respect to taxonomic classification, phylogeographic comparisons among different populations and sexual selection. Although overall successful, there is often much unexplained variation in these studies. Potential causes for such variation include differences among genotypes and breeding systems, as well as differences between populations. We investigated how these three factors affect call properties in male water frogs of Pelophylax lessonae (genotype LL), P. ridibundus (RR) and their interspecific hybrid P. esculentus which comes in diploid (LR) and triploid types (LLR, LRR). RESULTS We investigated five call parameters that all showed a genomic dosage effect, i.e. they either decreased or increased with the L/R ratio in the order LL-LLR-LR-LRR-RR. Not all parameters differentiated equally well between the five genotypes, but combined they provided a good separation. Two of the five call parameters were also affected by the breeding system. Calls of diploid LR males varied, depending on whether these males mated with one or both of the parental species (diploid systems) or triploid hybrids (mixed ploidy systems). With the exception of the northernmost mixed-ploidy population, call differences were not related to the geographic location of the population and they were not correlated with genetic distances in the R and L genomes. CONCLUSIONS We found an influence of all three tested factors on call parameters, with the effect size decreasing from genotype through breeding system to geographic location of the population. Overall, results were in line with predictions from a dosage effect in L/R ratios, but in three call parameters all three hybrid types were more similar to one or the other parental species. Also calls of diploid hybrids varied between breeding systems in agreement with the sexual host required for successful reproduction. The lack of hybrid call differences in a mixed-ploidy population at the northern edge of the water frog distribution is likely to be associated with genetic particularities, including a) low genetic variability and/or b) a local loss of genes coding for genotype-dependent call differentiation under conditions where female discrimination between diploid and triploid males is not beneficial.
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Affiliation(s)
- Alexandra Hoffmann
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Heinz-Ulrich Reyer
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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Pruvost NBM, Hollinger D, Reyer H. Genotype‐temperature interactions on larval performance shape population structure in hybridogenetic water frogs (Pelophylax esculentuscomplex). Funct Ecol 2013. [DOI: 10.1111/1365-2435.12049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nicolas B. M. Pruvost
- Institute of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Daniel Hollinger
- Institute of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Heinz‐Ulrich Reyer
- Institute of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
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25
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Daum JM, Davis LR, Bigler L, Woodhams DC. Hybrid advantage in skin peptide immune defenses of water frogs (Pelophylax esculentus) at risk from emerging pathogens. INFECTION GENETICS AND EVOLUTION 2012; 12:1854-64. [DOI: 10.1016/j.meegid.2012.07.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 07/30/2012] [Accepted: 07/31/2012] [Indexed: 02/08/2023]
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26
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Mee J, Taylor E. The cybrid invasion: widespread postglacial dispersal by Phoxinus (Pisces: Cyprinidae) cytoplasmic hybrids. CAN J ZOOL 2012. [DOI: 10.1139/z2012-023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peculiar reproductive processes that arise during sperm-dependent asexual reproduction may have important roles in allowing coexistence of sperm-dependent asexuals and their sexually reproducing hosts. Though typically clonal, nonclonal reproduction in the hybrid gynogenetic species Phoxinus eos–neogaeus can reestablish sexual northern redbelly dace ( Phoxinus eos (Cope, 1861)) nuclear genomes. These hybrid-derived P. eos biotypes, known as cybrids, have finescale dace ( Phoxinus neogaeus Cope, 1867) mitochondria but are otherwise indistinguishable from “pure” P. eos. Our goal was to determine the extent of the cybrids’ distribution, and hence to evaluate their role in mechanisms of asexual–sexual coexistence. We also set out to determine the geographic origins of P. eos–neogaeus and cybrids. Our sampling revealed that all Phoxinus species and biotypes are widely distributed in North America, but that cybrids have replaced pure P. eos, or preempted postglacial colonization by pure P. eos, in the northern portion of their distribution. Also, all P. eos–neogaeus and cybrids had mitochondrial DNA (mtDNA) sequences closely related to a lineage originating from a Mississippi glacial refugium. No P. eos–neogaeus or cybrids were derived from a divergent P. neogaeus lineage discovered in Atlantic Canada. It is therefore unlikely that P. eos–neogaeus or cybrids originated in any Atlantic glacial refugia. If P. neogaeus mitochondria are better adapted to northern environments, widespread mtDNA introgression may facilitate coexistence in northern areas by reducing the disparity in fitness between P. eos–neogaeus and its sexual hosts.
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Affiliation(s)
- J.A. Mee
- Department of Zoology and Beaty Biodiversity Research Centre and Museum, The University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
| | - E.B. Taylor
- Department of Zoology and Beaty Biodiversity Research Centre and Museum, The University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
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27
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Mee JA, Brauner CJ, Taylor EB. Repeat swimming performance and its implications for inferring the relative fitness of asexual hybrid dace (Pisces: Phoxinus) and their sexually reproducing parental species. Physiol Biochem Zool 2011; 84:306-15. [PMID: 21527822 DOI: 10.1086/659245] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
While theories explaining the evolution and maintenance of sex are abundant, empirical data on the costs and benefits of asexual relative to sexual reproduction are less common. Asexually reproducing vertebrates, while few, provide a rare opportunity to measure differences in fitness between asexual and sexual species. All known asexually reproducing vertebrates are of hybrid origin, and hybrid disadvantage (i.e., reduced hybrid fitness) is thought to facilitate long-term coexistence between asexual and sexual species. We used repeat swimming performance as a proxy for fitness to compare the fitness of asexual hybrid dace (Pisces: Phoxinus) and their sexually reproducing parental species, finescale dace (Phoxinus neogaeus) and northern redbelly dace (Phoxinus eos). We tested the prediction that, given the widespread coexistence of these hybrid and parental dace, the parental species should show equivalent and perhaps superior repeat performance relative to hybrids. A repeat constant acceleration test (U(max)) was conducted at both acclimation temperature (16 °C) and at an elevated temperature (25 °C) to simulate the combined influence of a repeat swim and acute temperature change that fish might experience in the wild. The asexual hybrids performed more poorly than at least one of the parental species. There was a negative effect of temperature on repeat swimming performance in all fish, and the repeat performance of hybrids was more severely affected by temperature than that of finescale dace. No difference in the effect of temperature on repeat performance was detected between hybrids and northern redbelly dace. These results suggest that hybrids suffer physiological costs relative to the parentals or at least that the hybrids do not gain advantage from hybrid vigor, which probably contributes to the coexistence of asexual and sexual species in this system.
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Affiliation(s)
- Jonathan A Mee
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia V6T1Z4, Canada.
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Schmidt DJ, Bond NR, Adams M, Hughes JM. Cytonuclear evidence for hybridogenetic reproduction in natural populations of the Australian carp gudgeon (Hypseleotris: Eleotridae). Mol Ecol 2011; 20:3367-80. [PMID: 21777320 DOI: 10.1111/j.1365-294x.2011.05206.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although most vertebrates reproduce sexually, a small number of fishes, amphibians and reptiles are known in which reproduction is asexual, i.e. without meiotic recombination. In fishes, these so-called unisexual lineages usually comprise only females and utilize co-occurring males of a related sexual species to reproduce via gynogenesis or hybridogenesis. Here, we examine patterns of microsatellite and mitochondrial DNA (mtDNA) variation in a widespread group of freshwater fishes (carp gudgeons; Hypseleotris spp.) to investigate a long-standing proposal that this group includes unisexual forms. We show that the mtDNA genome of most carp gudgeons in tributaries of the Goulburn River belongs to one of two deeply divided clades (∼10% cyt b divergence) and that nuclear variation divides the same individuals into four distinct groups. Group 1 exhibits the genotypic proportions of a random mating population and has a 1:1 sex ratio. Two other groups are extremely sex-biased (98% male, 96% female), exhibit excess heterozygosity at most loci and share at least one allele per locus with group 1. We propose that these two groups represent 'unisexual' hybridogenetic lineages and that both utilize co-occurring group 1 as sexual host. Interestingly, the fourth distinct group appears to represent hybrid offspring of the two putative hybridogenetic lineages. The propagation of clonal haploid genomes by both males and females and the ability of these clones to unite and form sexually mature diploid hybrid offspring may represent a novel mechanism that contributes to the dynamics of coexistence between hybridogenetic lineages and their sexual hosts.
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Affiliation(s)
- Daniel J Schmidt
- Australian Rivers Institute and eWater CRC, Griffith University, Nathan, Qld 4111, Australia.
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29
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Abbott JK, Morrow EH. Obtaining snapshots of genetic variation using hemiclonal analysis. Trends Ecol Evol 2011; 26:359-68. [DOI: 10.1016/j.tree.2011.03.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 03/10/2011] [Accepted: 03/13/2011] [Indexed: 11/30/2022]
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30
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Luquet E, Vorburger C, Hervant F, Joly P, Kaufmann B, Schmeller DS, Léna JP, Grolet O, Konecny L, Plénet S. Invasiveness of an introduced species: the role of hybridization and ecological constraints. Biol Invasions 2011. [DOI: 10.1007/s10530-011-0010-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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31
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Mezhzherin SV, Morozov-Leonov SY, Rostovskaya OV, Shabanov DA, Sobolenko LY. The ploidy and genetic structure of hybrid populations of water frogs Pelophylax esculentus complex (Amphibia, Ranidae) of Ukraine fauna. CYTOL GENET+ 2010. [DOI: 10.3103/s0095452710040043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Christiansen DG, Reyer HU. Effects of geographic distance, sea barriers and habitat on the genetic structure and diversity of all-hybrid water frog populations. Heredity (Edinb) 2010; 106:25-36. [PMID: 20372185 DOI: 10.1038/hdy.2010.37] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The history of population size and migration patterns leaves its mark in the genetics of populations. We investigate the genetic structure of the edible frog, Pelophylax esculentus in the Danish archipelago and adjacent countries. This frog is of particular interest because it is a hybrid that, in this area, forms all-hybrid populations of diploid (LR) and triploid (LLR and LRR) genomotypes with no (or very few) adults of the parental species (LL and RR). This study is the first to cover the entire geographic range of Danish, Swedish and German all-hybrid populations, documenting their extent and providing a broad picture of their diversity of neutral genetic markers and genomotype proportions. With 18 microsatellite markers, we found that genetic diversity declines northwards in agreement with the glacial refuge and central-marginal hypotheses; however, populations on small and medium-sized islands are no less diverse than those on large islands and continental peninsulas. Isolation by distance exists across the archipelago with limited influence of fragmentation by brackish seawater. The extremely low genetic diversity in all-hybrid populations, compared with adjacent populations, may be responsible for the maintenance of their special breeding system. We also show large variation among ponds in proportions of LLR, LR and LRR genomotypes, but little geographic pattern in their distribution. Instead, we found relationships between the genomotype proportions and some of 15 habitat parameters monitored. Body size differences among LLR, LR and LRR further suggest ecological differences.
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Affiliation(s)
- D G Christiansen
- Ecology, Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
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33
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Arioli M, Jakob C, Reyer HU. Genetic diversity in water frog hybrids (Pelophylax esculentus) varies with population structure and geographic location. Mol Ecol 2010; 19:1814-28. [PMID: 20374490 DOI: 10.1111/j.1365-294x.2010.04603.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pelophylax esculentus is a hybridogenetic frog originating from matings between P. ridibundus (RR) and P. lessonae (LL). Typically, diploid hybrids (LR) live in sympatry with one of their parental species, upon which they depend for successful reproduction. In parts of their range, however, pure hybrid populations can be found. These hybrid populations have achieved reproductive independence from their parental species by using triploid hybrids (LLR, LRR) rather than LL and RR as their sexual hosts. These different breeding systems also entail differences in reproduction (clonal versus sexual) and hence offer the opportunity to study how genetic diversity is affected by reproductive mode, population structure and geographic location. We investigated 33 populations in the Scania region (South Sweden) and 18 additional populations from Northern and Central Europe. Within both genomes (L, R), genetic variability increases with the potential for recombination and declines from the main species distribution area southeast of the Baltic Sea to the fringe populations northwest of the Baltic Sea. Within the main study area in Scania, genetic diversity is low and decreases from a core area to the periphery. Genetic differentiation between Scania populations is small but significant and best explained by 'isolation by distance'. Despite the low genetic variability within the discrete genomes, all-hybrid P. esculentus populations in southern Sweden are apparently not suffering from direct negative fitness effects. This is probably because of its somatic hybrid status, which increases diversity through the combination of genomes from two species.
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Affiliation(s)
- Martina Arioli
- Institute for Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
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34
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Paternity control for externally fertilised eggs: behavioural mechanisms in the waterfrog species complex. Behav Ecol Sociobiol 2010. [DOI: 10.1007/s00265-010-0934-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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35
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Christiansen DG, Reyer HU. FROM CLONAL TO SEXUAL HYBRIDS: GENETIC RECOMBINATION VIA TRIPLOIDS IN ALL-HYBRID POPULATIONS OF WATER FROGS. Evolution 2009; 63:1754-68. [DOI: 10.1111/j.1558-5646.2009.00673.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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36
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Christiansen DG. Gamete types, sex determination and stable equilibria of all-hybrid populations of diploid and triploid edible frogs (Pelophylax esculentus). BMC Evol Biol 2009; 9:135. [PMID: 19527499 PMCID: PMC2709657 DOI: 10.1186/1471-2148-9-135] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 06/15/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Triploid individuals often play a key role in speciation by hybridization. An understanding of the gamete types (ploidy and genomic content) and stability of hybrid populations with triploid individuals is therefore of importance for exploring the role of hybridization in evolution. The all-hybrid populations of the edible frog, Pelophylax esculentus, are unique in their composition and genetic dynamics: Diploid (genotype LR) and triploid (LLR and LRR) hybrids depend on each other's different gamete contributions for successful reproduction and maintenance of the populations, as the parental genotypes P. lessonae (LL) and P. ridibundus (RR) are absent among adults. This study provides data and interpretations on gamete types and sex determination that are essential for understanding the function, evolutionary potential and threats of this intriguing system. RESULTS Dissection of metamorphs from a crossing experiment confirmed that sex determination is an XX-XY system with the Y confined to the L genome. From microsatellite analysis of parents and offspring from the crossings, gamete frequencies could be deduced: Triploids of both sexes mostly made haploid gametes with the genome they had in double dose, however LLR females also made approximately 10% LL gametes by automixis. LR frogs showed much variation in their gamete production. In LRR-rich populations, their LR sperm production was sufficiently high (22%) to explain the observed proportion of LRR males, the formation of which has not previously been understood. A model was constructed to calculate equilibrium genotype proportions for different population types on the basis of the gamete proportions found. These equilibria agreed well with empirical literature data. CONCLUSION If population differentiation with respect to genotype proportions is really driven by gamete patterns, as strongly suggested by the present study, all-hybrid populations constitute not one, but several intrinsically different breeding systems. Tetraploidization could occur if the survival or fertility of both males and females increased. Whether introduction of hybrid or parental species individuals would threaten the all-hybrid populations cannot be predicted without further knowledge on the mechanisms behind non-hybrid inviability, but at least R genomes with Y factor are predicted to be invasive, if introduced, and could bring the populations to collapse.
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Affiliation(s)
- Ditte G Christiansen
- Ecology, Zoological Institute, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
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37
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Holsbeek G, Jooris R. Potential impact of genome exclusion by alien species in the hybridogenetic water frogs (Pelophylax esculentus complex). Biol Invasions 2009. [DOI: 10.1007/s10530-009-9427-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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38
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Abstract
The Red Queen hypothesis (RQH) is one of the most widely accepted hypotheses explaining the persistence of sexual reproduction despite its costs. It posits that sexual species, compared with asexuals, are more adept at countering parasites, because their per-generation recombination rate is higher. Despite theoretical support, current empirical studies have failed to provide unanimous support. Here, we suggest that future tests of the RQH should more thoroughly elucidate its underlying assumptions and potential alternative hypotheses. While the RQH predicts that negative frequency-dependent selection shapes host–parasite interactions, differences between sexuals and asexuals are potentially important. Key assumptions about asexual species and their sexual close relatives include (i) ecological and behavioral traits are similar, (ii) among-individual genetic diversity is greater in sexuals than in asexuals, and (iii) within-individual genetic diversity is similar in asexuals and sexuals. We review current evidence for the RQH, highlight differences between asexual and sexual species and how those differences might translate into differential responses to parasite infections, and discuss how they can influence the results and interpretation of empirical studies. Considering differences between asexual and sexual species in future tests of the RQH will help to refine predictions and eliminate alternative hypotheses.
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Affiliation(s)
- M. Tobler
- Universität Zürich, Zoologisches Institut, Winterthurerstr. 190, CH-8057 Zürich, Switzerland
- Department of Zoology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA
| | - I. Schlupp
- Universität Zürich, Zoologisches Institut, Winterthurerstr. 190, CH-8057 Zürich, Switzerland
- Department of Zoology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA
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Loewe L, Lamatsch DK. Quantifying the threat of extinction from Muller's ratchet in the diploid Amazon molly (Poecilia formosa). BMC Evol Biol 2008; 8:88. [PMID: 18366680 PMCID: PMC2292145 DOI: 10.1186/1471-2148-8-88] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 03/19/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Amazon molly (Poecilia formosa) is a small unisexual fish that has been suspected of being threatened by extinction from the stochastic accumulation of slightly deleterious mutations that is caused by Muller's ratchet in non-recombining populations. However, no detailed quantification of the extent of this threat is available. RESULTS Here we quantify genomic decay in this fish by using a simple model of Muller's ratchet with the most realistic parameter combinations available employing the evolution@home global computing system. We also describe simple extensions of the standard model of Muller's ratchet that allow us to deal with selfing diploids, triploids and mitotic recombination. We show that Muller's ratchet creates a threat of extinction for the Amazon molly for many biologically realistic parameter combinations. In most cases, extinction is expected to occur within a time frame that is less than previous estimates of the age of the species, leading to a genomic decay paradox. CONCLUSION How then does the Amazon molly survive? Several biological processes could individually or in combination solve this genomic decay paradox, including paternal leakage of undamaged DNA from sexual sister species, compensatory mutations and many others. More research is needed to quantify the contribution of these potential solutions towards the survival of the Amazon molly and other (ancient) asexual species.
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Affiliation(s)
- Laurence Loewe
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, King's Buildings, Edinburgh EH9 3JT, UK
- Centre for Systems Biology Edinburgh, School of Biological Sciences, University of Edinburgh, Darwin Building, King's Buildings, Edinburgh EH9 3JU, UK
| | - Dunja K Lamatsch
- Universität Würzburg, Institute of Physiological Chemistry I, Biocenter, Würzburg, 97074 Würzburg, Germany
- Freshwater Biology, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B – 1000 Brussels, Belgium
- University of Sheffield, Department of Animal and Plant Sciences, Alfred Denny Building, Western Bank, Sheffield, S10 2TN, UK
- Austrian Academy of Sciences, Institute for Limnology, Mondseestrasse 9, 5310 Mondsee, Austria
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Hotz H, Guex GD, Beerli P, Semlitsch RD, Pruvost NBM. Hemiclone diversity in the hybridogenetic frog Rana esculenta outside the area of clone formation: the view from protein electrophoresis. J ZOOL SYST EVOL RES 2007. [DOI: 10.1111/j.1439-0469.2007.00430.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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Mutation accumulation and fitness effects in hybridogenetic populations: a comparison to sexual and asexual systems. BMC Evol Biol 2007; 7:80. [PMID: 17517124 PMCID: PMC1891288 DOI: 10.1186/1471-2148-7-80] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Accepted: 05/21/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Female only unisexual vertebrates that reproduce by hybridogenesis show an unusual genetic composition. They are of hybrid origin but show no recombination between the genomes of their parental species. Instead, the paternal genome is discarded from the germline prior to meiosis, and gametes (eggs only) contain solely unrecombined maternal genomes. Hence hybridogens only transmit maternally inherited mutations. Hybridity is restored each generation by backcrossing with males of the sexual parental species whose genome was eliminated. In contrast, recombining sexual species propagate an intermixed pool of mutations derived from the maternal and paternal parts of the genome. If mutation rates are lower in female gametes than males, it raises the possibility for lower mutation accumulation in a hybridogenetic population, and consequently, higher population fitness than its sexual counterpart. RESULTS We show through Monte-Carlo simulations that at higher male to female mutation ratios, and sufficiently large population sizes, hybridogenetic populations can carry a lower mutation load than sexual species. This effect is more pronounced with synergistic forms of epistasis. Mutations accumulate faster on the sexual part of the genome, and with the purifying effects of epistasis, it makes it more difficult for mutations to be transmitted on the clonal part of the genome. In smaller populations, the same mechanism reduces the speed of Muller's Ratchet and the number of fixed mutations compared to similar asexual species. CONCLUSION Since mutation accumulation can be less pronounced in hybridogenetic populations, the question arises why hybridogenetic organisms are so scarce compared to sexual species. In considering this, it is likely that comparison of population fitnesses is not sufficient. Despite competition with the sexual parental species, hybrid populations are dependent on the maintenance of--and contact with--their sexual counterpart. Other problems may involve too little genetic diversity to respond to changing environments and problems in becoming hybridogenetic (e.g. disruption of meiosis and subsequent infertility or sterility). Yet, lower mutation accumulation in hybridogenetic populations opens the possibility that hybridogenetic species can develop into new sexual species once recombination is re-established and reproductive isolation from sexual ancestors has occurred.
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Waelti MO, Reyer HU. Food supply modifies the trade-off between past and future reproduction in a sexual parasite-host system (Rana esculenta, Rana lessonae). Oecologia 2007; 152:415-24. [PMID: 17333285 DOI: 10.1007/s00442-007-0671-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Accepted: 01/24/2007] [Indexed: 10/23/2022]
Abstract
Life history theory is concerned with the costs of survival, growth and reproduction under different ecological conditions and the allocation of resources to meet these costs. Typical approaches used to address these topics include manipulation of food resources, followed by measures of subsequent reproductive traits, and measures of the relationship between current and future reproductive investment. Rarely, however, do studies test for the interaction of past investment, present resource availability and future investment simultaneously. Here, we investigate this interaction in females of a sexual parasite-host system consisting of the hybridogenetic frog Rana esculenta (E) and one of its parental species Rana lessonae (L). We kept females from each of two groups (with or without previous reproduction) under two food treatments (low or high) and regularly recorded their growth as well as their body condition and hormone titres as measures of future reproductive condition. After keeping them in hibernation until the following spring, we exposed the females to males, recorded whether they spawned or not and related this response to their condition in the previous autumn. Past reproduction negatively affected growth during summer and condition during autumn which, in turn, reduced the following year's reproductive output. These costs of previous reproduction were less pronounced under the high than under the low food treatment and lower in R. lessonae than in R. esculenta. Increasing food supply improved reproductive condition more in L than in E females. These species differences in reproductive costs and food requirements provide a mechanistic explanation for why E females skip annual reproduction almost twice as often as L females. Since R. esculenta is a sexual parasite that depends on R. lessonae for successful reproduction, these species-specific life history patterns not only affect individual fitness but also the spatial structure and temporal dynamics of mixed LE populations.
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Affiliation(s)
- Marc Olivier Waelti
- Zoological Institute, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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Som C, Reyer HU. Hemiclonal reproduction slows down the speed of Muller's ratchet in the hybridogenetic frog Rana esculenta. J Evol Biol 2007; 20:650-60. [PMID: 17305831 DOI: 10.1111/j.1420-9101.2006.01243.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Rare recombination in otherwise asexually reproducing organisms is known to beneficially influence the fitness in small populations. In most of the investigated organisms, asexual and rare sexual generations with recombination follow each other sequentially. Here we present a case where clonal reproduction and rare recombination occur simultaneously in the same population. The hybridogenetic water frog Rana esculenta (E), a hybrid between R. lessonae (L) and R. ridibunda (R) produces gametes that only contain the unaltered maternal R part of their genome. New generations of R. esculenta usually arise from E x L matings. Intraspecific E x E matings produce mostly inviable offspring, but in rare cases, female R. ridibunda arise from such matings which are capable of recombination. In the absence of conspecific males, these R females have to mate with E males, which results in further R females, or with L males, which produces new E lineages. This indirect mechanism reintroduces recombination into the otherwise clonally transmitted R genomes in R. esculenta populations. In this study, we show through Monte Carlo simulations that, in most cases, it is sufficient that only between 1 % and 10 % of mixed water frog populations consist of R females to prevent or significantly reduce the fixation and accumulation of deleterious mutations.
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Affiliation(s)
- C Som
- Institute of Zoology, University of Zurich, Zurich, Switzerland
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Som C, Reyer HU. Variation in Sex Ratio and Evolutionary Rate of Hemiclonal Rana esculenta Populations. Evol Ecol 2006. [DOI: 10.1007/s10682-005-5631-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Shpak M. THE ROLE OF DELETERIOUS MUTATIONS IN ALLOPATRIC SPECIATION. Evolution 2005. [DOI: 10.1554/05-051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Christiansen DG, Fog K, Pedersen BV, Boomsma JJ. REPRODUCTION AND HYBRID LOAD IN ALL-HYBRID POPULATIONS OF RANA ESCULENTA WATER FROGS IN DENMARK. Evolution 2005. [DOI: 10.1554/04-211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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REYER H, WÄLTI M, BÄTTIG I, ALTWEGG R, HELLRIEGEL B. Low proportions of reproducing hemiclonal females increase the stability of a sexual parasite–host system (
Rana esculenta
,
R. lessonae
). J Anim Ecol 2004. [DOI: 10.1111/j.0021-8790.2004.00881.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- H.‐U. REYER
- Zoological Institute, University of Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, Switzerland
| | - M.‐O. WÄLTI
- Zoological Institute, University of Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, Switzerland
| | - I. BÄTTIG
- Zoological Institute, University of Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, Switzerland
| | - R. ALTWEGG
- Zoological Institute, University of Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, Switzerland
| | - B. HELLRIEGEL
- Zoological Institute, University of Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, Switzerland
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Guex GD, Hotz H, Semlitsch RD. DELETERIOUS ALLELES AND DIFFERENTIAL VIABILITY IN PROGENY OF NATURAL HEMICLONAL FROGS. Evolution 2002. [DOI: 10.1554/0014-3820(2002)056[1036:daadvi]2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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