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Kočí J, Röslein J, Pačes J, Kotusz J, Halačka K, Koščo J, Fedorčák J, Iakovenko N, Janko K. No evidence for accumulation of deleterious mutations and fitness degradation in clonal fish hybrids: Abandoning sex without regrets. Mol Ecol 2020; 29:3038-3055. [PMID: 32627290 PMCID: PMC7540418 DOI: 10.1111/mec.15539] [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: 04/04/2019] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 02/07/2023]
Abstract
Despite its inherent costs, sexual reproduction is ubiquitous in nature, and the mechanisms to protect it from a competitive displacement by asexuality remain unclear. Popular mutation-based explanations, like the Muller's ratchet and the Kondrashov's hatchet, assume that purifying selection may not halt the accumulation of deleterious mutations in the nonrecombining genomes, ultimately leading to their degeneration. However, empirical evidence is scarce and it remains particularly unclear whether mutational degradation proceeds fast enough to ensure the decay of clonal organisms and to prevent them from outcompeting their sexual counterparts. To test this hypothesis, we jointly analysed the exome sequences and the fitness-related phenotypic traits of the sexually reproducing fish species and their clonal hybrids, whose evolutionary ages ranged from F1 generations to 300 ky. As expected, mutations tended to accumulate in the clonal genomes in a time-dependent manner. However, contrary to the predictions, we found no trend towards increased nonsynonymity of mutations acquired by clones, nor higher radicality of their amino acid substitutions. Moreover, there was no evidence for fitness degeneration in the old clones compared with that in the younger ones. In summary, although an efficacy of purifying selection may still be reduced in the asexual genomes, our data indicate that its efficiency is not drastically decreased. Even the oldest investigated clone was found to be too young to suffer fitness consequences from a mutation accumulation. This suggests that mechanisms other than mutation accumulation may be needed to explain the competitive advantage of sex in the short term.
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Affiliation(s)
- Jan Kočí
- Department of Biology and Ecology, University of Ostrava, Ostrava, Czechia.,Institute of Animal Physiology and Genetics, Czech Academy of Science, Liběchov, Czechia
| | - Jan Röslein
- Department of Biology and Ecology, University of Ostrava, Ostrava, Czechia.,Institute of Animal Physiology and Genetics, Czech Academy of Science, Liběchov, Czechia
| | - Jan Pačes
- Institute of Animal Physiology and Genetics, Czech Academy of Science, Liběchov, Czechia.,Institute of Molecular Genetics, Czech Academy of Science, Prague, Czechia
| | - Jan Kotusz
- Museum of Natural History, University of Wrocław, Wrocław, Poland
| | - Karel Halačka
- Institute of Vertebrate Biology, Czech Academy of Science, Brno, Czechia
| | - Ján Koščo
- Department of Ecology, University of Prešov, Prešov, Slovakia
| | - Jakub Fedorčák
- Department of Ecology, University of Prešov, Prešov, Slovakia
| | - Nataliia Iakovenko
- Department of Biology and Ecology, University of Ostrava, Ostrava, Czechia.,Institute of Animal Physiology and Genetics, Czech Academy of Science, Liběchov, Czechia
| | - Karel Janko
- Department of Biology and Ecology, University of Ostrava, Ostrava, Czechia.,Institute of Animal Physiology and Genetics, Czech Academy of Science, Liběchov, Czechia
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Domingo E. Virus population dynamics examined with experimental model systems. VIRUS AS POPULATIONS 2020. [PMCID: PMC7153323 DOI: 10.1016/b978-0-12-816331-3.00006-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Experimental evolution permits exploring the effect of controlled environmental variables in virus evolution. Several designs in cell culture and in vivo have established basic concepts that can assist in the interpretation of evolutionary events in the field. Important information has come from cytolytic and persistent infections in cell culture that have unveiled the power of virus-cell coevolution in virus and cell diversification. Equally informative are comparisons of the response of viral populations when subjected to different passage régimens. In particular, plaque-to-plaque transfers in cell culture have revealed unusual genotypes and phenotypes that populate minority layers of viral quasispecies. Some of these viruses display properties that contradict features established in virology textbooks. Several hypotheses and principles of population genetics have found experimental confirmation in experimental designs with viruses. The possibilities of using experimental evolution to understand virus behavior are still largely unexploited.
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Innes DJ, Hebert PDN. THE ORIGIN AND GENETIC BASIS OF OBLIGATE PARTHENOGENESIS INDAPHNIA PULEX. Evolution 2017; 42:1024-1035. [DOI: 10.1111/j.1558-5646.1988.tb02521.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/1987] [Accepted: 02/11/1988] [Indexed: 11/27/2022]
Affiliation(s)
- David J. Innes
- Department of Biological Sciences; University of Windsor; Windsor ON N9B 3P4 CANADA
| | - Paul D. N. Hebert
- Department of Biological Sciences; University of Windsor; Windsor ON N9B 3P4 CANADA
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Vrijenhoek RC, Pfeiler E, Wetherington JD. BALANCING SELECTION IN A DESERT STREAM‐DWELLING FISH,
POECILIOPSIS MONACHA. Evolution 2017; 46:1642-1657. [DOI: 10.1111/j.1558-5646.1992.tb01159.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/1991] [Accepted: 03/07/1992] [Indexed: 11/28/2022]
Affiliation(s)
- Robert C. Vrijenhoek
- Center for Theoretical and Applied Genetics Rutgers University New Brunswick NJ 08903–0231 USA
| | - Edward Pfeiler
- Departamento de Ciencias Marinas Instituto Tecnológico y de Estudios Superiores de Monterrey Guaymas Sonora 85400 MEXICO
| | - Jeffrey D. Wetherington
- Center for Theoretical and Applied Genetics Rutgers University New Brunswick NJ 08903–0231 USA
- Agricultural Products Division Dupont Company Wilmington DE 19880‐0402 USA
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Vrijenhoek RC, Lerman S. HETEROZYGOSITY AND DEVELOPMENTAL STABILITY UNDER SEXUAL AND ASEXUAL BREEDING SYSTEMS. Evolution 2017; 36:768-776. [DOI: 10.1111/j.1558-5646.1982.tb05443.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/1981] [Revised: 09/10/1981] [Indexed: 11/29/2022]
Affiliation(s)
- Robert C. Vrijenhoek
- Department of Biology and Bureau of Biological Research Rutgers University New Brunswick New Jersey 08903
| | - Steven Lerman
- Department of Biology and Bureau of Biological Research Rutgers University New Brunswick New Jersey 08903
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Wetherington JD, Kotora KE, Vrijenhoek RC. A TEST OF THE SPONTANEOUS HETEROSIS HYPOTHESIS FOR UNISEXUAL VERTEBRATES. Evolution 2017; 41:721-731. [DOI: 10.1111/j.1558-5646.1987.tb05848.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/1986] [Accepted: 02/19/1987] [Indexed: 11/27/2022]
Affiliation(s)
- Jeffrey D. Wetherington
- Department of Biological Sciences and Bureau of Biological Research Rutgers University P.O. Box 1059 Piscataway NJ 08855
| | - Karen E. Kotora
- Department of Biological Sciences and Bureau of Biological Research Rutgers University P.O. Box 1059 Piscataway NJ 08855
| | - Robert C. Vrijenhoek
- Department of Biological Sciences and Bureau of Biological Research Rutgers University P.O. Box 1059 Piscataway NJ 08855
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Wetherington JD, Weeks SC, Kotora KE, Vrijenhoek RC. GENOTYPIC AND ENVIRONMENTAL COMPONENTS OF VARIATION IN GROWTH AND REPRODUCTION OF FISH HEMICLONES (POECILIOPSIS: POECILIIDAE). Evolution 2017; 43:635-645. [PMID: 28568401 DOI: 10.1111/j.1558-5646.1989.tb04258.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/1988] [Accepted: 01/23/1989] [Indexed: 11/26/2022]
Abstract
The frozen-niche-variation model was proposed to account for the coexistence of genetically related clones in naturally occurring unisexual populations. This model is based on two assumptions: 1) ecologically different clones have multiple independent origins from sexual ancestors; and 2) the population of sexual ancestors contains genetic variability for ecologically relevant traits. To test these assumptions, we produced 14 new "hemiclones" (nonrecombining haploid genotypes) of fish (Poeciliopsis: Poeciliidae). Our ability to synthesize many new hemiclones demonstrates the feasibility of multiple independent origins of nonrecombining genotypes. A substantial proportion (10-50%) of the phenotypic variation among hemiclones in size at birth, juvenile growth rate, and fecundity had a genetic basis. Thus, we conclude that multiple origins can give rise to an assemblage of genetically distinct hemiclones, each with a unique combination of life-history traits. Additionally, a comparative analysis of two natural hemiclones revealed that the synthetic strains represent a broad field of variation from which natural hemiclones can be selected.
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Affiliation(s)
- Jeffrey D Wetherington
- Center for Theoretical and Applied Genetics, Cook College, Rutgers University, P.O. Box 231, New Brunswick, NJ, 08903
| | - Stephen C Weeks
- Center for Theoretical and Applied Genetics, Cook College, Rutgers University, P.O. Box 231, New Brunswick, NJ, 08903
| | - Karen E Kotora
- Center for Theoretical and Applied Genetics, Cook College, Rutgers University, P.O. Box 231, New Brunswick, NJ, 08903
| | - Robert C Vrijenhoek
- Center for Theoretical and Applied Genetics, Cook College, Rutgers University, P.O. Box 231, New Brunswick, NJ, 08903
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Sites JW, Peccinini‐Seale DM, Moritz C, Wright JW, Brown WM. THE EVOLUTIONARY HISTORY OF PARTHENOGENETIC
CNEMIDOPHORUS LEMNISCATUS
(SAURIA, TEIIDAE). I. EVIDENCE FOR A HYBRID ORIGIN. Evolution 2017; 44:906-921. [DOI: 10.1111/j.1558-5646.1990.tb03813.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/1989] [Accepted: 10/01/1989] [Indexed: 11/28/2022]
Affiliation(s)
- Jack W. Sites
- Department of Zoology Brigham Young University Provo UT 84602 USA
| | | | - Craig Moritz
- Laboratory of Molecular Systematics, Museum of Zoology, and Department of Biology University of Michigan Ann Arbor MI 48109 USA
| | - John W. Wright
- Herpetology Section, Museum of Natural History 900 Exposition Boulevard Los Angeles CA 90007 USA
| | - Wesley M. Brown
- Laboratory of Molecular Systematics, Museum of Zoology, and Department of Biology University of Michigan Ann Arbor MI 48109 USA
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Leary RF, Allendorf FW, Knudsen KL. DEVELOPMENTAL INSTABILITY AND HIGH MERISTIC COUNTS IN INTERSPECIFIC HYBRIDS OF SALMONID FISHES. Evolution 2017; 39:1318-1326. [PMID: 28564256 DOI: 10.1111/j.1558-5646.1985.tb05697.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/1985] [Accepted: 07/23/1985] [Indexed: 11/30/2022]
Affiliation(s)
- Robb F. Leary
- Department of Zoology University of Montana Missoula MT 59812
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Bulger AJ, Schultz RJ. ORIGIN OF THERMAL ADAPTATIONS IN NORTHERN VERSUS SOUTHERN POPULATIONS OF A UNISEXUAL HYBRID FISH. Evolution 2017; 36:1041-1050. [DOI: 10.1111/j.1558-5646.1982.tb05472.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/1981] [Revised: 01/18/1982] [Indexed: 12/01/2022]
Affiliation(s)
- Arthur J. Bulger
- Biological Sciences Group The University of Connecticut Storrs Connecticut 06268
| | - R. Jack Schultz
- Biological Sciences Group The University of Connecticut Storrs Connecticut 06268
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Schenck RA, Vrijenhoek RC. SPATIAL AND TEMPORAL FACTORS AFFECTING COEXISTENCE AMONG SEXUAL AND CLONAL FORMS OF
POECILIOPSIS. Evolution 2017; 40:1060-1070. [DOI: 10.1111/j.1558-5646.1986.tb00573.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/1985] [Accepted: 04/28/1986] [Indexed: 11/29/2022]
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Antonovics J, Ellstrand NC. EXPERIMENTAL STUDIES OF THE EVOLUTIONARY SIGNIFICANCE OF SEXUAL REPRODUCTION. I. A TEST OF THE FREQUENCY‐DEPENDENT SELECTION HYPOTHESIS. Evolution 2017; 38:103-115. [DOI: 10.1111/j.1558-5646.1984.tb00263.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/1982] [Revised: 04/26/1983] [Indexed: 11/28/2022]
Affiliation(s)
- Janis Antonovics
- Department of Botany Duke University Durham North Carolina 27706
| | - Norman C. Ellstrand
- Department of Botany and Plant Sciences University of California Riverside California 92521
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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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KORPELAINEN HELENA. Ecological genetics of the cyclic parthenogens, Daphnia longispina and Daphnia pulex. Hereditas 2008. [DOI: 10.1111/j.1601-5223.1986.tb00634.x] [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] Open
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Lázaro E, Escarmís C, Pérez-Mercader J, Manrubia SC, Domingo E. Resistance of virus to extinction on bottleneck passages: study of a decaying and fluctuating pattern of fitness loss. Proc Natl Acad Sci U S A 2003; 100:10830-5. [PMID: 12960384 PMCID: PMC196888 DOI: 10.1073/pnas.1332668100] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
RNA viruses display high mutation rates and their populations replicate as dynamic and complex mutant distributions, termed viral quasispecies. Repeated genetic bottlenecks, which experimentally are carried out through serial plaque-to-plaque transfers of the virus, lead to fitness decrease (measured here as diminished capacity to produce infectious progeny). Here we report an analysis of fitness evolution of several low fitness foot-and-mouth disease virus clones subjected to 50 plaque-to-plaque transfers. Unexpectedly, fitness decrease, rather than being continuous and monotonic, displayed a fluctuating pattern, which was influenced by both the virus and the state of the host cell as shown by effects of recent cell passage history. The amplitude of the fluctuations increased as fitness decreased, resulting in a remarkable resistance of virus to extinction. Whereas the frequency distribution of fitness in control (independent) experiments follows a log-normal distribution, the probability of fitness values in the evolving bottlenecked populations fitted a Weibull distribution. We suggest that multiple functions of viral genomic RNA and its encoded proteins, subjected to high mutational pressure, interact with cellular components to produce this nontrivial, fluctuating pattern.
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Affiliation(s)
- Ester Lázaro
- Centro de Astrobiología (Consejo Superior de Investigaciones Científicas-Instituto Nacional de Técnica Aeroespacial), Associated with the National Aeronautics and Space Administration Astrobiology Institute, Torrejón de Ardoz, Madrid, Spain
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JOKELA JUKKA, LIVELY CURTISM, DYBDAHL MARKF, FOX JENNIFERA. Genetic variation in sexual and clonal lineages of a freshwater snail. Biol J Linn Soc Lond 2003. [DOI: 10.1046/j.1095-8312.2003.00181.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Schneider MV, Driessen G, Beukeboom LW, Boll R, van Eunen K, Selzner A, Talsma J, Lapchin L. Gene flow between arrhenotokous and thelytokous populations of Venturia canescens (Hymenoptera). Heredity (Edinb) 2003; 90:260-7. [PMID: 12634810 DOI: 10.1038/sj.hdy.6800245] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In the solitary parasitoid wasp Venturia canescens both arrhenotokously (sexual) and thelytokously (parthenogenetical) reproducing individuals occur sympatrically. We found in the laboratory that thelytokous wasps are able to mate, receive and use sperm of arrhenotokous males. Using nuclear (amplified fragment length polymorphism, virus-like protein) and mitochondrial (restriction fragment length polymorphism) markers, we show the occurrence of gene flow from the arrhenotokous to the thelytokous mode in the field. Our results reinforce the paradox of sex in this species.
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Affiliation(s)
- M V Schneider
- Animal Ecology, Institute of Evolutionary and Ecological Sciences, University of Leiden, PO Box 9516, NL-2300 RA Leiden, The Netherlands.
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Guex GD, Hotz H, Semlitsch RD. Deleterious alleles and differential viability in progeny of natural hemiclonal frogs. Evolution 2002; 56:1036-44. [PMID: 12093017 DOI: 10.1111/j.0014-3820.2002.tb01414.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Abstract.-Spontaneous deleterious mutations are expected to accumulate through Muller's ratchet in clonally reproducing organisms and may lead to their extinction. We study deleterious mutations and their effects in a system of European frogs. Rana esculenta (RL), natural hybrids R. ridibunda (RR) X R. lessonae (LL), reproduce hemiclonally; both sexes exclude the L genome in the germ line and produce unrecombined R gametes; hybridity is restored each generation by matings of RL with coexisting LL. Different allozyme-defined hybrid hemiclones (R genome haplotypes) are thought to have originated independently from primary hybridizations RR x LL. Natural matings between two hybrids usually lead to inviable RR tadpoles. This inviability is thought to result from unmasked deleterious alleles on the clonally transmitted R genomes. Most simply it reflects homozygosity for recessive deleterious alleles at particular loci; alternatively (consistent with absence of RR adults in multiclonal populations) it may reflect hemiclone-specific sets of incompletely recessive deleterious mutations that cumulatively cause inviability when two such genomes are combined. If inviability results from the former, progeny of two hybrids of different hemiclones, whether allopatric or coexisting, should be viable, because it is improbable that their R genomes share recessive deleterious alleles at the same set of loci; if inviability results from the latter, progeny of hybrids of different hemiclones should be inviable, especially when hybrid lineages are old. We tested these hypotheses in artificial crosses, using frogs from three regions: hemiclonal hybrids outside R. ridibunda's range from northern Switzerland (two abundant coexisting allozyme-defined hemiclones; estimated lineage age < or = 5,000 generations) and from Sicily, Italy (one hemiclone; estimated age > or = 25,000 generations) and R. ridibunda from Poland. We generated RR progeny, which we reared under benign conditions in the laboratory, by crossing (1) two hybrids from the same region (H x H local); (2) two hybrids from different regions (H X H foreign); (3) hybrids and R. ridibunda (H X R); and (4) two R. ridibunda (R X R). Survival to metamorphosis was similar and high for R x R, H X H foreign, and H X R, whereas all tadpoles of H X H local died before metamorphosis. This supports the hypothesis that homozygosity for recessive deleterious mutations at particular loci causes inviability. Crosses within and between the two coexisting hemiclones from Switzerland were, however, equally inviable. This result may reflect episodic sexual recombination in RR progeny from exceptional successful interclonal hybrid X hybrid matings, followed by matings of such RR with LL. This process would both slow down or halt Muller's ratchet and disrupt genetic independence of coexisting hemiclones, so that the same remaining deleterious R alleles could exist in different allozyme-defined hemiclones. Whereas all data are consistent with the prediction of Muller's ratchet operating on clonally transmitted R genomes of natural hybrid lineages, they are insufficient to demonstrate such operation, because deleterious recessives that mutated after clone formation and those that preexisted in the R. ridibunda source populations that formed the hemiclonal lineages are not distinguished. The possibility of episodic sexual recombination must be carefully taken into account when studying Muller's ratchet in natural populations of this Rana system.
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Affiliation(s)
- Gaston-Denis Guex
- Zoologisches Museum and Zoologisches Institut, Universität 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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Vorburger C. Non-hybrid offspring from matings between hemiclonal hybrid waterfrogs suggest occasional recombination between clonal genomes. Ecol Lett 2001. [DOI: 10.1046/j.1461-0248.2001.00272.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Vinogradov AE, Chubinishvili AT. Genome reduction in a hemiclonal frog Rana esculenta from radioactively contaminated areas. Genetics 1999; 151:1123-5. [PMID: 10049928 PMCID: PMC1460525 DOI: 10.1093/genetics/151.3.1123] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A decrease in genome size was found in the hemiclonal hybridogenetic frog Rana esculenta (R. ridibunda x R. lessonae) from areas of radioactive contamination that resulted from the Chernobyl fallout. This genome reduction was of up to 4% and correlated with the background level of gamma-radiation (linear regression corresponded on average to -0.4% per doubling of radiation level). No change in genome size was observed in the coexisting parental species R. lessonae. There was no correlation between genome size and body mass in R. esculenta froglets, which have metamorphosed in the year of the study. The hemiclonal forms may become a suitable object for study on biological significance of individual DNA sequences (and of genome size as a whole) because mutant animals with deletions in a specified genome can arise after a low radiation dose. The proneness to genetic damage makes such forms also a prospective bioindicator of radioactive (and possibly other mutagenic) pollution with the effects of genetic damage conveniently and rapidly monitored by DNA flow cytometry.
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Affiliation(s)
- A E Vinogradov
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia.
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Lively CM, Howard RS. Selection by parasites for clonal diversity and mixed mating. Philos Trans R Soc Lond B Biol Sci 1994; 346:271-80; discussion 280-1. [PMID: 7708824 DOI: 10.1098/rstb.1994.0144] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
On theoretical grounds, coevolutionary interactions with parasites can select for cross-fertilization, even when there is a twofold advantage gained by reproducing through uniparental means. The suspected advantage of cross-fertilization stems from the production of genetically rare offspring, which are expected to be more likely to escape infection by coevolving enemies. In the present study, we consider the effects that parasites have on parthenogenetic mutants in obligately sexual, dioecious populations. Computer simulations show that repeated mutation to parthenogenesis can lead to the accumulation of clones with different resistance genotypes, and that a moderately diverse set of clones could competitively exclude the ancestral sexual subpopulation. The simulations also show that, when there are reasonable rates of deleterious mutation, Muller's ratchet combined with coevolutionary interactions with parasites can lead to the evolutionary stability of cross-fertilization. In addition, we consider the effects that parasites can have on the evolution of uniparental reproduction in cosexual populations. Strategy models show that parasites and inbreeding depression could interact to select for evolutionarily stable reproductive strategies that involve mixtures of selfed and outcrossed progeny.
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Affiliation(s)
- C M Lively
- Department of Biology, Indiana University, Bloomington 47405
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Affiliation(s)
- D A Powers
- Hopkins Marine Station, Department of Biological Sciences, Stanford University, Pacific Grove, California 93950
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Kodric-Brown A, Brown JH. Anisogamy, sexual selection, and the evolution and maintenance of sex. Evol Ecol 1987. [DOI: 10.1007/bf02067393] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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